Stabilizing plus Casting?

[Bill Arnold]

The basis for my question is some dogwood trunk sections I let sit on a firewood stand long enough that it has a bunch of spalting. In some areas, voids have developed. Overall, it has the look of worthless wood. But, I'm thinking it's a good candidate for making some pen or bottle stopper blanks.

I've been studying posts on stabilizing and on casting. I have an HF pot that I'm converting to a vacuum/pressure chamber. Since casting resin is thicker than stabilizing fluid and begins to set up in the pot, would it be appropriate to stabilize the wood first, then cast it to fill the voids?

 

[Kenny Durrant]

I saw a video from Curtis on his website Turn Tex Woodworks or on You Tube and that's what he did. he used his Cactus Juice to stabilize then cast using Alumilite.

 

[robutacion]

The basis for my question is some dogwood trunk sections I let sit on a firewood stand long enough that it has a bunch of spalting. In some areas, voids have developed. Overall, it has the look of worthless wood. But, I'm thinking it's a good candidate for making some pen or bottle stopper blanks.

I've been studying posts on stabilizing and on casting. I have an HF pot that I'm converting to a vacuum/pressure chamber. Since casting resin is thicker than stabilizing fluid and begins to set up in the pot, would it be appropriate to stabilize the wood first, then cast it to fill the voids?

Well, stabilizing the wood with the proper stabilizing resins such as the Cactus Juice, is most certainly recommended for your wood as you have describe it. The casting with casting resin is the next step and the one where all the holes, voids, etc., are filled with either Polyester or Alumilite type resins.

If you are modifying you pressure pot to do both jobs, for casting, the blanks will be inside of molds so you don't need any lining of the pot inner however, and for stabilizing, I would suggest that you find a plastic bucket/containers that fits loosely in your pressure pot base and tall enough to not compromise the lid sealing properly, this way, the stabilizing solution is not in contact to the pot inner surfaces so, is always ready for casting when you want/need to...!

Good luck,:wink::biggrin:

Cheers
George

 

[plantman]

Bill; I agree with Kenny on checking out the videos that Curtis has put out there. Curtis's tip on adding the plastic bucket will save you a ton of time in cleanup. I think the general rule of thumb is stabilize with vacuum, cast with pressure. Vacuum will draw the air out of the wood pores and allow the stabliizing fluids to replace it. Pressure will force the PR into any voids that are left and give you a solid blank to work with. When I have realy punky wood to work with, I use a dental pick to remove any realy rotten or loose material before I stabilize. If the dents, cracks, or holes are large enough, I will fill with some contrasting powers or saw dust and add some thin CA to harden. Now you can eather turn your blank to size or cast in PR and turn. If you have worthless wood or wood in pieces, I would cast first, turn to size, fill any voids that may show up, sand smooth, and finish. Everyboby has there own way of doing things. It's best to look at all the options you can and pick one to suite you and the equipment you have to work with. Also check out the library on this site for suggestion and tips. Jim S

 

[Jim Burr]

The one reason no one mentioned yet it that stabilizing stops the PR color from bleeding into the wood. There are a couple of tricks that will make your life easier...I'll PM you on FW w/ a few ideas.

 

[Bill Arnold]

Thanks for the information, everyone. I was pretty sure I was interpreting the processes correctly, but it's always safe to get input from the real world.

As to using an inner container for stabilizing in my pot, I have a collection of 2lb plastic coffee containers that should work pretty good.

It'll be a couple of weeks before I get to try the process. I'm waiting for delivery of a couple of items for my pot conversion I had to order online. Also, I haven't ordered any stabilizing liquid or casting resin yet - that's next on the agenda.

 

[Monty]

The only problem with using a HF pressure pot for vacuum stabilization with CJ is you will not be able to see the bubbles coming out of the blanks and thus you will not know when all the air is out of them,

 

[sbell111]

I agree with Monty. To combat the issue of not being able to see what's going on, you will want to make sure that there is plenty of headspace in your coffee container so the goo doesn't overflow. Also, you'll want to keep them under vacuum far longer than you will think is necessary just to make sure that you got out as much air as you could.

