Anyone using food vacuum sealers for stabilizing wood?

As I think more about it, and in fact I remember now that I read a post here some months back, the vacuum should be pulled on the work piece then the sealant media introduced into the work piece.

It should probably be best to construct a container such that a vacuum could be pulled then through a valve allow the sealant to enter the container. It makes sense, to me, that evacuating atmosphere from the work piece would more readily occur when not protected by a submerging liquid.

Roger
 
Don't forget to add a little pressure, if you can. Although ambiant pressure of 14.7 will help if you can pressureize the container it will drive more of your stablizer into what ever you are stabilizing.

Do be carefull if you are using glass. It will usually hold quite a bit of pressure if the container breaks the borken glass moves fast!

Lynn
 
It was just my impression that with an overspill bottle, I could safely use the jar attachment and then the bag sealer could be used separately.

After all, isn't the point that it removes air?

Perhaps I am unfamiliar with the inner workings of the vacuum sealer.

Pen, Don't make this complicated. I've worked quite a bit with mechanical oil pumps and some with mercury diffusion pumps on high vacuum lines (better than a millionth of a millimeter of mercury vacuum). The following applies no matter how the pump operates.

1) The pump will remove ANYTHING that is volatile, and anything small enough to be floating in the air it pumps. If you can smell it will go through the pump. (Remember, vacuum means absence of everything, not just air.)

2) The better the vacuum, the more volatile just about anything becomes. Acetone will boil violently under dynamic vacuum from most any kind of pump--and pass into the pump as vapor i.e. like "air". It's very easy to boil water at room temperature under vacuum. With a good enough system you can vaporize substances with surprizingly high boiling points.

3) When lots of fast evaporation occurs, the container gets cold. Pretty much the same effect as using a spray can and having the compressed liquid volatilize when leaving the nozzle, and chilling. Liquids with moderate freezing points will solidify from this cold, but vapor will still leave the surface..."freeze-drying"

4) The only way to keep the volatized materials from passing through the vacuum pump is to cryogenically trap them. Like the "overspill bottle" idea, except cooled by a dry-ice/alcohol slush. Or even liquid nitrogen is used. Just make sure the design directs the vapor stream to the bottom of the recepticle, so freezes there, instead of in the inlet or outlet tube. The idea is to get so cold that most anything except things that are gases under normal conditions will liquify or freeze there, and they can't volatilize even under the vacuum. Result--pump and you protected, plus higher vacuum.

***Don't use liquid nitrogen unless you really know what you're doing though!! Oxygen liquifies a slightly higher temp than nitrogen, and it can build up as a liquid in an improperly used trap, or a system with a leak. Raise the temp a very few degrees and it goes back to a gas--Boom! Also a severe combustion hazzard--How better to get a very nasty fire than pure oxygen? Think rocket engine. The trap is essentially a closed system--much different than an dewar designed to handle cryogenic gases!!***

Cold trapping will keep the nastly stuff out of the pump, where it can eat seals, cause corrosion, and in the case of oil pumps, all of the above and greatly reduce achievable vaccum by condensing and vaporizing in and out of the expensive, special non-volatile vacuum oil. Plus it keeps you from breathing that same nasty stuff. Remember, if it was liquid at room temp and pressure, it will likely want to condense again under those conditions--like inside your pump, or at the pump exhaust. And if it evaporates readily, you'll be breathing it.

Acetone is pretty low boiling, I'd use something higher boiling as a thinner for vacuum use--better no thinner. Rembember, you can't get a good vacuum until all the volatile stuff is pumped out. But if you pump down, then add something thinned with volatile solvent it boils off a vapor--vacuum instantly and greatly reduced because of the vapor pressure of the solvent.

Keep the pump on, all the solvent will get pumped off--no thinner left. seal the pump off, the solvent vapor pressure will fill the container--vacuum essentially gone, you just have acetone vapor where the air was. A compromise is needed here--too volatile always crappy vacuum, quite non volatile--will never leave, or needs a long time under vacuum and heat to remove. (Come to think of it, zillions of tiny pockets of acetone sealed in an epoxy/wood matrix doesn't sound that great anyway). I'd go with the best vacuum I could get and the least viscous sealant and no volatile thinners.

I just thought that if you could use it (the bag sealer) with raw meat, then that must mean that no "microbes/etc." were passed into the machine. Otherwise they would warn against it because it would contaminate all future sealings.

