Cactus Juice questions

[Kevin Jenness]

I have a large quantity of spalted sugar maple salvaged from a standing dead tree. Naturally, a lot of the most spectacular stuff is so punky as to verge on unworkable. I am looking at using Cactus Juice to harden it up enough for turning. Most of the material has been sawn up into 3" x 7" planks and could be used for small boxes, bowls and hollow forms, although there are a few larger chunks. It is currently around 8-10% moisture content and if roughed out will get to around 6% in my shop at this time of year. I also have access to more and larger similar material.

The TurnTex FAQ section includes this response to a question about punky turning blanks

Yes, Cactus Juice will work fine on bowls. It may get expensive, though, due to how much resin they will take up. Since stabilizing punky bowls is primarily just to to make them turnable, I would suggest just getting a large enough container and just soaking the blanks. In my testing, punky wood will typically double in weight just by soaking. This will not be as well stabilized as if you used vacuum but for the purpose of being able to turn and finish them, it will be just fine. They will be hard and turn without tear out, they just may not be as resistant to moisture as a vacuum stabilized blank. The advantage of just soaking is you will use a little less resin and you don't have to try to get a large vacuum chamber.

No, you do not need to wrap them in foil. The primary reason for wrapping in foil is to contain the mess when some of it bleeds out (part of the process) and to allow you to put more blanks in the oven at one time. If you do not wrap them in foil, be sure to not stack them on each other or you will end up with a bunch of bowl blanks glued together! Also be sure you have a good drip pan under the blanks to catch the bleed out and prevent it from getting all over the inside of your oven!

Do any of you use this technique in lieu of vacuum infusion on largish blanks? I was intending to set up a vacuum chamber and have about $5 invested in an old pressure cooker, but if soaking will do the trick that's ok with me. Do you get acceptable results in the moisture content range I am talking about? For large pieces, would an enameled lobster pot work ok (I saw a 5 gallon one at the thrift store the other day)? The toaster ovens I have seen are a little small for some of the pieces I might make - have any of you set up a larger curing chamber? Finally, do you find that stabilized wood works best with certain finishes? I most often use wiping varnish (Sutherland Welles Hard Oil Sealer).

I am well aware of the saying, "Life's too short to turn crappy wood", but crap is in the eye of the beholder... oh wait, let me get my handkerchief.

 

[Charlie Knighton]

No answers have seen my share of punky wood.....are u going to use wife's oven? Haha.....post pics of process.....interesting thread

 

[Kevin Jenness]

No answers have seen my share of punky wood.....are u going to use wife's oven? Haha.....post pics of process.....interesting thread

Definitely not using the household oven. Mybe I can find a used small conventional oven or a combi microwave/convection oven. I wonder if a plain microwave oven would work?Thinking of adapting a small refrigerator with a heating element or fabricating an enclosure with sheet metal plus a toaster oven or such - ideas welcomed. Safety essential.

 

[Randy Anderson]

Let us know how this goes. I've looked at this before for punky wood, I see a lot of it and like it but would like a way to stabilize it. I wondered if just soaking would be a viable way to go about it. My resistance has been the cost, setup and process - cactus juice is not cheap, vacuum rig, cooking, etc. No way I can do this in the oven in the house. Considered a small cheap toaster oven but then get limited on size, etc.

 

[Kevin Jenness]

Another option of course is sozzling with low viscosity epoxy, which would eliminate the heat curing step. I am not a fan of diluting marine epoxy with solvent and the CPES formulations (and Minwax hardener) seem to be quite obnoxious in use. I am planning to try some Liquid Diamonds resin as a hardener, as that is quite thin.

 

[Tom Lucas]

I had posed a similar question over at SMC forum. One good input that I got was to removed as much known, unwanted material as you can before treating. This reduces the amount of juice needed and leads to better/easier curing. The challenge here is is the material sound enough to turn safely to do that? I'm going to give it a try once I can find an oven big enough that runs on 110V.

 

[Tim Tucker]

For the cost involved...I still prefer immersion of rough turned pieces in 50/50 pre catalyzed lacquer/lacquer thinner. Let it soak for a few days - heck even couple of weeks. Then take it out, allow it to dry outside until the smell is gone. Then turn it..The lacquer hardens the punky wood so that it cuts like silk.

 

[Richard Coers]

I had no idea any wood could get to 6% moisture just sitting in the air. Your skin must be cracking in your shop at that humidity level!

 

[Kevin Jenness]

had no idea any wood could get to 6% moisture just sitting in the air. Your skin must be cracking in your shop at that humidity level!

Good grief, I wish knew how to delete the above after fiddling around and messing it up.

Anyway, Tim, thanks but I don't think I want a vat of lacquer sitting around, plus the off-gassing would be pretty slow this time of year. The less solvent use the better I like it.

Richard, the rh in my shop is about 30% now which equates to about 6% emc- not uncommon here in midwinter. Maybe the second pan of water I put on the wood stove yesterday will push the rh up a couple of points. I try to keep it below 50% in the summer using the heat pump.

