How do I remove old case sealant from mating surfaces?
 

I am preparing to put my engine back together. After having the case washed at the machine shop, I spent an additional 30+ hours cleaning by hand.

I still can't seem to get the old sealant off of the mating surfaces. So far I have used a plastic sponge and plastic scraper with brake cleaner.

Is there a particular product that I should be using? I was considering trying to apply some heat with a propane torch if you all think that it will help.

Any suggestions?

Thanks,
Craig

Both Permatex and Hurth make a spray gasket remover. It's pretty harsh stuff but does the trick. You spray it on, let sit and bubble for 5 minutes and scrape.

Single-edge razor blade, very gently.

Craig-
Do you have Wayne's engine book? I can't remember what it recommends, but I found Scotchbrite pads to be a good way of getting old gasket stuff off.

I used all of the above plus a Dremel on low speed with a soft brass brush. That worked better than all the chemicals combined, especially removing the hard fiber gasket remains on the chain housings. Very easy and precise. Obviously you have to take care not to carve divot in the surface, but that's why you use brass and not steel brushes.

I'll say it and I don't care who knows it - I love my Dremel. ;)

I use that for the final pass to remove whatever hasn't come up with the chemicals and my plastic putty knife.

Thanks for the info. Nice array of input!

I do have a dremel but not sure if I have a brass fitting.

Air grinder w/roloc scotch-brite disc.

You can get both the scotch-brite and brass brush attachments for the dremel at Home Depot or Lowes, etc for a couple bucks each. Or, you can get a huge kit of them at Harbor Frieght for less than $20.

Good luck!

Great! Thanks.

MEK will do the trick.

Red Scotch Brite pad + brake cleaner. I would avoid any and all power tools in performing this task.

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