heat shrink bags

[healeydays]

Folks,

A question came up on another site that I thought I would ask over here.

Someone would like to fill the large voids in a vase that had been turned with a colored resin. The issue is how to do a pour and get the voids filled.

My suggestion was an air bladder for the inside and a heat shrink bag on the outside holding it all together. You could use release agent on the bladder and the outside bag will be a sacrificial bag. Heat shrink the outside bag to the piece, then pour your resin inside and pressurize the bladder.

Does anyone know if there is a heat shrink bag material that will hold up to pressure and resin to make this work?

Mike B

 

[RMayoIII]

I would try using plastic shrink wrap that is used to cover boats. You can wrap it around and "weld" it be back to itself with a torch. It may even peel off nicely once the resin is cured.

 

[low_48]

Won't the heat shrink, shrink into the void leaving a flat spot?

 

[snyiper]

I would think the reaction of the pour would heat and shrink the bag.

 

[healeydays]

I would think the reaction of the pour would heat and shrink the bag.

Usually you need more heat for the quality thicker bags than what would be generated from the resin.

As for the flat spots, I hadn't thought of that and that might be an issue unless you took the shrinkwrap to the point of not being overly tight and if there is a little leakage on the outside, so be it as you could cut it away on a lathe.

 

[RMayoIII]

I'm not sure if the vase is already at it's final size so this might not work but if you were to rough turn then the flat spots could be made round once it is final turned. I also don't think the resin would heat up enough to shrink the wrap further.