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Post by nashranch on Mar 13, 2018 22:40:23 GMT -5
What is best to use pressure or vacuum and why? I have the ability to do either
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Post by carol - Alumilite Corp on Mar 14, 2018 14:33:48 GMT -5
Nashranch,
For what application? Typically the turners use primarily pressure, there are some who do both degas by vacuum first and then put it under pressure. Why most use just pressure a multitude of reasons I have heard but I think the primary one... it is considered to be the best way to ensure your castings are bubble free by novices and professionals alike. In the pouring process after you vacuum there is a chance of introducing a bubble in your pour that may not gravitate to the surface and remains lodged in the casting as it is curing. Pressure casting typically eliminates that issue from happening, as long as the silicone mold is degassed too prior to using it in a pressure pot.
Regards,
Carol
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Post by johnny bee on May 12, 2018 15:45:45 GMT -5
I think another consideration is for what size project? if you are turning blanks then of course they'll fit both, and at that point its just an extra measure of protection from bubbles. But if you are casting a larger, oddly shaped project (maybe a long rectangular table top, filling in cracks) you obviously cant fit that into a pressure tank. So the simple answer is, you can easily put a cup of resin into a vacuum pot, but you cant fit a table top into a pressure pot. Pressure pot is for curing and vacuum is before pouring.
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Post by carol - Alumilite Corp on May 16, 2018 9:46:54 GMT -5
Johnny Bee you are correct, thank you for your input.
Warmest Regards,
Carol
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Post by catspraise on Feb 16, 2019 13:05:32 GMT -5
I vacuum part B before mixing with part A then vacuum again after mixing A into B, pour and finally place in the pressure pot.
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Post by Melu on Feb 24, 2019 3:40:01 GMT -5
Catspraise, how do you achieve all off that in less than 7 minutes? I´m having a lot of trouble with bubbles cause my pieces can't fit in a pressure pot.
I´m new with Aluminite Clear, It is normal to have part B with lots of Lumps?
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Post by notoes on Feb 25, 2019 18:53:45 GMT -5
NOT AT ALL! You should NOT have lumps in either side. Side A being a little thick is one thing but side B with lumps is not good at all. Give Alumilite a call and let them know you have lumps in side B, they'll make it right for you. I've had RC-3 that had a bit of the "crust-ies" in side B that had been opened a lot in humid environment but I've never seen it in the Clear.
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Post by catspraise on Mar 7, 2019 8:45:22 GMT -5
Catspraise, how do you achieve all off that in less than 7 minutes? I´m having a lot of trouble with bubbles cause my pieces can't fit in a pressure pot. I´m new with Aluminite Clear, It is normal to have part B with lots of Lumps? When you vacuum BEFORE mixing, the parts do not start to cure yet. So you have time to do it. I start the timer once I pour the A into the B. With the shorter cure time products, I wouldn't even bother unless I could pressure cast, but that's just me. Also, for larger pieces, I use my pressure pot mounted on it's side. I hope this helps.
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abtex
New Member
Posts: 3
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Post by abtex on Mar 17, 2019 12:58:34 GMT -5
If you’re not in a hurry to finish the project the same day, you might consider the Amazing Clear Cast. It has about a 45 minute work time and an 18-24 hour demold time. I use it exclusively and have had great luck with it from just a few ounces upto half a gallon for the castings I turn on the lathe. For small projects, it’s a lot more forgiving with the extended work time, and when I heat parts A&B prior to mixing slowly, the thinner mix allows bubbles to rise easier, then I just pop them quickly every ten minutes or so with a torch. Often I’ll use the pressure pot, but sometimes if things work out perfectly, I don’t even need to do that.
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