cometic gaskets

what do you do when installing cometic gaskets, install them out of the package or coat them with something? cometic says not to coat them with anything but many say you must coat them. I use PERMATEX HIGH TACK but am courious what you do.

Cooter. If its a multi layered gasket I think there has to be a very fine finish to both the block and the heads for this to work. If not they will leak. I assume your talking head gaskets

Ace

yes i am talking multi layered head gaskets.

Better call Lem or Charlie on this.

Ace

If the deck is nice and slick I don't use anything........some use the spray copper coat.

i believe they look for a 50RA finish or better , any ruffer will comprimise the design of the gasket

cometic says to install dry with a 50 ra but it seems that everyone else says you take a big chance of leaking if you install dry which is why i figured i would ask the people that use them. I sure like them but want to make sure i am not tearing motors apart to fix leaking gaskets. thanx for the help

what few 'leaks' I've seen have been but slight drips.........a little stop leak is all it takes to resolve it. Sounds like people have got you spooked for no good reason.

I am probably one of the few that have had a slight leak and it was tune related more than likely. I just reused one , cleaned it up and sprayed with copper coat and am having no problems , that's with a 10 bolt head. I don't see any problems using the copper coat if a guy wants to.

When I installed mine new I put them on dry. When I reused them I just cleaned them up and sprayed coppercoat on them. No issues that I have seen.

we put them on dry and have no leaks at the gasket. now these sb tfs heads keep cracking like crazy so we get some water in the chamber but I'm not starting that again on here.

I like using Copper Coat, since it is easy to find and seems to work well. I started out using spray Hylomar, but that is harder to find. I think you can buy illegal dope easier.
No drips...no leaks...10 bolt.
Keith

As long as the block and head finish is correct I typicaly install them dry the first time and the copper coat them for the next 2 installations, then get new ones. First time I used them I did have leaks on the exterior by the rivets and pulled my hair out about it, used some engine rebuilder stop leak pellets and everything was fine, haven't had an issue with them since then. That was Iron heads on a iron block too and that could have had something to do with it?

Surface finish of the adjoining metal is most important to sealing.
IF the finish is correct then you don't need anything however, most resurfacers leave a rougher finish than desired so, very SLIGHT copper coat or high tack may be needed.

The OE manufacturers combined for a large study on the multi-layered steel head gasket sealing and found that an Ra finish of 16 is the roughest it should be ... take that for what you think it's worth. They build millions of engines per year.

I used mine the first time right out of the pkg. Then when I put them back in this spring I used em dry again. No leaks either way.