I’m looking for this chemical called Tetrahydrofuran which supposedly is a non-toxic(ish) solvent of PLA. I intend to use it for smoothing out parts and sculptures that come out of my 3D printer.
This is where I got the idea from:
He mentions it’s readily available from Amazon, but I wanted to see if there were any local suppliers first. I imagine importing something like this might be a bit of a headache to get through customs.
I’m not really sure what this stuff is normally used for, but I would think that some scientific/industrial supplies stores might have it.
Two local chemical suppliers I’ve found are Advance Chemical, and New Horizons Scientific Supply.
New Horizons has a $100 minimum order, but is slightly cheaper than Advance.
As to your choice of solvents, I suggest you be very careful; According to wikipedia,
" THF [has a] tendency to form highly-explosive peroxides on storage in air"
and the comments from the Hackaday article itself state:
THF exposure limits 200-250 ppm
also causes cumulative kidney, liver and lung damage, known mammalian mutagen
Acetone exposure limits 750-1000ppm
makes you dizzy, can cause temporary deafness in acute exposure cases.
THF is nasty stuff and requires hazmat disposal in most states.
I don’t think I’d call this ‘safer’ than acetone, but with a VOC respirator, and nitrile gloves, I imagine it wouldn’t be too dangerous.
I’ve already tried New Horizons and they don’t carry THF. Advance Chemicals doesn’t look like they carry laboratory products, but I guess I’ll inquire about it anyways.
Yeah I’ve looked at the safety precautions, I think it should be fine if I can get stabilized THF which is inhibited with BTH to prevent formation of peroxides.
As for exposure risk, I intend to use it outdoors and in very very small quantities with nitrile or neoprene gloves.
I have a 10 gallon drum of RecoChem gunwash, which is a horrifically V OC. I’ve been meaning to test it against some PLA, so when I do, I’ll report back here. It was relatively easy to source too, I think I picked mine up at KMS Tools for <$50.
10 gallons?!? Wow, if that works let me know, maybe I can just grab a bottle? That’s pretty cheap compared to the ~$50 to buy 500 ml of THF and ship it.
I had a chance to test this over the weekend, but it’s not good news. I dipped a sample of printed PLA into the gunwash, and nothing happened. The surface showed some discoloration, but little else. I left the part suspended in a jar of gunwash vapor over several days, and upon inspection this morning, the sample part had become rubbery, but there was no change in surface texture, and no added ability to smooth those surfaces.
That’s too bad. I think for now I’ll go for the additive method - painting over the surface and sanding it smooth.
Buying THF is just too impractical. The only supplier who might sell it to me is quoting me about $100 for 500ml. So I think I’m gonna drop it. I guess if I really want smooth, non-painted parts then I’ll print ABS instead so I can use acetone.