Mill stabilized wood?

How To
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I am picking up equipment to do wood stabilization, probably going with cactus juice.

I was wondering if anyone here had insights or experience with cutting stabilized wood. Recipes, anecdotes, tips and tricks, all info is good info :slightly_smiling_face:

For feeds I imagine I could start with the hard plastics defaults, with one benefit being that the resin isn’t a thermoset plastic so I don’t need to worry so much about melting.

Maybe looking for info on milling phenolic would be a good analog :thinking:

If it matters, this would be for fairly small pieces like pendants. I’ll see if I can find a photo for example.

Very quick prototype:
Too much air caught in the resin, the tolerances aren’t great, CZ stars were a bit dislodged but it gets the point across.

I plan on stabilizing the wood, pulling a vacuum before curing the resin topcoat, and actually setting the stones.
I’d like to get away from the resin, maybe go with a sapphire watch glass for the cover.

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totally interested. also totally clueless to help. This sounds like an excellent adventure.

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I stabilize wood with cactus juice frequently for projects, usually with pieces of burl that I then combine with colored resins. I don’t think it requires anything special for cutting. It doesn’t make the wood noticeably harder. I would just start out using the same settings as for hardwoods.

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Another subject I have no clue about.
Today’s lesson.

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Highlighted the phrase “wood stabilization, probably going with cactus juice” and right clicked in my browser and it had an option to “Translate selection to English”: :smiley:

John

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I’m curious too. Been thinking about doing the same. I’ve done lots of epoxy carving before and just use my hardwood setting as well. I’d love to hear about your experiences. Might even be interested in purchasing stabilized wood. Keep us posted!

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I have my cactus juice and related equipment on the way! I’ve got high hopes for the pendants and the wife saw the stabilizing resin dye on lighter woods, so that’s going to be a thing :man_facepalming:

That also means I have a new toy to play with in some other applications as well.
Which makes me wonder, should I pull a vacuum for non-stabilizing finishes as well :thinking:

Will my tung oil finish get deeper penetration on my chopsticks if they’re submerged and put under vacuum to marinate for a bit :man_shrugging:
We’re gonna find out!

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My vacuum equipment was lost by FedEx.
For the replacement I’m going with a brushless pump made in America which should be here…eventually.
(A fancy brushless vacuum pump is by no means necessary for the cactus juice but I’ll be using it for carbon fiber as well, stay tuned for milling molds to make forged carbon fiber parts. I’m absolutely giddy about the prospect :nerd_face:)

Anywho, my apologies for the lack of updates for folks who are interested in the stabilizing :pray:

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Impromptu update!
I got lucky on Facebook market place (shout out Dale) and picked up an old vacuum oven and a ridiculously nice peristaltic pump. He threw in an impulse sealer too so I have a dedicated shop impulse sealer.
All that for $50 and an hour of driving. Well worth the trip.

The wood needs to be completely dry, 0% humidity throughout, before I can stabilize. This is usually done by leaving the wood in an oven at ~220f for about a day.
I’m hoping the vacuum oven greatly increases the drying speed, considering most of what I do is fairly small in terms of cross section :crossed_fingers:

I’ll let folks know how it goes :slightly_smiling_face:

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Drying wood:

I let it run at 220f overnight:

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should
(Drying the wood in your home oven seems fine to me, but final cure once resin impregnated should not be done in an oven you actually cook in.)

You can tell if your wood is dry by weighing it before drying, then weighing every few hours or so. Once the wood stops losing weight, you know you’re at 0%

Storing dried wood

Once the wood is dried, we’ve got to keep it away from all that awful water in the atmosphere.
The wood will pull in water if left out, so most folks wrap the wood in cling wrap, then shove that in a ziplock bag, and finally put all that in a gasket sealed Tupperware.
I’ve got a vacuum sealer, so I’m going to use that.
(Though water will still tunnel through the plastic over time. Monstrous stuff.)

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I wanted to ensure I could open each piece without releasing vacuum on the other pieces, so the sealing is done with some intention. Each square is in its own sealed packet.

Going forward, I’ll probably grab a bunch of to those tiny mason jars and store them in vacuumed jars. That also allows me to see the pieces clearly when selecting them which is nice.
Since stabilizing requires a vacuum anyway and it probably moves air at 4+CFM, the jars should actually be pretty quick.

Automation ideas (autonomous overkill)

Since I’ve got a vacuum oven now, I’m thinking of tricking it out with a scale for weighing the wood.
The automation can monitor the vacuum and the weight, checking for changes over time. Once the vacuum and weight have stabilized, we can cut power to the vacuum and heater.
Since it will be a sealed system, it can sit there happily at 0% until I get around to sealing the wood.

