COPPER HEAD GASKET

[broker-len]

I assume that using a copper head gasket some what crushes it when it is used and torque what is the best way to regain it's thickness so as to reuse it

thanks      BR

[Rusty_OToole]

Some British motorcycles had solid copper head gaskets. They could be reused if you annealed them. Annealing softens the copper. You did this by laying the gasket on a piece of flat steel and heating it up with a torch. Then let it slide off into a pan of water. This is the opposite of steel.

[Frank DuVal]

On small copper gaskets (like. Corvair head gaskets or banjo fittings), you can heat them with a torch to red and let them cool. Annealing this is called. 

 

If they have crushed a lot, then that won't work. What's a lot? ?

[Frank DuVal]

So, typing while I'm typing, Rusty!

[Spinneyhill]

I don't think you can regain their loft. But you can re-use them if the head and block deck are flat. There was a recent topic on re-using head gaskets. I used a copper cote (or copper kote or similar) spray-on stuff on the gasket. It is designed for the job apparently.

[Stude Light]

9 hours ago, Frank DuVal said:

On small copper gaskets (like. Corvair head gaskets or banjo fittings), you can heat them with a torch to red and let them cool. Annealing this is called. 

 

If they have crushed a lot, then that won't work. What's a lot? ?

To anneal the copper you have to quench it. If you allow it to slowly cool down it will harden the copper. So to reuse any copper gasket it is best to soften it (anneal) through quenching it first. As Rusty mentions above, this process is the opposite for steel.

Scott

[Bush Mechanic]

Hi, Broker, 

To know when it has been heated sufficiently, you can partially lift the hot gasket with pliers or similar, on one end. When it is ready it is 'saggy' soft, and will bend EASILY. Then it is ready for quenching. The copper will change colour as you heat it, and after the first couple of times you will be able to tell visually when it is ready to quench. Good luck, it's an easy process.

Mick.

[Spinneyhill]

You wouldn't attempt to anneal an ordinary copper sandwich head gasket, only the solid copper type. The sandwich material might not like being heated to several hundred degrees.

[Rusty_OToole]

Yes this can only be done on a solid copper gasket, only if it is going back in the same engine in the same position. O ring type cylinder seals for air cooled engines cannot be reused successfully.

[broker-len]

I really want to thank every one for their posts but I am more confused now than I was before--------this is for a copper over asbestos gasket on a 4 cylinder flat head      I was told by a friend to just soak it in water           looking to do it the correct way so it does not leak when put back together

[keiser31]

1 hour ago, broker-len said:

I really want to thank every one for their posts but I am more confused now than I was before--------this is for a copper over asbestos gasket on a 4 cylinder flat head      I was told by a friend to just soak it in water           looking to do it the correct way so it does not leak when put back together

I don't think I would use one over. Maybe as a last resort. If it has been torqued down and running for many miles,  just replace it.

Edited September 4, 2017 by keiser31 (see edit history)

[Guest]

Too bad you had not described the gasket properly in the beginning.  I have reused composite head gaskets as many a three times.  Soak them in water for a day and then install.  Also I don't use any kind of sealer or coating so when you go to remove it, it lifts right off.  If yours was cemented on and you had to pry it off it may or may not seal.

[Stude17]

21 hours ago, Stude Light said:

To anneal the copper you have to quench it. If you allow it to slowly cool down it will harden the copper. So to reuse any copper gasket it is best to soften it (anneal) through quenching it first. As Rusty mentions above, this process is the opposite for steel.

Scott

It does not make any difference if you quench or let copper air cool it will still be annealed, however, quenching will remove the scale.

Edited September 4, 2017 by Stude17 (see edit history)

[Stude Light]

I was taught to quench my brass and copper for annealing and always had good results doing so (particularly brass cartridges for reloading) , but after a bit a reading, you are right.  I stand corrected.  Thanks.

Scott

[Rusty_OToole]

Composite head gaskets can be soaked in hot water overnight and reused. You must put the gasket back in the same engine it came out of, and in the same position.  The gasket will be broken in, or compressed to fit your engine. It will probably work just as well without the soaking.

[Restorer32]

Soak composite gaskets in water overnight then sneak them into the freezer section of your refrigerator. The water will freeze and expand the asbestos by 10%. Next day let the gasket dry thoroughly before using.

[JV Puleo]

I used to rub solid copper gaskets (albeit not head gaskets) on a piece of 220 or finer paper on a piece of plate glass before anealing. It's only good for one or two applications but in a pinch it worked quite well. Mostly, these were the gaskets for banjo fittings.

[Frank DuVal]

I found the instructions I have for solid copper single cylinder head gaskets (six per engine in this case, three per head). They say to let them cool in air, not quench them. This is how I've always annealed copper. Same for pipe I have silver soldered. It gets softer and is air cooled.