 

[Bill Arnold]

Manny & Steve:

Thanks for your input. From what I've read and viewed, I figured I'd bleed the vacuum a little at first so it would take 10 minutes to build to maximum due to the initial bubbling. If I leave the blanks under vacuum for an hour and a half, that should get them where they need to be, unless I add some larger blanks to the run. At this point, I'll just be happy to get all of my stuff together so I can have a go at the process.

 

[flash691]

Manny & Steve:

Thanks for your input. From what I've read and viewed, I figured I'd bleed the vacuum a little at first so it would take 10 minutes to build to maximum due to the initial bubbling. If I leave the blanks under vacuum for an hour and a half, that should get them where they need to be, unless I add some larger blanks to the run. At this point, I'll just be happy to get all of my stuff together so I can have a go at the process.

Hi Bill, I just happened upon your post in here while searching for some suggestions on casting or stabilizing first. Your name actually caught my attention because we have a Bill Arnold in my woodturning club here in Tallahassee. We have members that come all the way from Albany, Bainbridge, and Moultrie, so if you're interested here's our website North Florida Woodturners > Home with info on our meetings. Anyway, enough plugging the club. I've done some stabilizing and casting over the last year or two and would be happy to trade tips.

Robbie

 

[jlnel]

I am just about to start the same thing. my question is, can you cast first to get the color into all the nooks and crannies then stabilize? would the stabilizing fluid fill some of the small voids that the casting could fill?? just wondering, thanks.

 

[Tim'sTurnings]

Stabilizing will not fill any voids or cracks. It is only for hardening/stabilizing the wood to make it harder and stay together. In my experience.
Tim.

 

[MesquiteMan]

Bill,

An hour and a half most likely is not long enough. There are so many variables that it is hard to predict how long it will need. Sometimes I am running my vac pump for 4-5 hours until the bubbles stop. Sometimes I only need a couple of hours. Very seldom will 1.5 hours do it. I would suggest considering making an acrylic lid for your pot if you are intent on using it. That way you can see what is going on.

As for the other questions...it looks like everyone else has them well covered!

Please let me know if you have any other questions I can help answer.

 

[flash691]

Please let me know if you have any other questions I can help answer.

How do I remove the Cactus Juice that sets up in the cracks and crevasses before casting? Picture attached of one I stabilized today.


Thanks,

Robbie

 

[robutacion]

Please let me know if you have any other questions I can help answer.

How do I remove the Cactus Juice that sets up in the cracks and crevasses before casting? Picture attached of one I stabilized today.


Thanks,

Robbie

Contrary to what someone said before here, stabilizing can fill lots of small cracks and when you want to cast that piece/blank, as in the case here, the bleed resin is a problem to get rid-of in those cracks but also in surfaces where is a lot of "spikes" as in burl caps and other flaw surfaces where the dry excess cactus Juice dries/cures on.

Is not always possible to clean those areas without causing some damage on the wood and the time it takes is just ridiculous so, how can you avoid the excess resin to become a problem...???

Firstly, you have to understand that, only some of the Juice inside the wood will stay there, the rest (excess) is repelled/boiled out of the wood and will be captured/retained if the wood was wrapped with foil so, you need to make sure, your oven as a "overflow" tray or you have to make one up to keep the juice from dropping on the oven's bottom heating elements.

That should be avoided at all costs, it may not turn into flame but, it will smoke ferociously and when fully hardened, you will have a hard time cleaning it without destroying the heating elements...!

The principal is simple, allow the excess resin to flow away from the wood/blank, that normally resolves the issue but, if you piece has lots of crevasses, make sure they are pointed downwards so, instead of trapping the excess juice and harden in there, it will run off and keep those crevasses clear for the casting resin to fill...!

