I just received the comments below, from someone who is probably pretty
trustworthy, about annealing copper gaskets.
Once again, a supplier has taken the time to give some expert information.
We should always give helpful suppliers our business.
Allen Hefner
- - - - - - - - - - - - -
"Annecdotal experience has been to anneal (soften) headgaskets made of solid
copper. I think that this is so because 50 or so years ago the heads were
not milled as smoothly as they are today. Steel head were probably milled
to RA specs to about 100. This is where not only can you see the concentric
arcing lines but, if you run you finger nail over the head you could almost
feel it. Today the heads are milled much smoother. So, you may need to
anneal a copper gasket if used on this older technology. However if you
have an older motor finnished to todays machine tolerances you probably
ought not to anneal unless you have an O ring around the bore using a wire.
Most of the copper used for HG's is copper 110. This alloy is almost all
copper with a trace of Oxygen. When heated to about 900d F this copper will
anneal to a dead soft state. If you do it in air it will develop an
oxidation film and will discolor. This will not harm the copper just
cosmetic. I have found that If you do this several times the copper changes
and becomes pitted. Commercial annealing services do this annealing in
atmospheres purged of oxygen. This is called bright annealing since the
finnished copper comes out shiny--.
With regard to cooling. The cooling method dosn't make any difference. It
is the heat that counts. The gasket is so thin typically that just letting
it air cool will allow you to be able to work with it in about 10 minutes.
Don't use Oxy acetylene....way too hot for most to use (unless your good).
Don't ever bead blast.
Heat from the bottom up -it makes it easier to see the color (dull
blood-red) in a darkened environment.
You don't have to get the copper heated all at once. You can do a corner
today , a corner tommorrow. The trick is to get the entire gasket to that
color at one time or another. More heat is not needed.
If you have any questions you can email me off-line.
M. Dunst
Gasket Works USA, LLC
626.358.1616 voice/page
626.358.7971 fax
www.headgasket.com"
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