Making copper flange gaskets

[AC sports]

Working through the turbo Subaru, I found all exhaust gaskets from turbo to tailpipe either wrong size or non existent.
I've got some 26 thou copper sheet here and started cutting, grinding and filing correct size replacements. The plan is to flatten all exhaust flanges with a file then anneal the copper gaskets and use them.
Question is, should I also run a thin skim of high temp silicon on the copper? A bit like the viton coating mls gaskets use. Maybe skim them and let it dry then use? Suggestions welcome.

[allencr267]

Can you put a bead on it that will crush?
IMO, Unless the mating surfaces are really good, flat & smooth, the surface area is too large for the copper to actually crush & conform to the surface irregularities without being REALLY tightened down way more then the size fasteners being used are capable of.
Copper, alum. or SS safety wire is my choice.
Good luck.

[agertz1]

McMaster Carr has copper, steam pipe flange gaskets,( flat and ruffled).

[Racer71]

If the fit is good ultra copper does a very good job with sealing. I think you would need a raised bead of some sort in the copper to be beneficial.