Replacing Copper Crush Gaskets with Fluorocarbon Gaskets

Every fusor and fusion system seems to need a vacuum. This area is for detailed discussion of vacuum systems, materials, gauging, etc. related to fusor or fusion research.
Post Reply
Joe Mayer
Posts: 5
Joined: Thu Oct 27, 2016 6:59 am
Real name: Joe Mayer

Replacing Copper Crush Gaskets with Fluorocarbon Gaskets

Post by Joe Mayer » Thu Sep 28, 2017 9:09 pm

I recently inherited an Osaka Turbo Pump for my project and would like to mate it directly to my vacuum chamber. The issue which I now face is that my chamber is 6061 Aluminum and I know that a copper crush gasket is not going to give me a proper seal. I feel like I came across a website before which explained this process but can't seem to find it again and all of my searches either show me how do replace gaskets on a car or the sites of companies selling gaskets.

After some research I believe that Fluorocarbon (Viton) gaskets will work for my needs but I would just like to make sure that this is an acceptable thing to do and if so, if anyone has any information or tips and tricks before I proceed. Thanks!

Jerry Biehler
Posts: 727
Joined: Tue Nov 24, 2009 8:08 am
Real name:
Location: Beaverton, OR

Re: Replacing Copper Crush Gaskets with Fluorocarbon Gaskets

Post by Jerry Biehler » Thu Sep 28, 2017 11:03 pm

I assume it has a conflat connection? They sell square cross section o-rings specifically for soft sealing conflats.

http://www.pchemlabs.com/subcatagoryb.a ... ton-Rubber

I am planning on using one to mate my bigger turbo with a 10" conflat to a piece of Mic6 tooling plate as an adaptor.

ian_krase
Posts: 348
Joined: Mon Nov 28, 2016 7:48 am
Real name: Ian Krase

Re: Replacing Copper Crush Gaskets with Fluorocarbon Gaskets

Post by ian_krase » Fri Sep 29, 2017 6:10 am

It's worth noting that these are not quite square. They are also kinda annoying/tricky to install in the larger sizes, but they work fine. For some reason they are kind of expensive.

If you could find an O-ring of exactly the right size to capture in the knife edge groove, that might also work, but I doubt you would find the right one.

Viton/Fluoroelastomer gaskets are good for vacuum chambers. Buna-N (Nitrile) ones are also potentially usable but not quite as good.


It is possible to make an aluminum conflat flange that gets sealed with an even softer aluminum conflat gasket (or maybe indium) but I don't think that is a good idea.

Joe Mayer
Posts: 5
Joined: Thu Oct 27, 2016 6:59 am
Real name: Joe Mayer

Re: Replacing Copper Crush Gaskets with Fluorocarbon Gaskets

Post by Joe Mayer » Sun Oct 01, 2017 5:31 am

Thanks for the replys, awesome info! I'm going to attach the pump to the chamber via a 4" CF100 flange for easy removal if needed. I did measure the knife edge and have been looking at gaskets that would fit to see if I could make that work.
When shopping around for gaskets there are quite a few cross section thicknesses from super thin up to quarter inch. Would either of you have a recommendation as to how thick of an o-ring I would need? Thanks again for the info.

Jerry Biehler
Posts: 727
Joined: Tue Nov 24, 2009 8:08 am
Real name:
Location: Beaverton, OR

Re: Replacing Copper Crush Gaskets with Fluorocarbon Gaskets

Post by Jerry Biehler » Sun Oct 01, 2017 8:49 am

Just buy the ones online, the squarish section will keep them from slipping out of place. I looked at using a round o-ring and it was not worth the trouble.

Post Reply