Stabilization question

[ironman123]

After blanks are wrapped in foil and placed in toaster oven, is it possible to "over cook" them, like leaving at 200 degrees for 2.5 hours?

Ray

 

[wood-of-1kind]

Good question, I look forward to some replies since I wanted to ask the same. I left
mine in the toaster oven for a full 12 hours and was not happy with the outcome. Was
originally told that it is better to overcook rather than "under", but I'm not totally convinced of this given my results.

 

[George Watkins]

I know that it is not possible to over cook cactus juice
you can leave them in the oven at the curing temp of 200f for days and it wont hurt them as once cured cactus juice is heat resistant to 400f

 

[lyonsacc]

I've had them in the oven for 5 or 6 hours and not had a problem.

 

[Jim Burr]

Nope...they can stay in there for days and be fine. I left some in last night because my wife came home with a new car...blanks took a backseat so to speak. Pulled them out this morning...everyone is happy!

 

[wood-of-1kind]

Without 'high jacking' Ray's thread here, can someone kindly post a picture here of what a 'typical' stabilized pen blank should like? I suspect that one would see "glazing" from the polymerization of the chemical being used. A picture(s) would really be useful as to what the results should look like.

 

[robutacion]

Without 'high jacking' Ray's thread here, can someone kindly post a picture here of what a 'typical' stabilized pen blank should like? I suspect that one would see "glazing" from the polymerization of the chemical being used. A picture(s) would really be useful as to what the results should look like.

You are quite right, pics always give a better idea to what to expect, and I have done today 3 lots of 2 different woods, one the very old, very spalted and very soft Golden Wattle, one batch of 82 blanks drunk 1 gallon of the juice, I've done also Bottle brush root, they didn't drink half of what the Golden Wattle did and I have the 3 batches (2 x golden Wattle, 1x Bottlebrush) about 200 blanks all together (have you heard this Curtis...???, 2 1\2 gallons done in one day, I'm down to 3 gallons from the last 4 you sent me, God forgive me if I continue to use this much juice for too much longer...!:bulgy-eyes.

Anyway, what I wanted to say is that, the wife and I unwrap the foil from all these blanks this evening, and I also found a few blanks that I wasn't happy about. The oven has a timer and goes for 90 minutes, this is exactly the amount of time that they are cooked for, the temperature is set to 120° celsius after I found out (bought an extra oven temp gauge to check it out) as I was suspicious that the temps didn't match the dial on the oven so, the 90° celsius recommended are achieved with the dial set at 120°.

Despite all this, and the size of the batches going in the oven are normally the same size, one full stabilising pot is a full load for the oven, the distance to the top and bottom elements were the same as normal, the foil wrapping is always the same however, I got a few blanks burn at the surface from both types of wood.

Interestingly, the Bottlebrush not soaking as much as the Golden Wattle, didn't have much excess juice on them, are parts of the blanks with a thin dry film of juice but not all through the blanks while the Golden Wattle drunk so much juice that, even with 24 hours of draining (I should get a spinner...!), each wrapped pack with the foil, was almost bursting with dry excess juice.

Some show also some surface burns, even though they spit out half of the juice they drunk (the bastards, what a waste..!) so, I will take a few pics in the morning (my time) and show you what they look like and what you should look for...!

Cheers
George

 

[wood-of-1kind]

Thanks George for the (upcoming) pics and the usual wealth of knowledge that you share with us.

Regards,

 

[Jim Burr]

There seems to be a glitch in my system. Can't send a pic from my phone to my computer!! Anyway...The short answer to the question is no...no glaze no haze. They are a tad darker than when they started however. had I been able to upload it, buckeye burl, manzanita, BLM burl cap and a cherry burl with sapwood...just as smooth as when they went in. I'll work on the picture thing

 

[Jim Burr]

Fixed it!!

 

[Brian G]

Hmmmm. . . .that's informative, but discouraging to me. My first run came out like they were wrapped in cellophane. I'll start a new thread after taking some pictures so I don't steal Ray's thread.

 

[JohnU]

Hmmmm. . . .that's informative, but discouraging to me. My first run came out like they were wrapped in cellophane. I'll start a new thread after taking some pictures so I don't steal Ray's thread.

