Steel Seal: what do we know to elaborated best application approach

[Dmitri]

There have been many post and threads on successful and disastrous results of Steel Seal application for leaking head gaskets. The main issue of all these communications is that almost nobody describes the exact procedure used and the coolant. Even a reference of following the the "official procedure" from manufacturer does not do the job. Because the right answer on the question on how should one apply Steel Seal is all about the chemistry between Steel Seal and the coolant, it is all about pH in the solution. No one speaks about chemistry of coolant and water (distilled, tap , hard water etc) used for treatment. No one discuss the coolant used after the application.

I propose to share and discuss in this thread the facts, knowledge and the experimental results : the liquides used with steel seal during the treatment (coolant type or water type) , the sequence of the treatment and the results in terms of the longevity of the "patch."

I will also share my experience in application of Steal Seal to leaking HG and the results of somme additional test. Since these are all utilise Steel Seal, hence the title of the proposed thread, but there are many other similar products on the market, which may share such chemistry "optimisation" approach.

 

[Dmitri]

Filed application experience

The car is Toyota Prius gen 3 (XW30) with 2ZR-FXE 1.8L engine prone of head gasket (HG) failures. For what follows it is important to note that the coolant system capacity is about 7 Litters , however only 5 L can be drained while 2 L remains in the system.

1. 46k @242k: The first coolant-cylinder failure occurs at 242k (in metric units ) revealing an excessive pressure in the cold coolant system, some whitish smoke out of the tile pipe and what was the worst of all the engine rattling on a cold start due to some coolant in the faulty cylinder. The Steal Seal patch was applied by professional mechanic upon my request. He has never used this product before and just follows the instructions on his manner. It needs to say the official instructions are unclear regarding many points, they are different for US and EU markets with respect to the "recommended" coolant (see below) and there is no just one unique procedure of application. I know the following about this first application of Steel Seal: he runs Steal Seal in water for more than 1 hour while keeping the coolant tank open and without disconnecting the spark plug and the injector on the faulty cylinder; lets the car to cool done for 24hr and after puts the Toyota coolant. I unfortunately don't remember precisely was it the pink SLLC (as per repair manual) or the red LLC.

The engine run healthy for another 46k till 288k in total. However at 280k I flush the clogged heater core using tap water, which occurs to be not enough efficient approach (see below an alternative approach). Because the cabin heating was not strong enough, at 288k I replace the thermostat and water pump. There are many discussions that these are worth to be replaced on Prius gen 3 as preventive measures to blown HG. However in my case the old thermostat and the water pump were good. At the end of these changes I put a new pink SLLC and the HG issue reappears almost instantly, after just 1k of run. After all application cases reported below, I attribute the most probable reason for the failure of HG patch to the pink SLLC coolant utilising sebacic acid and having pH of 7.5 ( for comparison Steel Seal water solution has pH of 11 before and after the application).

2. 2k @288k: Mechanic who made the first application went to retirement. I decided to make myself the second application. I drain the coolant, flush the system with distilled water several times (3 to 5) and apply Steel Seal in distilled water as prescribed: I put it in expansion tank , warm up the engine and run on idle (800-1000 rpm) for 40 min and let it cool down for 12 hr. I drive it initially very gently and later on highway for a week (500 km) with remaining solution. (As I learn later, after a week of driving the solution does not contain the sodium silicate any more and just keeps the pH to be of 11.) The patch was perfect . So I decided to put Toyota coolant, that is to flush the system several times with distilled water and after introduce the pink SLLC.

As I know now, that was a mistake. Indeed the car runs healthy for just 1 month (2k) after this.

3. 20k @290k: I was not aware yet of the pH and sebacic aside issues of the pink SLLC and decided that I should keep Steel Seal in the system as proposed in many sources (in fact this has no sense at all, as after a week of driving there is almost no sodium silicate left). But at that moment I wish to run the process with the coolant so as to keep it in the system afterwards. Under the Steel Seal guaranty I was granted a replacement bottle for free. A support engineer (from Germany) strictly prohibit to use anything else but "only 2-year old blue ethylene-glycol based antifreeze," of no more than 25% concentration. After additional clarifications it was confirmed that the coolant should be IAT, with silicates (as opposed to without silicates), and that G11 suits better than others coolant options I ask. There were no any specific coolant product recommendation. Interestingly, for US market, the officially recommended coolant for Steel Seal application is "Prestone conventional green antifreeze – (Ethylene Glycol— pH 8-11) Low solvent effect, silicate stabilizers and high pH provide the best protection". This IAT coolant utilises phosphate based corrosion inhibitors.

I apply Steel Seal as advised with blue G11 50:50 prediluted coolant (measured pH is of 8) and added more coolant after to get better protection at negative temperatures. I reach -16.5°C protection readings, which indicates the final coolant to water ratio to be of 32:68. In total the patch lasts for another 20k, (up to 310k on the car) but there were many issues with clogged heater core. Basically I have to unclog it each 2k.

Such frequent need for heater core unclogging allowed me to test different procedures from forums and identify the most efficient one. It consists of poring some water in heater core and blowing it out with 6-7 bar pressurised air, repeated several times in different directions. In very difficult cases, I use in the first run concentrated vinegar (of around 15 to 20% strength) heated to 60-70°C and letting it to seat in the heater core for about 30 min before flushing with air. Along this lines, following other preventive measures against blown head gasket on Prius 3 I cleaned the complete EGR system .