 

[Charlie Knighton]

Punky maple u find black lines....hard to get good cut.....juice might help

 

[Bob Brown]

Why don't you look for videos by turntex.com and others. It is somewhat expensive but sounds to wood was free. You submerge wood in vacuum pot, approximately 1+ inch above. Pull vacuum, it will bubble, cactus juice is pulled in. When bubbles stop, soak wood twice as long as displacement took. Heat in oven @ approximately 200 d ,yes I use kitchen oven. Wrap peices with al. foil and put on sheet pan. Cook until resin is solid. Curtis has videos. The above is the way I do it. If you want expert advice follow manufacturer rules. Any left over juice that is left is reusable.

 

[Tim Tucker]

Good grief, I wish knew how to delete the above after fiddling around and messing it up.

Anyway, Tim, thanks but I don't think I want a vat of lacquer sitting around, plus the off-gassing would be pretty slow this time of year. The less solvent use the better I like it.

Richard, the rh in my shop is about 30% now which equates to about 6% emc- not uncommon here in midwinter. Maybe the second pan of water I put on the wood stove yesterday will push the rh up a couple of points. I try to keep it below 50% in the summer using the heat pump.

Oh - I understand. I use a gasketed , screw on lid 5 gal. plastic bucket. I would not imagine using an open vat. This is a not an "odorless" method.....

 

[Kevin Jenness]

Why don't you look for videos by turntex.com and others. It is somewhat expensive but sounds to wood was free. You submerge wood in vacuum pot, approximately 1+ inch above. Pull vacuum, it will bubble, cactus juice is pulled in. When bubbles stop, soak wood twice as long as displacement took. Heat in oven @ approximately 200 d ,yes I use kitchen oven. Wrap peices with al. foil and put on sheet pan. Cook until resin is solid. Curtis has videos. The above is the way I do it. If you want expert advice follow manufacturer rules. Any left over juice that is left is reusable.

Bob, I have looked at videos by TurnTex and Zac Higgins and looked through Curtis' FAQ's, so I have a general understanding of the process. If you have answers to my specific questions about soaking vs. vacuum infusion for rough-turned blanks, finding/fabricating a larger curing chamber, finishing methacrylate modified wood and other products/ methods for hardening up my "free" wood I'm all ears. Thanks.

 

[Bob Brown]

Bob, I have looked at videos by TurnTex and Zac Higgins and looked through Curtis' FAQ's, so I have a general understanding of the process. If you have answers to my specific questions about soaking vs. vacuum infusion for rough-turned blanks, finding/fabricating a larger curing chamber, finishing methacrylate modified wood and other products/ methods for hardening up my "free" wood I'm all ears. Thanks.

Do you have a vacuum pump?

 

[Kevin Jenness]

Do you have a vacuum pump?

Yes, I do.

I just got off the phone with Curtis from TurnTex, a very friendly and informative gentleman. He told me that for my purposes soaking for a week after rough turning would suffice, and that pre-drying to 0% mc is desirable but not required. The less water is in the fibers the more resin can soak in. Soaking should harden up moderately punky wood and be more economical than vacuum infusion. If using vacuum, bone-dry wood is necessary to avoid gumming up the pump. He said that wiping varnishes tended not to work well with stabilized wood and that he recommended film finishes like lacquer. I hope that helps anyone interested.

I am going to give the Liquid Diamonds resin a whirl, as that is a quick and easy experiment and I have it on hand. If it works well, fine; if not, I'll order up some Cactus Juice and look for a small-mid-size 110 volt oven

 

[Tom Lucas]

Has anyone use an electric smoker to cure cactus juice? this seems like a good way to get a "big" chamber without resorting to a 220V oven. And they can usually be had used for cheap.

 

[Jim Harris]

Here’s my shop oven. Inside dimensions are 8” high, 11” deep, and 14” wide.

Ninja Foodi Smart XL oven

 

[Steve Chaplin]

I have used the Cactus Juice process with vacuum and oven. It does an excellent job but I would only recommend for wood that is very unstable.
For wood that is punky and wants to tear out, my go to is a thin epoxy which will flow into the wood well. It is important the the epoxy dries clear and hard. My favorite is MAS LV (Low Viscosity) with the medium speed hardener. It is thin enough to penetrate well, dries hard, and turns well. Poly works very well as a finish over it.

 

[Tom Lucas]

I have used the Cactus Juice process with vacuum and oven. It does an excellent job but I would only recommend for wood that is very unstable.
For wood that is punky and wants to tear out, my go to is a thin epoxy which will flow into the wood well. It is important the the epoxy dries clear and hard. My favorite is MAS LV (Low Viscosity) with the medium speed hardener. It is thin enough to penetrate well, dries hard, and turns well. Poly works very well as a finish over it.

Any value to doing both CJ and epoxy. Say CJ to stabilize what is otherwise very punky and then apply epoxy just before final finish cuts? Or does the CJ give equal tear-out abatement?