That's natural. The excess juice will coat and harden along the outer sides of the blank. I try to leave my blanks a littler larger than needed and then run each side along the table saw fence and trim them up. Once they are trimmed up they don't look any different than wood, just a little harder and heavier, and take a CA finish much easier IMHO.

 

[Brian G]

Now it's informative and encouraging to me! :biggrin: Thanks, John.

 

[MesquiteMan]

John is correct. You are going to get Juice cured on the surface. If you don't, you most likely did not let them soak long enough. As for leaving them too long in the oven...assuming one is talking about Cactus Juice, there is no such thing as too long. I have accidentally left blanks for 5 DAYS! One the Juice cures, it is heat resistant to 400 degrees F and nothing changes by leaving it in longer.

I am in Utah getting ready for the CSUSA Super Wednesday tomorrow and then the Utah Wodturning Symposium Thursday-Saturday. Typing on my iPad is not my favorite thing to do so please forgive the short reply or misspellings!

 

[MesquiteMan]

Here is a well stabilized blank before trimming for those interested.

 

[robutacion]

Hi peoples,

Sorry for my delay but, my morning plans turned out to be, late afternoon reality...!

Anyway, attached are a bunch of pics from blanks recently (yesterday) stabilized. Take note that, every wiid has its own way to react to the stabilisation process and this have to do more with the composition of the wood itself.

What I got here is Bottlebrush root and Golden Wattle, and while the Bottle brush did not soak as much resin as the Golden Wattle, the results are seen from the amount of extra resin that was expelled with the curing process/heat. Some do not show any signs of the juice while other are well covered and some only half of the blank or parts of it, show the dry juice film/layer on the outside.

The Golden Wattle did soak like a sponge and spend a long time draining but, the wood was saturated with the juice before is was cooked/cured. Now, these Golden Wattle did repelled a great percentage of the juice that was soaked into the wood, this happen every time and you may as, why...???

Well, in this specific case, what made the wood soak and maintain so much juice inside before curing was the "Silica" something that all Acacia species have but some more than others and the Golden Wattle is certainly on of the ones with plenty of silica. That same silica when expose to heat, expands considerably, squeezing all that juice out, that was soaked in excess anyway so, the juice that stayed in the wood was all of what could fit in within the wood cells, allowing still the wood to become nicely hardened by the process. They require some extra cleaning up but, a small price to pay for salvaging blanks that would be unworkable due to their softness.

So, the amount of dry resin outside of a stabilized blank, depend upon various factors, one of which is a very negative one is when the blanks are stabilized without drying all the moisture out, that (the moisture) doesn't allow the juice to stay inside the wood, the "water"/moisture inside the wood, boils out when the high temp is reached, foaming the juice and expel it out that endup drying/setting/hardening outside the wood, this dry resin tends to be full of tiny bubbles and doesn't set as hard as it should.

Stabilized blanks when are unwrapped from the foil, don't look pretty, some worse than others but that is just part of what stabilizing is about, the worse thing is when, the blanks went in straight and come out like bananas (sort of...!):frown:

The burn areas of the wood are quite visible on the Bottlebrush root blanks, and while they clean up (*sand) all that out, the sanded blanks never look much until they are coated with something, I use gloss spray varnish to enhance the colours and give them a finished look, something that, if you do the blanks only for yourself, you don't really need to go that far, saving you time and money...!

I hope this helps a little...!

Cheers
George

 

[wood-of-1kind]

Thanks George, that is exactly what I was waiting to see. Pictures are indeed worth a thousand+ words.

 

[robutacion]

Thanks George, that is exactly what I was waiting to see. Pictures are indeed worth a thousand+ words.

No problem...!:wink::biggrin:

PS: I just need to clarify something that I should have made very clear on my previous post. How the blank looks after being cooked, has nothing to do with the Cactus Juice deformations or pour performance, no Sir, this juice has been very regular in its performance, since the very beginning however, any poor results achieve, are more the operators fault than anything else and these, are some of the main culprits;

*- Trying to stabilize with wood that is not totally dry and free of moisture (should always give the wood a couple of hours in the oven at 60° celsius and put it in the juice as soon as the wood has lost most of its temperature, to prevent from soaking any atmospheric humidity...!)

*- Stop the pump when the air bubbles are still coming up in large numbers.

