Cleaning a Cast Iron Deck prior to HG Replacement

B

bunnspecial

Joined
Nov 23, 2015
Messages
2,391
Location
US
Suppose one has a head gasket failure(composite gasket) on an engine with a cast iron block/head. The cause of the failure has been determined, and the engine will remain in the car and assembled while the a machine shop does a light skim on the head(6 thou) to correct a small amount of warp.

Left behind on the deck of the block is some gasket residue and also some firing residue from the breached gasket. I'm guessing a plastic scraper is in order(after removing the head studs for complete access). Are the gasket remover sprays available out there(I think Permatex and CRC among others make them) worth it, or can I get the same result with carb/brake cleaner, a plastic scraper, some shop towels, and elbow grease?

Obviously I'm trying to avoid having to redo this job again soon. I hadn't done a head gasket in a few years, and often times it's an asbestos/copper factory type gasket coming off that leaves little to no residue

IMG_1748.webp
 
I have used a 3M green roloc on a drill and razor blade with a kubota iron block, chased all threads, shop vacced everything back out.

Since then I learned about Carbide gasket scrapers and picked up an Astro, but havent used it yet.

You mention the head was warped. Was the block checked also? If you were close i'd let you borrow my Starret straight edge, its collecting dust.
 
cptbarkey said:
I have used a 3M green roloc on a drill and razor blade with a kubota iron block, chased all threads, shop vacced everything back out.

Since then I learned about Carbide gasket scrapers and picked up an Astro, but havent used it yet.

You mention the head was warped. Was the block checked also? If you were close i'd let you borrow my Starret straight edge, its collecting dust.
Click to expand...
I would never use any form of abrasive to clean the deck.

Lots of people do it, and it’s a horrible mistake because you cannot ever remove all of the silicon carbide abrasive.

GM specifically prohibits abrasive materials from being used on any open engine part, including timing covers, oil pans, and cylinder heads.

Most of the major manufacturers prohibit this as well. Too many destroyed engines have resulted from the use of Roloc-type abrasive discs.

Solvent, elbow grease, and a razor blade, would be your best bet.

If a carbide scraper exists, that would be an excellent tool for this task.
 
I use a carbide scraper and follow that up with just a whisker of polishing from a 2" wool polisher on a die grinder.

You will love the carbide scraper. Just remember to draw and don't push. Some get damaged in shipping. Test how flat the edge is on something before using it.
 
Astro14 said:
I would never use any form of abrasive to clean the deck.

Lots of people do it, and it’s a horrible mistake because you cannot ever remove all of the silicon carbide abrasive.

GM specifically prohibits abrasive materials from being used on any open engine part, including timing covers, oil pans, and cylinder heads.

Most of the major manufacturers prohibit this as well. Too many destroyed engines have resulted from the use of Roloc-type abrasive discs.

Solvent, elbow grease, and a razor blade, would be your best bet.

If a carbide scraper exists, that would be an excellent tool for this task.
Click to expand...
Aluminum you are correct.
Iron its fine.
 
Abrasive schmootz gets down into the main bearings and wrecks them... supposedly.

If you're going to do it, try to figure out a "clean room" recovery system like having a shop vac sucking an inch away while you scrape, and wiping everything down with an oiled rag when done.

Also consider when is good enough, good enough-- if it's flat, going to seal, but cosmetically ugly, don't keep scraping to make yourself happy.
 
Last edited:
Astro14 said:
I would never use any form of abrasive to clean the deck.

Lots of people do it, and it’s a horrible mistake because you cannot ever remove all of the silicon carbide abrasive.

GM specifically prohibits abrasive materials from being used on any open engine part, including timing covers, oil pans, and cylinder heads.

Most of the major manufacturers prohibit this as well. Too many destroyed engines have resulted from the use of Roloc-type abrasive discs.

Solvent, elbow grease, and a razor blade, would be your best bet.

If a carbide scraper exists, that would be an excellent tool for this task.
Click to expand...
Didn't you have a long, painful and $$$$ experience with a dealer (Volvo?) on this subject?

Or was it the pan?
 
In an A1 video the lady used sandpaper on a sanding block. I had several misgivings about that.

Eric O used a solvent like brake cleaner and nylon brushes.

I will say I used a carbide scraper and I did use a small piece of woven abrasive (ScotchBrite) by hand for the stubborn areas. This was not kitchen stuff but fine and very fine ordered from MSC. I actually used it in conjunction with brake cleaner so it was "wet" for the most part.

I'm unwilling to believe a small piece of woven abrasive pushed around under my fingertip in select areas created enough dust to damage bearings. If I'm wrong and that makes me a hack, so be it -- I'm good with that.
 
If I absolutely had to use any kind of abrasive, I would tape up every single gap, crack, crevasse, to include piston/bore surfaces with the expectation that anything I miss will potentially ruin the engine. I understand sometimes shortcuts might be needed, but this would be a last resort.
 
meep said:
If I absolutely had to use any kind of abrasive, I would tape up every single gap, crack, crevasse, to include piston/bore surfaces with the expectation that anything I miss will potentially ruin the engine. I understand sometimes shortcuts might be needed, but this would be a last resort.
Click to expand...
Wouldn’t matter. You won’t prevent everything from getting in. Damage is assured, even if it doesn’t result in catastrophic failure. No abrasives. Period.

Building engines, you use Tide, and bottle brushes, and clean everything until it’s spotless. And then you do it again at least twice more. Silicon carbides will destroy everything they come in contact with. And when they’re in your oil, that means everything.
 
Astro14 said:
I would never use any form of abrasive to clean the deck.

Lots of people do it, and it’s a horrible mistake because you cannot ever remove all of the silicon carbide abrasive.

GM specifically prohibits abrasive materials from being used on any open engine part, including timing covers, oil pans, and cylinder heads.

Most of the major manufacturers prohibit this as well. Too many destroyed engines have resulted from the use of Roloc-type abrasive discs.

Solvent, elbow grease, and a razor blade, would be your best bet.

If a carbide scraper exists, that would be an excellent tool for this task.
Click to expand...
I have, with great care, used a thin piece of painters tape inside the cylinder walls, all the way to the point where the piston and wall meet, and lined the top of the piston aswell. Then some of your favorite, WD40 sprayed into it before I "shopvacced" it out, to hepl help suspend some residue. Then pulled the whole "cup" of painters tape out.

I used a piece of thick glass and fine sand paper, and planed the block, turned out real nice. Almost looked new. Ran the thing another 120k, before it got totaled. This was on a 4.0 I6 jeep engine.

Like you said, elbow grease, with a bit of unconventional warfare, so to speak.

With the same piece of glass I "planed the head", but that I just rinsed with water, and blew it out with brake cleaner.
 
You must log in or register to reply here.

Similar threads

JHZR2
Mercedes Diesel Misfire After HG Replacement
5 6 7
Replies
128
Views
8K
LDB
D
k24z6 rebuild or replace
Replies
13
Views
4K
Junk
A
  • Locked
Intake manifold gasket sealant?
2
Replies
36
Views
11K
Trav
B
Help reading head gasket
Replies
6
Views
2K
Chris142
D
  • Locked
Preparing Cast Iron Block for MLS head gasket and aluminum head?
2
Replies
31
Views
13K
dx92beater
Back
Top Bottom