Cleaning Copper Kote from Cometic gaskets - suggestions?

[shoedoos]

Anybody have suggestions on cleaning Copper coat from MLS gaskets? I started using acetone and while it does work, I can see it will be a long journey.....any other suggestions would be welcomed....

[Geoff2]

Lacquer Thinners.

[treyrags]

Xylene soaked rag. An excellent cleaning solvent that won't evaporate too fast. Wear hand protection!

[ijames]

Looking at the MSDS's for a few brands of copper antiseizes they are basically heavy hydrocarbons, maybe with alkaline earth and talc and limestone additives (think light grease), plus 3-10% copper. I don't know how sturdy the MLS gasket is but I'd start with a strong detergeant and hot water to soak off as much of the grease as possible. If the gasket will take it, a spray wash cabinet would be great. I'd start with a strong washing soda solution, then soak, scrub, rinse with water, and repeat. Then dry it thoroughly, and then use the expensive organic solvents like acetone or xylenes. Again, try a used gasket first to make sure the washing soda won't hurt it. Use a black shallow tray for soaking and cover with a layer of transparent cling wrap from the kitchen and then put the tray in the sunshine - free solar heat .

[Schurkey]

Copper Coat gasket sealer would be much more difficult to remove than Copper anti-seize.

"I" would be trying mineral spirits, as I have that handy. After that, I'd be using "Carb spray", which according to the ingredients list of the can I looked at yesterday, is a mix of Xylene and Toluene, with CO2 for propellant.

[peejay]

I believe I have used detanured alcohol to good effect.

Wear gloves if you don't want to get contact-drunk!

[Ericnova]

Good old fashioned spray oven cleaner will lift it off also, but you need to cover it with plastic wrap and give it some time to work.

[427dart]

How did copper coat get on the gaskets? They are supposed to have that seal all tacky layer on both sides and shouldn't need anything put on them.

[tresi]

I believe I have used detanured alcohol to good effect.

Wear gloves if you don't want to get contact-drunk!

I believe you're correct and if anybody is thinking about drinking it they denature it with gasolene.

[Newold1]

I believe Cometic"s MLS head gaskets are coated with a special sealant coating and I believe some solvents and cleaners will damage or remove those coatings. I would recommend you contact Cometic directly and get their methods for removing coatings and spray on materials.

[shoedoos]

These particular MLS gaskets don't appear to have that slightly tacky coating I think you are talking about. They have three layers, the two outside have what looks like a black oxide coat. It isn't sticky and does not appear to be lifting with semi-agressive use of acetone...

[groberts101]

I believe Cometic"s MLS head gaskets are coated with a special sealant coating and I believe some solvents and cleaners will damage or remove those coatings. I would recommend you contact Cometic directly and get their methods for removing coatings and spray on materials.

Right. Cometic uses a viton rubber coating on both exterior sealing surfaces. Problem with sealers containing small metallic frit is that they can literally be burnished/impregnated into the viton rubber costing as you continually scrub and abrade the surface while attempting to remove them. Stay away from acetone and lacquer thinners as continually rewetting or soaking the surface while trying to soften the sealer will also eventually eat away and soften the viton rubber as well. Which then causes bubbling and eventual tearing away of the viton rubber from the stainless shim stock.

I would try denatured alcohol as it is much less aggressive.. but if you thought acetone would be time consuming to begin with then you'll really be hating life with a less aggressive solvent like denatured alcohol. I doubt oven cleaner will work either as you're basically dealing with a heat cured paint at this point with metallic frit encapsulated within the coating.

Another option might be something like goo-gone or painters helper which are much less aggressive to composite materials but need to remain wetted for some length of time to even start softening cured on coatings such as that. Might be time to replace the gaskets at this point. Good luck with it.

[shoedoos]

just a quick update, the thinners worked well, no hard rubbing, maybe two times across each side and I was back to the black surface of these MLS gaskets.

My take on use of copper kote etc is after first cycle of head gaskets and the inevitable cleaning of surfaces with semi-aggressive solvents, for a second, third, fourth use of the gaskets, a shadow coat of copper spray (or whatever) is to replace any possible removal of the viton coating....

When using the thinners, I certainly removed that slight stickiness and in some areas the black was removed from raised edges.

Another train of thought is copper cote will also fill any slight imperfections on the block and head surfaces when the RA isn't exactly ideal.