gasket sealant

HI, Just wonder what sort of stuff you guys out there use to seal cork gaskets such as those on thermostat housings I have tried a couple of different types on my Austin Cambridge and after a few days they start weeping again, I also when I took it off made sure the surface was flat and un damaged as I have heard that housing can get damaged easy anyone got any tricks out there?? Thanks George

Reply to
George Weatherley
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The best for this is the purpose designed grey sealant , loctite 5699, car shops sell it. It is expensive about 5 pounds for a tube but it works well. Alternately use body seam sealer , comes in a mastic type tube, made by TEX, very similar to the loctite stuff. I used to get the Suzuki crankcase sealant which again is like the Loctite stuff but even dearer.

MrCheerful

Reply to
MrCheerful

distort making sealing them nearly impossible . If its not flat , then time for a bit of filing. Steve the grease

Reply to
R L Driver

Ordinary clear silicone general purpose sealant at £3 or less for a 300ml tube from B&Q or a DIY shop. That's what I've used for years on all my race engines on sump, water pump and all other gaskets except head gaskets. Nothing supposedly purpose made at several times the price does a better job.

Ideally on modern engines with catalytic convertors you want silicone that doesn't release acetic acid as it cures but that won't be a concern for you.

Dave Baker - Puma Race Engines

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Reply to
Dave Baker

The ally housings do distort, and the faces can get gouged. Get a piece of plate glass and some 400 wet or dry, and machine it flat by rubbing it over the combination. Needs a little skill to keep it flat while doing this.

It shouldn't need any gasket gunge if it's flat - a drop of grease will be good enough. But if it does, I still think Hylomar takes some beating.

Reply to
Dave Plowman

I entirely agree. I just smear the gasket with a little heavy grease and don't tighten the studs too much. Hylomar of Hermetite Red would be much better than DIY sealant if you need it. Also put a bit of copper grease on the studs so the cover doesn't get corroded on.

Reply to
Richard Porter

Thanks for all your ideas i shall start by doble checking the houseing face is flat and try and seal it without sealant i will let you know how i get on. Just need a dry day now. Thanks again George

Reply to
George Weatherley

I was wondering. I'm replacing the gasket for the carb on a 1977 mainer outboard. Should I use a salant?

Reply to
kevin Farber

I have never worked on an outboard, but I don't imagine that they are significantly different to any other type of engine, other than the fact that the gasket really does need to be water tight in an environment where spray is going to be present.

I advise you to clean the mating surfaces, whatever was or was not used to seal the gasket you are taking off. Then it depends on what the replacement gasket is made of.

Cork ones don't need any sealants for gaskets but I have found that they seal best with a film of grease on the mating surfaces.

Corrugated metal ones normally seal OK as they are, provided you tighten them evenly, but if you are a "belt and braces" type then a gasket sealant doesn't harm them.

Paper or multi-layer gaskets definitely need sealant. There are two types, one seals and sets hard (eg "Green Hermetite") and you don't want that one. "Red Hermetite" sets semi-hard and allows easy future removal, and this is the one you will want. The alternative to "Red Hermetite" is "Blue Hylomar", which I think is slightly better but there isn't a lot in it. To confuse you even more there is a "Red Hylomar" which is designed for use on pitted surfaces, and it sets harder than the Blue Hylomar but not as hard as Green Hermetite. Only use that one if you do have pitted surfaces.

Try to avoid any sealant getting inside the gasket opening. You really don't want that being sucked into the engine.

Jim

Reply to
Indy Jess John

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