Degreasing threads

Status
Not open for further replies.
Joined
Aug 15, 2002
Messages
2,441
Location
Indiana
I wanted to degrease some threads on my bike before using the torque wrench since the torque specs are for dry threads. I'm curious - what is a safe way to degrease aluminum and steel threads? I thought about using a speed degreaser and then it occurred to me it might be harmful to aluminum. Would rubbing alcohol be okay?

Thanks
 
Originally Posted By: VeeDubb
Would rubbing alcohol be okay

Yes, I use it to clean threads and many other things when I work on all my stuff.
 
I have no proof but I don't believe a degreaser is going to damage aluminum threads.

Perhaps a resident metallurgist will chime in.
 
Rubbing alcohol or brake cleaner. Be careful about getting the brake cleaner on painted or plastic surfaces. Both of these are volatile and will evaporate with no residue, except for the alcohol leaving a little bit of water behind depending on the purity but usually the common 70% leaves so little water it evaporates as well. I use these two to clean everything, my tools, auto parts, et cetera.

Originally Posted By: ArcticDriver
I have no proof but I don't believe a degreaser is going to damage aluminum threads.

Perhaps a resident metallurgist will chime in.

Certain degreasers can cause awful etching/staining of aluminum if left in contact for too long, allowed to dry or directly in the sun. For steel, degreasers can cause hydrogen embrittlement. There are metal-safe degreasers out there like Simple Green Pro HD. If you're going to use degreasers make sure to rinse it well.

http://www.velonews.com/2005/11/bikes-an...le-green-2_9216

I left an aluminum casting for a distributor soaked in Purple Power + water mixture to degrease and it came out stained a dull gray.
 
Isopropyl is what I use to clean basically everything. I keep a 5 gallon can around. In a good spray bottle, it's very good for flushing out contaminants and quickly.

Many common degreasers are harmful to aluminum if left in contact long term - like inside a blind hole or a lap joint. Simple Green stands out as a common degreaser that is harmful to aluminum. It should be diluted for use and flushed heavily with water afterwards. Even then, you may get some streaking on an aluminum part.
 
Originally Posted By: rooflessVW
Isopropyl is what I use to clean basically everything. I keep a 5 gallon can around. In a good spray bottle, it's very good for flushing out contaminants and quickly.

Many common degreasers are harmful to aluminum if left in contact long term - like inside a blind hole or a lap joint. Simple Green stands out as a common degreaser that is harmful to aluminum. It should be diluted for use and flushed heavily with water afterwards. Even then, you may get some streaking on an aluminum part.


There appears to be two different conversations going on.

The OP asked specifically about aluminum threads and many of the responses have discussed aesthetic issues on aluminum surfaces.

Can someone please tell me how these various degreasers destroy aluminum bolts or threading? Do they cause oxidation? Do they cause brittleness?

I have used Brakleen and PB Blaster for decades on aluminum bolts with no apparent ill effect. I have never later had one of these bolts snap off or show any other signs of fatigue. I would like to know how degreasers destroy an aluminum bolt.

Acids? Yes.
Degreasers? Please explain.

Thanks
 
Originally Posted By: ArcticDriver
There appears to be two different conversations going on.

The OP asked specifically about aluminum threads and many of the responses have discussed aesthetic issues on aluminum surfaces.

Can someone please tell me how these various degreasers destroy aluminum bolts or threading? Do they cause oxidation? Do they cause brittleness?

I have used Brakleen and PB Blaster for decades on aluminum bolts with no apparent ill effect. I have never later had one of these bolts snap off or show any other signs of fatigue. I would like to know how degreasers destroy an aluminum bolt.

Acids? Yes.
Degreasers? Please explain.

Thanks

What do you think streaking or oxidation on aluminum is? It is corrosion. Normally it stops by itself - the oxidized layer acts like a barrier.

Most degreasers are heavy alkaline solutions and will continue to corrode aluminum. Think Simple Green, Purple Power, Grez-off, etc.

Brakleen and PB Blaster are solvent degreasers, PB Blaster has oil in it as well. Much safer for aluminum, and not what came to mind when I posted.
 
Originally Posted By: NoNameJoe
Rubbing alcohol or brake cleaner. Be careful about getting the brake cleaner on painted or plastic surfaces. Both of these are volatile and will evaporate with no residue, except for the alcohol leaving a little bit of water behind depending on the purity but usually the common 70% leaves so little water it evaporates as well. I use these two to clean everything, my tools, auto parts, et cetera.

Originally Posted By: ArcticDriver
I have no proof but I don't believe a degreaser is going to damage aluminum threads.

Perhaps a resident metallurgist will chime in.

