Best way to fix a copper gasket leaking air?

[student123]

My novice build of the littlemachineshop oscillating engine continues…

http://littlemachineshop.com/Projects/OscillatingEngine.php

piston brass , theres a copper gasket , all else aliminum
testing on compressed air, no long term plans for steam running
a pic all assembled:

Now in the testing stage
However air is escaping thru the copper gasket


Any suggestions please as to what the solution is? Ptfe tape any good ? Glue ? Replace the copper with a better material ?


Mike

 

[cidrontmg]

There´s lots of silicone-based gasket materials, any such would be just fine. In a pinch, I´ve used even normal household silicone. Copper gaskets are usually needed only with high temperatures, not an issue with compressed air. And there are lots of silicones even for quite high temps.

 

[tel]

I usually only ever use oiled paper for gaskets. slightly heavy (110gsm) is good and the beauty of it is you can draw & print 'em out on the computer.

 

[Mosey]

Ran across something really neat for gasketing some time ago. Goretex makes a full line of sheet and cut gaskets fro all kinds of engines and other applications. It is rally cool stuff, and can be had in precut sheets of gaskets. Just thought you might find this interesting. It is pretty much resistant to high temperatures, self adhesive, etc.

 

[shred]

Given this is an oscillator, more or less anything gap-filling should be ok if all you want to do is get it working. I've used RTV from the auto parts place before in similar situations.

 

[wheeltapper]

you could try annealing the copper gasket by getting it red hot and quenching to soften it.
it might bed in better then.

Roy

 

[Bill S]

I second annealing, we used to do it all the time with motocross 2 stroke engine head gaskets.

Bill

 

[bearcar1]

I think Tel, has the right idea. Get a hold of one of those heavy, brown paper shopping bags from the grocery store (you'll obviously most likely have to ask for one since most places use those God awful plastic sh*tters) and then trace your gasket outline with a pencil (do several at the same time, you never can tell) and after cutting out with a sharp hobby knife, rub some common household oil (3 in 1) into the paper fibers and you are done. I say this method as opposed to RTV compounds for several reasons, one of which is the cost factor and the ease of future disassembly if required.

BC1
Jim

 

[stevehuckss396]

I like the bag idea.

I make my gaskets from teflon film. Seems to work good and they hold up well. It comes in .005 to .125 thick. I seem to use alot of .010 and .020 for most of my stuff. May be a bit over the top for an air engine.

 

[student123]

Guys thank you all - several options there.

It so happens I have both 200gsm & 300gsm paper from art class.
So I'll first try the 300gsm lightly oiled with 3 in 1.

Mike

 

[doubletop]

I'd vote for the auto parts RTV gasket. Just too easy to use on any surfaces you want to seal, joints and unions. One tube will last you ages.

Pete

 

[Lakc]

I read in a steam engine book last night that to anneal copper gaskets, you should heat them red hot, and then let them cool slowly.

That got me thinking because I had always heard the opposite, or rather that red metals were the opposite of steel in which the quench does annealing instead of hardening.
Wiki says it works both ways. I wonder why and which is best.

http://en.wikipedia.org/wiki/Annealing_%28metallurgy%29

 

[krv3000]

HI as a reference to gasket matereal i have yous aluminium foil and led for thin gaskets

 

[GOOFY063]

just use good ole spray paint put a cote on each side let it dry and you should be ready to go, but as someone said you may need to heat the gasket in the oven to soften it

 

[Dan Rowe]

I read in a steam engine book last night that to anneal copper gaskets, you should heat them red hot, and then let them cool slowly.

Pat,
The diesel generators I worked on had hundreds of copper gaskets. Each banjo fitting has one on both sides of the banjo. Mostly we would use new gaskets but we always saved the old ones to use when we ran short.

Anyway the standard procedure is to load up a wire with a handfull of gaskets and heat with the torch untill dull red. They can be left to cool if you have the time or dunked in water if you are in a hurry it makes no difference with copper.

RTV will handle the temperature of hobby steam and any high quality paper will work fine. We used old charts on the ships for paper gaskets.

Dan

 

[rleete]

Where I work, they use .010 teflon sheet to cover the vacuum chucks. Lots of scraps trimmed off, and occasionally sheet of the stuff get discarded. Anyone interested in having some?

 

[student123]

It so happens I have both 200gsm & 300gsm paper from art class.
So I'll first try the 300gsm lightly oiled with 3 in 1.

By way of closing this one, I tried the 300 gsm & 3 in 1 and it worked fine.

I now have a new 'challenge' , which I'll do as a separate question.

Thanks again

Mike

 

[tel]

Thm:

 

[ozzie46]

Where I work, they use .010 teflon sheet to cover the vacuum chucks. Lots of scraps trimmed off, and occasionally sheet of the stuff get discarded. Anyone interested in having some?

I'm interested. ;D



Ron

 

[tel]

Where I work, they use .010 teflon sheet to cover the vacuum chucks. Lots of scraps trimmed off, and occasionally sheet of the stuff get discarded. Anyone interested in having some?

As, indeed, am I - if I can stand the postage.