The clogging of heater core is caused by detached solid debris of degrading Steel Seal patch and by reaction of the antifreeze on high pH of Steel Seal. Thus Steel Seal being mixed with G11 coolant keeps the pH as high as 11 after the treatment. Such high alkalinity leads to additional solid silicates dropping out from the G11 coolant itself. Therefor in the middle I switched to conventional green (Prestone Prime). Another motivation of having a coolant "compatible" with Steel seal was the possibility of ice protection during next possible application in a winter time so as to let it cool down for 24hr after the treatment.

4. 2k @310k: However I cannot consider conclusive the results of my next application of Steel Seal in the presence of conventional green coolant. To safe some money I purchase Steel Seal on ebay, which was a mistake. The bottle arrived wrapped in a black film. When opened and poured in expansion tank I noticed pieces of sodium silicate being already in the foam form indicating the bottle has been previously heated to about 60°C. The sealant worked on the HG issue, but process clogged the whole cooling system and seemingly caused engine overheat (there were no overheat light). I find a large "stone" in the coolant tank ("degas bottle" at 108 kPa) that block coolant from circulating through it. Because of overheating, conventional green coolant exhibits tendency for phosphates dropping out, creating a mud. I flushed the entire system with vinegar and distilled water water and restoring. After several flushes with distilled water and restoring pH to neutral i replace the coolant tank and fill the system with Toyota pink SLLC. As previously, the patch lasts for only 2k in total. Prior to the next application I decide to make a few additional tests which I will describe below in a separate post.

In case this is of a value, the procedure to flush the entire cooling system was to fill it with vinegar (1 L of 15% strength) and distilled water (6L) mixture, to run the engine to operating temperature for 20 min so as the thermostat opens, and to drain the coolant system just in 10 min after the engine stop, while the thermostat is still open. The pressure cap on the coolant tank of Prius is regulated to 108 kPa, which is just 7% above the normal atmospheric pressure. It can be opened on a hot engine by gently releasing the excess pressure. However after several additional flushes with the water and open thermostat , the pH was still of 4.1. Exercising with samples taken out of the cooling system I find the amount of baking soda necessary to neutralise the pH. Adding, in my case, 1.5 tee spoon of soda I reach pH around 7 and flush again the cooling system several times with water.

Prior to provide details of my last Steel Seal application I will describe several additional experiments that help me to get some insight on what could possibly be the best application procedure.

 

[LineArrayNut]

I used k-seal, just for the reason that the coolant does not need to be a particular type.

 

[Dmitri]

I used k-seal, just for the reason that the coolant does not need to be a particular type.

I am curious what is pH of k-seal ?

 

[Dmitri]

Filed application experience

The car is Toyota Prius gen 3 (XW30) with 2ZR-FXE 1.8L engine prone of head gasket (HG) failures. For what follows it is important to note that the coolant system capacity is about 7 Litters , however only 5 L can be drained while 2 L remains in the system.

1. 46k @242k: The first coolant-cylinder failure occurs at 242k (in metric units ) revealing an excessive pressure in the cold coolant system, some whitish smoke out of the tile pipe and what was the worst of all the engine rattling on a cold start due to some coolant in the faulty cylinder. The Steal Seal patch was applied by professional mechanic upon my request. He has never used this product before and just follows the instructions on his manner. It needs to say the official instructions are unclear regarding many points, they are different for US and EU markets with respect to the "recommended" coolant (see below) and there is no just one unique procedure of application. I know the following about this first application of Steel Seal: he runs Steal Seal in water for more than 1 hour while keeping the coolant tank open and without disconnecting the spark plug and the injector on the faulty cylinder; lets the car to cool done for 24hr and after puts the Toyota coolant. I unfortunately don't remember precisely was it the pink SLLC (as per repair manual) or the red LLC.

The engine run healthy for another 46k till 288k in total. However at 280k I flush the clogged heater core using tap water, which occurs to be not enough efficient approach (see below an alternative approach). Because the cabin heating was not strong enough, at 288k I replace the thermostat and water pump. There are many discussions that these are worth to be replaced on Prius gen 3 as preventive measures to blown HG. However in my case the old thermostat and the water pump were good. At the end of these changes I put a new pink SLLC and the HG issue reappears almost instantly, after just 1k of run. After all application cases reported below, I attribute the most probable reason for the failure of HG patch to the pink SLLC coolant utilising sebacic acid and having pH of 7.5 ( for comparison Steel Seal water solution has pH of 11 before and after the application).

2. 2k @288k: Mechanic who made the first application went to retirement. I decided to make myself the second application. I drain the coolant, flush the system with distilled water several times (3 to 5) and apply Steel Seal in distilled water as prescribed: I put it in expansion tank , warm up the engine and run on idle (800-1000 rpm) for 40 min and let it cool down for 12 hr. I drive it initially very gently and later on highway for a week (500 km) with remaining solution. (As I learn later, after a week of driving the solution does not contain the sodium silicate any more and just keeps the pH to be of 11.) The patch was perfect . So I decided to put Toyota coolant, that is to flush the system several times with distilled water and after introduce the pink SLLC.

As I know now, that was a mistake. Indeed the car runs healthy for just 1 month (2k) after this.

