Pressure Pot VS. Ultrasonic for getting the bubbles out

[doberman]

I know some are using an Ultrasonic cleaner instead of a pressure pot (Don, AKA It's Virgil) comes to mind for getting the bubbles out of casting's. I have a very nice and large commercial ultrasonic cleaner and would like to try the process - how are you (those that are) going about it? Wil it work with embedding things like pinecones and such??


Thanks

Dan the shredder man

 

[td]

I'll leave it to Don to answer for himself. I use vibration (ultrasonic) before I put it into the pressure pot. Before I got my pot I used vibration only with fairly good results. After adding the pressure pot I got great results.

With stuff like pinecones you really need the pressure to squeeze PR towards the middle of the cones. IMHO, vibration will not be enough, but it could help.

Terry

 

[its_virgil]

I actually use both. I place the (uncatalyzed)resin in jar and then the jar goes into the water bath in the cleaner. I also use hot tap water and use the heater in the cleaner. I run the cleaner for 20 or 20 minutes...which may be overkill...while I get the tubes ready to cast.

I place the molds in the pressure pot at 30 psi. I only do snake skins and computer labels but the combo works great for me. But, the process should work for other castings also.

Some materials may need more pressure. I know Serge makes coffee bean blanks and uses about 60psi for them. I once did that much pressure on my snake skins but have backed off to 30psi.

Do a good turn daily!
Don

I know some are using an Ultrasonic cleaner instaed of a pressure pot (Don AKA It's Virgil) comes to mind for getting the bubbles out of casting's. I have a very nice and large commercial ultrasonic cleaner and would like to try the process - how are you (thaose that are) going about it? Wil it work with embedding things like pinecones and such??


Thanks

Dan the shredder man

 

[doberman]

OK - using both - thanks for the reply's I will try BOTH and see what happens!!


Dan the shredder man

 

[Glass Scratcher]

I finally unboxed my ultrasonic recently and have to say, maybe anecdotally, I think it helps get colors and powders mixed in the resin better. Especially powders, even though I thought I mixed the pearl-ex in completely with the drill, and let it sit, when I put it in the ultrasonic, powder bubbles rose and popped on the surface.

 

[BRobbins629]

There are 2 type of bubbles/voids that you can get when casting. The first is from air in solution. These can be minimized by either degassing in vacuum or even better in an ultrasonic bath (put 1/2" of water and put small container of resin in water), or by a pressure pot. The first takes the air out of solution, and the pressure pot keeps the air in solution - just like a soda bottle. 20 psi is more than enough.

The other type of bubble/void comes from the resin not wetting the surface or object being casted. Vacuum, ultrasonics, pressure will do nothing for this. The only solution is to clean the part or try painting the part with resin before casting and see if any beads up. If it does, you need some kind of surface preparation/cleaning. The analogy is water beading up on a waxed surface.

 

[Druid]

I just started getting into casting and made a pressure chamber out of the HF paint pot. Reading about using an ultrasonic bath for mixing intrigues me. I already have a Branson B200 that I use to clean jewelry and fountain pen nibs. If I read this thread correctly, the ultrasonic bath can be used to mix uncatalyzed resin and it does a better job than hand or drill mixing?

How long do you leave the uncatalyzed resin in the bath to get a good mix and what do you use as a container that wont leak and is re-usable?

 

[its_virgil]

Listen to what Bruce has to say. He helped me immensely when I was having problems with my snake skins. Once I understood that the pressure pot didn't actually shrink the air bubbles as I once thought then the use of the pressure pot made much more sense. I now understand why just 20psi works as well as 60psi. Also, the analogy of water beading on a waxed surface helped. I now paint non-catalyzed resin onto the snake skins and let them set while zapping the resin in the ultrasonic cleaner. Bruce also introduced me to using ultrasonics. I must say thanks to Bruce for his help when I was really discouraged about snake casting. I was going south quickly and Bruce headed my back north. Thanks Bruce!
Do a good turn daily!
Don

There are 2 type of bubbles/voids that you can get when casting. The first is from air in solution. These can be minimized by either degassing in vacuum or even better in an ultrasonic bath (put 1/2" of water and put small container of resin in water), or by a pressure pot. The first takes the air out of solution, and the pressure pot keeps the air in solution - just like a soda bottle. 20 psi is more than enough.

The other type of bubble/void comes from the resin not wetting the surface or object being casted. Vacuum, ultrasonics, pressure will do nothing for this. The only solution is to clean the part or try painting the part with resin before casting and see if any beads up. If it does, you need some kind of surface preparation/cleaning. The analogy is water beading up on a waxed surface.