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o-ring help

Posted: Fri Apr 03, 2009 8:55 pm
by spudtyrrant
i just have a simple problem i am redoing my 2 inch piston gun and i want to have a 2 inch plug held in by screws into a peice of 2 inch pipe i need to cut a o-ring groove and i was wondering the best way to go about doing that. btw if anyone knows what size o-ring i should use that would be helpful too

Posted: Fri Apr 03, 2009 9:39 pm
by inonickname
A lathe and tooling is the best method, even if it's a wood lathe. Alternatively you could use a bolt and chuck it into a drill press (or even standard drill in a vice) then use hand held tooling or hold a chisel or similar in a vice.

If you don't have access to such machines you can mark a line, then use a hacksaw to cut the line (don't go through) and finish it up with a rounded or triangular file.

Use an o-ring that will stretch and still have some showing.

Posted: Fri Apr 03, 2009 10:33 pm
by roboman
If you don't have access to a lathe, I would use a table saw. Just lower the blade to the desired groove depth, and rotate the piece over it, ,until the groove is uniform. I'm pretty sure that there are a couple of videos on youtube...

Posted: Sat Apr 04, 2009 2:14 am
by mark.f
You can make an O-ring groove to sit in 2" PVC using 1-1/4" pipe/plugs and fittings.

Here's a 2" piston I made using this method. The O-ring sits on the 1-1/4" pipe or plug, and the couplers sandwich the ring in place. I usually use a few wraps of teflon tape in the groove as well to aid in sealing.

Image

It seals extremely well (no pressure drop over a 10 minute test, for me), and clide has even used this method to make chamber sealing pistons before.

Posted: Sat Apr 04, 2009 2:51 am
by i-will
a while back i mentioned a (extremely) simple tool i made for makind easy o-ring grooves. http://www.spudfiles.com/forums/basic-f ... 16295.html

i hope it helps.

Posted: Wed Apr 08, 2009 5:46 pm
by jmeyer1022
Mark if you don't mind me asking what are the specs on your O-rings.

Posted: Wed Apr 08, 2009 5:52 pm
by Hubb
The easiest way I've found to make o-ring grooves is with mark's method above. The second easiest is by using a table saw. Set the blade to the proper depth, then work the piece over the blade. This is easier than a lathe.

Posted: Wed Apr 08, 2009 6:28 pm
by Gippeto
Here's a handy little o-ring size chart for you. :)

http://www.acdepuydt.com/standard_seals ... _chart.htm

Posted: Wed Apr 08, 2009 11:09 pm
by mark.f
jmeyer1022 wrote:Mark if you don't mind me asking what are the specs on your O-rings.
The O-rings are 2" OD x 3/16" wall. I ordered them from McMaster, and then finally found them in the Ace Hardware of a nearby town.