Thread: New Tube Stabilising tank

Thanks for that Neil, what sort of vacuum pump are you using and how much vacuum does it pull?
I'm looking at getting one, as I had to do 60 plates recently, and went through 20 +ml of CA. Not good for the sinuses. Thoughts were if I got a vacuum pump, I could put the blanks in epoxy and seal the cracks, worm holes etc. Would Cactus be better or not for filling gaps or worm holes?
Regards
Kryn

Originally Posted by KBs PensNmore

Thanks for that Neil, what sort of vacuum pump are you using and how much vacuum does it pull?
I'm looking at getting one, as I had to do 60 plates recently, and went through 20 +ml of CA. Not good for the sinuses. Thoughts were if I got a vacuum pump, I could put the blanks in epoxy and seal the cracks, worm holes etc. Would Cactus be better or not for filling gaps or worm holes?
Regards
Kryn

Hi Kryn, I've done a bit with Cactus Juice. It's not good for filling gaps and holes as it's very viscous, which makes is brilliant for stabilizing but not that good for bigger gaps.

Casting resin or epoxy would be the better option in my opinion.

Cheers,

Matt


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Thanks for the reply Mat, I thought so, but had to ask.
Regards
Kryn

Originally Posted by KBs PensNmore

Thanks for that Neil, what sort of vacuum pump are you using and how much vacuum does it pull?

I bought mine off Ebay, not one of the super cheapies, but a cheap decent one. See the stabilising vid ~1min https://www.youtube.com/watch?v=7Kftchv8gkc As I live near the coast, and it is a decent pump, I basically pull full vacuum.

Originally Posted by KBs PensNmore

Thoughts were if I got a vacuum pump, I could put the blanks in epoxy and seal the cracks, worm holes etc. Would Cactus be better or not for filling gaps or worm holes?
Regards
Kryn

As others have said, Cactus Juice is no good for filling, it is for filling the micro holes between the cells only. It is mainly used for rotten or very soft wood, banksia pods, grass tree, bone etc.

Using vacuum for casting can be done but you must be careful. Vacuum pulls the air out of you resin, but also out of your wood, so bubbles can often be still coming out after 2 hours! You can imagine what your resin will look like if it goes off before the bubbles are removed. Also, under vacuum you are at an equivalent higher temperature, not sure of the exact relationship but if it is 25C outside it will be ~30C or more in your vacuum tank (ie so resins go off quicker).

Filling gaps and worm holes etc is best done under pressure, as much as your tank can take, but remember resin can only get to the holes etc that are open to the surface (ie a void inside a blank will not be filled).

Just as a note too polyester resin will not stick to Cactus Juice, so if you need to stabilise and cast with poly, do your casting first (the Cactus Juice afterwards also heaps the poly stick). If using casting epoxy this is not an issue.

You could do both. use your vaccum to cast in cactus juice to stabilize the wood. Then go back and cast it in your resin. Under pressure would probably be better, as it will force the resin into smaller spaces.

Darrin I think it has to be done the other way around and by that I mean you have to cast the blanks before you can stablize them because the resin does not stick very well to the cactus juice but the cactus juice will stick to the resin. I realize that this may sound a bit strange but if you check with Neil (Dai sensai) he may be able to confirm or deny this,

Cheers Ian

PS I always cast then stabelize

Originally Posted by dai sensei

Just as a note too polyester resin will not stick to Cactus Juice, so if you need to stabilise and cast with poly, do your casting first (the Cactus Juice afterwards also heaps the poly stick). If using casting epoxy this is not an issue.

I am curious how this works. I am planning on trying the combination of casting and stabilizing but thought the casting process would seal the timber and prevent the air escaping and resin impregnating the timber.

Some wisdom from someone that knows better would be greatly appreciated.

Matt


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Originally Posted by mattm82

I am curious how this works. I am planning on trying the combination of casting and stabilizing but thought the casting process would seal the timber and prevent the air escaping and resin impregnating the timber.

Some wisdom from someone that knows better would be greatly appreciated.

Matt


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In that case I would also like to know from someone who may be a lot wiser than me as I don't do much casting or stabelizing

Cheers Ian

Originally Posted by mattm82

I ... thought the casting process would seal the timber and prevent the air escaping and resin impregnating the timber...

If you timber is completely immersed in the resin, yes it will be sealed but not stabilised, but then you can sand the cast to expose some surfaces of the timber (assuming more timber than resin). My castings usually don't involve immersing the timber, more placing timber against the mold (with hot melt glue), then placing resin to fill gaps.

Casting under pressure generally doesn't penetrate the timber, it only fills the exposed voids (ie not internal voids), unless you are using extreme pressures. I only achieved it once on a rotten piece of wood with voids using warmed poly resin in Robutacion's (George in SA) pot at 100psi.

Originally Posted by dai sensei

If you timber is completely immersed in the resin, yes it will be sealed but not stabilised, but then you can sand the cast to expose some surfaces of the timber (assuming more timber than resin). My castings usually don't involve immersing the timber, more placing timber against the mold (with hot melt glue), then placing resin to fill gaps.

Casting under pressure generally doesn't penetrate the timber, it only fills the exposed voids (ie not internal voids), unless you are using extreme pressures. I only achieved it once on a rotten piece of wood with voids using warmed poly resin in Robutacion's (George in SA) pot at 100psi.

Well that makes sense, I was thinking of immersing it. Righto, just need to build a pressure pot (Ueee).

Sorted with the stabilizing setup.

Thanks for the info.

Matt


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Matt, a lot of people use this type of pressure pot for casting. Supercheap have them about half price at certain times of the year, or you can look for a secondhand one.

Originally Posted by Treecycle

Matt, a lot of people use this type of pressure pot for casting. Supercheap have them about half price at certain times of the year, or you can look for a secondhand one.

Thanks Treecycle,

I'll have to keep an eye out $150 is very reasonable.

Matt


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Usually on special they are just under $100

It's exactly as Neil has said PR doesn't penetrate the fibres so once it's cast sand back till you expose timber and then use cactus juice to penetrate and harden the blank .. Also after you vacuum to remove all the air and them release , make sure you let the blanks sit in the juice for an extra 20-30 mins to ensure 100% saturation