I’m pretty sure I could just chuck the wood into the mason jars and put the jars into the oven. The vacuum oven is essentially a vacuum chamber, so as long as the jar lid is just a little loose it should act as a one way check valve. Allowing the vacuum to be pulled but sealing once the chamber is opened.
Auto sealing at 0% humidity in a nearly hermetic jar.
Pretty sick.

We’ll be getting to stabilizing soon :crossed_fingers:

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@HeuristicBishop

I think the mason jar is the way to go for long term storage to minimize the moisture. Even the plastic bags I get the 3D FDM filament in will tell you that eventually the moisture will return when seal welded much less a zip-lock type seal. The jar and lid assembly should easily perform the one way check valve theory in your vacuum chamber.

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I use an old microwave oven in my workshop along with a cheap postage scale to dry wood quickly before stabilizing it with Cactus Juice. I stick the wood in the microwave for a very short intervals until I see that the weight stabilizes. I don’t want to do this in my kitchen oven and it is much faster with the microwave. I use a moisture meter to monitor the moisture level although the scale is also a pretty good indicator. As soon as the wood is pretty dry, I use my Glass Vac aluminum vacuum chamber and my Robinair Vacuum pump to soak it in the Cactus Juice. A high quality vacuum pump is needed to maintain and accurately monitor the pretty high vacuum pressure that is needed for Cactus Juice. I then cook it quickly in a cheap Walmart toaster oven that I only use for stabilizing as I monitor the temperature closely to get proper curing of the Cactus Juice.

Once the wood is stabilized I store it on the shelf until I use it. There is no need for sealing it. In fact, I want it to stabilize to the normal room humidity level. This has worked perfect for me for years.

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@Redlander
Yeah, I was thinking of my 3d printer filament as well. Pretty sure the best way for a vacuum bag would be those fancy Mylar coated ones. The metallic layer doesn’t let much through so they hold much longer.

@jrobe
A microwave is interesting. With the small pieces I do it would probably be very quick. I’ll have to give it a shot, thanks for the rundown on your process :beers:

The vacuum is an interesting bit. I have a nice vacuum on the way since I’ll be using it for so many other projects but I’m also thinking of how it might be improved.
Leaving a 4+ cfm vacuum on for a day feels like an awful lot when we’re not actually needing to move much. For the initial drawdown to very low pressures, it makes a ton of sense. Once it achieves those low pressures, I’m wondering if we could get away with a much smaller, quieter, and easier to control vacuum.

We need to keep pulling the vacuum as the vacuum pulls air out of the wood but it’s such a small amount compared to the initial drawdown. I think ultimate vacuum is the thing we actually need to keep in mind. So I might search for a 24v lab vacuum unit that isn’t capable of moving much, but has a decent ultimate vacuum. That would be much quieter and easier to control than a 120v 5Amp monster.
Since I’m on residential circuits and I’m gathering more long running projects/processes, reducing load on the circuits is becoming more valuable :sweat_smile:

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After some research, I don’t think a small vacuum will be able to maintain the full vacuum necessary for infusion. Bummer.
Though I’m pretty sure we don’t need full vacuum overnight for this, so I might rig up a system to trigger the vacuum at a setpoint. Pull the chamber to full vacuum, then switch off the pump until enough off gassing has occurred to trigger the pump back on.
My hunch is that pulling the air out of the wood requires less total vacuum than these units pull at full duty. We probably see diminishing returns past a certain vacuum level.
So my hope is that the range of effective vacuum is large enough to cut the vacuum duty cycle down to something more reasonable. (A side benefit being the vacuum oil lasts longer which might be nice)

I’ll put together a parts list and try it out. While it would be pretty sweet to gather the data and record it for science I might just go the dumb equipment route first. Get some initial feedback and see if there’s any promise before investing time into a more complex automation.

Still, for anyone reading this…just run your pump constantly like the Cactus Juice creator recommends :slightly_smiling_face:
Anything else is just nonsense to satisfy my own curiosity :nerd_face:

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Watch this guys wood stabilizing videos. Stabilizing wood means sucking air out of the wood with very high vacuum pressures (25-29" Hg) and replacing the air with Cactus Juice resin and then curing the resin with oven heat. With my Robinair vacuum pump, I seal the vacuum chamber, turn the Robinair on to full vacuum pressure and leave it running for 4-12 hours depending on the size of the wood. As the vacuum is sucking the air out of the wood, you can watch the air bubbles coming out of the wood which gradually reduces over time. At first you have to even apply the vacuum slowly or it will foam up. You definitely need full vacuum pressure for the required time. I do exactly what is shown in this video with similar equipment.

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I’ve watched a good bit of Zac Higgins and some other creator, so I’m familiar with the process (YouTube is such an awesome resource :slightly_smiling_face:)

It’s just a matter of curiosity and testing to see if the full vacuum is really necessary or if it’s just more convenient to perform and explain.
I know we can’t pull the vacuum and just seal the system because the off gassing will start to equalize the pressure in the chamber and reduce the vacuum that’s exchanging the air for resin in the wood. I’m just not sure what ultimate pressure is actually required to yank that air out of the wood.

