why copper coating

[PR CB7]

i've seen this on manny racin aps
why they spray the copper gaskket shit

where can i find one if needed

[The G-Man]

You spray the copper gasket stuff on head gaskets and exhaust gaskets.

[PR CB7]

i know u spray it in those gaskets
but why

[johnl]

i know u spray it in those gaskets
but why

My understanding is that it acts as a lubricant, and also tends not to stick to things over time so makes disassembly easier.

As the head and engine and gasket heats up they don't all reach the same temperature (the head will be hotter than the block), and even if they did but are not made from identical materials, the different parts expand at differing rates. This means you can get very slight movement between the components as they expand / contract when they heat up and then cool down, or if movement doesn't occur then you get stresses and strains. This movement and / or stress can eventually lead to gasket failure if the gasket is 'stuck' to the different components.

[NAiL05]

Its an extra seal. The copper spray is usually sticky. It also helps in evening up the surface patching up the uneven spots when it gets compressed. It also helps as protection.

[djphonics]

I'd like to tell you the details of how it works...but I dont . I am curious too. However, I can tell you that I've used the Spray-on Copper (i think Permatex brand) on a shit load of headgaskets and never had a problem.

[johnl]

Its an extra seal. The copper spray is usually sticky. It also helps in evening up the surface patching up the uneven spots when it gets compressed. It also helps as protection.

My understanding (which could be wrong) is that the stickiness will go away when the goo is fully cured. Before full cure copper particles do get squeezed from areas of higher clamping pressure into areas of lower pressure, thus helping the seal.

I use a paint with aluminium particles (a brand called 'Silverglo', but I'm sure there are plenty of others). I pour off the liquid (probably turpentine) from the top of the can leaving the thick particulate paint in the tin, then paint it on the gasket with a soft brush (as evenly as I can but it's not super critical) and leave it to dry for a short while before fitting. The aluminium particles squeeze into any imperfections in the sealing surfaces and assist in the seal (as above), as well as acting as a lubricant for expansion / contraction of the parts.

This trick was told to me by a bloke who made custom gaskets for a living, for everything from racing cars to humungous ship engines. Always worked well for me.