Oneway vacuum chuck question

[Quinn McCarthy]

I am trying to get my vacuum system working correctly. I have an vacuum leak coming from where the adapter attaches to the chuck. I tried seating it in better with a rubber mallet but that didn't work. I am wondering if I can put a samll bead of silicon in between the adapter and the chuck? Or make a gasket out of something that would seal the leak.

Thanks

Quinn

[Joe Bradshaw]

Maybe, if you posted a picture of the problem area, we could help.

[Quinn McCarthy]

I can't do that until tonight.

There is a little gap between the adapter and the body of the chuck. THere is a bout a 1/32" gap there that the vacuum is leaking out through.

Thanks Joe.

[John Giem]

[QUOTE=Quinn McCarthy;1848581]I am trying to get my vacuum system working correctly. I have an vacuum leak coming from where the adapter attaches to the chuck. I tried seating it in better with a rubber mallet but that didn't work. I am wondering if I can put a samll bead of silicon in between the adapter and the chuck? Or make a gasket out of something that would seal the leak.

Thanks

You are on the right track with silicon sealer. I have been using silicon on threaded connections for over 40 years. Apply it liberly and screw the parts together into the final position. Wipe off the excess with paper towel or rag. If the surfaces are clean and dry, it will hold pressure or vacuum very well. In General, silicon does not like oil product and will cause it to release. It is also weak in shear. This means that it is relativley easy to take the joint apart. Use a small wire brush to clean up any rmaining residue before applying new silicon and putting back togethr.
John Giem

[Pete Jordan]

Quinn,

I have used O-rings and plastic gaskets with success.

[Mark Levitski]

I used some teflon plumber's tape on the grub screws that were leaking on mine. 1/32" seems like a lot though. Are you certain that it was seating completely and correctly?

[Quinn McCarthy]

I put some silicon between the chuck and adapter and that helped a bit but there was still too much leaking. So I put some teflon plumbers tape on the adapter and chuck threads and that stopped all of the leaking.

Quinn

[Steve Schlumpf]

Quinn - glad you got it figured out! Have fun with your new system!

[Quinn McCarthy]

I haven't had a chance to tyry it yet. Maybe this weekend.

[Jon McElwain]

The 1/32 gap between the adapter and the chuck is normal for a Oneway system. The tapered fit inside is where the seal is made. My system holds pretty good pressure, but I have never been much over 25 mm Hg. I have given some thought to adding a sealer to the system. The o-ring might be a good idea since the adapter is tightened to the chuck with machine screws.

Are you using the Oneway vacuum drum chucks? Have you had any problems with the neoprene gaskets? Mine go on just fine, but as I form the gasket and stretch it around the drum to adhere to the drum, it will hold for a couple of weeks, but then it begins to peal up so that the neoprene ring is only touching on the top of the drum.

John Giem, who commented above, has an article in one of last years AAW magazines - check it out for some really helpful info.