Whoever has done balance shaft housings, oil pump, split a 911 case, etc...

How do you clean off the old Loctite 638 (now 574) from the mating surfaces? I'm doing a reseal of the balance shaft housings and so far have had no success getting the old stuff off. I've tried brake cleaner, mineral spirits, and soaking them in lacquer thinner for a couple of hours. The stuff has laughed defiantly at all my efforts.

I wouldn't think I'd want to go after it with a scraper or razor blade, so how can I get this stuff off without damaging the surface?

 

I would use a soda blaster. Makes a huge mess but will clean the area in literally seconds, plus it dissolves in oil so you won't have to worry about contamination. This is the method that I used for the balance shaft covers, crank girdle, and both sides of the cylinder head.

 

I've used a good heat gun and 1/4" thick Plexiglass scraps I cut at a 45* angle on my table saw. The heat helps and plastic scrapers won't scar the aluminum. This was done on an engine stand though so it might not be practical if the engine is in the car.

 

MEK works well, agitate it with a small stainless brush and wear mask & gloves.

 

From the spec sheet:

LOCTITE® 638
For Cleanup
1. Cured product can be removed with a combination of
soaking in a Loctite solvent and mechanical abrasion
such as a wire brush.
http://65.213.72.112/tds5/docs/638-EN.pdf

The solvent is Nitromethane, fun stuff.

http://www.allfasteners.com/Loctite-...M49_p_431.html

 

I've used a fresh, sharp razor many a time. I wouldn't waste my time with solvents on that stuff.

 

That is how I got 99% off, then some scotch brite and solvent.

 

Yeah, I could scrape, just wanted to avoid taking a chance on scratching the mating surfaces. Since I don't have any nitro left over from my top fuel dragster days , I'll maybe try the MEK and/or some careful scraping.

Thanks!

 

You should be good with MEK, I got the hint a while back from the Pelican forum when I did mine. Here's the link: http://forums.pelicanparts.com/911-e...4-removal.html

 

Turns out, soaking in the lacquer thinner did soften it up a bit, and I was able to get it clean using light brushing followed by a fine scotchbrite pad soaked in more thinner. Next time if I'm out of the lacquer thinner I'll try some MEK to see which is better. Thanks everyone for the suggestions.

 

Dykem remover works well too to get stuff like that loose. I love scotch brite.

 

I have used a Dremel with a small wire brush, worked great.