How to Restore your VAT!


#1

SOOOOO, you ruined your PDMS layer in your VAT???
Buy new one? Sure (I do suggest a vat for each resin type you use)
The Resin tank silicone layer PDMS (polydimethylsiloxane) wears out over time. It can also pull away, tear, or cloud causing failed prints.
Lets save the VAT with making a new PDMS layer. Lets show you how to do this.

First you need to remove the old PDMS layer. You can get the spatula and pry up on the vat from a corner. BE CAREFUL to not scracth the acrylic if you can.

Here it is out.

If any of the resin gets on the acrylic be sure to use a little IPA and clean it up. Use a LINT free towel. I use bounty towels and it works well. Coffee filters work as well.

So now lets address what happens if you do scratch the acrylic. I had my PDMS layer tear and some resin cured on the bottom acrylic. Removing it scratched it pretty bad.

You can see it in the middle to the left where the blue is distorted

So what you are going to need is the Novus acrylic polish and cleaner. I got mine from amazon:

I used a sponge pad I got from a 3M headlight restoration I already had. You COULD do it by hand but it will take you forever and this works so well.

If its a bad scratch start with 3 until it is almost all gone, then go to 2, for the fine polish and then 1 is a wipe clean. Do not use a cloth for the cleaning. Use a bounty towel, a lens cleaner sheet, or coffee filer.

Now that the acrylic is cleaned and clear of scratches, you will need to get some sylgard 184. This is the same stuff they put on solar panels. I was about to buy the actual sylgard 184 on amazon (its also backordered a lot) from dow corning:

BUT Paul Yanzick found some on ebay for much cheaper; about half the price. The sylgard from dow corning was backordered for a few weeks so i decided to try the same stuff Paul came upon. You can find it on ebay or amazon from the same seller. Fast shipping!


http://www.ebay.com/itm/Cell-Guard-PDMS-Material-Compare-to-Sylgard-184/172542720937?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

A side note: One bottle of silicone and 1 bottle of activator we figured can do 5 vats at once, or probably 4 if done separately. You will have some excess that you will lose each time.

I bought bulk because I am testing a lot of resins out and was tearing the PDMS layers.

You will need a 10:1 ratio of silicone to activator

FOR ONE VAT: 80mL of Silicone and 8mL of activator

80mL of Silicone

8mL of activator

Mix the two together in a disposable cup. Mix it well. It will develop a lot of bubbles. This is OK.

Take your empty and clean (of dust too) Vat and put it on a scale.
0 (zero) the scale with the vat on there.
Pour in about 65-70 grams into the vat.

You will now need to level it.

Cover the vat up to keep dust off of it. I printed off a members vat cover and it works well as a dust cover.
I let the vat sit for 2 days to fully cure. Test this by gently poking a corner and see how it feels. It should not be sticking and bounce back if a finger nail is gently pushed into it.

WHAT ABOUT ALL THOSE AIR BUBBLES!?!?!?!?!?
Well this material is designed to self clear the bubbles out.
20 mins after pour

45 mins after pour

I have restored 5 vats with this method and have already been printing on these. I feel these may be a little stronger, but still have to be careful with it.


Ripped PDMS layer
Tutorials, Guides, Work Flows, Profiles
Removing cured resin from acrylic vat
Artwork to laser cut replacement vat
Build Plate adhesion and offset prints/sliding
Z Height Seems Distorted
Has anyone tried FunToDo PDMS?
Broken FEP acrylic tensioner
Dissolve resin from vat acrylic?
#2

Couldn’t believe I’ve been just waiting for a new vat when this was an option, thank you so much!


#3

such useful post, David. Thank you so much.


#4

Your welcome. I hope this helps everyone out. I’m on my 20th print on one of my redone vats. My only screw ups are when I’m testing new resins.


#5

I had been googling this and reviewing docs for replacing the PDMS layer on that other SLA printer, and I’m definitely glad someone beat me to the punch with doing this

I get the impression that a lot of the cost of a new Acrylic Vat is because of machining and gluing the VAT, plus shipping. It seems that self-pouring the PDMS is a much more cost effective alternative

Thanks!


