Pressure vs Vaccum

[dbarrash]

I have molds and resin on order......can't wait to try some ideas I am dreaming up.

I understand the concept of Vacuum for "Juice" and stabilization. But in terms of casting resin (Alumilite) I am confused in Pressure vs Vacuum.

Which process is preferred. On some videos it looks like air vs vacuum. Do both process types remove air bubbles. Thanks in advance. Dave

 

[Ed McDonnell]

I'll offer you my opinion (based on my experience, which can easily vary from other members):

Pressure will make bubbles smaller. They won't go away, but they will hopefully not be visible to the naked eye in the cured resin.

Vacuum can completely eliminate bubbles if done appropriately for the situation.

Pressure can be applied almost immediately. Vacuum takes time. With a quick resin like alumilite, you will find it a challenge to get the resin mixed, apply a vacuum and have enough time for the bubbles to clear before the resin sets.

I use vacuum exclusively on PR with complete success. Every attempt to use vacuum on alumilite has ended in failure for me. I would either use pressure or nothing.

That's my experience anyway.

Ed

 

[longbeard]

JMO and my experience, i use pressure (around 50lbs ) for PR and alumilite.
As Ed said, probably not enough time to mix the alumilite and then vacuum.

 

[dbarrash]

Also in the beginning I will be using Alumilite Clear as my resin if that matters. Dave

 

[Justturnin]

If you are going to Vacuum Alumilite do it before you mix the parts together and put it in a container about 3x's larger than your pour because it will expand like mad. Once you degas the resin parts then mix them together slowly. I use a lot of Alumilite and have never done this and never had an issue. I only use pressure and it woks great, but be fast and watch Curtis' (Mesquiteman) videos on it.

 

[resinman]

I use pressure and Alumilite clear with dyes and powders. Never found an air bubble yet.
One misconception about alumilite Clear is you don't have a lot of time. You have 6 to 7 minutes. When you keep working at it steadily, it is easy.
First, mix your dyes and/or powders in the "A" side. I've done this and gone out to lunch. It is when you add the "B" side when the clock starts.
Mix for 2 minutes and pour and put in the pressure pot. (add another 2 minutes of time for this.)
That makes a total of 4 minutes.
No air bubbles! Once I figured out that I didn't have to go so fast, I have not spilled anymore either.
Although I am waiting for the day when I trip or bump my elbow on something I left in the way.
Thanks, Gary

 

[sbell111]

One misconception about alumilite Clear is you don't have a lot of time. You have 6 to 7 minutes. When you keep working at it steadily, it is easy.
First, mix your dyes and/or powders in the "A" side. I've done this and gone out to lunch. It is when you add the "B" side when the clock starts.
Mix for 2 minutes and pour and put in the pressure pot. (add another 2 minutes of time for this.)
That makes a total of 4 minutes.
No air bubbles! Once I figured out that I didn't have to go so fast, I have not spilled anymore either.
Although I am waiting for the day when I trip or bump my elbow on something I left in the way.
Thanks, Gary

Where time gets tricky with alumilite is when you are using multiple colors. You have to wait until the perfect point to pour and then swirl the colors and still get it under pressure before it gels. Many people have the process worked out and are able to do this with amazing results. Still, it's a handle.