3. 20k @290k: I was not aware yet of the pH and sebacic aside issues of the pink SLLC and decided that I should keep Steel Seal in the system as proposed in many sources (in fact this has no sense at all, as after a week of driving there is almost no sodium silicate left). But at that moment I wish to run the process with the coolant so as to keep it in the system afterwards. Under the Steel Seal guaranty I was granted a replacement bottle for free. A support engineer (from Germany) strictly prohibit to use anything else but "only 2-year old blue ethylene-glycol based antifreeze," of no more than 25% concentration. After additional clarifications it was confirmed that the coolant should be IAT, with silicates (as opposed to without silicates), and that G11 suits better than others coolant options I ask. There were no any specific coolant product recommendation. Interestingly, for US market, the officially recommended coolant for Steel Seal application is "Prestone conventional green antifreeze – (Ethylene Glycol— pH 8-11) Low solvent effect, silicate stabilizers and high pH provide the best protection". This IAT coolant utilises phosphate based corrosion inhibitors.

I apply Steel Seal as advised with blue G11 50:50 prediluted coolant (measured pH is of 8) and added more coolant after to get better protection at negative temperatures. I reach -16.5°C protection readings, which indicates the final coolant to water ratio to be of 32:68. In total the patch lasts for another 20k, (up to 310k on the car) but there were many issues with clogged heater core. Basically I have to unclog it each 2k.

Such frequent need for heater core unclogging allowed me to test different procedures from forums and identify the most efficient one. It consists of poring some water in heater core and blowing it out with 6-7 bar pressurised air, repeated several times in different directions. In very difficult cases, I use in the first run concentrated vinegar (of around 15 to 20% strength) heated to 60-70°C and letting it to seat in the heater core for about 30 min before flushing with air. Along this lines, following other preventive measures against blown head gasket on Prius 3 I cleaned the complete EGR system .

The clogging of heater core is caused by detached solid debris of degrading Steel Seal patch and by reaction of the antifreeze on high pH of Steel Seal. Thus Steel Seal being mixed with G11 coolant keeps the pH as high as 11 after the treatment. Such high alkalinity leads to additional solid silicates dropping out from the G11 coolant itself. Therefor in the middle I switched to conventional green (Prestone Prime). Another motivation of having a coolant "compatible" with Steel seal was the possibility of ice protection during next possible application in a winter time so as to let it cool down for 24hr after the treatment.

4. 2k @310k: However I cannot consider conclusive the results of my next application of Steel Seal in the presence of conventional green coolant. To safe some money I purchase Steel Seal on ebay, which was a mistake. The bottle arrived wrapped in a black film. When opened and poured in expansion tank I noticed pieces of sodium silicate being already in the foam form indicating the bottle has been previously heated to about 60°C. The sealant worked on the HG issue, but process clogged the whole cooling system and seemingly caused engine overheat (there were no overheat light). I find a large "stone" in the coolant tank ("degas bottle" at 108 kPa) that block coolant from circulating through it. Because of overheating, conventional green coolant exhibits tendency for phosphates dropping out, creating a mud. I flushed the entire system with vinegar and distilled water water and restoring. After several flushes with distilled water and restoring pH to neutral i replace the coolant tank and fill the system with Toyota pink SLLC. As previously, the patch lasts for only 2k in total. Prior to the next application I decide to make a few additional tests which I will describe below in a separate post.

In case this is of a value, the procedure to flush the entire cooling system was to fill it with vinegar (1 L of 15% strength) and distilled water (6L) mixture, to run the engine to operating temperature for 20 min so as the thermostat opens, and to drain the coolant system just in 10 min after the engine stop, while the thermostat is still open. The pressure cap on the coolant tank of Prius is regulated to 108 kPa, which is just 7% above the normal atmospheric pressure. It can be opened on a hot engine by gently releasing the excess pressure. However after several additional flushes with the water and open thermostat , the pH was still of 4.1. Exercising with samples taken out of the cooling system I find the amount of baking soda necessary to neutralise the pH. Adding, in my case, 1.5 tee spoon of soda I reach pH around 7 and flush again the cooling system several times with water.

Prior to provide details of my last Steel Seal application I will describe several additional experiments that help me to get some insight on what could possibly be the best application procedure.

Steal Seal Hardening Tests: Background

There is a couple of youtube video showing Steel Seal curing with an open flame. The result is a fin white film deposition. The film is highly brittle. The first series of tests was used to find conditions for a less fragile film deposition.

According to SDS, Steal Seal solution consists on 10-20% of Sodium Silicate and incorporates stabilizers to pH 11. According to numerous posts, Sodium Silicate is the working engine of the process to remedy (or not ) a leaking head gasket.

From the literature, two process may occur in sodium silicate solution: (I) gelation and (ii) curing. (ii) differs from (i) by presence of additional links with carbon C from carbon dioxide CO2 in air or in flame https://www.sdlookchem.com/how-to-cure-sodium-silicate.html .

All processes are characterized by rate constants (e.g. % of sodium silicate converted to gel or hard film per second). The larger the rate constant the more volumetric deposit.

However at a very high rate, the deposited material may become porous. To avoid this, layered deposition is proposed by Scotty Kilmer among others with the car engine being periodically switched on and off on about 30 min intervals.

