The $149.99 one pulls to 22.5 microns. Can anyone help translate that into gunsmithing-ese? Specifically, is that enough vacuum to do the job? On a conversion table that translates to 0 bars. Am I correct that 0 bars is a greater vacuum than the 3 bars damascus mentioned? Or, am I bassackwards?
This apparatus could be a huge improvement over soaks if it will work and could be assembled for under $300. I believe I can make the pressure vessel from salvaged pipe, etc. It would be so easy to repeat the toilet tissue wrap, and let sit overnight in the container, as many times as needed to remove most of the oil. The possibility of picking up a used one cheap is a good idea too, craig, thus lowering the initial costs even more.
SRH
I was commenting from the perspective that relatively common, inexpensive things can create enough vacuum to draw natural oils and water out of wood. I'm pretty sure damascus is using equipment that can do a better job.
My understanding is that almost all vacuum pumps can get to a certain point, and then to get the last little bit, the cost starts to go way up or go very slowly. I think it's pretty well known that oil can be drawn out of a stock basically by chemically diluting it and or wicking it out with an absorbent. I wouldn't be surprised if a little warmth to lower the viscosity and some vacuum could work well.
I think a home setup vacuum tank may slowly leak, so if someone wanted a long vacuum hold, they might want to check it and refresh it if needed. I wouldn't buy it from a purpose built supplier, but if you look at wood working bag clamps, you can get an idea of how a vacuum pump and shut off valve could be hooked up to a tank. Those bag systems have an advantage though that the atmosphere collapses the bag around the work piece so it's easier for the pump to do its job.
I haven't looked in a number of years, but I've seen Gast brand double vane pumps come up for very inexpensive prices. But, maybe a tad bit more vacuum wouldn't make much difference that could be made up with a bit more time. It's interesting to me that damascus had success, but as he reminds, there's caution not to mix apples with oranges.
