Home Vaccuum/Press chamber

etp777

etp777

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Aug 12, 2002
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OK, I picked up some Minwax wood hardener yesterday, but need something to pull a vacuum in, then put it under a bit of pressure to help get hardener absorbed in as much as possible.

I'm still stuck with hand tools for most of this. I have a Pump N Seal http://www.pump-n-seal.com/ which I know does a good job of drawing a vacuum in a mason jar. The only thing I have that is close to being able to push some pressure though is either the little 12V compressor in my truck(but I park in front of apt, and do most of my work in back) or a bike foot pump. Either way, I needed some way of making a container where I could draw a vacuum and put under pressure, and with some element of safety.

As I said, I know a mason jar works well with the vacuum pump. But a mason jar isn't rated for pressure, and even if it was, had no way of hooking it up to the bike pump(or compressor).

SO on way home from work today, I picked up some of those regular pop in valve stems, in the smaller .453" size. I'll take a mason jar lid, drill a hole(29/64" drill bit shoudl do it) and pop in the stem. THis should allow me to put pressure in a mason jar(Though it may require bit of extra gasketing.

THat let me draw vacuum or pressure, but wasn't safe. So I thought about what else I had around here. I got some christmas cookies from my mom in a little tin,a bout 4" wide and 6" high, that a mason jar drops in perfectly. Obviously, this isn't enough though if the jar shatters under pressure. SO I picked up a gallon can from the floor. It's 1.5-2" wider than the cookie tin. So I put an inch or so of sand in bottom of gallon can, put tin in middle,t hen poured sand around tin(again free, have approximately 120# of sand in two 5 gallon buckets in back of my pickup for weight). Mason jar jsut barely fits in inner tin, and then have 3/4"-1" of sand and another can around that for protection if jar shatters.

Total cost on this was $2.44 for the valve stems, rest I had around.

You could jsut bury the jar directly in sand, most of way up, but makes it harder and longer process to remove it to pour out extra hardener, or to put back down into sand. THis way I can do it quickly and easily.

So anyways, should be testing this out tomorrow or sunday(depends on how long jars take to dry, as they're full of soapy water right now). All I do to change from vacuum to pump is switch mason lids.
 
you may want to have a system of two jars in sequence, connected by a long hose going in towards the bottom, "slightly inserted" hose coming out to the pump. this is what's called a "bump trap" in lab jargon. it's purpose is to collect any foaming that goes up the vacuum line, thus keeping it out of the pump.
 
Thought about it, but not to concerned right now. WIll try it first and see how it works. Part of reason tis that I don't have the stuff to make a second protective container(yes, I knoww the danger is with pressure, nto vacuum, still do'nt like unprotected glass around me, no matter which way pressure is going.
 
vacuum is as dangerous as pressure, I've seen enough glass implosions.

the only other thing i'll point out is that you will be sucking solvent vapors up into something intended for aqueous exposure. hopefully nothing in there will dissolve.

your business, though, not mine.........
 
I'd stick that jar ina box with a lid on it before I pressurised it. And put a face sheild and a heavy coat and two pair of pants on.

I wouldn't do it.

The "old archives" had a lot of stuff on pressureizing and vaccuming containers. Old ammo boxes, pressure cookers and those $20.00 pump up garden weed sprayers have been used as pressure vessels. Of thehose the weed sprayer worked best for me.



Pressure vessels can get you killed.
 
You can get a hand brake bleed pump at Shucks that will pull 20+ inches of vac. I use a 2 qt mason jar,punch 1/4 inch hole in the lid, put in a 1/4 inch brass tube, seal it with goop and you got a vacumn chamber.You can also put the tube on the exhaust side and get a little pressure. You don't need more than 3-4 # I sure wouldn't try more than 5. My$.02
Take Care
TJ
PS Always keep the pump higher than the jar so foam doesn't run into the pump. glues everything together or so I've heard.
 
