What to do with left over resin in resin tank?


I have just finished my first print on the Form 3, I have resin left in the resin tank,
Can this be filtered and funnelled back into the cartridge?

The high temperature resin I am using has a screw able lid on top of the cartridge which I can remove. At points I will go a long time without printing and it is recommended to not leave resin in the tank so would filtering and replacing be an option?

or what do you do with left over resin.

Thank you!


You leave it in the tank for the next time you want to print with that resin. Don’t pour it back in the resin bottle. The printer tries to keep track of how much resin has been dispensed and it won’t realize you have more than it thinks there is…

Using the tank for different resins is kind of sub-optimal Ideally, you want to dedicate the tank to a particular resin. For my Form2 tanks, I put the lid back on the tank and store it in the cardboard box it came in (with a clean sheet of aluminum foil inserted in the bottom of the box to keep cardboard lint off the underside of the tank).

I just got my Form3 and those tanks come with a handy plastic enclosure for the entire tank. No more foil and cardboard boxes. But I’ll still do the same and swap tanks for different resins, leaving whatever is in the tank in the tank when I put the tank in storage.


@Randy_Cohen is correct, you never want to pour resin back into a cartridge (unless you don’t care about potentially contaminating the rest of the cartridge’s contents).

You may also want to check in on this thread once it gets a response from Formlabs:

There was some suggestion that emptying the tank may prolong its lifetime, if you’re not printing frequently. If you go that route, you’ll want to filter and store it in dark place in an opaque container.


To clarify, I didn’t mean to imply that I was going to empty the contents of the tray back into the cartridge! I’ve been printing on the Form 2 now for a couple years, so I am familiar with the procedure of handling resin. : )

(Actually, one thing I’ve fortunately been free of experiencing has been failures where parts have broken off into the tray. I’ve had a couple small pieces when a tray has been totally worn out burn-wise and I was “pushing it” , but no catastrophic failures. I treat my hardware with “kid gloves”, so maybe that’s why I’ve been spared such things. Warping and other issues, on the other hand…)

Logically, if it were possible to REALLY clean out the tank of resin, only the thin film left behind would be able to eat away at the lining holding the PDMS in place, and a thin film can only eat so much until the solvent becomes inert, thereby prolonging the lifespan a little, but not as much as if it were completely clean. But it’s still a bit of a risk.

And as I wrote, FL customer service reps wrote me directly via e-mail that emptying was a viable method, but they couldn’t guarantee that it was completely safe.