Several factors enhance the deposition rate such as temperature, pH (this is why Steel Seal is stabilized to high pH, https://www.sdlookchem.com/how-to-harden-sodium-silicate.html ), and surprisingly, Ca2+ and Mg2+ ions (from https://doi.org/10.3390/en7020568).

Temperature factor: some communications say that critical temperature for hardening is above 96°C (which is normal hot engine coolant temperature), and is in the range around 106°C (aka coincidence with engine overheat light trigger temperature). In fact, there is no one single critical temperature. The deposition rate varies as an exponent of temperature so as it will deposit even at 60°C. This is useful to keep in mind considering proposals on Steal Seal use as a preventive measure against potential leaks. It will deposit anyway until the sodium silicate solution is exhausted. The open question is where it will deposit if there is no hot spot on a leaking HG. The test below are done with temperature from 96 to 100°C.

pH factor: Because of high required pH, there is no sense to perform Steal Seal treatment with OAT based coolants. They have stabilizers to keep pH near 7.5, which lead to low deposition rate and gelation (I will make a separate post on these test). The IAT based coolants already have high pH around 9 but further higher pH due to Steal Seal lead to solid drops out in silicate-based coolant. The tests below are done with water , as recommended by Steal Seal and also using highly diluted Toyota pink SLLC (1%) to check the effect of residues in the coolant system after several flushes.

Ca2+ ions: I used distilled water, clean water and hard water . I am leaving in mountain region and the coming water is extremely hard with high concentration of Ca2+ ions. The tap water after resin-based water softener is labeled here as clean water. It has reduced concentration of Ca2+.

In what follows I will introduce sample preparation and hardening methods

 

[LineArrayNut]

I have not tested it's pH. As there is probably a bit still in the overflow cannister that I could not get into the top radiator hose I could pH that.

 

[LineArrayNut]

Sds says 5.9
https://www.google.com/url?sa=t&sou...MQFnoECBAQBg&usg=AOvVaw3LhGqXgLmbH4x5a-3-fm9T

 

[Dmitri]

Steal Seal Hardening Tests: Background

There is a couple of youtube video showing Steel Seal curing with an open flame. The result is a fin white film deposition. The film is highly brittle. The first series of tests was used to find conditions for a less fragile film deposition.

According to SDS, Steal Seal solution consists on 10-20% of Sodium Silicate and incorporates stabilizers to pH 11. According to numerous posts, Sodium Silicate is the working engine of the process to remedy (or not ) a leaking head gasket.

From the literature, two process may occur in sodium silicate solution: (I) gelation and (ii) curing. (ii) differs from (i) by presence of additional links with carbon C from carbon dioxide CO2 in air or in flame https://www.sdlookchem.com/how-to-cure-sodium-silicate.html .

All processes are characterized by rate constants (e.g. % of sodium silicate converted to gel or hard film per second). The larger the rate constant the more volumetric deposit.

However at a very high rate, the deposited material may become porous. To avoid this, layered deposition is proposed by Scotty Kilmer among others with the car engine being periodically switched on and off on about 30 min intervals.

Several factors enhance the deposition rate such as temperature, pH (this is why Steel Seal is stabilized to high pH, https://www.sdlookchem.com/how-to-harden-sodium-silicate.html ), and surprisingly, Ca2+ and Mg2+ ions (from https://doi.org/10.3390/en7020568).

Temperature factor: some communications say that critical temperature for hardening is above 96°C (which is normal hot engine coolant temperature), and is in the range around 106°C (aka coincidence with engine overheat light trigger temperature). In fact, there is no one single critical temperature. The deposition rate varies as an exponent of temperature so as it will deposit even at 60°C. This is useful to keep in mind considering proposals on Steal Seal use as a preventive measure against potential leaks. It will deposit anyway until the sodium silicate solution is exhausted. The open question is where it will deposit if there is no hot spot on a leaking HG. The test below are done with temperature from 96 to 100°C.

pH factor: Because of high required pH, there is no sense to perform Steal Seal treatment with OAT based coolants. They have stabilizers to keep pH near 7.5, which lead to low deposition rate and gelation (I will make a separate post on these test). The IAT based coolants already have high pH around 9 but further higher pH due to Steal Seal lead to solid drops out in silicate-based coolant. The tests below are done with water , as recommended by Steal Seal and also using highly diluted Toyota pink SLLC (1%) to check the effect of residues in the coolant system after several flushes.

Ca2+ ions: I used distilled water, clean water and hard water . I am leaving in mountain region and the coming water is extremely hard with high concentration of Ca2+ ions. The tap water after resin-based water softener is labeled here as clean water. It has reduced concentration of Ca2+.

In what follows I will introduce sample preparation and hardening methods

Hardening test: sample preparation and methods

Samples were prepared with Steel Seal to coolant or water weigh ratio of 1: 6 , representing the ratio in the engine coolant system during the treatment. The acidity is measured with a pH meter unless stated otherwise (pH litmus stripes with resolution of 0.5 units and scale up to 9 pH)

	Coolant			Steel	Seal	Mixture
Sample #	Component	pH	Mass, g	pH	Mass , g	pH	Mass, g
1	1% pink SLLC	7.5​	6	11.2	1	>9 (stripes)	7
2	Hard Water	7.6​	6	11.2	1	11.1	7
3	Clear Water	7.4​	6	11.2	1	>9 (stripes)	7
4	Distilled Water	6.5​	6	11.2	1	>9 (stripes)	7

The samples were placed in receptacles made of cut aluminium cans which in turn were placed in a heated water bath. Temperature was periodically controlled with a probe thermometer.

