You need to put a second jar in your set-up between the pump and the
way too small jar you are using to hold what ever stabilization material you are using ... I highly suggest you try Mesquiteman's "Cactus Juice!"
AND ...
BEWARE of using GLASS IN ANY PRESSURE SITUATION! Vacuum is one thing, but PRESSURE is just making a potential grenade just waiting to go off in your face. Always check for scratches on any glass jar and do not use one that is scratched, cracked, or chipped.
I have great success using a LARGE glass dill pickle jar ... a gallon size. $5 or so at SAM'S. Throw out the pickles if a gallon is a life time supply and you need the jar now! You do not have to fill the jar with 'liquid', but instead have enough to completely cover the wood with allowances for that 'liquid' which is taken up by the wood, etc. A one inch 'cover' is what I use normally. Different density wood will absorb different amounts. Think along the line of Balsa vs. Oak ... unbelievable differences in absorption!
What looks to me from your pictures is that the instant you put the vacuum on you will fill the small jar with boiling foam ... and I mean instantly in that you will not be able to turn the pump off before damage is done and you and dead in the water with a ruined pump. I believe you should seriously shorten the vacuum line.
The second jar will protect your pump from any fluid that will be sucked up into your vacuum line in your present set-up. This liquid will NOT BE COVERED UNDER ANY WARRANTY you may have regardless of expense.
Not all liquid will affect all vacuum pumps. Rotary vane vac pumps like used by HVAC technicians frequently get liquids and moisture sucked into them during the HVAC evacuation process. If you stop right away and change the oil, you will not necessarily damage the pump. I have sucked my stabilizing resin into my vac pump a couple of times with no adverse effects. Of course the resin I use has no solvents in it so there is no issue with it eating up anything inside the pump.
Also, solder any fittings you use in the lid. Much better vacuum than any washer use ... in a home-built system. You will probably need to remake the lid gaskets as the soldering heat will probably destroy most gasket material already in the lid.
The stabilization liquid you use will have volatile materials in the composition. These volatiles will actually boil the instant you put
any vacuum on the jar. The boiling foam can enter your vacuum line and down into the pump it goes. End of pump and end of your experimenting.
This is certainly not the case with all stabilizing resins. The one that I use has a vapor pressure of less than 5 mm Hg at 72°F which is a very stable material with very little VOCs at at room temperature. It will not boil until it reaches a really deep vacuum and has to be over 85 degrees to do so from my experience and from calculations done by my friend. If the temp is lower than 85 degrees, it will not boil. At my elevation, a really deep vacuum is 28.5" Hg with a maximum theoretical vacuum of 28.92" Hg since I am at about 1,000' above sea level and you loose 1" of Hg for every 1,000'.
BTW, it is not the amount of vacuum you pull, it is
the time under vacuum that makes a difference. A 5 inch reduction in ambient pressure over several hours time will render results that will come close to 28 inches in a few minutes. Also, depending on where one's physical location is you may never be able to reach 28 inches of vacuum. It's a physic's thing related to being at seal level and at an elevated location.
This is not what I have experienced, researched, or had verified by my chemical engineer friend. I am no physicist, just a dumb college educated builder but have done a tremendous amount of reading and experimenting with vacuum.
The definition of a perfect vacuum (not obtainable, btw) is the absence of all molecules. The lower the vacuum, the less air molecules there are in the chamber and thus the wood. A 25.98" Hg vacuum at sea level is only an 87% vacuum or 87% of the air evacuated from the chamber. If you bump that vacuum up to 29.62" Hg at sea level, that is a 99% vacuum or 99% of the air evacuated from the chamber.
Remember, wood in very simplistic terms, is a bunch of straws filled with air that were filled with water at one time. As long as that air is still in the wood, the resin can not fill that "straw". The more air you can remove, the more resin you can get to fill those "straws" once the vacuum is released and the air inside those "straws" is compressed by atmospheric pressure. Pulling a lower vacuum for a longer time will not change the physics of removing the air.
Think of it in reverse...stand a pen blank up on your work bench. If you can not knock it over by lightly blowing on it, it will not help any to sit there all day long and keep blowing on it. However, if you use an air gun attached to your air hose and hit it with 50psi, it will blow right over.
This issue has been discussed here over and over again ... kinda like beating the proverbial dead horse. Use the 'Search' function on the Forum for 'vacuum' and be prepared for a lifetime of reading.
Mesquiteman is
quite successful in using vacuum for stabilization and you should trust all he, and several others, have to tell you about the process. Some of us have been doing this for years with very satisfying results!