#6

Just a heads up I weighed my PDMS after resin got under it. Mine weighed 55 Grams so I mixed up 50 Grams and 5 Grams of activator, poured into Resin Vat and covered with foil, kept in warm level place 24 hours new VAT!


#7

At that rate, could the frame be laser cut on it’s own and then filled with silicone? Homebrew the whole vat!


#8

yes, you could that. But you would need acrylic that can stand up to alcohol and is optical clear enough. there is a form1 design file on Thingiverse.


#9

Very fast shipping on this. I got the package today and will give it a try when i get off work. I managed to tear my vat on the third print so I ordered two new ones and a new build plate. Looking forward to getting back in operation.


#10

3rd print? perhaps it was curing too well and a very strong bond. what object were you printing?


#11

My first print was The ring supplied on the SD card turned out perfectly. The next print was the Egyptian god doglike sculpture that someone posted a month or so ago on the facebook forum. I printed it twice since the first one broke partially away from the supports after it was 85% complete. So I added a number of additional supports and printed it again to find just a glob on the build plate and a 3 inch tear on pdms liner in the vat. Once the new liner cures i am going to re-level the build plate then try again and carefully follow the instructions in the new video on supports.


#12

It should be pointed out getting all these tools and materials will cost more then a new vat. What I would like to see Peopoly offer is a GLASS vat upgrade option on their website. I know some people/places have them for $100-150 range already, there is one guy who makes and sells them on his website but I long lost the link.

Also I have been told that RAIN-X type stuff can help extend vat life so I use some of that, not sure how long it would last so whenever I need to refill tank I put some more in. There is a rain-x plastic version now btw, you just spray a decent amount in the vat and swirl it around then absorb up excess with towel.


#13

Nevermind, turns out it still needs that damn silicon layer, just easier to apply. I’ll be scratching my head over this one for some time, because I know people are using straight glass somewhere. Think it took me a couple hours google searching last time.


#14

This is going to be frustrating. Barely had the thing running for a week and already have some marks on my PDMS layer.

Hard to get the camera to focus on it but you can see 3 sizeable marks in my layer. It would be nice if there was some kind of upgrade that could remove the need for the PDMS layer. What is optically clear, but bonds to the resin significantly less than the aluminum bed? Even if it was something like a crystal, I’d be willing to pay the cost of 5-10 vats if it was a lifetime product instead of a consumable.


#15

I know there is a printer that has a flexible bottom insert for their trays, it would make it easier to replace. As for the straight glass idea, I know some people tried it out and had success, but there is issues some people experienced with the print being stuck to the bottom and/or breaking during the tilt motion.

You could brush on a thin layer of glycerine to overcome this as its heavier then resin and wouldn’t rise, but then I don’t know if the glycerine would stick in between layers or remain separated. Just a thought, I’m sure all this has been attempted and documented in some dark corner of the web somewhere…


#16

Hi,
today after 20+ prints I ripped the PDMS layer in my VAT. I will buy a new VAT and my second liter of Resin. But I also want to renew my old VAT. But here in Italy I can`t get the ml solar set @Fezzik recommended. Can anyone recommend an other product in Italy or also Germany that would work to?


#17

I’m gonna try with prochima crystal rubber ( http://www.prochima.com/ENG/product.asp?id=6 ). Not sure it will work as it seems slightly foggy but it’s the easiest to source. I’ll let you know if it works


#18

That’s a mold making silicone, not what you want for your vat at all.
Stick to the clear PDMS materials designed for solar cell packaging.


#19

Would that one work for recoating the VAT ?

It seems like the same type for solar cell encapsulation, since it is made by smooth-on maybe it is more widely available.


#20

It seams that you need a primer first to get better adhesion, according to the technical guide, Not sure if it is crucial or not. Also if this one really needs a good setup first what about the other alternatives?