The evaporation of water and hardening was achieved in 65 min starting from the RT with the temperature profile as shown in the figure below. It resembles the temperature profile of the engine coolant during the Steel Seal application.

In the next post I will present the results of hardening

 

[Dmitri]

Sds says 5.9
https://www.google.com/url?sa=t&sou...MQFnoECBAQBg&usg=AOvVaw3LhGqXgLmbH4x5a-3-fm9T

So it is acidic. Perhaps it can live with OAT based coolants (pH ~7.5). This is drastically different from Steel Seal, which in my experience is not compatible neither with OAT no IAT coolants. And it is not based on sodium silicate. Interesting how long does it last ?

 

[LineArrayNut]

Don't know yet personally.
Have just done 2 30 minute sessions. In the cool of the morning.
Did see after 3 minutes a steady progression to about half of the previous amount of white sweet smelling smoke(vapor).
Second session saw that to be about 25 percent to almost gone.
Will try a third session this weekend.
Most people say an improvement, maybe 80 percent. Some say miracle in a bottle, some say useless as...
Most say it's semi permanent, a few say reapplying is necessary.
I used a box fan to blow at the radiator to try to keep the system cool besides the head. Did not run the heater.
2008 Buick lucerne csx northstar v8 128k miles

 

[Dmitri]

Don't know yet personally.
Have just done 2 30 minute sessions. In the cool of the morning.
Did see after 3 minutes a steady progression to about half of the previous amount of white sweet smelling smoke(vapor).
Second session saw that to be about 25 percent to almost gone.
Will try a third session this weekend.
Most people say an improvement, maybe 80 percent. Some say miracle in a bottle, some say useless as...
Most say it's semi permanent, a few say reapplying is necessary.
I used a box fan to blow at the radiator to try to keep the system cool besides the head. Did not run the heater.
2008 Buick lucerne csx northstar v8 128k miles

Curious about the final result. Some people clamp the inlet pipe on the heater core but that may cause an engine overheat. That largely depends on a specific engine. In my case, I had an idea to bypass the heater core but finally don't apply this, just run it at highest heating temperature and blowing speed settings to have the heater core cooled as much as possible.

 

[Dmitri]

Hardening test: sample preparation and methods

Samples were prepared with Steel Seal to coolant or water weigh ratio of 1: 6 , representing the ratio in the engine coolant system during the treatment. The acidity is measured with a pH meter unless stated otherwise (pH litmus stripes with resolution of 0.5 units and scale up to 9 pH)

	Coolant			Steel	Seal	Mixture
Sample #	Component	pH	Mass, g	pH	Mass , g	pH	Mass, g
1	1% pink SLLC	7.5​	6	11.2	1	>9 (stripes)	7
2	Hard Water	7.6​	6	11.2	1	11.1	7
3	Clear Water	7.4​	6	11.2	1	>9 (stripes)	7
4	Distilled Water	6.5​	6	11.2	1	>9 (stripes)	7

The samples were placed in receptacles made of cut aluminium cans which in turn were placed in a heated water bath. Temperature was periodically controlled with a probe thermometer.
View attachment 243352 View attachment 243357

The evaporation of water and hardening was achieved in 65 min starting from the RT with the temperature profile as shown in the figure below. It resembles the temperature profile of the engine coolant during the Steel Seal application.

View attachment 243358

In the next post I will present the results of hardening

Steel Seal Hardening tests: results and discussions

The images below show the results of the evaporation and hardening test for four samples. The main deposition occur within the grove of the aluminum can while nearby wall and curved bottom of the can are also partially covered with thin film.

The first samples that were curried were Samples 1 and 2 (at 60 min) while the samples 2 and 4 required additional 5 min heating. Sample 2 also shows the most volumetric deposit. That points in favor of Steal Seal treatment in hard water having the highest deposition rate, which can be expected due presence of Ca2+ ions (https://doi.org/10.3390/en7020568). Testing deposits with a tooth tip revealed that Sample #2 is much less brittle than the other.

Sample #1 (StSl in 1% Toyota pink SLLC)	Sample #2 (StSl in Hard Water)
Sample #3 (StSl in Clear Water)	Sample #4 (StSl in Distilled Water)

Based on these tests my choice for the last treatment of the leaking HG was made in favor of using hard water in the engine coolant system.

However next interesting question was which coolant should be used in the system after the Steel Seal application in order the patch lasts for a longer time. I attempted to address this question with a series of additional tests that I will present in a next post.

 

[Dmitri]

Steel Seal Hardening tests: results and discussions

The images below show the results of the evaporation and hardening test for four samples. The main deposition occur within the grove of the aluminum can while nearby wall and curved bottom of the can are also partially covered with thin film.

The first samples that were curried were Samples 1 and 2 (at 60 min) while the samples 2 and 4 required additional 5 min heating. Sample 2 also shows the most volumetric deposit. That points in favor of Steal Seal treatment in hard water having the highest deposition rate, which can be expected due presence of Ca2+ ions (https://doi.org/10.3390/en7020568). Testing deposits with a tooth tip revealed that Sample #2 is much less brittle than the other.

