How do i recoat my z-vat?
As with the OEM resin trays, the optical silicone layer (PDMS) on the bottom of the Z-Vat will begin to cloud after extensive use, eventually needing to be replaced. One main advantage of the Z-Vat versus an acrylic tray is that it is very easy to re-coat without damaging it. Doing so will take a little prep, but once you get the hang of it the process is simple and inexpensive (It costs less than $12 per try to re-coat the Z-Vat 2 and $7 for the Z-Vat 1).
Re-coating your Z-Vat will effectively make it good as new! And the best part is that it can be performed over and over again.
Materials needed to recoat:
Instructions for recoating:
Following these steps will effectively make your Z-Vat good as new! Please contact us with any questions regarding the coating process.
Re-coating your Z-Vat will effectively make it good as new! And the best part is that it can be performed over and over again.
Materials needed to recoat:
- -We recommend Qsil 216 for your PDMS layer. Here is your favorite distributer via Amazon.com.
- -A sensitive scale to measure the PDMS for mixing, as well as for measuring the right amount of PDMS to be poured into the tray. We recommend a scale like this one.
- -A clean vessel to mix the silicone, as well as a clean stirring utensil. We use plastic disposable "party" cups for vessels and disposable plastic knives for stirring sticks, both that can be found at the grocery store or online. Here are the cups we use as well as the knives for stirring.
- -A heat gun or vacuum chamber for removing bubbles after mixing. We prefer to sue a heat gun. Here is an example of a heat gun that will work well.
- -A level surface for curing the PDMS after it's poured. We use a thick glass plate which sits on three adjustable 'legs' (simply short stacks of scrap paper) for leveling. A common mistake is using a surface that is not perfectly flat, like a slightly warped piece of wood. Three "legs" makes leveling much easier than four.
Instructions for recoating:
- Set up a level surface for curing. It's extremely important that this surface is perfectly flat and level, as an off-level PDMS layer could cause errors in printing.
- Remove the old PDMS layer from the tray. You can use a razor to cut it near the edge, making sure not to scratch the optical window. Then lift and pull the rest away.
- Clean the surface thoroughly. We use a microfiber cloth and ISO alcohol to clean all debris and smudges. This spray foam glass cleaner also works extremely well. Avoid paper towels, they will leave small fibers all over the surface. A bright light, or rather the reflection of light on the face of the window (glare), helps to see the surface clearly.
You can also use the sticky side of blue tape to stick to nab any big pieces of dust, dirt or fibers that settled on the window just before the pour to make it as clean as possible. - Add the PDMS solution.
For the Z-Vat 1, the recoat amount is 57g.
For the Z-Vat 2 the re-coat amount is 100g.
Make sure your mixing vessel and stirring stick are completely clean. Then pour the 2-part solution to the manufacturers instructions. For QSil 216, the mix proportion is 10:1. This means ten parts of the A mix to 1 part of the B mix. We recommend to mix about 12g extra than you will actually be using, as there will always be a little leftover on the sides of the vessel.
Example- If you are coating a Z-Vat 1, you will need 57 grams to recoat. Add 12g to allow for a little waste, so that is 69g total. 69g divided by 11 (10:1 mix means 11 parts total) equals about 6.3g per part. So you will add 63g of the A and 6.3g of the B. Pour the solution slowly into your mixing vessel while it's sitting on the scale, being careful to use exacting amounts. Be sure to 'recalibrate' after placing the vessel on to zero it out. Another trick is to recalibrate after adding part A to avoid having to perform math on the fly when adding part B. - Mix thoroughly for about 2 minutes. Make sure to scrape the sides and bottom of the mixing vessel to get a thorough mix. For best results, it is recommended to pour your mix into a second clean vessel and mix again for one minute. This way there is less of a chance of having any residual unmixed solution.
- You will need to de-gas the mix to remove air bubbles prior to curing. If you have a vacuum chamber use it on the mix now. Remember that the mix will temporarily expand 4x in it's container so you must have a vessel large enough to handle this. We prefer the use of a heat gun to pop the bubbles instead of a vacuum chamber
- Place your clean, dust free vat on a scale and recalibrate/zero it out. Then pour the mixed solution in at the center of the vat. Once you hit the required amount depending on the model of vat, move the vat to the level surface.
- If you use a heat gun to de-gas (our preferred method) instead of a vacuum chamber, use it on the tray now. As the solution is spread thin the bubbles will all pop very quickly. Note that the heat gun is blowing air which can accentuate the spread of dust/particles into your solution, so do this step carefully and quickly directly over the vat so as not to contaminate your clean mix.
- Cover the top with a couple clean pieces of paper to keep dust or other particles from entering while the vat cures.
Cure time for Qsil 216 is 24-48 hours. Heat will speed up cure time but make sure not to add too much, only a little is needed. We have built an enclosure using reflective insulation foam with a shop-light directed through a hole in the top about 9 inches from the trays. This setup effectively reduces cure time to less than 12 hours when paired with a heat gun without building up so much heat to damage the trays.
Following these steps will effectively make your Z-Vat good as new! Please contact us with any questions regarding the coating process.
What is the difference between the amber and clear z-vats?
The amber filter blocks the wavelength of light (405nm) which cures the photosensitive resin inside. Thus it helps prevent stored resin from curing while the tank is outside the printer, exposed to light in your shop. The manufacturing of the amber trays is more costly than the clear, so they are priced accordingly. Please note that the filter is only rated to block ~90% of light, so it is still advised to keep your tray in it's box as much as possible.
Where do you ship?
We ship internationally. Contact us for rates.