Vacuum Pump for Beginner.

General Composites Discussions Equipment Talk
#1

I want to start messing around with composites. Watching the videos and reading a lot, but want to get started. Everything I am planning on doing should be no bigger then 2x2 feet. What do people of the below setup?

http://www.harborfreight.com/two-stage-3-cfm-air-vacuum-pump-66466.html

[ul]
[li]Durable die cast aluminum housing and convenient top handle for easy maneuvering
[/li][li]Easy-access oil fill port with viewing window for easy maintenance
[/li][li]25 micron/3 Pascal rating
[/li][li]Thermal and current overload protection
[/li][li]330ml pump oil bottle
[/li][/ul]139.99

#2

While I have no knowledge of the vacuuming process I do have lots of experience with Harbor Freight tools.

Simply put, if your life or business depends on it, stay away from their tools. Even their non-moving tools are crap. I bought a plastic 6" carpenters square that wasn’t square, it was about ~2 off!

All of their tools are manufactured oversees and shipped to the US for cheap.

I’m sure there are better options out there. Don’t waste your money on a tool you’ll have to replace down the road because it’s cheap and garbage.

#3

I sometimes sell similar pumps, but in general I do not like them. They spit lots of oil from the exhaust, as the vacuum at which they do not spit oil, is extremely hard to reach in a bag setup.

These pumps are designed to dry out airco systems, and that is what they work for properly.
Also keep in mind that the connection has some odd size, which you need to get a connector for (I believe 5/16th UNC thread, but I am not sure) and order an extra bottle of oil. Do not run inside, as it will generate an oil mist, although your link does include an exhaust filter which filters some of the mist.

Either source a dry pump with decent vacuum (-0,95 bar or 50 mbar as a bare minimum, 5 mbar would be much better) or even a 2nd hand pump (oil lubricated vane pump) would be a better choice.

However, the thing comes in a nice package, so if you can live with the downsides, you can at least start with things.

#4

I’ve seen many people build setups using refrigeration compressors and a small air tank for a reservoir with decent results.

Anyone have any experiences with these to share?

Just found this to add. fair warning: mute before watching
[ame=“http://www.youtube.com/watch?v=OSFbQQ8Kfq4”]refrigerator compressor pulling 29 inches of vacuum… :slight_smile: - YouTube[/ame]

#5

Nice ghetto-style setup.

I know of people that blow up these pumps in minutes rather than hours, but also people that have them running for months, if not years.

#6

I used this one for 2 years without problem:

For a description of the parts look here.

#7

Very nice, Is the jar in the middle a catch for discharge?

That’s an interesting controller, looks like it came off something very expensive :slight_smile:

I want to make a two stage setup like that with shutoff valves at each pump in case of an internal failure, I could run off the other to finish the part.

#8

Thanks. In the meantime I bought a real vacuum pump to replace the compressors.
The jar is to catch oil. It needs to be airtight when both stages are running. It is better to leave it open when pulling the bulk of air out and close it when you reach the limit of the first stage pump. What’s not in the pic is a switch to turn the second stage pump off until needed.

The controller was made by a now closed Scandinavian company. It is programmable with up to 99 vacuum pressure stages each up to 18 h. It also has an input for a thermal-couple to prevent the pump from overheating but I don’t use it. I got it for € 25.00 on ebay.

A modification I would have added is a 3-way valve between the 2 compressors so I could switch them to run parallel to debulk. Once the air is out switch to series for full vacuum.

#9

Seems like people have been using these with decent luck and they only spit oil when sucking air. I am think maybe a setup with a vacuum cleaner to get air down to a min then the pump may work well with a filter on the exhaust.