Best gasket removal techniques?

[ralan]

Hi guys,

What is the best way to remove an old, stubborn gasket that is sticking to the surface. This is a general question and can apply to any gasket, i.e. water pump, valve cover, intake manifold, etc.

I've seen many people use a scraper to get most of it and then they clean up the surface with scotchbrite. This works well, but I won't use scotchbrite in an area that opens to the crankcase because it leaves abrasive particles in my engine

My current procedure is to scrape the old one off with a freshly sharpened plexiglass scraper, then I soak the remnants with something, usually WD-40, then I scrape the rest off. I wipe away any residual with a shop rag. This gets maybe 90% of the really stubborn ones, though. Sometimes I just leave the other 10%, rather than gouge up the surface. If possible, I will stuff rags into the hole to block any gasket material from getting inside. But this can't always be done.

I'm interested to hear how some others here handle this job. I know most of us have been there!

Also what gasket compound, if any, do you use on the new gasket? For me, it depends on what I'm sealing; For cooling systems, say, a water pump, I will use some RTV silicone. For oil, I like a light coat of NAPA's aviation "form a gasket" on the gasket. Sometimes I use nothing at all.

I generally always use the compound that a service manual says to use, however, and I never "make" a gasket with some compound, unless that is what is called for. (some GM cars)

 

[shortyb]

I basically use the same techniques as you. Really stubborn paper or fiberous gaskets will get a long soak with PB Blaster or similar penetrant (got some Penetro 90 now) or if some is around, used engine oil.

I don't use metal scrapers, have a bunch of plastic ones in several shapes and sizes that I've made over the years. It can be anything from a scrap piece of carbon fiber sheet to a plastic orange peeler. I try to attach the scaper to the small crevice tool of my shop-vac to suck up any debris.

I follow recommended gasket sealer applications for whatever needs sealing. I have had good luck with Permatex, 3M, and Yamaha or Honda (Yamabond, Hondabond) sealers.

 

[Kestas]

I usually line up a bunch of different tools and pick one that works... chisel, stiff putty knife, flexible putty knife, scotchbrite. It depends on how tough the gasket is stuck and whether I'm working on aluminum, cast iron, or steel. The tool or method that maintains the balance of aggresive removal and is easy on the metal is the one to use. Sometimes it's not the sharp tool that's best, but one that is dulled just a little bit so it won't gouge the metal.

I don't worry too much about abrasive particles getting in the crankcase. I expect them to get filtered out at the oil filter. That, and whatever work I'm doing at the time probably has a much larger impact on the health of the engine than the damage from contaminants in the crankcase.

When it comes to exhaust gaskets, I always replace the original with fabricated copper gaskets. They never disintegrate or blow out and they're reuseable.

 

[labman]

I go along with the slightly dull tool not gouging the metal. For the last bit of residue, if you can get at it, I use the Scotch paint and rust stripper in an air grinder. I keep a selection of states of wear giving me a range of sizes for getting at hard to reach places. They seem to remove the gasket while sparing the metal. I am wondering if in assembly, they use a dab of Super Glue to hold the gasket in place, giving one small spot that will not scrape off. I think on some jobs, removing the old gasket takes more time than anything.

 

[SteveD2]

I HATE removing the gaskets...allways takes me longer than any other part of the job. I have a small putty knife that has the blade cut so it is about an inch long (very stiff this way) and is sharpened. Works...ok...

 

[speedy341]

I use this...

http://www.permatex.com/auto/autouh.asp?automotive=yes&f_call=get_item&item_no=80646

...and it works pretty well.

**IT EATS PAINT be careful**