Thread: Refrigeration Vacuum Pump

G'day Alan

Yes it certainly needs the oil. It would not pull a vacuum without it. The oil forms the seal. And it would most likely seize up too.

Mine does the oil mist thing too. I open the doors when using it or put a hose on the outlet and run it outside.

A filter or vapour capture device would be good.

Greg

Hello Alan, I'm thinking of getting one of the pumps off ebay for vacuum bagging surfboards. Did you get the XP 135, it seems to be available from a couple of sites for less than $200, pulls 4.2 cfm. I was wondering if they were a bit cheap and nasty, but I won't be using mine that much so guess it will be fine. I guess I might be putting it outside if they smoke like you say!

My li'l bro is a fridge mechanic and he modified his by simply adding a shortish length of copper pipe to the exhaust vent, with a few holes drilled in the sides. Then wrapping it in thin foam rubber sheet held in place with a few rubber bands. An air-filter in reverse, as it were.

He seems to be happy with it.

I got a price for an oil plume filter that would do the job nicely, BUT it was nearly $200, far more than the pump cost! I am working quite well with a few bits of garden watering pipe directing the exhaust out the window. I have not got the sealing around the exhaust port tight enough at the moment and get some splattering of oil around the pump. I will work on a better system for sealing it.
Someone else also suggested that a sealed unit from an old refrigerator also works well for both clamping and veneering, even surfboards! I have yet to track a working one down to try it out.

Cheers,

Alan

Thanks for the quick replies guys. Interesting little article here

http://www.seabreeze.com.au/Articles...0_1293413.aspx

about a home made pump from a refrigerator. I have read that these are not ideal for a whole large surfboard because it takes too long for them to evacuate a large bag. Pretty sure it would work fine for repairs and woodwork laminating etc.

The old fridge compressor will generaly not last too long as they will also pump out their oil. You would need to top up the oil now and then by tipping a little down the suction line but not too much or you will flood the motor windings and it will burn out. They still won't run too long as while it's running in a vacuum state the vacuum causes the windings to arc and once again you will let the smoke out.

If you want to make you own system then this site has all you need.
http://www.joewoodworker.com/veneering/welcome.htm
Greolt made a very good vacuum pump by reversing the lines on a cheap air compressor. Have a hunt through the threads for his unit. He now uses a vacuum pump but only because they run a lot quieter than an air compressor.
I have a vacuum pump and an old air reciever from a compressor. Having a reciever helps pull down the initial vacuum.

You can also use a household vacuum cleaner to evacuate the bag then switch to the vacuum unit. A hand vacuum pump can also be used.
This technique is used in vacuum forming polystyrene and it is interesting to play with. I saw a demonstration last weekend on this and the detail captured in the process is remarkable. The robotic guys are leading the field in DIY vacuum forming.

Fridge compressors work well on a budget and the bonus is they are quiet. I have seen one hooked up to an LPG cylinder and it has been operating as an air compressor for over twelve months without a hitch. It is used as a mist sprayer on a mill and air line for cleaning up the machines. Not high pressure but enough to do the job.

The vapour is from non-condensable gas (air) as the vacuum gets lower this will stop. As you are using it for a vacuum clamp I presume there are holes still open in the base. You can try covering these. The vacuum pump is designed to work on a closed system and get to a vacuum of 200 microns or lower for a refrigeration system. I hope this helps you.

My vacuum unit uses a venturi valve on my compressor, with the compressor placed outside the shed, the noise is bearable.

It is not smoke coming from exhaust. It is non-condensable gas (air), when then pump gets to a lower vacuum this will stop. These pumps are designed to work in a sealed system. If you have any leaks on your clamp base you might want to block them up and the vapour will stop coming from exhaust.
Phil