Air motor repair

[MashingMetal]

I am hoping someone more familiar with gasket material can help me. The seals are 0.001 in thickness for the caps use some sort of Mylar? I was hoping to make the new seals as the rebuild kits are $$$. I am setting up an inexpensive mixer for industrial finishes, yes it will br grounded.
Thanks!

 

[Ironman]

I would use a sheet of writing paper for the gasket. Or get a tube of The Right Stuff and apply a thin layer and after it starts to skin over, bolt it together. Any excess will squeeze out and may cause a rotor issue. You would need it to be thinly applied, but it is a super good product.
Another gasket material that works for some applications is pop can aluminum.

 

[Former Member]

0.001 is a very thin gasket, go pick up some drafting vellum (used for ink drawings) has a very similar feel to mylar and is about that thickness (forewarned there are different wts aka thicknesses). It also has body and strength.

This may be what they are using.

I used it as feeler gauges to set up the CNC touch off point (until I found 0.0005 feeler gauge stock which last longer) as it lasted because it could handle pressure and moisture.

 

[PeterT]

PTFE is commonly used as gasket material. Its pretty impervious to oils, fuel & heat although you probably don't have much of that. I had to get some PTFE for my model engine. It cuts pretty easy with a sharp Xacto. Its on Ebay & AliExpress etc. but I saw this on Amazon, 0.1mm = 0.004".

https://www.amazon.ca/Transfers-Resistant-Protects-Thickness-%C3%971000mm/dp/B078N3WN32/ref=sr_1_26?crid=1WU2TE5KIOCVN&keywords=ptfe+sheet+gasket&qid=1681623600&sprefix=ptfe+sheet+gasket%2Caps%2C162&sr=8-26

If you do try a sealant I recommend you do a test fit up first, say 2 opposing sections just with a 1" bead. Because some of the sealants I tried between aluminum blocks stuck too well & removal would have been a problem on some dainty high value parts. I think machine or auto components are beefier & stronger so you have more leverage to shear the goop. Anyway a little test wouldn't hurt.

 

[MashingMetal]

PTFE is commonly used as gasket material. Its pretty impervious to oils, fuel & heat although you probably don't have much of that. I had to get some PTFE for my model engine. It cuts pretty easy with a sharp Xacto. Its on Ebay & AliExpress etc. but I saw this on Amazon, 0.1mm = 0.004".
Inches l

Hi Peter, Thanks for your help! I think the 0.001 thickness is important or the air bypasses the air veins over the top and bottom. I was doing so poking around and found McMaster Carr has something that thin available and I will be in the States next week.
I like your method for cutting out the gaskets, I will definitely use a similar method.
Thanks, Mark

 

[phaxtris]

Are you sure if was a gasket and not just a sealant? I would give anaerobic sealant a go, it works in extremely tight fitting parts without gaskets

 

[MashingMetal]

Are you sure if was a gasket and not just a sealant? I would give anaerobic sealant a go, it works in extremely tight fitting parts without gaskets.

Yes it is a “gasket” probably the clearances can be controlled that way. All the rebuild kits have replacements

 

[PeterT]

What I forgot to mention was I used a super light mist coat of spray adhesive, like what crafters use on paper. Stuck the PTFE sheet on my template & it was a lot more stable to cut the outline along the edges using a backing board r cutting mat. Not sure you could do your part the same way. Then acetone or similar just removes the adhesive.

 

[MashingMetal]

What I forgot to mention was I used a super light mist coat of spray adhesive, like what crafters use on paper. Stuck the PTFE sheet on my template & it was a lot more stable to cut the outline along the edges using a backing board r cutting mat. Not sure you could do your part the same way. Then acetone or similar just removes the adhesive.

That’s another good idea, it’s so thin it would be easy to stretch out of dimention. Thanks Peter