Head gasket question for Jim Schmidt or others

jseng1 said:
Here are the test results I made with sealers.

HEAD GASKET SEALER COMPARISON





Pliobond darkens & hardens at 450 to 500F and loses integrity at 500 but still stays in place and when its cooled it remains adhered to the metal. Stays adhered at 400 F (the best results so far).



JB epoxy weld good to 450 and still stays in place at 500 but loses adhesion.



Permatex copper “spray a gasket” high temp – starts smoking and loses adhesion at 400 F but stays in place and is still adhered when cooled.



K&W “Copper coat” brush on gasket sealer – loses adhesion at 400 F but stays in place and is still adhered when cooled.



Silicone sealer resists heat up to 500F, starts to fail by 550 and loses its adhesion. Did not harden but has mediocre oil resistance. Silicone leaks oil as a head gasket sealer.



Permatex “Ultra” silicone based oil resistant gasket maker loses adhesion at approx 500F and fails. Minimal hardening. Silicone leaks oil as a head gasket sealer.



“The right stuff” by permatex should have worked but failed in a Norton as a head gasket sealer.



Hylomar AF stays gooey – non-hardening and no adhesion but good to 500 deg. Aerograde Hylomar is semi hardening and has some adhesion (but not much) after drying and is good to about 450 but looses adhesion around 500 and has poor adhesion compared to pliobond at all temps (worse at 500 deg - loses all adhesion permanently).



Wellseal stays gooey – non hardening and has no adhesion, starts smoking at 400 and turns to water consistency at 450F



Gasgacinch Weldwood and Barge contact cements burned black & hardened before pliobond and lose their adhesion at lower temps around 400F.



Permatex motoseal 1 grey (same as popular Yamabond 4) bubbled at 400F and hardened but did not lose its adhesion. Became very brittle but was still adhered when cool.



Yamabond 5 (clear contact cement) bubbled at 400F burned black, became brittle and lost adhesion.



Permatex high tac turns to liquid, smokes and loses adhesion at about 350 F.



Silver paint gets soft and loses adhesion around 350F



Permatex formagasket starts smoking & bubbles and fails at 250 – 300F.
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I am aware of at least three "Permatex formagasket" each with different use cases. Please state which you tested as you did with most of the rest. For instance, #3 is totally inappropriate as a head gasket sealer so testing it would make no sense.

Also, a description of how you tested would be nice.
 
marshg246 said:
I am aware of at least three "Permatex formagasket" each with different use cases. Please state which you tested as you did with most of the rest. For instance, #3 is totally inappropriate as a head gasket sealer so testing it would make no sense.

Also, a description of how you tested would be nice.
Click to expand...
I tested Permatex formagasket 1B - the dark brown stuff that dries hard and is difficult to remove.
All sealers were tested on aluminum and heated to various temps - higher and higher until they failed using a temp gauge. Most of those that survived up around 400 deg F were also tried in my test bike in Fresno temps around 110 Deg F. These hot weather tests caused a lot of failures. Composite gaskets work but I've had them leak after a couple years. Copper spray is popular but It failed on me because its medium us just regular paint liquid that doesn't hold up to high temps. Maybe sprinkling on a layer of dry copper powder might work but I haven't tried it. Glued on Silicon rings are used on composite Auto gaskets but that doesn't hold up under hotter Norton temps. I prefer the solid copper gaskets because they don't crush like composites and that helps prevent head warpage/distortion but all the copper gaskets I've used on Nortons needed sealer to prevent leaks.
 
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