Sample #1 (StSl in 1% Toyota pink SLLC)	Sample #2 (StSl in Hard Water)
View attachment 243477	View attachment 243478
Sample #3 (StSl in Clear Water)	Sample #4 (StSl in Distilled Water)
View attachment 243479	View attachment 243480

Based on these tests my choice for the last treatment of the leaking HG was made in favor of using hard water in the engine coolant system.

However next interesting question was which coolant should be used in the system after the Steel Seal application in order the patch lasts for a longer time. I attempted to address this question with a series of additional tests that I will present in a next post.

3. Steel Seal film dissolving test

The sodium silicate films achieved in the previous hardening experiment are the result of a superposition of gelation and curing of the sodium silicate. The differences between the deposited film samples is due to the uneven rates of the two processes in function of the environment (pH, Ca2+ concentration etc). The deposited films are only partially representative to the real process of Steel Seal application in the engine coolant system. Nevertheless, attempting to dissolve these films in various coolants provides useful hint on the possible coolant choice after the Steel Seal application.

Film dissolving test was performed by placing four hardened film samples in Toyota pink Super Long Life Coolant (SLLC) and Toyota red Long Life Coolant (LLC). The SLLC was introduced by Toyota as a novel coolant replacing the LLC. Both are using organic additives (a kind of OAT technology) for the corrosion prevention. The first is based on sebacic acid with pKa= 4.59 (or 5.59 ?) (https://www.chemicalbook.com/ProductChemicalPropertiesCB0329394_EN.htm ) while the second is using sodium benzoate (benzoic acid sodium salt) with pKa=4.03 (https://www.chemicalbook.com/ProductChemicalPropertiesCB0698779_EN.htm ). More details about composition of SLLC and LLC coolants can be found here https://www.toyotaofnorthcharlotte.com/service/what-coolant-does-toyota-use/#:~:text=When%20it%20comes%20to%20the,(111-20-6) .

From the acidity kPa numbers of the benzoic and sebacic acids, the Toyota red LLC should be more aggressive. However the opposite has been previously debated, that the Toyota pink SLLC may “eat” some engine components (https://bobistheoilguy.com/forums/threads/ditch-the-toyota-super-long-life-says-mechanic.232745/). The results of the dissolving test reported below point in the same direction.

A 30:70 Toyota pink SLLC in water solution was put in the aluminium can receptacles with Sample #1 (StSl hardened with 1% pink SLLC) and #2 (StSl hardened in hard water). The 50:50 Toyota red LLC was used with the Samples #3 (StSl in clear water) and #4 (StSl in distilled water). The initial pH values where respectively 8.75 and 7. 8 for the two coolant solutions. After 4-8 days the measured pH growth to 10 indicating that gel fraction of sodium silicate undergoes dissolving in all four samples.

The table below represents the appearance of the samples at the end of the test and indicates the final pH values. Although sample #3 hardened in a clean tap water with non-vanishing concentration of Ca2+ ions and subjected to red LLC shows the lowest pH (lowest dissolving), the scatter of the pH values between the samples is within the error of measurements and thus is not a conclusive indicator.

However a difference can be seen in the appearance of the samples. The films subjected to Toyota pink SLLC reveal detached and floating film flakes while those with red LLC do not show them. The first pair of films can be easily scratched from the aluminium can walls with a toothpick, and respectively, this occurs to be more difficult for samples kept in red LLC coolant.

Sample#1 (StSl SLLC1%) in pink SLLC30% pH=10.1	Sample#2 (StSl hard water) in pink SLLC30% pH=10
Sample#3 (StSl clean water) in red LLC50% pH=9.9	Sample#4 (StSl dist. water) in red LLC50% pH=10.2

The conclusion I drawn from these test is that a preference should be given to use of Toyota red LLC coolant (vs pink SLLC) after application of Steal Seal.

However this contradicts to the post https://www.toyotaownersclub.com/fo...ze-after-applying-steel-seal/#comment-1563003 . Therefore I performed some additional tests addressing the gelation of Steel Seal in various coolants subjected to a heat, which I will report next.

 

[toocan]

Dmitri, this is a great post thankyou for all the effort you have put in to doing these tests,​

i am looking into using steel seal in a toyota 1kz-te 3l diesel that currently has red oat antifreeze, i have steam from the exhaust and some fumes from the radiator/expansion tank, i think the head is cracked, the engine takes a little turning over to start and runs rough for a few seconds, but it runs ok after this and doesnt overheat + the exhaust clears up after a little while
i think i will remove the thermostat, bypass the heater matrix, flush the current coolant mix, maybe do a vinegar then bicarb flush, fill with water and steel seal, maybe just 1 bottle, run the engine through 2-3 heat cycles drain the water/steel seal mix, then refill with 50:50 water coolant, should i go with the recomended red oat toyota coolant?
does this sound like a reasonable procedure to try or would you do anything differently?

have you made any further tests/assesments since your last post?

many thanks

 

[Dmitri]

Dmitri, this is a great post thankyou for all the effort you have put in to doing these tests,​

i am looking into using steel seal in a toyota 1kz-te 3l diesel that currently has red oat antifreeze, i have steam from the exhaust and some fumes from the radiator/expansion tank, i think the head is cracked, the engine takes a little turning over to start and runs rough for a few seconds, but it runs ok after this and doesnt overheat + the exhaust clears up after a little while
i think i will remove the thermostat, bypass the heater matrix, flush the current coolant mix, maybe do a vinegar then bicarb flush, fill with water and steel seal, maybe just 1 bottle, run the engine through 2-3 heat cycles drain the water/steel seal mix, then refill with 50:50 water coolant, should i go with the recomended red oat toyota coolant?
does this sound like a reasonable procedure to try or would you do anything differently?

