Cleaning/reusing a resin tank?


#1

Has anyone tried reusing a tank for a different type of resin? I have a tank dedicated to the flexible resin right now that I’d like to switch to draft but i cant seem to find documentation for how to properly clean my tank to make the switch. Advice would be appreciated.


#2

Yes, I do it all the time and expect most people do the same. I drain the resin from the tank back into the cartridge using a paint strainer to catch any solid bits. I then use a solution of my own to clean out the tank ready to accept the new resin. I’m still experimenting but I’ve found a solution consisting of 6% Butoxyethanol, 10% UN90/90 Surfactant and 84% Deionised water works really well. I’ve also found that a reduced UN90/90 content of 5% also works well. I’ve been using it for about a year on the orange tanks as well as the LT tanks without any apparent degradation and you can also reuse the solution as the resin settles out into a separate layer. Once I’ve washed the tank I just give it a good wipe with some paper towel to dry it as much as possible before putting resin into it. I’m sure other people don’t go to the extent that I do but that’s just me!


#3

In the interest of using what i already have, would some combo of water, IPA, and maybe some detergent work? I do worry about leaving some kind of residue or damaging the film.


#4

The Orange tanks mustn’t come into contact with any IPA at all, otherwise the plastic could crack. You should be able to get away with a strong detergent solution but to be honest just a really good wipe around with a paper towel will be sufficient. I’m just a bit particular about getting them super clean!

Formlabs provide tank care and cleaning instructions here.


#5

Can confirm. I’ve cleaned out tanks with less OCD than @mrwakefield and had success.

Like him, I drain everything out through a paint strainer. Unlike him, I don’t usually put it back in the cartridge (unless the resin in the cartridge is already old, almost empty, and/or I don’t care about contamination - although honestly the contamination worry is probably a little overrated).

Then I use my scraper to get all the resin I possibly can off the interior sides and bottom of the tank. I use paper towel on the sides of the tank (but try not to let it touch the PDMS). With some care, you can usually do a reasonable job of cleaning it out, and in my experience the printer tends to be forgiving if trace amounts of the old resin mixes with whatever new one you’re putting in.

The IPA degrades the tank plastic and can cause it to crack (which could lead to a catastrophic resin spill!). I know some people have put a drop or two on their scraper and run it along the PDMS to really clean it up, but as pointed out you need to be very careful not to let any of it come in contact with the plastic. Unless you’re having a real hard time cleaning out the bottom it’s probably best not to use it, and just accept a tiny amount of cross-contamination in your first print.

That custom surfactant solution sounds interesting, I might try it out if I ever manage to source the components.


#6

I bought grey pro with my form 3. Turns out that resin compromises the resin tank. So I took the tank out, drained and cleaned it with alcohol. Do you think the tank is compromised? I hope I didn’t ruin the tank :frowning:

J


#7

Yes, Formlabs state you must use the LT tank when using Grey Pro as the resin makes the PDMS in the standard (orange) tank swell. You mustn’t use IPA on the standard tanks as it can cause cracking. However, it is ok to use IPA on the LT tanks, as long as you don’t get it on the clear acrylic window.
Here are some links that you might find useful:


#8

Thanks for the info. I’ll read up on the system, buy some new trays and get back to it.