Gray material flexible?

I had by far may best results last night. For the first time I am starting to remove the supports While the walls are on my recent items are rather thin I am surprised the gray material is flexible. I did not want brittle but flexible is not good too. Is this normal? Is it cured correctly? I have 98% alcohol. If it is normal THAT is a big problem for me as it limits what I can do.

Flexible train cars = very bad!

As usual I am

Here are some photos.

give it some time. Just leave it out so it can be fully cured by the uv coming from the sun (even if it’s cloudy), or put it in a uv curing booth for an hour or so… I have a piece of grey resin which has a similar thickness as your your train-carts roof and it’s hardened. Of course you can move it if you really want to, but it’ll probably break before you get too much movement.

The gray tends to be a little flexible until it has fully cured. Very normal.

I know that UV is what cures the resin, but it sure seems like warmth helps too. I noticed that if I put my parts in warm / hot-ish water after the IPA rinses, it seems to speed up the curing but it is an observation not a scientific test.

Nice looking parts, by the way.

Hey Bill,

Those are some awesome prints. The gray resin is no more flexible than any of our other general purpose resin. Post-curing your prints in the sun or a UV cabinet will substantially strengthen them. If you look at our clear resin datasheet (the general purpose resins all have very similar material properties), the Young’s modulus more than doubles between ‘green’ and fully cured resin.

Another thing to keep an eye out for is not soaking your parts in IPA for too long. I noticed that your parts have quite a lot of surface area combined with very thin cross-sections. If you allow your part to stay in the IPA for too long, you’ll likely experience some softening and warping of thin features, caused by IPA seeping into the part and weakening the cured resin. I’ve definitely made the mistake of forgetting parts in IPA over the weekend, only to come back Monday morning to soft, deformed prints.


I was told 2 minutes agitating in 1 tub and 10 minutes soak in the other. Having spent obscene amount of time in a darkroom years ago I am attuned to timing items that are soaking!

I don’t have plans on using the clear materiel any time soon. As a matter of fact almost all of my items will not be the color they are printed in when I am done.

Thanks for all the replies.