have you made any further tests/assesments since your last post?

many thanks

Hi Toocan, thank you for you interest. I will finalise the post with remaining data. Your procedure looks to me correct. I have just a few comments: (1) heater core: If you run the application process with the heat and vent both at max in the cabin, there is no practical need to bypass the heater core. Further more if you pull out the thermostat, this adds additional protection to the heater core. The heater core gets clogged later with the debris in the coolant of degrading Steel Seal patch. (2) In order to switch from red (toyota LLC) to water (for the Steel Seall application) and back to red LLC there is no need to flush system with vinegar. Just flush it each time several cycles with water (it was 5 cycles in my case needed with 2L out of 7L remaining each time in the system, drive to open thermostat each time to make coolant circulating) (3) Buy Steel Seal only at official distributer to avoid crap. The amount needed is defined in function of the engine volume on their website. I have no experience about different engine sizes. In case of 1.8L engine, 1 bottle is enough. (4) In the application process, heat the engine and apply 5 run/stop cycles for 20 / 40 min to enable layer deposition. Most importantly let it stay and cool down for 24 hr after the last cycle. Keep it in system for a 2-3 drives before flush (about 5 cycles with water) and switching back to red LLC.
Let us know how it goes

 

[Dmitri]

Hi Toocan, thank you for you interest. I will finalise the post with remaining data. Your procedure looks to me correct. I have just a few comments: (1) heater core: If you run the application process with the heat and vent both at max in the cabin, there is no practical need to bypass the heater core. Further more if you pull out the thermostat, this adds additional protection to the heater core. The heater core gets clogged later with the debris in the coolant of degrading Steel Seal patch. (2) In order to switch from red (toyota LLC) to water (for the Steel Seall application) and back to red LLC there is no need to flush system with vinegar. Just flush it each time several cycles with water (it was 5 cycles in my case needed with 2L out of 7L remaining each time in the system, drive to open thermostat each time to make coolant circulating) (3) Buy Steel Seal only at official distributer to avoid crap. The amount needed is defined in function of the engine volume on their website. I have no experience about different engine sizes. In case of 1.8L engine, 1 bottle is enough. (4) In the application process, heat the engine and apply 5 run/stop cycles for 20 / 40 min to enable layer deposition. Most importantly let it stay and cool down for 24 hr after the last cycle. Keep it in system for a 2-3 drives before flush (about 5 cycles with water) and switching back to red LLC.
Let us know how it goes

On more point to consider : its is hard to get ph of 7 after vinegar . The amount of baking soda should be adjusted precisely, which is quite tough . If there is a little excess, pH quickly goes to high alkali values, which is again not good for red LLC. Therefore after vinegar followed by baking soda, there will be a need for several flushes with water. As such, if the cooling system is clean, I would skip vinegar and flush the system multiple times with water.

 

[Dmitri]

3. Steel Seal film dissolving test

The sodium silicate films achieved in the previous hardening experiment are the result of a superposition of gelation and curing of the sodium silicate. The differences between the deposited film samples is due to the uneven rates of the two processes in function of the environment (pH, Ca2+ concentration etc). The deposited films are only partially representative to the real process of Steel Seal application in the engine coolant system. Nevertheless, attempting to dissolve these films in various coolants provides useful hint on the possible coolant choice after the Steel Seal application.

Film dissolving test was performed by placing four hardened film samples in Toyota pink Super Long Life Coolant (SLLC) and Toyota red Long Life Coolant (LLC). The SLLC was introduced by Toyota as a novel coolant replacing the LLC. Both are using organic additives (a kind of OAT technology) for the corrosion prevention. The first is based on sebacic acid with pKa= 4.59 (or 5.59 ?) (https://www.chemicalbook.com/ProductChemicalPropertiesCB0329394_EN.htm ) while the second is using sodium benzoate (benzoic acid sodium salt) with pKa=4.03 (https://www.chemicalbook.com/ProductChemicalPropertiesCB0698779_EN.htm ). More details about composition of SLLC and LLC coolants can be found here https://www.toyotaofnorthcharlotte.com/service/what-coolant-does-toyota-use/#:~:text=When%20it%20comes%20to%20the,(111-20-6) .

From the acidity kPa numbers of the benzoic and sebacic acids, the Toyota red LLC should be more aggressive. However the opposite has been previously debated, that the Toyota pink SLLC may “eat” some engine components (https://bobistheoilguy.com/forums/threads/ditch-the-toyota-super-long-life-says-mechanic.232745/). The results of the dissolving test reported below point in the same direction.

A 30:70 Toyota pink SLLC in water solution was put in the aluminium can receptacles with Sample #1 (StSl hardened with 1% pink SLLC) and #2 (StSl hardened in hard water). The 50:50 Toyota red LLC was used with the Samples #3 (StSl in clear water) and #4 (StSl in distilled water). The initial pH values where respectively 8.75 and 7. 8 for the two coolant solutions. After 4-8 days the measured pH growth to 10 indicating that gel fraction of sodium silicate undergoes dissolving in all four samples.

