Stabilizing woods: vacuum vs pressure

[rashid11]

Some woods are stabilized (plasticized) by forcing the agent into the wood under pressure. Was wondering what difference (pros/cons) are there between this method and more common "vacuum" way of accomplishing the same ?

For DIY types, vacuum way is definitely more established - with folx reporting success with setups as simple as hand vacuum pumps and plastic containers.

Would pressure way be as simple as dropping some wood into a pressure vessel like http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93119, pouring the agent in till the wood is fully submerged and pumping the whole thing to 50psi ?

 

[Edro20]

Maybe you could vacuum pack some wood along with the stabilizing agent. Then you could take the package and weight it and then use a rod and reel to sink it into the deepest lake you can find. If you could get 50-100 feet deep, that would be quite a bit of pressure.

How's that for a hare brained idea?LOL

 

[rashid11]

Unless it bursts down there and then you'd need a different lake when you want to go swimming/fishing ?

 

[richard j]

from what i was told, when you send wood off to get it done they put it in a vacuum chamber to draw all the air and any moisture out. then while the chamber is under vacuum they fill an attached chamber with epoxy that gets sucked in when a valve is opened. then the valve is closed and the chamber pressureized. vern6 fixed up a paint pot that allows the wood to soak in polyurethane (or whatever he is using) during the vacuum process. then after a week or so he applys pressure so the polyurethane is forced into the wood. if you want a vacuum pump there are medical supply stores that might have small vacuum pumps cheap.

 

[mtodriscoll]

I saw a DIY vacuum setup on the web involving:
- your wood
- Minwax wood hardener
- a mason jar large enough for wood, clean lid, metal band
- a coffee can
- boiling water

I haven't tried it, but have thought about it for my next project.
Here's the link:
http://www.northcoastknives.com/northcoast_knives_tutorials_hints_tips3.htm

 

[AcridSaint]

Someone who does a lot of business with WSSI should see about getting a rep to post here and explain the differences between DIY and commercial stabilizing. I would really like to see what is said.

 

[WadeH]

Are just post a reply from an email sent to them asking them the question would be just as great as getting one of them to post an answer. I would like to know myself too.

 

[stephanfowler]

I saw a DIY vacuum setup on the web involving:
- your wood
- Minwax wood hardener
- a mason jar large enough for wood, clean lid, metal band
- a coffee can
- boiling water

I haven't tried it, but have thought about it for my next project.
Here's the link:
http://www.northcoastknives.com/northcoast_knives_tutorials_hints_tips3.htm

FYI this method can be VERY DANGEROUS if your using open flame to boil the water.

 

[mtodriscoll]

Agreed! That post does mention no open flames and plenty of ventilation. I think he recommended performing this outside, bringing the boiling water from your "heat source" outside to the coffee can / mason jar unit.

You definitely wouldn't want to be smoking while you do this either...

I'd be interested on comparison of results between DYI vs. Professional stabilization from a knife maker who has tried both. I'm sure the "pros" would give many reasons why their approach is better. But as I've heard quoted before, "sometimes better is the enemy of good enough".

Matt

 

[rashid11]

There's no reason for frugal types amongst us not be able to build a $5 etcher.
Ditto for wood stabilization. Stuff can be as simple as a brake bleeder kit (under $20) and a plastic (ideally, transparent) airtight container - big nuff to submerge yer wood

Make sure the wood is dry (I guess it has to be under %8, quick way to dry it is to submerge it, for a while, in a de-naturated alcohol and then let it dry for a week inside of a brown paper bag).

Cut the wood into strips of just over the required size - this way it is thin nuff and easier for the hardener to penetrate. Into the plastic container it goes. Pour in yer
hardener till the wood is completely submerged. Put the lid on and pump vacuum till
you see the air bubbles emerge from the wood and surface. Make sure the vacuum doesn't drop, pump more if you have to - keep it like that for a day. But that time bubbles should stop.

Remove the vacuum, let it sit for another few hours. Get the wood out, collect and store leftover hardener. Done.

Folx that did it also performed penetration tests. The test pieces were cut and cross section examined for hardener penetration. Tests revealed 100% penetration.

My question has to do with doing it by pressure-forcing the hardener into the wood. This is where the paint pot I mentioned comes into the picture. It is capable of withstanding some mean vacuum _AND_ up to 70psi pressure.

It does appear that even when pressure-stabilizing, first they go through regular vacuum routine ?

 

[SBuzek]

I was told the differance was not penatration but the compounds used for stabilizing.The stuff the pro's use IE wssi & K&G is far better than anything avaible to the DYI er's.
Stan

 

[B. Davis knives]

to dry the wood get an old frig.. put a light bulb in the bottom of the frig... and put the wood in there for about a week.

 

[rashid11]

there's nelsonite :

Nelsonite 30B02 is the wood stabilizing compound that leaves your wood/bone/horn/ivory handle material feeling natural, not like plastic! This stabilizer has long been used in the woodworking and pool cue fabrication communities, and is just now being discovered by knifemakers as an alternative to products such as MMA and Resinol 90C. Several prominent knifemakers use this stabilizer and prompted us to start carrying it.



Nelsonite has a very long shelf life in the unopened container, approximately 10 years according to the manufacturer. However, exposure to oxygen (air) degrades the material and starts to affect its efficacy within 3 - 4 months. It is advisable to either purge your opened containers with an inert gas (nitrogen, argon, etc) or top up your container with something like ball bearings or clean pieces of steel to keep the air head space to a minimum. You can also store your opened container in your vacuum chamber (if you use one) and keep it pumped down.

from
http://home.comcast.net/~eellis2/EllisCustomKnifeworks/nelsonite.html

 

[Hawks Nest]

I have been stabilizing my own wood for almost 4 years now using a vacuum pump and vacuum chamber, however I send some wood off to be pressure stabilized as that is the only way to penetrate certain woods. Most woods can be stabilized under vacuum but woods like Redwood burl, Yellow Cedar burl, or other very dense/tight grained woods need pressure to help push the resin inside the middle/center of the wood.

Now to stabilizing:
I use a vacuum pump, vacuum chamber, and stabilizing resin to stabilize most woods. The vacuum is basically forcing out air in between the grains of the wood allowing resin to fill inside the grain, when you finally release the vacuum it sucks in the rest of the resin it can intake. Soaking is done after to allow it to absorb as much resin as possible.

Hope this helps!



-Hawks Nest