RTV exhaust gasket sealer

[melugin]

I need exhaust gaskets for some KG-9 motors. I have NOS brittle gaskets, but they probably wouldn’t be serviceable. Several decades ago I cut replacements with an exacto knife, using a lot of Band-Aids along the way. Would the black RTV gasket material work for this application?

[dave-bernard]

soak the gaskets in oil.

[PugetSoundBoater]

dave-bernard wrote:

soak the gaskets in oil.

good idea

"Some people want to know how a watch works, others just want to know what time it is"
Robbie Robertson

[melugin]

I will need more gaskets than what I have.

[green-thumbs]

I attempted to make gaskets from dried out brittle FelPro Karropak gasket material . Without success. until I soaked it in warm/hot water. The damp gasket material became soft, pliable and easy to work with. Probably a very old school technique
but, it was new to me.
May be worth trying with factory gaskets that have become stiff and brittle due to
long storage.
Karropak is a vegetable fiber material, some older factory gaskets are made of similar
material and may respond well to a short soak. Gaskets will dry out again overnight
so I had to soak them again to install and do final trim

Louis

[A Hoskins]

I think the answer to the question is “No”. According to Permatex, the black RTV is good to about 500 degrees F. Permatex Ultra Copper says it’s good for 700 F. I cut gaskets with a slow hand (Clapton ?), working with a No.11 Exacto on a sheet of plate glass. It takes many, many passes with the knife. I do the bolt holes in a drill press by spinning sharpened gasket punches or brass shell casings and backed up with a piece of wood. The result is clean and neat.

"Fox News" isn't.

[melugin]

With the water cooled exhaust and each gasket captured between aluminum castings and a stainless plate, we may not see 500 degrees. I think I’ll go for it and save my original gaskets for templates. These motors have stock exhausts. Thanks for the input. Don’t hold your breath, there’s only a narrow window to run one of my KG-9s. Cool enough I don’t suffer heat stroke cranking one, and warm enough I don’t get hypo-thermia if I get tossed. Years ago, I had one which gave problems.

[billw]

I think everything is four stroke these days, but the argument could have been made for a two stroke with oil injection. My question is, why? I guess it would be greener….or would it? I think propane has something like 20% less energy than gasoline ( don’t quote me on that number) so, even though it would burn cleaner, you’d have to burn MORE, to get the same results, much like when oxygenated fuel came on the market and gas mileage went down noticeably. I guess if you plan on operating the outboard in a closed building, it would be a good idea. Lol. And if you think a leaking rusted GAS tank was a bad thing…..

Long live American manufacturing!

• This reply was modified 5 years, 3 months ago by billw.

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