*- Remove the blanks from the juice immediately after stopping the pump, (part of the juice soaking happens only after the pump is stopped so, you should leave them submersed, for a few hours, at the least and then let them drain for a few hours also, that will save you some juice that will otherwise, endup wasted at the bottom of the oven or attached to the wood in a big dry lump...!)

*- Using incorrect oven temperature (90° celsius - 200° Fahrenheit)

*- Not letting them be in the oven to the recommended curing times ( 90 minutes, minimum)

There are other reasons why, stabilization can fail totally or partially, oily or contaminated woods, extreme dense woods, etc, are just some of the reasons...!



Cheers
George

 

[Brian G]

I think my main problem was not letting them drain long enough. They look more like the ones in the first two pictures in the bottom row than any of the others.

I'm also going to buy a small scale as a check on how well I'm drying them prior to stabilizing. I let them dry at 200 °F (as measured by 2 oven thermometers) for 24 hr before stabilizing, and that was after letting them air dry "jenga style" in my cozy basement shop for 6 months. I don't like not knowing whether I've hit maximum dryness.

I'll be trying a batch of FOG wood for my PITH pen, but it needs to finish drying first.

I might even get a chance this weekend to turn a pen using platypus gum! :biggrin:

Thanks for all of the helpful hints.

 

[robutacion]

I think my main problem was not letting them drain long enough. They look more like the ones in the first two pictures in the bottom row than any of the others.

I'm also going to buy a small scale as a check on how well I'm drying them prior to stabilizing. I let them dry at 200 °F (as measured by 2 oven thermometers) for 24 hr before stabilizing, and that was after letting them air dry "jenga style" in my cozy basement shop for 6 months. I don't like not knowing whether I've hit maximum dryness.

I'll be trying a batch of FOG wood for my PITH pen, but it needs to finish drying first.

I might even get a chance this weekend to turn a pen using platypus gum! :biggrin:


Thanks for all of the helpful hints.

You're welcome...!

Not letting the blanks drain properly, may not be a big deal when you are in the same country where the Juice is made and you only do a few at the time, takes you a little extra time to sand the dry stuff of the blanks but that is pretty much all however, if you leave in Australia and the juice comes from the USA, the shipping costs the get it here, almost matches the cost of the juice so, an expensive product to import to start with so wastage, is not welcome...!

Doing batches of up to 85 full size pen blanks (full vacuum chamber and oven capacity), the amount of juice that runs off from letting the blanks drain a few hours or overnight as I like to do, is well visible from the amount of juice at the bottom of the draining setup I have (1 x oil pan and a plastic filter (leafs catcher) from a plastic water tank (perfect fit).

Foe most of the woods, and overnight drainage is sufficient but, for some of my many Acacias and other identical woods, it would be well worth it if I make myself a spinning drum, like in a washing machine spinning cycle, all the excess Juice would come out and I may would be able to save another 1/2 of Juice that way in a full capacity batch...!

The scales as a tool to check the wood weight loss as it dries in the oven/microwave, is a good tool to have however, pretty useless if you simply want to know how much MC% a piece of wood may have before you stabilize it. For that, a MC% gauge would be your best tool however, its accuracy will depend upon the amount of money you are prepared to spend to buy one, that is just a reality...!

Cheers
George

 

[MesquiteMan]

Draining the blanks makes no difference, Brian. Not sure which blanks or George's are the one you mention since I am on my iPad and the rows are different. I am guessing it is the ones with the white looking excess. If so, that is 100% positively the result of the wood not being 100% dry.

 

[Bob Wemm]

I've had them in the oven for 5 or 6 hours and not had a problem.

That long Dave???
Must be time to pack it up and send it over to me.
I'll check the mail next week.
Cheers,
Bob.

 

[robutacion]

Draining the blanks makes no difference, Brian. Not sure which blanks or George's are the one you mention since I am on my iPad and the rows are different. I am guessing it is the ones with the white looking excess. If so, that is 100% positively the result of the wood not being 100% dry.

Hi Curtis,

In general terms you are correct, 95% of times, is the moisture in the wood that makes the juice to look like that, and I have no doubt of it however there are some woods I get from around here that, consistently come out of the oven looking like those blanks you are referring to. you may have not experienced stabilizing old Acacias/Wattles woods, with large amounts of silica, this is the only reason I believe, make that happen as the blanks are getting dry as a bone in the oven before they go in the stabilization chamber and its seems to do only with these types of wood, that also happen, are the greatest % of woods needing stabilization. I got used to that and, is no longer an issue, the 12" disk sander takes care of the excess resin, quite easily...!