 

[Earl McLain]

I have used the Cactus Juice process with vacuum and oven. It does an excellent job but I would only recommend for wood that is very unstable.
For wood that is punky and wants to tear out, my go to is a thin epoxy which will flow into the wood well. It is important the the epoxy dries clear and hard. My favorite is MAS LV (Low Viscosity) with the medium speed hardener. It is thin enough to penetrate well, dries hard, and turns well. Poly works very well as a finish over it.

Steve--i know it will vary by species and degree of punkiness--but how much penetration would you expect to get with the MAS LV? And...do you try to wait to apply until you get close to finish shape if the wood allows that?

@Tom Lucas Thanks for sharing you conversation with Curtis on just soaking--i should send you half of what i was thinking of spending on a bigger vessel!!

I'm not a fan of toaster ovens for anything. Using a temperature controlled switch, i have observed a quality oven switch off at 154 f, then continue to heat to 350 f just on the residual heat from the coils before they cooled. For those do do use a toaster oven, whether for wood or cooking--don't leave them unsupervised. Picked up a vacuum oven a few years ago--easy to control temps within a few degrees. Downside is that i use a clamp to shut the door, since i don't want to pull a vacuum while curing--though it only takes about 5" of vac to seal the door. I'm still watching for a lab oven (or dental oven) which would be larger than my vac oven--but need to be local enough for pick-up. Size & weight make shipping a bit expensive. My vac oven was from a research hospital, draws only about 4 amps and will hold 200 f for hours because of its mass.
earl

 

[Steve Chaplin]

I have not seen any advantage to using both Cactus Juice and epoxy, have only used one or the other.

Penetration of the LV epoxy will vary based upon the type of wood an how punky it is. In general the punkier it is, the more it will penetrate. I usually try to get a rough shape before applying the epoxy. How close to the final shape depends a lot on how deep the tear out is. Turning with a 40/40 grind helps reduce the tear out. You will be surprised by how much epoxy will go into punky wood. Since epoxy is expensive better to get close to the shape you want. I apply the epoxy with a brush, usually foam but bristle works too.

Here is a bud vase from punky Black Gum burl that was epoxy treated:

 

[Allen Mattsen]

I've seen a few folks use an electric smoker for the larger capacity and temperature control improvement vs the smaller toaster style ovens.

 

[Tim Tucker]

Electric smokers are notoriously bad for temperature swings. Only if you wire them to be run via P.I.D. are they something that can hold a set point temperature very well. ( note my profile....)

 

[Doug Freeman]

I have tried thinned lacquer and thinned resin (separately, not at the same time) for punky wood, thinned 50/50 (lac thinner/acetone). The pieces were turned down to 1/8-1/4” of final dimensions, and had moisture, but I didnt measure. If the tenon needed it I reinforced with thin ca. I just brushed the thinned mixture on with chip brush, pretty heavily, trying to saturate. Did it outside due to fumes, and left the pieces outside a few hours to outgas. Then I let thhem sit a couple days for the epoxy, about a week for the lacquer.

The pieces turned similarly, but the epoxy seemed to have a bit more solids content in the wood. The epoxy cures quicker, since its a chemical reaction in addition to the acetone evaporating. Both finished ok with wipe on poly.

Havent tried emersion, but I might. The biggest issue would be ensuring the wood was completely covered and what to do with the left over mixture - no problem with lacquer, but whatever resin is mixed is used.

Yes, it must be done outside, but the solvents will still flash at low winter temp as long as you can stand to be out there to brush it on.

One thing I dont like about the cj with vac is having to bake the wood before - concerned with cracking. I need to check moisture content next time I cut into punky piece just to see how hi it is.

 

[Steve Chaplin]

The Cactus Juice can be reused, it cures by only heat.
The 2 part MAS epoxy I use is always brush on. You can use any thinner epoxy that dries clear and hard, many casting epoxies work.
I have tried sanding sealer, and also freezing the wood. Epoxy works better.

You can thin the epoxy for better penetration:
I have used DNA, you can also use acetone or lacquer thinner. No more than 5% because it will change it cures. There will be strength loss, longer cure time and it can also change color. The strength issue doesn't matter in most cases for stabilizing wood, the color change is a negative in some situations.

I have also used the microwave to heat it. You have to be very careful, a small amount of epoxy takes no more than a few seconds. It also will cure faster when heated. Be very conservative on heat times, first time I tried this it was a bubbly mess that cured in 10 seconds.

Here is an excellent article on thinning epoxy: http://www.seqair.com/skunkworks/Glues/WestSystem/Thinning/Thinning.html

 

[Doug Freeman]

Thinning epoxy - I used Famowood glaze coat epoxy (not the lacquer) as its available at the local Lowes. Im sure there are better products. This was for initial process testing/development. As stated, I thined it 1:1 with acetone, and it cured and cut just fine, point being that this is a somewhat unique application vs a more typical coating, structural, finishing application, so the directions from the mfr are not really applicable. The thinner the viscosity the deeper the penetration, and this epoxy was fairly viscous since its for doing large flat surfaces.

As for some of the thinner penetrating expoxies, they were about the same $ by ounce as the thicker stuff. I deemed it more $ effective to try thinning thick stuff and if it worked I was $ ahead.

I have done 3 pieces with it and all turned out well.