I hope this helps you...!

PS: I only recommend this "unwrapped process" in situations explained above, for any normal wood stabilizing, I recommend to have the wood wrapped with the foil paper, there are some advantages with that, firstly the excess juice is contained and therefore does't mess out inside your oven, the wood won't stick to other pieces, the wood will get a slight better results, the heat is maintained within the wrapping in a much more controlled manner, any of the juice that may be expelled at first, when the wood get hot, will have a chance to penetrate the wood again as the wood porous open due to the heat, if it runs off the wood in the unwrapped situation, that juice can no longer return to the blank (unless Curtis come out with a way to make the juice to "walk" back up...!:wink::biggrin

Cheers
George

 

[flash691]

Thanks for the tips George. I'll give that a try.

Robbie

 

[rblakemore]

Still confused

OK, I came across this thread a few days ago (I have read thru this several times) looking to post some questions on casting and stabilizing; but, this thread has introduced questions that I did not know to ask.

I thought that casting was to create a solid blank the shape of a mold and could have some material in it, such as a piece of wood. And the casting resin was essentially forced into the cells, nooks, voids, and crannies of the material by relatively high pressure.

Stabilizing uses vacuum to remove the air in a material (like a piece of soft or spalted wood). Stabilizing does not necessarily create a "block" but leaves the material in basically its original shape.

I have not heard yet about stabilizing a piece of material and then casting it. Why?? I do not understand, why stabilize a piece if it will be cast?? Casting has color in it anyway, so why is there an issue of color bleeding from the casting resin to the material? If the stabilizing resin is drained off to create void for casting, why was the stabilizing done?? And won't the hardened stabilizing resin prevent the casting resin from penetrating the material?

 

[George Watkins]

I think i can anwser a few of your questions:

If i have a stunning piece of natural edge burr buts its gone too soft/punky then i need to stabilise it so that it is hard enough to turn once its cast with the resin, if i dont stabilise it the colour from the casting resin will seep into the wood and when its turning (if the wood doesnt fly apart) then the soft wood will break away from the resin or be too soft and create a problem with an uneven surface.

a good example of this is the burr horse chestnut i had to stabalise with cactus juice before i could cast the blanks to make boxes like this one



the burr was very highly figured but had been outside for several years and had gone like balsa wood, an average piece increased in weight by 250% by being stabilised.

it was so soft in places that when i went to blow the dust away with my compressor after cutting it... it blew chunks out of the wood!!

 

[rblakemore]

George, that is a really nice piece, I like the Burr Horse Chestnut a lot.

Wow, well, I had not expected that. I was under the impression that a stabilized piece was strong enough for turning. I take it that a "regular" shaped blank that is soft is ok after stabilizing. I have some fairly firm spalted pecan that I intend to start practicing with today or tomorrow. But, a really soft, irregular piece, that is going to be cast anyway should be stabilized first??

 

[George Watkins]

thank you

there is degree's of soft, and most soft woods will turn just fine with the correct technique and sharp tools.

stabilising really comes into its own with wood that has gone too far, whether that's spalted or just been left out in the weather and its began to rot.

a potential problem with a hybrid style blank like I make is that you don't want one material to be vastly different in density to the other or as you sand it you will sand away the softer material quicker than the hard and you will have an uneven join. This is similar to working with a wood with a really wide growth ring like certain cedar's or wellingtonia if you sand to aggressively or with a very small pad you will sand away the summer growth faster than the winter and have an uneven surface. That is why I stabilised this horse chestnut but I don't stabilise ozzy burrs as they are hard enough to begin with and probably wouldn't take up any stabilising resin anyway.

hope this helps

 

[rblakemore]

Thanks for the last comment; also, I apologize to all, I have usurped this thread; but, thanks again.
I had not really considered that after casting or stabilizing there would be an issue of different degrees of "softness", I will definitely keep that in mind.