RE: Resin Leaks between tank and frame
Well... That didn't take long. The tank I have given the elegant name of #4 sprung a leak in less than 60 minutes (upper corner and around the mounting hole):
RE: Resin Leaks between tank and frame
Pretty telling though that it also persists with a factory install. Certainly vindicates you from the "you're installing it wrong" excuse.
RE: Resin Leaks between tank and frame
Pretty telling though that it also persists with a factory install. Certainly vindicates you from the "you're installing it wrong" excuse.
Both my original failures were Prusa installed FEPs too. The first was replaced after they tested the printer while it was back for repair. The second was my spare tank which, like these, came with the FEP already installed.
RE: Resin Leaks between tank and frame
@gnat
Ya, they are certainly relying on the increased viscosity of resin to ensure it doesn't leak. Which is a very poor implementation of the design as all resin is not created equal and will have different viscosity. Also it's not uncommon (and even a tip) to dye your resin as well with custom colors, which also change your viscosity.
RE: Resin Leaks between tank and frame
And down goes tank #3 after about 3 hours (next to my finger):
Not to be out done, tank #4 added a new leak at the other mounting hole:
Meanwhile tank #1 (silicone test) is still rocking on with 7 hours left to hit it's 72 hour mark...
RE: Resin Leaks between tank and frame
I'd like to ask you to guess which is tank #1 after 72 hours, but you can zoom in and see my identification on two of the tanks 🙄
So #1 made it the whole 72 hours without a single drop escaping. You can also see that at 9ish hours #3 and #4 were done. I sent my findings to support and we'll see what they say ☹
Unlike my previous disassemblies, the retaining ring was completely dry. There was one corner where it looked wet, but I apparently just ended up with excessive silicone in that area and it spread quite a bit. The other good news is that the FEP didn't seem to react negatively to the silicone (didn't really expect it to, but I can't find information one way or the other).
As I feared, however, the silicone is proving to be a pain to remove. It is too thin of a layer so it won't simply peel away and between the texture of the tank and the tight work spaces it doesn't want to scrub off either. I need to find something I can put it in where I can have the bottom soak in IPA or something else for awhile and see if that helps. The Walmart down the street is already closed for the night so I'll have to try to run out tomorrow and find something. So this will delay turning it around so I can do another water test so my sample size is greater than 1 and then (hopefully) pouring some resin in and trying some prints.
RE: Resin Leaks between tank and frame
@gnat
Leave the silicon on to smooth out the edge. Just so long as it is all intact and not broken you can reuse it as an o-ring almost. Though you might want to take a razor to the inside edge to scrape off the excess so it doesn't end up in your next print.
RE: Resin Leaks between tank and frame
@ryan-c29
Nah I don't trust it and trusting the tank is the goal here. Most came up on the FEP itself. It is just a light film left on the lip and the inside of the retaining area, but it's not consistent all the way around. It should be OK if I just add another layer, but I'd hate to go to all this trouble and end up with a leak simply because I didn't clean it properly first.
If you want useful test results, you have to control your variables 😉
RE: Resin Leaks between tank and frame
I have read the post and it seems you have not tried using a torque wrench on the screws, that and tightening in a 'pattern' evenly is the way you normally would control distortion like on an engine head.
RE: Resin Leaks between tank and frame
I have read the post and it seems you have not tried using a torque wrench on the screws, that and tightening in a 'pattern' evenly is the way you normally would control distortion like on an engine head.
Please note that no where in any manual or instruction from Prusa does it say to use a torque wrench, or does it even state the required torque spec for these screws. Also depending on the instructions from Prusa you follow, some say you tighten in a cross pattern evenly as you suggest, others say circular pattern. I personally have tried both using a torque wrench to ensured the torque on screws was even and it still leaked. Finally, tank #3 and #4 from @gnat were brand new factory installed, and still leaked. We ain't installing the FEPs wrong.
RE: Resin Leaks between tank and frame
@ryan-c29
I would use the torque wrench every time for consistency and to eliminate that as a potential problem. Maybe you are obsessing about the water leakage whereas the seal would be sufficient for the resin because of the viscosity.
RE: Resin Leaks between tank and frame
that and tightening in a 'pattern' evenly is the way you normally would control distortion like on an engine head.
Yeah I mentioned that (though I used tightening a drum head as my example) to support when I explained that the circular pattern was not the normal procedure for such a task. As with @ryan-c29 I did it anyway to appease them and move things along, but both processes failed to create a seal.
RE: Resin Leaks between tank and frame
@ryan-c29
I would use the torque wrench every time for consistency and to eliminate that as a potential problem. Maybe you are obsessing about the water leakage whereas the seal would be sufficient for the resin because of the viscosity.
As noted before, the viscosity of resin differs from brand to brand and also if you add pigment or not to the resin. So while the increased viscosity might be more than enough in some cases, it certainly is not enough in all cases as I have already had leaks with Siraya Tech's fast resin the same way as these water leaks. So while water certainly isn't resin, it is an appropriate stand-in for exposing leak problems faster, cheaper, and cleaner than using resin.
RE: Resin Leaks between tank and frame
Maybe you are obsessing about the water leakage whereas the seal would be sufficient for the resin because of the viscosity.
The resin will leak more slowly due to the viscosity difference, but it will still leak.
On my second tank (Prusa installed FEP) I water tested it for an hour before putting it in service. There was no signs of a leak. 4 days and 5 prints later I had to waste a second day in the same week cleaning up resin that leaked from the tank.
So far everyone I've talked to that initial says they don't have this problem ends up admitting that they do find resin under the FEP in the retaining area when they change their FEP. This means it is leaking on them, it just hasn't made it to the point of getting around the FEP and onto their LCD where they notice it.
RE: Resin Leaks between tank and frame
Seems like you have discovered a design flaw, it probably needs an 'O' ring. It is tough not having it right but maybe after getting it as good as you can just wiping the bottom clean or the like after each use as part of your procedure.
RE: Resin Leaks between tank and frame
It occurs to me that one could probably make an impromptu seal with resin - add a thin coat to the mating surface before installing the FEP, and after it is installed, use one of those handheld UV flashlights (or sunlight) to cure it. This will both make a seal for that install and likely help with future ones as it will give you a smooth surface for future FEPs to sit on (assuming it doesn't chip/break and separates cleanly on disassembly)
RE: Resin Leaks between tank and frame
@bayes7m
On a $200 printer I would expect to have to do such things to work around the corners that had been cut. On a $1400 printer (especially one that doesn't otherwise offer much over the abilities of the $200 printers) I expect a more finished product and better support.
As this really looks like a design issue I'm not expecting an overnight solution from them. I do, however, have some irritation that they are treating me as if this is the first time it has been brought to their attention even though @ryan-c29 was clearly talking to them first.
RE: Resin Leaks between tank and frame
What we want is a reliable printer over time, this is the first iteration, it is a solid unit, I feel they will come up with a solution, you have definitely made them aware of the issue.
RE: Resin Leaks between tank and frame
Soaking the bottom of the tank in 99% IPA did not dissolve or loosen the residual silicone. Other options I've found I would be concerned about being able to thoroughly clean off all remaining residue of the cleaning product and the impact that might have on various things.
I like @vintagepc's idea with the resin. I'm thinking of smearing some on the lip, installing the FEP, and then blasting it with UV. The compression of the FEP should help get the resin into the low spots and then cooking it would hopefully seal it up. I'll see if I can set that up with tank #2 tonight.