Certain degreasers can cause awful etching/staining of aluminum if left in contact for too long, allowed to dry or directly in the sun. For steel, degreasers can cause hydrogen embrittlement. There are metal-safe degreasers out there like Simple Green Pro HD. If you're going to use degreasers make sure to rinse it well.

http://www.velonews.com/2005/11/bikes-an...le-green-2_9216

I left an aluminum casting for a distributor soaked in Purple Power + water mixture to degrease and it came out stained a dull gray.


I read the link of hydrogen embrittlement on a SRAM chain which was left soaking for 6 months. The concern is the mixture became acidic over that long period of time.

When I read the OP, I did not see that he intended to soak the aluminum bolts for several months.

I don't use Simple Green or Purple Power since a thorough rinse is necessary and that defeats the point of it for cleaning threads IMO. I would use a wire brush and brakleen.
 
Originally Posted By: rooflessVW
Originally Posted By: ArcticDriver
There appears to be two different conversations going on.

The OP asked specifically about aluminum threads and many of the responses have discussed aesthetic issues on aluminum surfaces.

Can someone please tell me how these various degreasers destroy aluminum bolts or threading? Do they cause oxidation? Do they cause brittleness?

I have used Brakleen and PB Blaster for decades on aluminum bolts with no apparent ill effect. I have never later had one of these bolts snap off or show any other signs of fatigue. I would like to know how degreasers destroy an aluminum bolt.

Acids? Yes.
Degreasers? Please explain.

Thanks

What do you think streaking or oxidation on aluminum is? It is corrosion. Normally it stops by itself - the oxidized layer acts like a barrier.

Most degreasers are heavy alkaline solutions and will continue to corrode aluminum. Think Simple Green, Purple Power, Grez-off, etc.

Brakleen and PB Blaster are solvent degreasers, PB Blaster has oil in it as well. Much safer for aluminum, and not what came to mind when I posted.


Yes, its corrosion. So you are saying that the threads on the aluminum bolts will corrode right off?

The alkaline degreasers that you mention...how do you stop them from causing corrosion? Rinse them thoroughly with water?
I guess I never considered that someone would not rinse a bolt in water after it was soaked in a Simple Green or purple Power. I used PP once and found it left a noticeable film of the surface of the material I was degreasing even after I rinsed it. That is why I stick with Brakleen. It evaporates quickly and displaces water.

To the OP...I will include a disclaimer that i did not think was necessary. If you are going to use a degreaser such as SG or PP, then don't leave the bolts in there for several months and do be sure to thoroughly rinse the bolt in water when finished.
grin.gif
 
I'm saying that given enough time and vibration, bad things can happen. With enough time to work, I suspect aluminum threads could come right out with the fastener the next time it is removed.

He asked about cleaning threads but he never said bolts specifically. If would think that cleaning bolt threads would be obvious and wouldn't merit a post, so my mind went cleaning blind holes. Plenty of steel fasteners pull out aluminum threads to begin with - no need to help the process along.
 
Originally Posted By: 4WD
Kind & gentle - WD40 to remove grease & Dawn to remove WD40 ...


The guys at work think I am quite A-R but even I have never considered lovingly caressing my aluminum bolts in a dish soap detergent before use.

I suppose Palmolive would be gentler on the threads than Dawn...we wouldn't want something that causes dishpan hands to make contact with our aluminum? Then a rinse with pure glacial water? And then is a pat dry with a chamois recommended or a hair dryer set on low heat? Then place them on a silk pillow until they are to be used?
grin.gif


Joking aside, I see from these posts that I have severely underestimated the strength and integrity of an aluminum bolt.
 
I wouldn't do it, since I don't like dry threads in any material, but if I was going to do it I'd use acetone or an alcohol, either of which will evaporate without residue.

Allegedly methanol corrodes aluminium so best avoid that.
 
Last edited:
Thanks for the responses. I asked specifically about aluminum because the stem threads are aluminum and the bolt is steel. I just assumed that steel was more robust because the degreaser I use (White Lightening Clean Streak) is designed for steel drivetrains on bikes. But I wasn't sure about aluminum. But maybe I'm wrong?

I will probably just stick with Isopropyl alcohol on both bolt and thread unless someone tells me it's a bad idea.
 
Someone back on page one mentioned starting fluid. Works like a charm. When I used to fix/ rebuild diesel gensets, starting fluid was great.
 
Originally Posted By: ArcticDriver
Can someone please tell me how these various degreasers destroy aluminum bolts or threading? Do they cause oxidation? Do they cause brittleness?


They have acids in them; either citric acid or a caustic acid like Simple Green has.

Petroleum solvent based degreasers have no acids, but they will leave a slight oily film behind.
 
Status
Not open for further replies.
Back
Top