LT Tank Very easy to damage


Now Im working with LT Tanks for about 2-3 weeks and for the first prints it was very normal.
Not really a big differents of detail but the prints are very continuously succesfull.
Then I had 1 failed print that didn’t stick to the platform and had to remove it from the LT Tank.
It was very difficult to remove because the surface of the LT Tank is more rubbery then the Normal Tank.
Because of that, I had to push really hard to get under the part to remove it.
But it leaves pretty easy marks in the LT Tank.

And in the picture you can see that a big mark is causing to release the first layer of the PDMS.

It is very easy to damage the layer of LT Tank.

Im just saying this to warn you to be more carefull.


Same experience here. No sign of wear on the tank due to printing, but I did scratch the surface when I needed to remove a part that didn’t adhere to the build platform.

how are you getting the stuck resin off?

I am thinking it needs a material that is close to the same hardness as the rubber surface.
I have used a stiff silicone kitchen spatula on regular tanks to good effect- have not had the LT tank long enough to mess with the bottom yet.

The LT tanks can be a bit more sensitive to the metal scrapers, and we’ve been removing stuck on prints by gently prying it up by hand. You might give that a try to see if it works for you, as it does seem safer than using the metal scraper.

Thanks for the Heads-up. Just running my first LT with Black v4, all good so far…

How about putting some uncured resin on top of the part stuck on the bottom and UV cure the ensemble to obtain a kind of construct that would be easier to take out with a twizzer? That’s something we do sometimes in DLP by flashing the whole construct area - makes it easier to take out small debris without damaging the VAT layer.

Failures are relatively easy to remove with hand, while wearing a glove. In general, I would avoid using any sharp objects against the surface of LT Tank (including scrapers with sharp corners) it is a optical surface. I will highly discourage curing whole construct area for cleaning with LT tanks, because this method does not clean sides of the tank. If you start a new print and there is still some debris in the tank, it can be pressed by build platform against optical surface, effectively damaging the tanks surface.

Thanks for chiming in, duly noted. It would have been nice to advise us against using the metal scrapper supplied with the Form2 to clean the LT tank, as it is the recommended method for the Standard Tank which is why I was doing it like that.

Maybe a PSA on the forums or a user manual with the tank ?

The new tank lid has a new sticker that warns against using it with spatulas with sharp corners or tweezers. But providing this info from more sources might be good idea, I will see what I can do. Thank you for feedback!

Ok good if by hand with glove it works!

Yea, it’s on the cover that sticker, mostly when I take a new tank, it’s always in the printer so the cover is mostly stacked away.
Maybe it’s beter to put a sign on the tank itself.

And removing the stuck part in the tank is working just by hand (Gloves), sometimes still difficult but it works. Thanks.

To be fair, the sign doesn’t tell anything useful. It shows that you should not use the pointy part of the scrapper on the tank, just like the standard tanks, but it doesn’t show or warns that the LT tank’s surface is much more fragile than the PDMS of the standard tank when using hard objects.

Formlabs advice to use the supplied metal scrapper to clean their standard tanks but also warns against making contact with the pointy part. The LT tank is another story and despite having never damaged any of the dozen tanks I have had, I damaged th LT tank the first time I had to remove a cured layer of resin.

This is not an issue with the tank, it’s an issue with the instructions. @Marcin’s remarks just points to the same instructions and warning that come with the standard tanks.

I could use some clarification here. Using a newer scrape with the rounded edges (with normal care) is okay on the LT tanks but using the sharp corner scrapes is a bad idea. Correct?

FormLabs changed the supplied scraper to be narrower and have rounded sides so older Form 2 machines were shipped with the sharp one and newer ones have the rounded edges.

Yes, the scraper with sharp corner is a very bad idea for the LT Tank and the newer scraper with the rounded corners it’s okay but it can still leave marks on the surface of the tank.
Now I do it by hand and it works perfect.

When I first got my F1+ I had a failed print and ended up scratching the pdms with the metal scraper. After that I took the scraper and polished the edge and corner of the blade and never had an issue scraping. If you have access to a buffing wheel you can use emery compound and it should bring that edge to a nice smooth mirror, just make even passes so you don’t leave recesses along the edge.

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