How to refurbish your resin tank for about $10

The following is what I’ve tried that works on my Form1+:

NOTE: The silicone inside the tank weighs 64 grams (I weighed two of mine). If you are interested in dimensions of the silicone removed - the outside square is approx. 6.5” and 0.80” deep. The inside square is approx… 5.38” and 0.110” deep.

I purchased Slygard 184 silicone from

Remove current silicone from bottom of the used tray by picking at one corner and pulling it up. It comes out pretty easily.

NOTE: Sanding the edges of the inside bottom of the tray outside the print area may help the silicone to adhere to the tray bottom. I have had the edges peal up on mine but not in the printable area. I’ll try sanding the next one to see i4 that helps.

Clean everything with soap and water and a clean microfiber cloth. Make sure the inside surface of the tray is perfectly clean before proceeding.

NOTE: Minimize exposure of the silicone to dust and particles. Keep the work area very clean and place the tray cover over the tray when you can.

Mix 80 ml of Slygard 184 per mfg instructions in a 1 liter container. You will need 65 ml per tray and you can’t get all of the silicone out of the mixing container so you have to mix some extra.

NOTE: Pouring 5 or 6 trays at a time saves you the wasted silicone that doesn’t come out of the mixing container so you will get around 6 tanks per 16 oz of Slygard 186 if you do them all at once. You should get 5 if you do them one at a time.

Degas the silicone in a clean, dust free, vacuum chamber for 30 minutes. The silicone volume will expand approximately 10x so make sure its in a large container so it doesn’t overflow.

NOTE: Place the tray cover over the tray at an angle so that it can’t form a seal. Otherwise, when you let air back into the chamber the cover will implode into your tray.

NOTE: It may be possible to get all the bubbles out just by using a heat gun. I’m not sure. I’ll try that on one tray during my next round of refurbishments.

Ensure the bottom inside of the tray is clean and clear. Place print tray on a scale accurate to 1 gram and pour 65-70 grams of mixed Slygard 184 into the bottom of the tray.

Place the tray on level surface. I suggest making a level place on a counter and marking it so you can use the same spot every time and not have to check level every time. Put tray cover on the tray and let the silicone level and allow bubbles rise near the top for 15 minutes

Remove the cover and use a heat gun over surface of the silicone and surface bubbles will pop instantly. Don’t hold the heat in one place for long. Just enough to pop the bubbles. Its very satisfying to see how quickly they pop.

Once all of the bubbles are gone allow at least 48 hours at 70F or higher for the silicone to cure.

NOTE: I placed the tray in a 150F a Nuwave Convection oven for a few hours to accelerate the cure time of the silicone. I didn’t want to go higher for fear of damaging the acrylic in the tray. Remember, the tray has to be level wherever you put it while its curing.


There is another silicon for those who want to get it in europe:

I got the info from:

…they were looking for a local available alternative. Also I had success with a slow curing silicon in the past getting no air bubbles without evacuating the air. I have to add this was on making props not on my form1+. So I will give it a try sooner or later as I have no vacuum chamber.

Marcus… Thanks for posting the link. try using a heat gun or a torch to blow hot air over the silicone after the bubbles rise for a while. That will cause all the bubbles anywhere near the surface to pop instantly. I’m not sure how deep it will reach though. Next time I refurbish a set of trays I’ll try one with just the heat gun and report back if that is sufficient or not.

There’s also a link somewhere in these forums that suggests that applying RainX to the silicone lengthens the life of the trays. I haven’t verified that one myself yet.

Guardian of Fertility here:

Quoted from the MSDS for SYLGARD® 184 SILICONE ELASTOMER KIT (CURING AGENT) available at:

Effects on fertility:
Test Type: Two-generation reproduction toxicity study
Species: Rat, male and female
Application Route: inhalation (vapor)
Symptoms: Effects on fertility.
Remarks: Based on test data

Reproductive toxicity - Assessment: Some evidence of adverse effects on sexual function and fertility, based on animal experiments.

The issue here is that it’s just via inhalation of the vapor, which is really hard to avoid unless you’re wearing essentially an oxygen tank or a ton of ventilation. Filters only filter out certain elements. Although they are pretty vague about what the effects, concentration, and duration are, effects were seen in only two generations. So avoid sterility and the Darwin award gentleman =)

Hold on. Cheaper trays and a chemical vasectomy. Win.


Nice Tony I am looking forward to your report :slight_smile:

There’s Qsil 216 as well.
You can get it from Farnell in EU.

Well, you can Thank these guys lol:


Hmmm… QSIL216 looks okay, although I just glanced through it. Although that’s pretty much what I expect from a silicone rubber. I do resin casting and the silicone is the same as the PDMS, soft+non-stick surface. Also the silicone I use for resin casting is very safe.

Forgot to say… QSil tends to wear out a slight bit faster than Sylgard.
Your mileage may vary, but i get a print or two (4-8 hours) at any single spot before it starts to cloud.

That’s with a 150mW laser and Makerjuice resin, though - your mileage may vary.

Hi all,

Cool advice about the heat gun with bubbles in the PDMS. I will have to give it a try next time I make a one-off tank!

I do believe our tanks are a very good value when you factor in time spent refurbishing your current tank, as well as the chance of PDMS failures and print issues/wasted resin if the recoated surface is not correct.

If you use our replacement tanks and have issues cause by a replacement tank, we always stand behind our products.



I built a three point stand and leveled it. Now when I sit a tray on the stand I know its always level. The Machinist level is a good idea for setting up the stand. Also, make sure to put the tray cover on the tray after pouring and heat or vacuum degassing the PDMS so it doesn’t get any dust in it.

Thanks for your information, regarding your data sheet.
P210 Keep away from heat/sparks/open flames/hot surfaces.
And the experiment application route is done on inhalation.
I would not use torch or heat on this chemical.

Dear Jing_Luo,
How about the photo-curing resin that we are working on(hard, flexible, castable)? What is the proper name to look up in the MSDS data sheet? Thanks a lot.

Resin Tank PDMS material.

Smooth On - Solaris Clear Encapsulating Silicone!

Has anyone ever tried this stuff. Not sure if it would work but looks like it would.

Shore A Hardness: 15

Thanks for the tip :slight_smile:

Hi Guys,

I have one tank with a dead silicone layer. I want to try to refurbish it. Any suggestion to remove air bubbles if we don’t have a vacuum chamber?

I’m in europe so I will probably buy Qsil 216. I saw also that Smooth-on has distributors in europe, but buying from Farnell or RS Components is a lot easier.

I used sylgard and just made sure it was thoroughly mixed, made sure my tank was level and poured it. Did it in my kitchen, no special equipment, just had to cover the tank to keep dust free and it took about 48 hours to cure. Worked fine.

One thing that concerns me is the adhesion from the silicon to the tank itself. I’m concerned that during the peeling process it may rip of the pdms layer from the tank. Any special precaution to prevent that situation from happening?

In my experience adhesion wasn’t an issue - so long as the tank interior is clean and grease/dust free you shouldn’t have any issues.

Thanks, I think I will give it a try. Hope it works…it’s a waste to trash the tanks with clouded pdms layer.