[Shop-talk] Removing hardening-type Permatex No. 1

[Karl Vacek]

I'm often faced with removing and replacing parts installed over 10 years
ago with what appears to be old-fashioned, hardening-type Permatex No. 1.
The gaskets are glued onto both parts with the Permatex, and thanks to many
joints between steel and magnesium or aluminum, differential expansion has
disturbed a majority of the joints enough to cause oil leaks.  No idea why
the previous mechanic used this crap, but it's there now and I have to
remove and re-gasket most every part where he used it because of oil leaks.

 

Once the joints are apart, the real fun begins as I try to remove the
remaining gasket and sealer without hurting the engine case (magnesium), and
the mating parts, which are mostly steel or aluminum.

 

I've tried pretty much every solvent I have - naphtha, mineral spirits,
lacquer thinner, acetone, MEK, xylene, heavy-duty methylene chloride
stripper, and even oven cleaner.  I've also applied enough heat that the
gaskets begin to burn, but no effect on the Permatex.  Nothing seems to
touch it.  Permatex says isopropyl alcohol works on cured material, but it
doesn't as far as I can tell.  This stuff has been heat-cycled many times
over at least 10 years, and it's pretty hard and the excess oozed out is
fairly crumbly.

 

Many of the joint surfaces are very hard to get to in order to scrape, and
when it's on magnesium or aluminum, I don't want to scrape with anything too
aggressive, so as not to mar the surface.  I wind up using sharpened oak
scrapers, popsicle sticks, plastic putty knives, and lots of time and elbow
grease.

 

Anybody ever successfully and simply remove this stuff ?

 

Thanks!
Karl

 

 

Pilots -

Looking down on people since 1903