Vacuum pump for chucking

[Ed Marks]

I'm looking at the vacuum chuck from Simply Woodworking and wondering what type of pump to use with it. I do lots of veneer work with a Vacupress Systems 1.5 CFM pump (cyclic and maintains 25" or however I set it); but I see most posters are using 3+ CFM refrigerant evacuation pumps. Does air leak into these chucks faster than the typical veneer poly bag system? Also, I'm not a fan of oil based pumps due to the residual in the shop. Recommendations for oilless options or whether the pump I have will work would be appreciated.

 

[hockenbery]

Does air leak into these chucks faster than the typical veneer poly bag system?

Wood leaks. Some leakage around the seal if wood is a tiny bit out of round.

1.5 cfm might work. Depending on the wood. Red oak leaks air a lot. Holly very little.
You can put plastic wrap on the outside of a leaky bowl.
You will want an inline bleeder valve to reduce the vaccum.
I like to use enough vaccum to pull the piece a 1/16” off the tailstock center.
It’s easy to crack thin pieces with vacuum.

A pump that can remove 3 cfm of air is a good choice.

Dave Lancaster wrote a pretty good article for the winter 1998 journal.
Go oiless on the pump.
This screen shot has his pump recommendation.

 

[Noah Peters]

FrugalVacuumchuck.com has a good oilless pump for fairly inexpensive, I think its a Thomas pump.
Gast vacuum pumps are a common one that is also oilless, but finding one with 1/3 or more HP at a reasonable price can sometimes be difficult.

 

[Richard Coers]

If you get a leak, there is a great possibility the bowl will leave the lathe no matter how many cfm the pump has. It's not like a bag when you get a leak and you can put a piece of tape on it. I've never used a big pump, always the cheap AC pumps with oil.

 

[Brent@TurnRobust]

Plus one on the oil-less chuck from Frugal: FrugalVacuumchuck.com It's an import and rated around 4CFM. Excellent customer service too.

 

[Dwight R Rutherford]

Just looked on E-Bay, no less than 10 used Gast rotary vane (oiless) vacuum pumps. Price range $400-$150. All are 4cfm models. If needed, rebuild kits are less than $100.

 

[Roger Wiegand]

More cfm will give you more latitude with thin or porous wood. Sometimes I give the bowl a quick coat of shellac on the inside to improve the airtightness. Keeping the tailstock in place until you really need to remove it will also reduce the likelihood of unscheduled departures from the lathe.

I found a NOS Gast on ebay for about half the normal price of used pumps because it was 240V. Since I already had 240V in place for the lathe it was easy to add a switched outlet for the pump. I did need to make up a cord for the pump. it was made for internal use in some medical device so had an odd power connector.

 

[Hugh]

A layer of painters tape will stop a bowl from leaking for the most part.
I have been know to put a plastic bag over the bowl also. A porous bowl will suck it right down and slow the leak.

 

[Darryn Achall]

Oilless pump I use. Been very happy with it over the past year. Works well not loud, 6 cfm, no oil! Can't say anything on the long-term reliability but for the price I'll take my chances.

 

[JeffSmith]

I've got two vac pumps that I've used for a very long time now - bought a Thomas Riechly (sp?) wobbling piston type pump on ebay for less than $35 about 15 years ago. If I remember correctly, they are often used to aerate ponds - continuous duty. It develops 26 inHG and has consistently done everything I need. I have no idea of the CFM, but it handled vac chucking on a Jet 1642 without issues. Rebuild kit was available on line a few years ago. Replacing the startup capacitor has been the only fix to date. I upgraded lathes to an AB, and when I had an opportunity to get a Gast rotary vane pump new, in the box from an outfit that was liquidating surplus hospital equipment stores on ebay for less than $100 with shipping, I hopped on it. Both have been working ever since - the Gast handles vac chucking on the lathe and the Thomas easily handles duty on a WoodCut carving stand that takes the same vac chucks. Both have been virtually trouble-free. The Thomas is a joy to use with the carving stand - very quiet.
I've seen vac pumps available as diaphram based, wobbling piston types, rotary vane types and oiled or oil less - I wouldn't want to deal with the issues of an oiled pump in my shop, that leaves the diaphram style, the wobbling piston type and the rotary vane style - any of them work well in the application. Look around, there are still deals available and these things respond very well to a simple rebuild - most are made for continuous duty cycles.

 

[Ed Marks]

Thanks everyone. There's lots of useful info here.

 

[Darryn Achall]

Oilless pump I use. Been very happy with it over the past year. Works well not loud, 6 cfm, no oil! Can't say anything on the long-term reliability but for the price I'll take my chances.

I just followed my link. The price has gone crazy. I paid $146 for this pump. Now it is listed for over $400. There are some other off brands available that look very similar for low prices. Most likely from the same factory.

 

[Tim Otto]

FrugalVacuumchuck.com has a good oilless pump for fairly inexpensive, I think its a Thomas pump.
Gast vacuum pumps are a common one that is also oilless, but finding one with 1/3 or more HP at a reasonable price can sometimes be difficult.

Gast for the win. good work never was cheap.

 

[Tim Otto]

Just looked on E-Bay, no less than 10 used Gast rotary vane (oiless) vacuum pumps. Price range $400-$150. All are 4cfm models. If needed, rebuild kits are less than $100.

One can buy them new from suppliers of sanitation equipment for around $400. They are called aeration pumps. Reverse the hoses and they become a vacuum pump.

One can get them from Oneway or big wood turning stores for $900.