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.
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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.
 
Is it possible to combine spray-on copper kote (my traditional favorite) with pliobond/copper wire, or will the pliobond not adhere to the gasket once it's coated with copper kote?
 
Copper is good because reusable.
The flame-ring composite can get expensive over time if you're removing the head often.
They are up to 13.55 GBP now!
 
acotrel said:
If you are concerned about the clearance between valves and pistons, normal practice is to fit the head with pieces of plasticine on the crown of the piston, turn the motor over - the remove the plasticine and section it with a razor blade.......
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Yes, but he said he wasn't going to do that.......
 
If you have never worked with Pliobond and that skinny wire on a copper head gasket you are in for a test of patience. Use the copper kote spray and forget the Pliobond if you prefer an easy installation of the head. It wouldn't really be necessary with the spray, and would drive you nuts trying to lay it on top of copper kote. The spray is about 1 billion times easier to work with and not an issue for a street engine as long as the barrels and head are surfaced flat. If you do nothing to the surfaces of an old head and barrels you will probably have oil weeping under or over the gasket if you ever turn the wick (throttle) way up for any extended period of time. A head adhered to the barrels with Pliobond on the head gasket is very difficult to remove. It's not easy with copper kote either, but a lot easier than with Pliobond.

I'm not selling copper kote or Pliobond, but I've used both, and have not had issues with copper kote.
 
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An easy way to loosen a head sealed with pliobond is to loosen the bolts a little and kick it over. Or tap it under the exhaust nut with a wooden block. Copper coat is good up to about 400 degrees then it loses adhesion. Pliobond is good up to about 500 degrees and in hot weather as in calif some parts of your head can get over 400 degrees as shown with temperature tests.

I've tried Copper coat and it worked for a while. But the pliobond and wire has lasted the longest - over 10 years. For me the choice was to remove and reseal the head every couple years or take a few minutes to lay down the fine wire and forget about it.
 
BrianK said:
Thanks Schwany and Jim. Can one combine the copper kote and pliobond/wire routes?
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I have a feeling you'd be the first to do it. You won't need copper kote if you use Pliobond and the wire. I don't think the Pliobond would adhere correctly if you spayed copper kote either before trying to lay down the Pliobond or after laying down the Pliobond on clean surfaces.

Back in my youth I used aluminum paint and at some time probably nothing other than the copper gasket. If the barrel deck and head are surfaced completely flat and the fasteners torqued down right, it'll seal up with either of those sealants.
 
When using the wire do you put the looped wire on both faces of the head gasket i.e. the side facing the barrel and the side facing the top? Watched the video and this intrigues me.
 
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