Vacuum pump opinions

Hi all,

I’m a newbie/lurker here, but I’m interested in learning about vacuum bagging. I’m a long way off making boards, but ultimately I’d like to try and make a board and maybe some snow skis. But I’m going to start with things like fins and maybe a dining table. So I’ve got simple needs initially but they might get more complex over time.

I’ve come across a source for reconditioned vacuum pumps at a reasonable price so I wanted to get the forum’s opinions. It’s the Robinair 15501, the 240V equivalent of this one:

http://robinair.com/product-new/detail.php?id=1060&catid=11

The pdf brochure says it will pull down to 40 microns ultimate pressure if I’m reading it right, which is very low (== down to 0.04Torr or 0.0053329kPa or 0.0007735psi ultimate pressure). It’s got a displacement of 118L/min or 4.167cfm, which is also more than enough. Assuming I set it up right with appropriate pressure regulators and switches for the job is the pump OK? Or is it overkill? I’m particularly interested in duty cycle, which I couldn’t find anything about. If I’m pressing something overnight will it stress the motor too much or are these types of pumps designed for permanent duty? I searched here and the wider internet but can’t find much on the use of these automotive purge pumps for bagging.

Thanks in advance,

Toby

Hi Toby .Yes it will do the job fine .I personally would go for a rotary vane pump with regulator . We use Rietschle ,the Picolino vte ,swith it on and away you go ,no oil leaks etc . you can leave them on for as long as you like . For vacuum and pressing,great www.rtpumps.co.uk/

http://search.ebay.com/search/search.dll?from=R40&satitle=gast+vacuum+pump

I bought mine on eBay for $39. I’d recommend just not overthinking it. Mine has low CFM so I suck most of the air out of the bag first with a shop vac. They all work. Get a vac switch & use a guage so you can set your switch right & it won’t run continuously anyway.

Here’s a nice cheap guage

http://cgi.ebay.com/New-Vacuum-gauge-for-Gast-Thomas-pump-or-2-1-2-SZ_W0QQitemZ220107708167QQihZ012QQcategoryZ11773QQrdZ1QQcmdZViewItem

Mine runs about 30 sec every 7 minutes. So it takes 6:30 to bleed down from about 9"Hg to 5" where it kicks on again. That’s all you need to put skins on foam…

I’m not in America so I’m not spoiled for choice like you guys are. Our ebay only has a few and they’re inferior quality and/or overpriced. I’d get an American ebay one if it wasn’t for the shipping, which would kill the deal. I’ve got a few feelers out at the moment and price is the restricting factor. I’m looking at about US$200-$250 and that’s about as cheap as this sort of pump gets over here. Sounds like I can’t really go wrong with this type of pump, though. Thanks guys.

I built my own using an old refrigerator pump cost me less than $50. Check out this link for inspiration http://www.joewoodworker.com/catalog/vacuum_press.php

Here’s the one I use. Very simple to operate.

you can use an old fridge pump that you can get from the dump

200US sounds like alot

that should get a top of the line rotary vane with filters and switch and gauges