bg
New Member
Posts: 9 
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Post by bg on Jul 2, 2016 14:58:43 GMT -5
Hello, I am fairly new to using Alumilite, and I am having some issues. I am painting pen tubes and then casting in Clear Alumilite and pressurizing to 55-60. After they are done, everything looks just about perfect except that at both ends of the tube, almost everyone of the tubes has large air bubbles. I cannot figure out why such large air bubbles are present on each end. They are large enough I have to try to fill them or I would not be able to use the blank. Thank you for your help, Greg Attachments:
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Post by mike on Jul 5, 2016 7:19:24 GMT -5
Air pressure takes a small bubble and makes it smaller. It will also take a big bubble and make it smaller but not necessarily small enough that it is too small for the human eye to see it. My suspicion is that there is a large amount of air inside the tube that you are battling. Perhaps it is stuck at the top/flat area of the tube. If there is a way to tilt the mold or somehow make sure you have completely filled the tube with resin prior to pressure casting, the big bubbles should go away.
Mike
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bg
New Member
Posts: 9
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Post by bg on Jul 6, 2016 18:14:48 GMT -5
Thank you Mike, I will give that a try.
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Post by fr0gman on Jun 4, 2018 16:56:27 GMT -5
Air pressure takes a small bubble and makes it smaller. It will also take a big bubble and make it smaller but not necessarily small enough that it is too small for the human eye to see it. My suspicion is that there is a large amount of air inside the tube that you are battling. Perhaps it is stuck at the top/flat area of the tube. If there is a way to tilt the mold or somehow make sure you have completely filled the tube with resin prior to pressure casting, the big bubbles should go away. Mike Mike, The tubes in tube-in castings do not get filled with resin. They are plugged with silicone plugs to prevent them from being filled with resin. |
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johnb
New Member
Posts: 4
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Post by johnb on Jul 6, 2018 15:16:46 GMT -5
most people who make pen blanks use solid wood/resin and drill it afterwards. If you are trying to "cap" the ends and then putting 60 on it you are probably leaking air. especially if it is only happening around the holes that are plugged. try inserting a solid core, not just a plug if you can. having large pockets of air inside ANY piece in a tank is a bad idea. good luck and stay safe!
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Post by NeilO on Nov 4, 2018 5:45:43 GMT -5
3/4 fill your tubes with sand before inserting them into the mould. The mould plus will take up the remainder of the air inside the tube. After it's cured and removed from the mould, the sand will just shake out.
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