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PLA + Sodium Hydroxide for support material on ABS prints?

Posted: Wed Jan 27, 2016 4:57 pm
by msmollin
Dual extruder peeps: Have you heard about using PLA + Sodium Hydroxide baths for support material and subsequent removal? I came across this blog post: and was curious if anyone has tried it. Looks like you probably should have an ultrasonic cleaner to go along with it which don't seem terribly expensive for smaller ones (compared to the cost of like an M2 or a 3D scanner kit).

My main interest in dual extrusion is the dual material options - which I know can get tricky but experimenting is part of the fun, so if this works I'll probably take the plunge and go from single to dual. The v3b and v4 single has just been so robust that I haven't had a super huge need for dual v4s yet, but if this works... possibilities are sweet.

Disclaimer: Yes I realize there's alternative materials that are water soluble - but they are all kind of frustrating to print with in my experience. If anyone has any good links to dissuade me from that opinion, please send them along!

Re: PLA + Sodium Hydroxide for support material on ABS print

Posted: Wed Jan 27, 2016 5:31 pm
by Jules
I've never heard of dissolving the PLA with sodium hydroxide, but I did discover how wonderful PLA is when used as support for PETG when I was puzzling out the profiles for the dual extruder. (Put a couple of FFF profiles for it in those S3D Dual Profile Writeups.)

The PETG just doesn't bond to the PLA. Breaking off the support is "literally" a snap. And unless you absolutely can't get the support out through a hole somewhere, you wouldn't even need to dissolve it to get it off. Just pull it away - it comes off clean as a whistle.

So if you were willing to go with PETG instead of ABS, it might not even be necessary to dissolve it. (Haven't tested the bonding between ABS and PLA, that might require dissolving.)

(And you're so right - the water soluble stuff is a holy mess. Better than nothing, (barely), but too expensive to be that much trouble to print.) :roll:

Go order that dual! :lol:

Re: PLA + Sodium Hydroxide for support material on ABS print

Posted: Thu Jan 28, 2016 12:00 am
by Rara
Does the PLA bond to the PETG when it's printed on top of PETG?

Re: PLA + Sodium Hydroxide for support material on ABS print

Posted: Thu Jan 28, 2016 12:45 am
by Jules
Nope. No bonding. :D There's a picture of a calibration square that I did on one of the posts, it was a PLA square with 85% PETG infill. I was able to just peel that infill out of the square and get a perfect little PLA tray. (How I tripped over it, actually.)

Don't think I posted a picture of the other way (PETG with PLA support) but I printed it once that way when I was running some little "print-in-place" folding cube things, and it worked a lot better than the water-soluble filament did. That was just a mess to print, and didn't really provide enough support in the tight areas. Made a complete wreck of the (rather weak) hinges.

Because that was a closed cube, I had to be a little bit careful initially when prying up the segments (the PLA is stiffer than that dissolving filament), but once I got a knife in there, it came off clean. Got busy doing other things and never really finished testing it completely. (But it never did actually bond.)