brownmound

I've heard that copper crush washers can be annealed and thus fit for reuse by heating them with a torch until red hot and letting them cool.

Has anyone heard such thing, and can I do this over the stove!? I don't own a torch.

And why are copper crush washers $2 each when a penny costs, well a penny?

Right on.

MikeLMR

yep the annealing process softens the copper washer so it can be used again ... usually its a good idea to buy a new one though

jeremy

iTrader: (1)

cheap skate :p

brownmound

Mazda wants about $2 each. I have to get 20 so $40 for little washers seems like a lot. I'm a free spender for sure but I'm not about to get ripped off. They were $2 ea. at Advance also...I guess it's the copper that's expensive...a guy Autozone gave me some for free though they are not as thick as OEM.

Right on.

MikeLMR

why do you need 40??

do a search on annealing tho' as I think you have to heat the copper up till its cherry red then quench it in water, not just let it cool

(If I recall my manufacturing technology lessons correctly!)

Wankelguy

You do.

brownmound

I'm not a metalurgist, nor can I spell it, but wouldn't heating then rapid cooling be called quenching. From my experience this makes a metal harder, and more brittle. The idea is to soften the metal by annealing it, which my understanding is too cool it controlled like.

I'll do some research if I can't find the new ones for cheap.

Right on.

MikeLMR

your thinking of carbon steels ... copper is very different

MikeLMR

Nonferrous Metal

Copper becomes hard and brittle when mechani_cally worked; however, it can be made soft again by annealing. The annealing temperature for copper is be_tween 700°F and 900°F. Copper maybe cooled rapidly or slowly since the cooling rate has no effect on the heat treatment. The one drawback experienced in annealing copper is the phenomenon called "hot shortness." At about 900°F, copper loses its tensile strength, and if not properly supported, it could fracture.

Aluminum reacts similar to copper when heat treat_ing. It also has the characteristic of "hot shortness." A number of aluminum alloys exist and each requires special heat treatment to produce their best properties.

we were both correct

it is preferential to cool rapidly in water though, as allowing it to cool slowly in air will cause the surface to oxidise

This is really bringing back some memories of college and engineering materials now !

brownmound

OK that makes sense....my experience is with steel.

So, I did the Auto Parts store drive around tonight one place gave me the washers for free. The inner diameter is the same, but the outer diameter is slightly smaller and the thickness is about half. Do you think these will be OK?? (these are all crush washers on the oil metering lines, for the most part)

Right on.

MIKE-P-28

iTrader: (1)

take a penny, smash it flat and drill a hole in it LOL

wwilliam54

if you really need that many annelaed PM me
I work at a place were we anneal steel
im sure I could chunk some copper in

BTW our annealer uses liquid nitrogen to cool the steel