Get some pipe. Steel is best, sced 40 pvc will work. Put one solid end, and one removable end. Make it big enough so your bottle will sit inside of it. Pull your vaccuum on your bottle then remove the lid and place your bottle in the pipe and apply pressure. As long as you dont let the liquid get below the level of your wood, your vaccuum will not be compromised. The bottle keeps the stabilant from being contaminated or causing a reaction with the pipe. Bottles are cheap and easy to clean and you can store different dyes etc right in your "vaccuum chambers" just put a solid lid on them. I use Weck style canning jars (available on the internet). They are more expensive than mason type, but the wide mouth makes up for the cost. you just have to drill one hole in the glass lid then JB Weld a vaccuum barb into the top.
 
I have no worries of jar collapsing under vacuum. BUt reason I say that is from experience, I've been using this same vacuum pump(or rather, another one of same model,t hat I keep clean for food stuff) to vacuum pack stuff in jars for at least 4 years(oldest jar I have here is oen from december 98 of dehydrated corn, but belivee first started using it that april, jsut have sine used the contents of those jars). SO that's not really a worry. Under pressure it's a slight worry,b ut won't be using much pressure, can will be sitting inside a room by itself, and I"ll be wearing extra heavy clothes, etc so not too concerned.

This is only a temporary steup anyways, have knives to mail by the second, so wanted something right now, that I could make out of stuff I had here.
 
I must have missed something in my studies about stabilizing... so why ADD positive pressure? Does this help the stabilizer get deeper into the wood? I was always in belief that enough vacuum removes the atmosphere in the jar and then the only thing that can replace it is the stabilizer. Am I wrong?
 
The commercial outfits tend to cycle several times between vacuum and pressure, Jeff. The "push-pull" dual mode apparently gets better penetration of the stabilizing agent.
 
The "push-pull" dual mode apparently gets better penetration of the stabilizing agent.

Just bought one of those pump systems for sealing/ marinating food and the instructions for marinating food is to cycle between suctions as well...
 
vacuum pulls out air through the stabilant which works as a one way valve. pressure pushes stabilant into voids. pull out more air, push in more stabilant and so on untill all voids are nicely filled.

You wont collapse a good canning jar without an incredible vacuum pump, pressure on the other hand, wouldn't go there at all. 60 to 120 lbs work real well. Tried the low pressure method. Takes to long to get real good penetration.
 
Leonard, what are you using for a vacuum/pressure vessel? I'm still looking.
 
If you use canning jars you will be replacing the lids quite often...ask me how I know this!
I am switching to a 1 gal paint can with open jar set inside. Use a one way valve from the Auto parts store for AC and add a valve stem to release the vacuum. No seals to eat away but you can't see the cool Bubbles:D
 
well, pulled the first batch(two sets of slabs, were in same jar) out today. Ended up not trying any rpessure, want to see what else I can do with the setup before I tried that, but sat under vaccuum since Friday I think it was, and pulled it again at least once a day, to make sure it was still under vacuum. The red heart still floated, so not as good a penetration as I might like, but should still be enough as I rough finished the handles to start.

The bocote sunk in the stuff to begin with(and no, bocote doesn't really need this, was just trying it).

First experiment with this wood hardener, so will see if I like it.
 
I would be tempted to simply vacuum bag the material. Don't use a jar at all, just a heavy plastic bag. Put the wood and the stabilant in the bottom of the bag. Put a long piece of pvc pipe in the bag (to keep from sucking in stabilant). Draw a vacuum with something like a shop vacuum. Seal the bag and allow to sit. If you want to keep messing with it, try massaging the bag from the outside.
 
I use a canning jars from Weck. They have glass lids and rubber gaskets. Then I trasfer the jar to a piece of 8" pipe with a solid bottom and a flanged lid with a 60# pop off valve for a pressure chamber. I could do it all in the pipe but I like to watch the bubbles. Just one of my quirks. Gotta see it to believe it. I think the address for Weck jar supplier is www.weckcanning.com
Maybe tomorrow I will take some pics and try to post them.
 
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