Rigid and Flexible old resin


I have just took out from the the closet the rigid and flexible resins and tanks.
They have not been used for almost a year (if no more). There was a separation of the materials to layers in the tank. The flexible (that is gray) turn into very dark chocolate color at the top layer and the bottom was completely white. It was extremely hard to remove the white layer from the silicon of the tank, took me about 30 mints to scrap it all from the silicon and put it in a different container. I put this aside for now.

Took the Rigid and in the tank, the bottom layer turned into dense material (like caramel) that was stick to the shovel. Didn’t have a change to mix it together again. I also scratch the LT time while trying to remove it, it was so sticky so I put it aside as well.
Took a new LT tank and mixed well the rigid cartridge. Started a print and… no resin going out from the cartridge. Pulled the cartridge out and fliped it so the valve is facing up. I’ve advanced a flat screwdriver through the valve and it was hard to pass through a thick layer of very dense material.

My question is how do I store a used cartridge and tank for a long term? Is it got expiration? couldn’t find anything on the box or on the cartridge labels.

Wants to know if I have no other choice but to dispose 2 LT tanks (printed twice on each) and 2 almost full cartridges.


Interested in an answer to this as well, as I haven’t been able to find something in the docs about longer term storage (I might have missed something).

Bumping up this thread. Any idea - Formlabs employees?

Between these two support articles, I think they’ve answered these questions pretty well:



Long story short, resin lifespan is 24 months, but environmental/storage factors can and will change this. They can’t give you a hard timeline, because if you store your resin in a covered tank out in the open with ambient sunlight, vs pouring it into an opaque bottle, the lifespan of your resin will change drastically. Nearly all these resins have something suspended in them to give them their mechanical & visual properties. These additives can settle, that is why the cartridges tell you to shake thoroughly, why the tank has a wiper, why they all have different settings. If you have scraped and discarded some of the settled material, you have changed the formulation of the resin in the tank, and it should be discarded. If it has clumped up, solidified, or just completely unable to be mixed back in even after heating, then yeh, it’s no good anymore.

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Thanks @DustinJayH,

This is exactly what I was looking for.

So these resins and tanks are busted. For future storring they recommend on mixing it every 2 weeks and store the resin from LT tank in opaque bottle.

My resins and tanks are placed in a close - out of sunlight cabinet so it should hold for the 24 month’s mentioned in the articles. It just need to be agitated regularity to maintain uniformity of the resin.

Thanks for the help!

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