Vaccum pump filter?

[bertterbo]

I've been doing some experimenting recently with wood stabilising. Making my own wood hardener from acetone and plexiglass.

I now want to experiment with using a vaccum to draw it into the timber. However, I'm guessing that the acetone fumes will not be good for the pump and will damage the internals or contaminate the oil.

Is there a filter I can add onto the tube before it reaches the pump? Like you see with the water filters on compressors?

 

[bertterbo]

Bump

 

[Dibs-h]

Maybe draw it thru a container that is partially filled with fluid (water of something else), where the inlet (where the fumes enter) is submerged and the outlet (to the pump) is above the fluid.

 

[bertterbo]

Maybe draw it thru a container that is partially filled with fluid (water of something else), where the inlet (where the fumes enter) is submerged and the outlet (to the pump) is above the fluid.

Ah interesting. If it was water though, wouldn't that draw moisture into the oil in the pump?

 

[Dibs-h]

Ah interesting. If it was water though, wouldn't that draw moisture into the oil in the pump?

Yes it may. Maybe use a water-trap filter after that?

 

[Inspector]

I can't say with certainty but drawing the fumes from the vacuum chamber though water will not capture all the acetone and it will still end up in your pump. You would have to draw the fumes through an activated charcoal filter as well. I don't know how the "plexitone" will fair when it looses a lot of the acetone as it evaporates quickly under normal atmospheric pressure.

Pete

 

[bertterbo]

I can't say with certainty but drawing the fumes from the vacuum chamber though water will not capture all the acetone and it will still end up in your pump. You would have to draw the fumes through an activated charcoal filter as well. I don't know how the "plexitone" will fair when it looses a lot of the acetone as it evaporates quickly under normal atmospheric pressure.

Pete

Ah yes, another good point.

 

[chaoticbob]

I've been doing some experimenting recently with wood stabilising. Making my own wood hardener from acetone and plexiglass.

I now want to experiment with using a vaccum to draw it into the timber. However, I'm guessing that the acetone fumes will not be good for the pump and will damage the internals or contaminate the oil.

Is there a filter I can add onto the tube before it reaches the pump? Like you see with the water filters on compressors?

The filters on compressors are (afaik) simple mechanical meshes designed to capture particulates and oil/water mist, so not applicable here where the contaminants are vapour phase. In my experience the only way of catching volatile contaminants is by using a cooled trap (liquid nitrogen temperature) - so not applicable in an amateur setup!
Laboratory grade oil filled vane pumps cope with volatile contaminants by the use of 'gas ballast valves'. These introduce a restricted flow of atmospheric air into the pump in the 'compression' chamber which sweeps out contaminants before they have a chance to condense into the oil. Your pump may or may not have one - if it has it will look like a screw on the side of the pump towards the exhaust port.
However, I suspect that the problem with your proposal is, as Pete said, the volatility of acetone. It has a vapour pressure at room temperature of ~200mm Hg, or around 270 mbar. Presumably you will be aiming for a much lower pressure than that, so the acetone based solution will just boil and make a bit of a mess! As I understand it conventional vacuum stabilisation resins have much lower vapour pressures so don't have this problem.

I should say that I've never stabilised wood myself - all this is based on experience working in Chemistry labs.
Bob.