Issue with Vacuuforming. NEED HELP!

[Crescentmage]

I'm trying to vacuuform some lenses for a Madness Combat mask I'm working on. The bucks are resin printed, and originally the thermoplastic would pick up the print lines when I'd do pulls, so I decided to sand out the print lines on the bucks to a glasslike finish. Upon attempting to vacuuform the lenses again, a new issue occured; the pulls now develop a cloudy film(?) on them, which compromises their use as lenses. Could someone help me figure out what's going on here? I suspected it may be moisture, but I wasn't having this issue before I removed the print lines.

 

[JPH]

Can you make the buck out of something more inert, like concrete or plaster?

Or try a thin sheet of paper over the buck lens part. Maybe something is coming off the buck onto the vacuformed sheet.


My first thought is the resin and the heat of the clear petg (or whatever you are vacuforming) is reacting and leaving a residue

Also, try subjecting the smoothed resin buck to uv light, just in case not fully cured.

 

[Crescentmage]

Can you make the buck out of something more inert, like concrete or plaster?

Or try a thin sheet of paper over the buck lens part. Maybe something is coming off the buck onto the vacuformed sheet.


My first thought is the resin and the heat of the clear petg (or whatever you are vacuforming) is reacting and leaving a residue

Also, try subjecting the smoothed resin buck to uv light, just in case not fully cured.

I'll see if leaving it in the curing chamber for a good long while helps out. I also considered getting some kind of mold release to create a barrier between the buck and the plastic. Might try both.

 

[division 6]

You might want to take a look at what Punished Props did to make some visors for Adam Savage's spacesuit helmet.
LINK

 

[Mr Mold Maker]

It is a pain to peel, but what I sometimes do with lenses is leave the film on the side that touches the buck. I’ve successfully pulled a ton of lenses this way. I never do it with anything more complex though.

Alternatively molding and casting the bucks in 1630 would be good.

 

[Crescentmage]

It is a pain to peel, but what I sometimes do with lenses is leave the film on the side that touches the buck. I’ve successfully pulled a ton of lenses this way.

Alternatively molding and casting the bucks in 1630 would be good.

I never even considered that holy heck

 

[Crescentmage]

I never even considered that holy heck

Your method seemed to work best, but now I'm stuck with some bubbles. Should I try another plastic, like HIPS? If so, where can I purchase it without spending hundreds or thousands on a whole pallet

 

[Pro Mod]

The bubbles are either:
a. The material has moisture in it and it needs drying out.
b. It's been over heated

What's the material?

 

[Crescentmage]

The bubbles are either:
a. The material has moisture in it and it needs drying out.
b. It's been over heated

What's the material?

Unsure specifically, but I believe it's PETG

 

[Mr Mold Maker]

I’ve only every gotten bubbles like that in old sheets that had taken in a lot of moisture. Usually the fix for that is baking it out, I think about 150-165f in an oven for a few hours.


It looks like you’re using a dental vacuum forming machine right? Look into clear splint material, it comes precut to size and in my experience has been nicer to form and more durable than PETG. I just checked old orders and what I have is “Proform Splint Material 5x5.”

 

[Crescentmage]

I’ve only every gotten bubbles like that in old sheets that had taken in a lot of moisture. Usually the fix for that is baking it out, I think about 150-165f in an oven for a few hours.


It looks like you’re using a dental vacuum forming machine right? Look into clear splint material, it comes precut to size and in my experience has been nicer to form and more durable than PETG. I just checked old orders and what I have is “Proform Splint Material 5x5.”

That's exactly what I'm using, actually! I always thought it was PETG, is it not?

 

[Mr Mold Maker]

That's exactly what I'm using, actually! I always thought it was PETG, is it not?

I’m not entirely sure to be honest with you. It’s hard to find info on exactly what it is, but it definitely forms a little different from the standard PETG I get in large sheets. It seems to be a little more consistent in the way it heats and stronger once cooled, in my experience.

 

[Crescentmage]

I’m not entirely sure to be honest with you. It’s hard to find info on exactly what it is, but it definitely forms a little different from the standard PETG I get in large sheets. It seems to be a little more consistent in the way it heats and stronger once cooled, in my experience.

Should I still give it a bake in the oven to remove moisture? I live in Florida, where it's been exceedingly humid this hurricane season

 

[Pro Mod]

PETG (Co-Polyester) doesn't normally require pre-drying but its worth trying.

 

[Mottrex]

I’ve only every gotten bubbles like that in old sheets that had taken in a lot of moisture. Usually the fix for that is baking it out, I think about 150-165f in an oven for a few hours.


It looks like you’re using a dental vacuum forming machine right? Look into clear splint material, it comes precut to size and in my experience has been nicer to form and more durable than PETG. I just checked old orders and what I have is “Proform Splint Material 5x5.”

I've got a ton of old 1.5mm sheets for Dental splints..
I concur moisture on any open packets is always an issue.
Those Proform machines ( I have two) are great but can create a lot of moisture and it depends or is influenced by the room temp too..

 

[JPH]

entirely up to you, buut...

Consider making a mold of Sorta-clear, then cast in Epoxacast 690 instead of vacuforming.

 

[Crescentmage]

entirely up to you, buut...

Consider making a mold of Sorta-clear, then cast in Epoxacast 690 instead of vacuforming.

Oooooh I've never heard of that stuff

 

[JPH]

Oooooh I've never heard of that stuff

Something to consider if you are spending $ on PetG sheets and still having issues.

If you have the lenses, make a two-sided mold out of Sorta Clear.

Make the lenses out of Epoxacast 690.

See if a you have a Reynolds Advanced Materials near you. They have great tutorials on youtube and on their website.

I am just throwing out ideas, since it looks like your goal is not accomplished.

Even if you are in Florida, if you are indoors and air conditioning, the humidity shouldn't be an issue.

 

[swgeek]

If you are using one of those little dental vacu-formers, you don't need to raise the plastic all the way up to the oven. If you leave it a bit lower it may solve your bubbling issue.