What to use to seal old compressor head?

[sabinoerc]

I have an old craftsman air compressor which still can pump up but noisy as heck. I thought I’d try to quiet it down a bit with a muffler as it had just as a foam intake filter. (It didn’t work). I attempted to seal the gap between the muffler pipe and compressor head with some high temp Rtv but I screwed up and turned it on before it completely cured and sucked some into the compressor. @#&$#! So pulled the head off and scraped a few bits off the reed valves and compressor is back to old noisy self. The head is actually a two piece head, one chamber on bottom, middle plate, and top chamber with a thin rubber like gaskets apparently integral to one side which mates against an opposing flat surface. I checked for leaks after with soapy water and have a spot it bubbles. I was wondering if there was something which might be able to be used as sealant? It’s not too bad of a leak, working ok for its age and I didnt want to make it worse trying something which screws up the existing rubber seals - so was wondering if anyone has experience with something which would work or I should just let it be.
thanks for the advice!

 

[Olafur]

Why not try high temp RTV again, I have had great luck using it on compressor manifolds and cylinder heads and valve plates.
Just like with a gasket or whatever sealing method you use, surfaces need to be clean and flat. Then give it 12 hours to cure for good measure.

Chances are you need only very thin layer of it. I apply this stuff with my finger (nitril gloves) and use just enough to cover the surface -paper thin film, so I can almost see the metal through the RTV film. And assemble quickly after applying RTV. Don't give it time to cure before assembly.

Good luck.

Edit:
Sorry I didn't read your post properly, not quite awake yet, just got out of bed. What I said above is probably irrelevant to your problem. If the compressor sucked in the RTV - it wasn't cured, and it wasn't because you are trying to bridge some gap with it. That's probably going to be difficult. You need some thick soft gasket material I guess. Perhaps this muffler isn't flowing enough as well - since it sucked in the RTV it's clearly providing some resistance.

 

[charbar]

What about a sheet of gasket paper and just cut out your own gasket?

 

[joshmodelskidoo]

Ereplacementparts.com sells parts for that last I knew

 

[sabinoerc]

Sorry I didn't read your post properly, not quite awake yet, just got out of bed. What I said above is probably irrelevant to your problem. If the compressor sucked in the RTV - it wasn't cured, and it wasn't because you are trying to bridge some gap with it. That's probably going to be difficult. You need some thick soft gasket material I guess. Perhaps this muffler isn't flowing enough as well - since it sucked in the RTV it's clearly providing some resistance.

thanks, but I think it was my post which wasn’t very clear.
I was looking for advice on the compressor head flat mating surfaces with that little rubber ribbon integral seal. that is, something to hold pressure. I was wondering if anyone had something they’ve used with success and thanks for you advice on that.

on the intake side, I had cut up the plastic holder for the foam and it fits the copper pipe for muffler pretty well with just a little gap. I think rtv will work there also, I just didn’t let it cure long enough.

 

[sabinoerc]

Ereplacementparts.com sells parts for that last I knew

Thanks - I don’t think I’ll spend anymore money on this one. I bought a new bigger compressor for myself and was giving this to my son. Just wanted to stop the little leak if reasonably possible without trashing it.

 

[sabinoerc]

What about a sheet of gasket paper and just cut out your own gasket?

Thanks. I thought about a gasket but the design is such the mating surfaces are essentially line-line. I was worried about the gasket thickness changing the volume in the chambers too much and lowering compression.

 

[driftpin]

Harley used to use aluminum paint for a 'head gasket' on the K flathead engines.

 

[Walkers]

With those old oil free compressors, the best way to quiet them down is to bury them under about 6 deet of mud.

 

[marinusdees]

With those old oil free compressors, the best way to quiet them down is to bury them under about 6 deet of mud.

Amen! Amen!! Oilless are bad technology gone bad.