As for draining the blanks making no difference, well...! yes and no, didn't make any difference with the Acacia blanks, that were supersaturated when they come out of the juice and drainage didn't avoid all that "dry foam/juice" to be stuck to the cooked blank but, I had a mix of the Acacia and Bottle brush root blanks stabilizing at the same time, when the blanks were put in the drain tray, all the juice was removed from the plastic oil pen underneath and put back into the plastic drums. In the morning, was enough juice in the plastic oil pen to fill 2 of the bottles of hardener you send with the gallon containers of juice so, even without spinning motion, that is juice saved that otherwise would endup crusted all around the blank.

I once actually wonder if I was letting too much of the juice, out of the wood, before it was wrapped in foil and cooked, from the tests I done but repeating the process with the same wood and not draining them at all, I found that, the blank weight after if was all cleaned up, was exactly the same as when I allow good drainage before cooking so, I concluded that, in my case and with the woods I was working with, I could save some juice with the drainage and the blank was not compromised in any way shape or form that I'm aware of but, I have been wrong before and won't be the last but this is what I got from my testings...!

To give a perspective on things, the vacuum chamber capacity is of 16 litres, I put the full size blanks up-right in the stainless steel pot (chamber) and I fit about 85 blanks. It takes the best part of 2 gallons to get it to lever however, and because I know, it doesn't leave much room for the foam when the pump is first turned and until it removes most of the air, I cover the blanks with the juice (1 1\2 gallons) let them soaked naturally for a few hours with the lid off. The juice level is now lower so I top up, leaving about 1" 1/4 over the top of the wood, this is actually the thickness of the round steel disk I use as a weight.

Putting the lid on and turning the pump on, you still have to "nurse" the air valve to control\stop the foam from coming too far up and get into the intake however, this will take only a small portion of the time that would normally take, if I hadn't soak well the wood before starting to pull the vacuum.

Anyway, are you having some fun, where you are at the moment..??? I hope that you do, it will be a lot of work to do, by the time you get back home, not that you needed to be reminded, huh...???:wink::biggrin:

Cheers
George

 

[Brian G]

For my purpose, the digital scale is for calculating loss on drying and being satisfied with a toaster oven getting the moisture down as low as possible. If we really wanted to get to 100% dry, then we'd be investing in a vacuum oven. In a previous vocation, I spent a lot of my day worrying about whether cellulosic material was 100% dry. We won't get there with a toaster oven, drying 3/4" thick (or more) ingots of wood. We can get close if we set the temperature to a shade above boiling and heat them long enough.

After studying my first effort, I think my fretting was an idle worry.

#1 and #2 are from a cherry branch a coworker wanted made into a pen.
#3, #4, and #5 are some spalted, worm-tunneled, curly soft maple from my wood pile.
#6, #7, and #8 are the same, but I attempted to dye them red. I managed to tint them nicely. :redface:
#9 and #10 are unknown driftwood that washed up on New Smyrna Beach, Florida. Wife and I took a vacation there back in January. I'm making memory pens from those.



Thanks again for the pointers, Curtis and George.

 

[steve worcester]

...
Well, in this specific case, what made the wood soak and maintain so much juice inside before curing was the "Silica" something that all Acacia species have but some more than others and the Golden Wattle is certainly on of the ones with plenty of silica. That same silica when expose to heat, expands considerably, squeezing all that juice out, that was soaked in excess anyway so, the juice that stayed in the wood was all of what could fit in within the wood cells, allowing still the wood to become nicely hardened by the process. They require some extra cleaning up but, a small price to pay for salvaging blanks that would be unworkable due to their softness.
...
Cheers
George

Well, actually, it is unlikely to be the silica, but could be some other chemical in the wood. I use pure silica in glass mold making and the amount of expansion at these temperatures (250f) is pretty minimal. It may be the wood wasn't all the way dry?

But bottle brush, when I lived in California, that was the hardest native wood I ever encountered when my dad asked me to cut the tree down with an ax.