Home-grown vacuum

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grawulf

Joined
Feb 16, 2005
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After posting a question about a do-it-yourself vacuum and getting lots of great ideas, I thought I'd show you where I'm at and see if anybody has any suggestions. I'm going to try to post an image but I'm not sure how it works...

Anyway I couldn't find the trigger-type vacuum pump at Kragens but I got an oil-changing type pump. No go, only works with liquids. Then I found the food-saver on sale at Home Depot for $40! So I grabbed it, and found a large acrylic food-saver chamber at Wal-Mart. I filled it with my stabilizer about 2/3 and threw in some scrap hardwood. I couldn't tell how much vacuum I was getting, but it really seemed to pull the oxygen out. It bubbled like crazy.

So I pulled the whole thing apart and drilled a whole for a vacuum gauge, and then sealed it with a small rubber hose for a gasket and a bunch of 2 part epoxy. So now hopefully I can tell if I'm getting sufficient vacuum, if the thing doesn't implode!

Anyway, that's the plan. If anybody has tried this method or has any advice, I'd love to hear it.
Thanks,
Jeramy

 
As long as the stabilant doesn't eat the acrylic, it should work ok. I have no idea how much vaccuum the sealer pulls. I JB welded hose barbs it my glass chamber and they have been in there for 4 years or so with no problems.
 
I believe the missing link is that after a partial vacuum has been pulled and the acrylic introduced, at some point thereafter, the chamber is pressurized.

RL
 
Of course you're a step ahead of me on that! I figured if I can get this to work I'm at least halfway there. I don't know what kind of pressure this thing could take but I have a separate stainless tank that I have ideas about pressurizing if this won't hold it. Still not sure how to move my material from one chamber to the other without exposing it to oxygen though. So far I'm not feeling too bad about the cost. I figure I could still replace either one of my canisters and still come in under $80. If I have success it'll pay itself off after a couple of batches of wood. If not, I'm $80 smarter ;)
 
If you get another tank to presurize you can always just take the lid off the foodsaver and put the whole thing in the tank and add pressure. Out of curiosity what are you using to stabalize with?
 
I have zero idea except what I was hinted at and shared above. I suspect it true though. Pressures and lack of I do not know.

RL
 
Still in the experimental mode on the stabilizer. I heard a lot of talk about minwax hardener, but read in one of the forums that it eats acrylic, so I tried a couple of their other wood treatment products hoping for something less corosive (so far so good). The first I found was a high-resin polyurethane, my logic being that if I could actually get it to impregnate the wood it would be very durable. So far I've tried a couple small blocks of redwood and oak, vacuumed for about 5 hours. they're still drying so I havent cut to check penetration yet, but if nothing else it looks like it will take a nice gloss :-)

Any thoughts? Am I way of course with this stuff? It seemed logical to me that resin would be a good preservative, and that a product actually designed to seal hardwood floors might be kind of what I'm after, in terms of durability.
 
I've chimed in on this before.But here goes again.
Minwax wood stabilizer is NOT the same kind of stabilizing as "stabilized wood".
You need an acrylic resin specifically made for this.It is expensive stuff,and has a short shelf life.It has to be vacuum/pressure cycled and then catalyzed.
Have fun experimenting on your own knives,but if you sell a professional quality knife,get a professional to stabilize your wood.
 
Ok, I guess I was way off course! I hope you don't mind, but this does leave me with a couple of questions :-)

1) I'm not sure if you meant to imply that its better to treat wood not at all than it is to do what I'm doing, but That's kind of what I'm inferring. Unfortunately I have already sold and traded knives that had hardwood that had either been oiled, or stained and sealed; my understanding was that anything you do along those lines is probably an improvement over dry, untreated hardwood. My extension of that belief was that in using this process to totally impregnate the wood with some sort of resin would 'Stabilize' it, which I now understand was completely inacurrate terminology, as the word 'stabilize' apparently refers specifically to to the acrylic resins used commercially in this process. That being said, is it right or wrong to use anything else other than acrylic resin in this process? Is the final result going to be worse than doing nothing if I use a different product?

2) My second question is really based on a comparison of the acrylic Stabilization and other (minwax-type) of treatments, which a lot of people seem to be using. I understand that professional stablization is the ideal, but I've also been told it renders the wood fairly delicate, which-if true- is not that great a trade-off. Of course with all other things being equal, the minwax version certainly isn't going to be as weather- and time resistant, right? So ultimately I guess what I'm asking is whether the professional acrylic stuff is as superior as the price would suggest, and how would it compare in real-world scenarios?

