Are old copper YZ head gaskets reusable

mark_swart
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mark_swart
Edited Date/Time 10/24/2015 9:00am
I want to pop the head off my late 70s YZ for a look inside, but new head gaskets are around $30. From the pics I've seen, they look like thick copper - are they are reusable?

Thanks!
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Bultaco
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Bultaco 10/11/2015 11:03am
10/11/2015 11:03am
Yes. To anneal (soften) heat it up and quench it in water. Use a propane torch tr just put it on the stove.
wfopete
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wfopete 10/13/2015 5:26pm
10/13/2015 5:26pm
I had a tuff time getting my 465 head gasket to the required bright orange color all the way around with propane and even MAPP gas. Went EZ with Oxy Acetylene a torch.
19673ontree
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19673ontree 10/15/2015 5:20pm
10/15/2015 5:20pm
I used to reuse those all the time , dont remember ever having a problem
RiV
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RiV 10/15/2015 6:02pm
10/15/2015 6:02pm
Bultaco wrote:
Yes. To anneal (soften) heat it up and quench it in water. Use a propane torch tr just put it on the stove.
It works for sure, sometimes impurities will surface,
I always used a scotchbrite to clean it up and make
it a nice presentable surface.

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markit
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markit 10/16/2015 8:04am
10/16/2015 8:04am
Bultaco wrote:
Yes. To anneal (soften) heat it up and quench it in water. Use a propane torch tr just put it on the stove.
Quenching the copper in water will actually reverse the annealing.
Bultaco
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Bultaco 10/16/2015 8:38am
10/16/2015 8:38am Edited Date/Time 10/16/2015 8:39am
markit wrote:
Quenching the copper in water will actually reverse the annealing.
I respectfully disagree.

Annealing, in metallurgy and materials science, is a heat treatment that alters the physical and sometimes chemical properties of a material to increase its ductility and reduce its hardness, making it more workable. It involves heating a material to above its recrystallization temperature, maintaining a suitable temperature, and then cooling.

In annealing, atoms migrate in the crystal lattice and the number of dislocations decreases, leading to the change in ductility and hardness.

In the cases of copper, steel, silver, and brass, this process is performed by heating the material (generally until glowing) for a while and then slowly letting it cool to room temperature in still air. Copper, silver[1] and brass can be cooled slowly in air, or quickly by quenching in water, unlike ferrous metals, such as steel, which must be cooled slowly to anneal. Van Vlack, L. H. (1985). Elements of Materials Science and Engineering. Addison-Wesley


• Cooling rate after annealing does not matter (except at 10 million degrees per
second the material would get harder again)www.materialseducation.org/educators/matedu-modules/docs/Work_Hardening…
mark_swart
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mark_swart 10/18/2015 5:57pm
10/18/2015 5:57pm
Thanks for the metallurgy lesson, I learned a new word in this thread haha!

I did reuse it, but just cleaned and scuffed it with a green scouring pad. Running fine... no issues.
PN27416
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PN27416 10/19/2015 2:02pm
10/19/2015 2:02pm
Some copper ones have ridges, once there flat there not the same. Yes in a bind but new is new.
markit
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markit 10/22/2015 10:05am
10/22/2015 10:05am
The sentence in the second paragraph is correct the note after the (1) is missing on the copied text, im sure it explains that quenching of copper and silver will result in hardening. I work with copper on a daily basis and have been for 30+ years. I could be wrong but my schooling was 30+ years ago though.LOL But i know for a fact if you quench copper its harder than if you let it cool at room temp.
markit
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markit 10/22/2015 10:08am
10/22/2015 10:08am
mark_swart wrote:
Thanks for the metallurgy lesson, I learned a new word in this thread haha! I did reuse it, but just cleaned and scuffed it with a...
Thanks for the metallurgy lesson, I learned a new word in this thread haha!

I did reuse it, but just cleaned and scuffed it with a green scouring pad. Running fine... no issues.
I just did a top end on a friends rt100,I did the same thing.Smile
wfopete
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wfopete 10/22/2015 11:13am
10/22/2015 11:13am
My understanding is the thought behind quenching all has to do with the differant gain structures between ferrous and non-ferrous metals that support annealing process.
markit
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markit 10/24/2015 9:00am
10/24/2015 9:00am
I'll have to so some research on it as i said i could be wrong.

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