Not unless there is a filter--which would have to be changed regularly, and would be a probably more hazardous source of now-concentrated microbes. I suspect that the whole thing is that there is no flow from the pump to the food in normal use, the pump can't support microbe growth, and it is assumed that one will not vacuum seal "food" that contains pathogens. Anyway, most sanitation involves minimizing numbers of microbes, and preventing any growth-- not sterilizing or removing ALL of them.

Me, I wouldn't use the same pump for food and stabilizing. Sorry for the length, I can't be bothered to edit for succintness.:)
 
Hope someone finds it useful.


One more thing...

I wouldn't use volatile solvents for pressure impregnation either. They may want to weep out after the pressure is removed. The movement/evaporation of the solvent occuring at the the same time the sealant is drying can't be good for keeping the integrity/strenth of the sealant/wood composite.

I understand a lot of problems with fiberglass degradation comes from bits of un-reacted components or volatiles that get trapped in the hardened material. Stabilized wood is a similar composite material.

Oh yeah, remember that you can only get about 15 lbs of pressure difference with a vacuum. (I think vacuum should help it wick in, though). Don't know how they pressure treat wood, but with pressure, a lot more force can be applied. Maybe something like a big, closed off syringe milled from teflon or similar (so stabilizer can be cleaned off) encased in metal so the teflon doesn't cold flow?? Lots of you guys seem to have big presses. Safety shields a must if you try something like this!
 
I had a 2 gallon paint tank, an automotive air conditioner compresser and an old electric motor lying around. I attached the compressor suction side to the paint tank and can pull 27.5" vaccum. It is also good for 110lb + presure. Have not had an opportunity to try it out but i plan to pull a vaccume and then presurize the paint tank with compressed air. Should be able to force the stabilizer in with that.
Sure would like to know chemical the commercial stabilizing folks ues.

Pupandcat
 
Just in case somebody hasn't thought about it--

If you presurize by using compressed gas, failure is more dangerous as the gas wants to expand back and occupy LOTS more volume--bits and pieces can really fly around. And the sealant will probably go everywhere.

A liquid which is essentially incompressable, only needs to expand a tiny bit and it's pretty much happy.

It's probably best to maximize sealant volume, and minimize headspace of compressed gas. And use the smallest container that works.

Please be sure that you'd be safely protected if the the pressure vessel fails, and that you can release the pressure while protected. A mist or foam of sealant may come out, depending upon how well the gas dissolves in the sealant, like opening a warm beer, but more exciting. Cooling before venting may help. Also include a shutoff valve to your compressor--any small leakage once the compressor is turned off could allow a foam of sealant to work back towards the compressor. Viscous liquids can make really nasty, persistant foams. A rupture disc that would go before the rest of the equipmet and safely vent any included sealant isn't a bad idea either.


Sealant-covered shrapnel or just a sealant shower or glued-up compressor would dampen most anybody's fun, I think.
 
Originally posted by pupandcat
Sure would like to know chemical the commercial stabilizing folks ues.

Pupandcat

The most popular stabilizer uses a type of liquid acrylic, among other things. And they use vacuum first, then later, pressure, followed by baking, to solidify the acrylic.

http://www.stabilizedwood.com/

I've said this before, and I'll say it again, doing this at home is not worth the exposure to toxic chemicals, some even put this stuff in their refrigerators, with their family's food. Your time alone takes it out of the realm of feasible. You can have Mike at WSSI do it in 10# batches, for 8.00 a pound, and get professional results.
Sorry to preach, just my .02.
 
Gee thanks Firkin,

DAMN PHYSICS. It's just like the law is to the Democrats. It's always in the way.

Roger
 
Gee thanks Firkin,

DAMN PHYSICS. It's just like the law is to the Democrats. It's always in the way.

:)

It's not that bad, the physics can work for you--like those delightful bubbles in the beer.

But it's a b*tch when the physics works against you. It's certainly possible to rig up a safe home-brewed set up, but a few safety features are desirable, local Swagelock distributer should have rupture discs ,isolation valves and stuff. Things do get a little more complicated if pressure is used.

A few times I've worked with small laboratory reactors under a couple thousand pounds of gas pressure with heating. You don't get that kind of thing at Wally World or see it advertised on late-night TV, but the plumbing isn't complicated. Just way more expensive, heavy, and precision-machined.

Hate to see somebody get hurt or ruin their equipment is all.
 
Firkin,

I believe the way I'd, now, like to try is to pull a partial vacuum on a container and then introduce the undiluted sealant. I'll have to fabricate my container and such but go with a dedicated vacuum pump (not the food saver stuff as was ealier 'blue skyed' about). The addition of pressurizing may cross the cost effectiveness barrier for one who will probably make such few knives. Research should be done to discover what sealant(s)the professional stabilizers use and, if readilly possible, the theory of their operation - which may well be posted somewhere in this forums achives.