I hope I don't offend anyone by my questions; as you can see I am truly ignorant on the topic and simply want to learn. Like everybody else (I think) I want to build the best product I can at the lowest price.Thanks again for all your help
Jeramy
 
You need to leave it submerged in the solution. The liquid works as a check valve. If you pull it out, air will get back into the material which is what your trying to keep out. It is also important that the whole thing is submerged for the same reason. As was mentioned earlier, just build a pressure chamber large enough to accomodate your vaccuum chamber. Pressure is important. Atmospheric pressure is only about 14 psi so anything over that is a bonus. It can be done with out pressure but will take many weeks, depending on your wood.
 
What about using vacuum/pressure to force linseed oil into wood instead of having to wipe it with oil several times and wait between times for it to soak up.

Ok, I realise it wouldn't be any stronger than normally linseed oiled wood, but surely one vacuum/pressurise and then let it sit on a shelf untill need would be easier than puttign it on and rubing and rubbing it on.
 
grawulf said:
I understand that professional stablization is the ideal, but I've also been told it renders the wood fairly delicate,
Click to expand...
The soft woods we send to WSSI come back like a solid block of acrylic. It is definitely not delicate.
 
Here is the problem with do it yourself stabilizing. Is it better than nothing? Yes. Is it as good as professionally stabilized woods? No.

Are you going to point this out to your customers? And will they understand the differance?

Are they going to treat your wood like other makers wood? If so, what happens when the wood on your handles start to warp, crack, fad and otherwise do the things that wood will naturally do if not taken care of? Are they now going to have a diminished view of all stabilized wood?

This may sound harsh, but let the pros do what the pros do. If you want to save some money do what I do.

I go to my local exotic wood importer. I buy a larger block (12"X12"X12" or bigger) of my favorite woods. Sure this may cost upwards of a $1000 but this is where it gets fun. Now re-saw it down to the max size that the pros tanks can handle. Send it off to have it stabilized. When you get it back. Re-saw it again into standard knife size scales and blocks. Cherry pick out the best of lot for yourself, then sell off enough of the remainder to break even on the deal.

Last time I did this, I ended up with enough top end rare exotic stabilized woods for about 300 knives for free. Plus I ended up with so much extra I sold a bunch more and ended up making about $1500 off the deal. I still have a drawer full of the stuff. I only buy woods now when I need that one wierd piece every now and then.

If you want to be really creative, use your vacuum chamber as a dye pot and color up some Buckeye or Curly Maple blocks before you send them off.
 
The other problem with forcing oils deep into the wood is that they will slowly leech out for a long time.Polyurethane and linseed oil have to air cure.If you force them into the fiber of the wood,all you have done is create an oily wood.Minwax will penetrate and the solvent evaporate better,but it will still not stabilize the wood,nor last long.
As R.W. said,if the customer is full advised that the wood in NOT really stabilized,just heavily soaked,that would be one thing,but I would suspect that most who use these home brews say,"I stabilized it myself".Thus the whole knife industry must suffer the poor results down the road when the customer tells someone,"I bought a stabilized handle knife ,and it didn't last ."
 
Well first I have to thank all of you for taking the time to post to this thread and shed some light on this issue for me. I'd already gleaned from archived forums that there was some controversy there, but I didn't really understand the nature or reasoning behind it.
R.W. Clark, I really appreciate the idea about buying a bulk quantity of stabilized stuff and then selling off what I'm not going to use. I may give that a shot in the near future.

As for the home-vacuum stuff it almost seems that the real root of the problem is that people are calling it 'stabilzed' when it's NOT. I may personally continue to experiment with this process (I've already purchased most of the equipment; though the dye idea is intriguing as well) but I promise I'll never label it 'stabilized'. It almost seems like one of the pros should register that term as a trademark and nip this whole issue in the bud. At any rate, I have always gone to great lengths to tell people who have my knives that I use natural materials, and they require care and maintenance, whether its wood that needs oiling or a blade that needs oiling. If I use any home-vacuumed materials I will spell it out in so many words. In fact I've been thinking about using the term resin-treated or something like that so that I can intentionally distinguish the product from Natural wood and Stabile wood. If the project calls for it, I might even just use plain old wood with a little oil (Does such a thing exist anymore?)

At the moment its mute for me anyway, because I'm setting up a new shop from scratch and still working on the whole wood treatment idea. Between now and then I plan to come up with paperwork that goes with my blades, detailing what the materials are and how they should be treated. I will also take my product and test it to the point of destruction. If I'm not satisfied it goes in the garbage and I move on. That's how I learned to make knves and the method has served me pretty well so far. If I can stick a knife 1/2" or 3/4" deep into a 2x4" and then bend or break it, it goes to the garbage. (Yes, there have been a few, especially when I was using a coal forge and leaf springs) I guess since I have a full-time job and this is only a little more than a hobby for me I have the luxury of being wasteful like this, but as was implied above, its also a matter of integrity.
Thanks again, you've all been extremely helpful
Jeramy
 
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