Can You Pour Resin Back Into the Bottle? How to Do It Properly

After completing a 3D print, there is usually some leftover resin in the vat. Since many people wonder whether you can pour resin back into the bottle, I decided to write an article and clear all the confusion.

Keep reading for more information and to know how it should be done.

Can You Pour Resin Back Into the Bottle?

Yes, you can pour resin back into the bottle but you want to use a filter to separate out any cured resin. If you pour resin from the vat back into the bottle, these hardened pieces of resin can later cause print failures if it goes into the vat and blocks the UV light during a print. It can also damage the FEP film.

A lot of the time, you can simply leave your resin in the resin vat and not pour it back into the bottle. I’d usually pour it back into the bottle if there was a print failure and I’m trying to clean out the vat, or if I’m changing to a different resin.

When you leave resin in the vat, the UV acrylic cover of your resin printer will protect that resin from curing so it can be used days, weeks, and months into the future.

If you don’t have filters, you can store the used resin into a separate bottle, then filter it later when you pour it back into the vat. Make sure to put some type of label as a reminder that the bottle hasn’t been filtered.

Your resin 3D printer usually comes with a set of paper filters for this purpose. Some people mention to only leave resin in the vat for 2 days or so, but many people have left it in there for months and been just fine.

Check out this short video on why filtering resin before pouring it back is important.

After 1 year of continuous 3D printing, one user claims that it is safe to pour resin even without filtering unless you have a failed print or you are sure that there are hardened bits of resin in the vat.

How to Pour Resin Back Into the Bottle?

Here is how to pour resin back into the bottle:

1. Wear protective gloves and have paper towels ready.
2. To stabilize the bottle, place it on a level surface or use a bottle holder.
3. Insert a funnel with a mesh filter into the bottle’s opening.
4. Pour the resin through the funnel, carefully, slowly, and steadily to prevent overflows or spills.
5. Use a rubber, silicone, or plastic spatula to gently scrape leftover resin from the vat.
6. Close the bottle cap and store it.
7. Clean the vat using paper towels while making sure not to scratch the FEP film.

A good option is the Diyeen Foldable Silicone Funnel + Metal Filter Mesh from Amazon. It is considered an excellent product by users however the cone and the filter could be larger to accommodate more resin.

You can also go with something like the Sovol Stainless Steel Funnel from Amazon as well. Many people find it very easy to strain and filter out resin without wasting paper filters.

One user who uses paper filters suggested printing a Funnel Filter Holder or Adjustable Height Resin Vat Drainer from Thingiverse. It fits and works well for Anycubic Photon, Elegoo Mars, Saturn, EPAX X1, Prusa SL1, Phrozen Mighty 8K Vat, Phrozen Sonic Mini 4K Vat, and more.

Placing a silicon mat under the resin bottle can make cleaning easier and the AmazonBasics Mat is a great option from Amazon.

One user appreciated the mat saying that it effectively protects the desk from resin and IPA spills. Does not cover much space and makes cleaning easier, leaving no trace of liquid behind.

Check out the video below for a cool method for reducing spills and stabilizing the resin bottle while filtering.