Pressure or suction

[Haynie]

Do I need vacuum or pressure to cast items to remove air bubbles?

 

[lorbay]

Pressure.

Lin.

 

[G1Pens]

I thought it was vacuum to remove bubbles and prestture for things like worthless wood..

 

[BRobbins629]

Both do similar things and one may work better depending on what you are trying to do. If the bubbles are caused by air dissolved in the resin, either can work. Vacuum will cause the air to come out of solution and pressure will keep it in. If the bubbles are caused by other things such as resin not wetting the surface of an object, neither will work.

 

[Phunky_2003]

I dont use vacuum for any type of casting. For Silmar 41 I do not use pressure for casting. I use Silmar for colored casts and label type casting (label type includes anything attached to tubes prior to casting). I use pressure for any type of Alumilite casting.

 

[Haynie]

I am wanting to cast clear resin with like feathers or bits and pieces from around the boat shop. Maybe some fishing flies. I have read the casting feathers article and am looking for people's experiences. I have the resin, mold making material and am ready to play.

 

[leehljp]

In general, Vacuum is used for stabilizing wood. Often, after a period of 30 minutes to an hour, pressure can be added to help increase the penetration. But some people let the vac hold for several hours to overnight and do not use pressure. Vac is more effective with thinner viscosity stabilizing material.

Pressure is used more for casting. Vacuum on casting will often increase the amount of bubbles, so pressure minimizes it.
Pressure is more effective on thicker viscosity casting material.

I have not used either for a couple of years due to a move from overseas. Lots of things have changed in that time but this is the way it was back then.

 

[arioux]

I invite you to go thru this thread (read thru the whole thread), you will find great information and very well xplained by Curtis (aka mesquiteman). You should find all your answers in there.

http://www.penturners.org/forum/f43/can-you-stabilize-blanks-without-vacuum-test-results-91355/

 

[Haynie]

I am not stabilizing anything. I am planning to:
1-Paint or wrap a tube
2-CA or epoxy foreign material onto the brass tube
3-Cast the conglomeration in PR to make a barrel

There will be no wood involved.

 

[leehljp]

I am not stabilizing anything. I am planning to:
1-Paint or wrap a tube
2-CA or epoxy foreign material onto the brass tube
3-Cast the conglomeration in PR to make a barrel

There will be no wood involved.

This information is much more helpful in giving the answers you need. Since "casting PR" was not included in the original post, we only could give general references.

PR - use pressure . . . or I think Curtis or maybe someone else, on some occasions - uses/casts in ultrasonic cleaners to get the bubbles out instead of pressure. So, Pressure or ultrasonic cleaners. Do a search here for ultrasonic cleaners and see what is available and how to do it.