Looking for options and ideas for making/buying cheaply/hiring locally a vaccuum pump suitable for a couple of lay ups. If i can make one easily i will, but from what ive found on google, a fridge pump could do short term, but dont know whether i need to look for anything particular. Any suggestions or advice please?
Brake servo pump from a diesel could be adapted perhaps
Have a word with 907, he offered me his when i enquired.
linky
ebay has lots
linky
907's is a bit more than i was looking at at the mo, but that one on ebay- will that do any good? I have a small airbrush compressor which i reversed the valves on, but it doesnt pull much vaccuum, and i dont fancy leaving it on all day!
Will something like a mityvac work?
quote:
Originally posted by andrew-theasby
907's is a bit more than i was looking at at the mo, but that one on ebay- will that do any good? I have a small airbrush compressor which i reversed the valves on, but it doesnt pull much vaccuum, and i dont fancy leaving it on all day!
Im not sure what i need either, was hoping for some advice
fridge compressor
Thinking out of the box on this you can get about 19 inches of mercury by tapping into a petrol engine inlet manifold.
Just bought a fridge pump, so going to give that a go for now, thanks
can do it with a vacuum cleaner, though it needs to be a healthy one!
Go Carefully with a vacuum on wet layup, it's very easy to pull the resin out, and end up with a lot of voids. You don't need as much vacuum
as a shop vac will pull, so an industrial vacuum cleaner will do the job more than enough. Even a household vac cleaner will do the job, but will burn
out without air flow through it. Bleed a bit of air into the suction tube to regulate the vacuum.
If using prepreg, then you need as much pressure as you can get on the layup. Only an autoclave can do that.
Cheers,
Nev.
[Edited on 3/5/10 by Neville Jones]
I would just add that if you are intending using you vacuum pump a second time, it is a good idea to put a condenser in the line to trap out any resin that might be pulled over.
Ok, thanks for the tips, ill post my results when im done for anyone else who might find it useful. How much vacuum (on a gague) do you suggest it should be set to for a wet lay up? Im just watching a few gauges on ebay at the mo. Thanks
What resin system are you using? It makes a difference.
Cheers,
Nev.
At the moment just having a play with fibre glass and polyester resin
Poly resin only needs the faintest of vacuum, as any more pulls out the styrene, which can cause bubbles in the layup.
You only need anough vacuum to pull out the air.
Cheers,
Nev.
Oh right, maybe my airbrush compressor would have done if id have sealed it up properly then. I can lay it up with a roller, so really only want the vacuum to pull it to the mould, so might try this. Thanks