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Deep bubbles
Posted: Sat Nov 14, 2009 11:27 am
by T3pipes
First. This briar was small and not too good, so I just used it to try out some things before I made one out of a plateau.
The problem is a large amount of small, deep, deep bubbles in the acrylic that can not be sanded out.
Are these caused by over heating? Over bending (the curve was much deeper at first)? Or, something else?
Thanks
Re: Deep bubbles
Posted: Mon Nov 16, 2009 12:58 pm
by akr
T3pipes,
Acrylic is a little more tricky to bend than vulcanite, and bubbles in the acrylic can be caused by overheating it. They are a pain to get rid of because they can go quite deep--so next time try going slower and using less heat.
Good luck.
Re: Deep bubbles
Posted: Wed Nov 18, 2009 12:11 pm
by Alan L
Yes, it looks like overheating to me too. Those acrylics with metallic flakes as part of the decoration tend to burn MUCH faster than straight acrylic. For that matter, I've found when using PME's "ice" acrylic (transparent with a white swirl) the white part will burn and blister before the transparent is hot enough to bend if I'm not extremely careful.

Re: Deep bubbles
Posted: Wed Nov 18, 2009 12:42 pm
by T3pipes
Thanks. Will be good to remember in the future, but luckily my plateaus finally came in and I was very pleased to see this
not going to be using much more than a mouth piece for this one.

Re: Deep bubbles
Posted: Sun Feb 21, 2010 8:00 pm
by Briarfox
I just finished a very nice bent dublin and after I hit the stem with white trip I noticed that there are small "sand pits" in the stem. I use ABS rod for my stems and have yet to have this problem. My guess is I overheated the stem. (It was a pain to bend). Any suggestions for getting this out? I've been sanding on it without luck. The stem has such a nice insert that i cant bare to toss it.
Re: Deep bubbles
Posted: Sun Feb 21, 2010 10:51 pm
by KurtHuhn
Sand them out. Start with 220 or 320 and go up from there.
Re: Deep bubbles
Posted: Mon Feb 22, 2010 1:04 pm
by Briarfox
Re: Deep bubbles
Posted: Mon Feb 22, 2010 1:23 pm
by KurtHuhn
I'm not all that familiar with ABS. However it certainly looks like the material got overheated. The real question is how deep the bubbles go. You might be effed here, and you might have to start over. You could use a 180-grit nail file to quickly cut into the surface and see how far the bubbles go.
Personally, knowing how ebonite reacts under similar circumstances, I'd just start over. Call it a lesson learned and keep it in mind for the future.
Re: Deep bubbles
Posted: Mon Feb 22, 2010 2:16 pm
by T3pipes
It looks like you can already see the airway in these pictures. And with that much surface area bubbled on and around a curve, odds are it's deep. Most likely better to just start over. At least you can mate the tenon ends of this one and the new stem together to speed up the shaping and sizing of the new one with less risk of sanding the shank.
Re: Deep bubbles
Posted: Mon Feb 22, 2010 2:27 pm
by Briarfox
Thats not the airway, it's just the lighting. Another stem it is!