Weld On spotting

[Steve Clarkson]

I used weld on to join two pieces of clear acrylic and there is spotting all over the piece.......is there anyway to fix this? Either by annealing or flame polishing maybe?

[Gary Hair]

Those are bubbles - the only way I have eliminated them is to flood more of the weld on into the joint before you put them together. Another possibility is to use the thicker weld on instead.

[Clark Pace]

I used weld on to join two pieces of clear acrylic and there is spotting all over the piece.......is there anyway to fix this? Either by annealing or flame polishing maybe?

What do you mean by spots? Do you mean a drop of weldon splashed on a parts of the acrylic you didn't want it to go? Or did you mean bubbles.

1. drop of splashed weldon 3/4. Just let it dry, don't try and remove the excess. There will be a mar, it will look better then trying to brush the excess off.

2. Bubbles. Bubbles in acrylic are common, and usually only experienced acrylic fabricators get it right most of the time. It's kind of a tightly held secret how to reduces them. I searched, the internet for tips, but usually have found very little. The thicker the acrylic the harder it is to have the acrylic bubble free. Part of the key is a perfect fit. So a flat to flat surface will yield the best results. And usually a laser cut won't do it as it will craze(crack), and or not be flat enough.

I've been fabricating acrylic for years, and still don't have it down pat. I know a guy who has been doing acrylic fabrication, and he is really good. Taught me some stuff, and I'm not as good as he is.

But I have been doing it for a while so if you have questions I may be able to help further.

[Mike Null]

If they are bubbles then, to Gary's point, you have starved the joint. You must use enough solvent to allow it to flow. Once you have joined the pieces lay some more solvent around the base or edge of the area you have joined.

High humidity will also negatively affect gluing acrylic.

[Steve Clarkson]

Thanks for the tips!