To get into more specifics about the hunch I mentioned earlier, I think there may be a bottleneck in how the air travels through to wood. Some relation between flow and pressure. (Negative pressure in this case, but I think it still applies)
We might be at a point where yanking harder on that trapped air (pulling a stronger vacuum) doesn’t actually impact how quickly that air is able to flow out of the wood. If this is the case, we could use a lesser average ultimate vacuum to achieve roughly the same evacuation rate.
Ideally, we’d be able to tune the vacuum to suck less hard. Basically, lower rpm to maintain a higher pressure equilibrium in the chamber…but that’s hard.
So we might be able to achieve a similar higher pressure vacuum in the chamber by bouncing back and forth in a dead band of pressure. Turn on the pump and let it pull far lower than is strictly necessary, then let the chamber pressure rise to a point where we suck it back down again.

Most folks are doing this stuff to get a job done and make some money, so just doing what the manufacturer recommends is the right answer. I’m more interested in the process itself, so these kinds of shenanigans may seem unnecessary or silly but I think it’s worth the effort :slightly_smiling_face:
I’ve seen a lot of folks explain how it works at a high level and run through the process start to finish with some beautiful work to show for it.

I’ve not been able to find anyone who really dug into the process itself :man_shrugging:
Hopefully we discover something interesting. We might not though and that’s ok too :grin:

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I’m trying to be more concise and do more video content. This seemed like a fine subject to practice. Enjoy a ~3 minute video explaining why I think there’s a world where we can pull the initial vacuum, seal the chamber, and still end up with a good result.

It’s a little counterintuitive since the solution is simply increasing your vacuum chamber size in relation to the amount of wood you are stabilizing, but I think it makes sense. Probably. Maybe. We’ll see.

If you watch it, let me know what you think. About the idea itself but also about any of the production stuffs. Was my voice clear, was the video clear, was there a ton of annoying background noise, whatever your thoughts I’d be happy to hear em :slightly_smiling_face:

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I’ve been thinking about a decent way to get a large vacuum ballast to test this out. I want something that has a fairly large volume that can hold a good vacuum for a long time without leaking or imploding.

First I thought of was my glass mason jars with bulkhead fittings. Not huge volume but that could be daisy chained and I’ve got em already. The bulkheads are about $2 a piece though and I’d want quite a few. So on to other ideas.

Used welding tanks were interesting. Easily holds the vacuum with no risk of imploding. But they’re heavy as frig and I don’t need all that metal for what little pressure full vacuum would entail.

Here’s what I’ve landed on: Stainless steel keg.
Should be plenty sturdy without being so heavy. I can get them in the most appropriate size for my space. They’re about $30 used around me. Just need to give em a good cleaning and soak in some kind of sanitizer. (I don’t need my vacuum ballast smelling up my tiny shop)

So I’ll probably have to make a custom vacuum lid for it but I know a guy with a CNC :sunglasses:
I’ll likely run it through a vacuum manifold with the vacuum pump and a quick disconnect for the resin chamber. A check valve on be vacuum port should allow me to disconnect the pump while maintaining the vacuum (so I don’t have to fully draw it down every time)

Maybe I’ll be able to pick up a keg for a steal after the long weekend :crossed_fingers:

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Don’t forget to put a vacuum trap before your pump so you don’t pull the resin into it. In chemistry one way we do that is with a side arm Erlenmeyer flask. There are also ground glass traps as well.

One possible source for your ballast idea is look at the large molded filter housings. Probably can find some used ones cheap. https://www.ebay.com/itm/226819041947 one randomly from ebay. I know there are bigger ones out there (also look for equipment that use them that you can scavenged them from). They are plumbed and gasketed so it might make it easier.

Also be careful on thinking things that hold pressure are going to be equally good at holding a vacuum. See the youtube videos imploding railroad cars. etc. Though I did see a guy do a test on a beer keg.

There is also just getting pump that is good for continous duty. (the pump works less hard once things are pumped down to a vacuum)

John

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I do like those little filter housings. Used to use them as pressure chambers for resin work, super convenient. I’m looking for something closer to 5 gallons or so, a decent volume comparatively.

Yep, mason jar with some bulk heads makes a reasonable resin trap :slightly_smiling_face:

Yeah, positive pressure and negative pressure aren’t the same thing but I think I’m within the margins. Worst case I’ll pick up a used cylinder and be perfectly comfortable using it even though they’re not rated for vacuum.

And yeah the pump duty cycle is something I’ve been concerned about. I went with a brushless pump to try and ensure some longevity and one of the benefits of this vacuum ballast is to try and keep that duty cycle down. Big ol vacuum battery I can use instead of keeping the pump on constantly.