Signs of material expiring

Hi,

Is bubbling a sign that a material is expiring?

Lately I’m noticing more bubbling inside our Form 1+ Gray prints, especially along straight edges, and I was wondering if this indicated that the resin was about to go bad. If so, I"m not surprised since this bottle was purchased quite some time ago. (I’ll need to check the exact date.)

But if not, I was a little concern that bubbling meant something more serious.

Thanks in advance for any helpful info.

picture? always helpful.

I’ll try to get a example up later but really it looks there are small air pockets or bubbles just under the surface or even breaking the surface. It’s not all over the part, just under certain edges.

My guess is that the material is starting to break down and the heat from the laser is creating vapors and trapping it as it cures the resin. That’s a totally unscientific guess of course. :slight_smile:

I’ll order some new material before I finish this off and see if that solves the problem.

We printed a couple of large parts today and they look fine.

Based on what I’ve been reading elsewhere in the forums, I think the problem I was seeing with the earlier prints had to do with the ‘thickness’ of the parts. They were mostly blocky shapes and completely solid. I wonder if those parts would have printed better if I had hollowed them out and put a drain hole in them.

Anyway, even though the resin I’m using will be a year old this month, I no longer think this problem has to do with the material’s shelf life expiring.

Are you getting bubbles in the actual print or just the liquid resin?

It’s in the print.

Here’s an example: I printed a Nerf gun stock adapter for a friend last week and one part printed fine but the other had a void just under one corner edge. The void was visible as a small hole after printing and it became worse when I sanded it slightly–almost followed the entire length of the corner (maybe an inch.) The orientations of the two parts were different so I rotated the ‘bad’ piece to match orientation of the one that printed without the void, but I got a void along a different edge. The edge is just a 90-degree corner–it’s a very ‘boxy’ part. The part was printed at an angle and not flat-on, as typically recommended. The duplicate part was much better then the first one though so we filled the hole and went with it.

We printed a few things successfully (no voids) after that one so I thought maybe it everything was okay, but over the weekend we had another part that had a void in the middle of a flat plane surface, breaking through both sides. The plane wasn’t especially thin and it was printed at an angle as recommended. Supports were auto-generated in PreForm and there were no supports in that region but it really didn’t need supports there.

I would post a pic except my daughter might have already assembled the model. Will check tonight and post a pic if possible.

My feeling is that this was random though and probably won’t happen if I printed the same part again.

Okay, now I’m curious. I had saved the form file so I’ll print it again tonight. Will let know if the void appears again.

The only time I’ve had holes in a print was when there was a spot of something on the mirror or glass which blocks the laser. Since you have a Form1/1+ it is very susceptible to dust, try to clean the big mirror first and make sure the bottom of the tray is also clean. Don’t use air to blow the dust off–that’s likely to move the dust further into the printer where there are other mirrors that are even more sensitive to dust.

Thanks! I’ll check that tonight.

What’s the currently accepted method for cleaning the main mirror? I got one of those Giotto Rockets a few months ago just for this purpose but never used it–I guess that’s not recommended now?

Yeah, best avoid using air.
Here’s their guide on how to clean it: http://formlabs.com/support/printers/form-1/cleaning-mirror/

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