The table below represents the appearance of the samples at the end of the test and indicates the final pH values. Although sample #3 hardened in a clean tap water with non-vanishing concentration of Ca2+ ions and subjected to red LLC shows the lowest pH (lowest dissolving), the scatter of the pH values between the samples is within the error of measurements and thus is not a conclusive indicator.

However a difference can be seen in the appearance of the samples. The films subjected to Toyota pink SLLC reveal detached and floating film flakes while those with red LLC do not show them. The first pair of films can be easily scratched from the aluminium can walls with a toothpick, and respectively, this occurs to be more difficult for samples kept in red LLC coolant.

Sample#1 (StSl SLLC1%) in pink SLLC30% pH=10.1	Sample#2 (StSl hard water) in pink SLLC30% pH=10
View attachment 243861	View attachment 243862
Sample#3 (StSl clean water) in red LLC50% pH=9.9	Sample#4 (StSl dist. water) in red LLC50% pH=10.2
View attachment 243863	View attachment 243864

The conclusion I drawn from these test is that a preference should be given to use of Toyota red LLC coolant (vs pink SLLC) after application of Steal Seal.

However this contradicts to the post https://www.toyotaownersclub.com/fo...ze-after-applying-steel-seal/#comment-1563003 . Therefore I performed some additional tests addressing the gelation of Steel Seal in various coolants subjected to a heat, which I will report next.

4. My Steel Seal application procedure on Prius gen 3 for cylinder to coolant system head gasket leak.

I assume the initial state is with Toyota coolant in the system and environmental temperature is positive .

1. Drain the coolant and flush the system with water 4-5 times. That is, each time heat the engine to thermostat opening (on idle or driving) and further until the hot coolant start to circulate through the degas (expansion) tank. That will allow to get uniform mixture of the coolant. Jack the left front wheel. Wait 10 min. Very gently open the pressure cap on the expansion tank while protecting your face (turning away) and hands (with thick gloves and rag) to release the pressure. Go in steps of 5 angular degree of rotation of the pressure cap. Drain the coolant though radiator valve on the left hand side of the care . There is no need to undo the protection. The valve knob is accessible through the opening in the bottom protection. I put a resin tube on the output nozzle through an adjacent opening. That allows to avoid splashing and safely use a receptacle for the coolant (remember it is still hot). Once it drained, close the radiator valve , un-jack the car and wait for 1.5-2 hr till the engine cools. Add water (5L) upto the Bleed mark on the degas (expansion) tank and close the pressure cap till the click.
2. After the last drain, fill the system with 2L of water , then put Steel Seal and finally top up the system with water to the Bleed mark. I use hard water as I expect it provides better result as compared to distilled water (see above). Run the engine on idle (service mode of Prius) to the temperature when coolant starts circulating via degas (expansion) tank (well after the thermostat opening) and next run it for another 15 min . In my case, the whole process is pictured in Fig. 1 and starts at the time axis label of 700 sec on the figure and at the cold engine. The onset of coolant circulating through the expansion tank can be noticed as a sudden drop in the electric water pump speed at 2000 sec axis label. It thus takes me 20 min to reach this point. After that I run it for another 15 min so as the whole 1st application process takes 35 min. Please note that if there is a strong extra pressure in the system, Steel seal manual recommends to start the process with pressure cap opened. But without pressure cap in place, it might be very long to reach the point of thermostat opening and coolant circulating through the expansion tank. Therefore it is better to close the pressure cap when the white smoke at the tile pipe starts to reduce.
   
3. Let the layered deposition process to work through for 4-5 cycles. Each time let the engine to run till thermostat opening and coolant circulating through the expansion tank and then for another 20 min. After that stop the engine let it cooldown. I followed the approach that the whole cycle should take 1 hour. This is pictured in Fig. 2 . It shows the engine stop of the previous run (on axis label 150 sec) followed by the engine off time, when data readings were not available until till axis label 1200 sec . The straight lines connects the initial and finals state parameters. The next run process is started at 1200 sec and the coolant start to circulate through the expansion tank at about 1550 sec (just 5 min later). Since this moment I let it run for another 25 min. I repeat start/stop sequence 5 times.
   
4. After the last run, leave the car on the same place for 24 hr to let the deposited patch to harden.
5. I followed the recommendation to make a few gentle drives with Steel Seal being in the system and drive the car for a week once per day. However it think that by this time there were no anymore sodium silicate left in the coolant (see below).
6. Flush the system with water 4-5 times (as in #1) and fill it with 50/50 red Toyota LLC /distilled water, bleed the system as per manual.

In overall the procedure is time consuming and impossible at negative environmental temperatures (or even near zero temperatures if you are well above the sea level!) because of the cooling for 24 hr without antifreeze in step #4.

In next post, as promised, I will report on the gelation of various coolants in high pH solution of Steel Seal.

 

[LineArrayNut]

Car is sold, no complaints from buyer, may not be relevant as I showed her I made zero on the deal.

 

[Dmitri]

Car is sold, no complaints from buyer, may not be relevant as I showed her I made zero on the deal.

Good for you ! How much miles has it made after the treatment ? Was the K-Seal patch still good?

 

[LineArrayNut]

One assumes so, as no complaints from buyer. Miles unknown , approximately 2 months.