Your extensive and well written posts here have born out things that should have come as obvious before even asking and I have learned a thing or two new from those.

Truely, Roger
 
Picked up a rebuilt one I think it was at the factory site. I am sure ebay would have some. The rebuilt was a lot cheaper than the new and works fine.
I use a hand pump and a 2 quart mason jar. works fine. Just punch a 1/4 inch hole in the lid and goo in some 1/4 tubing. Go down to Al's and get their brake vacumn hand pump.
Always keep the pump higher than the top of the jar so you don't get liquid into the pump.
Does anyone need a totally glued together pump to look at?
Take Care
TJ Smith
 
Ok....here's a question for ya...

At $12/lb. (finished product) I really would like to know something:

If I send off 2 lbs. of wood - what will it weigh (typically) after it's been stabilized by WSSI, Mike, etc.?

Does it double, or triple in weight?

Just curious..
 
TJ,

I just got sent to school by the physics major firkin warning me about the very possibility of me blowing up the entire state of West by god Virginia. What's this about glued together pumps???
 
Originally posted by pendentive
..If I send off 2 lbs. of wood - what will it weigh (typically) after it's been stabilized by WSSI, Mike, etc.?
Does it double, or triple in weight?
..

Depends. I've sent off real punky wood and I'd bet it easily doubled in weight. Hard, dense wood seems to increase by 1/4 to 1/3.
 
This WSSI place: about what kind of turn around and what kind of pricing (approximate)?? Not that I don't want to stabilize myself if I can but until after the first of year I won't be able do anything about it. In the mean time I could use a few pieces stabilized if it does not take too long.

Thanks; Roger
 
rlinger,

I just got sent to school by the physics major firkin warning me about the very possibility of me blowing up the entire state of West by god Virginia. What's this about glued together pumps???

ROTFLMAO.....:D :D

1) Not physics--organic and organometallic chemistry...including the "Pile higher and Deeper" smart-paper more than a few years ago. I can't do math good enought to even consider physics. Those guys are really good there. I suck at that. Big time, as the expression goes.

2) Worst you'll do is spray up your shop with sticky stuff and sharp bits...your neighbors won't even know unless you wander over looking like a deranged tar-baby with pointy bits sticking outta yo'self. Don't do that to them if you like them.
I guess if you start a fire somehow, they might catch on, even if you don't show up at their place.

3) Vacuum is a lot easier, only one atmosphere of pressure difference...just avoid vessels with sharp corners or scratches if they are glass. Tape them up well with duct tape or put them in a metal enclosure to contain broken bits...Even heavy metal window screen will work. I know of someone who died when he dropped a wrench while working on a vacuum pump--he dropped it on a very thick evacuated glass vessel designed for that very purpose...a piece of glass cut his carotoid artery. They found him the next day, he was working alone late at night. Not an explosion, a genuine implosion, but but at least one nasty piece passed through the center and kept on going...for a while. Maybe just a scratch most cases, but why take the chance?

4) Any pressure of more than two or three atmospheres, you oughta put your thinking cap on, especially if a substantial volume of compressed gas is involved and you're building things out of stuff maybe not meant for that purpose. Blast shields are employed in such cases even with specially designed equipment intended for that type of use. This kind of safe habit like using those tops over the valves of compressed gas bottles and securing same are just as important as not pointing guns at something you don't want to shoot. Familarity should breed safety, not the reverse.

5) Suck or push most any gunk into a machine that it wasn't intended for and it dies...You'all pro'lly knew that already, but you wouldn't believe how many trashed laboratory vacuum pumps exist from that very problem. Lots of folks who should know better destroy them regularly. Smart-papers don't imply common sense, but I bet you already knew that too.

BTW, everything I've described I've seen happen to me or others, or start to happen (except the guy with the cut throat--but I talked to someone who was in the facility the next morning...the blood ran under the lab door and way down the hall). In some cases, there were more extreme conditions than home-brew rigs can achieve, but the basic ideas are the same.

Now go make sumpthin'....and post a pic. I really enjoy reading here until I can try it myself. Someday I'll try and make one of those simple forges. All I manage at the moment is putting tedious tung-oil finishes on HI khukuri handles and maybe carving and polishing them a bit, but you guys are gonna get me hooked someday. Love the stock in your sig pic.
 
Roger,
Most of what you ask about can be found here WSSI .

Moons ago the was a page or two on the net that gave an average for the amount of weight gain by different woods, it may be gone now cause I am having NO luck finding it now.

Mike K
 
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