Castable resin drying process issue. Need tip

Hi everyone.

I modelized a ring and printed the model in F2 castable resin. Result in resin is ok, but i face issues when i try to cast it in silver (see pix).

I think the problem appears during the resin drying process bcs i also use other resin with another printer and they work good.

Here is the drying process:

1 - I shake the object on IPA for 1 minute and let it stay during 9 minutes.
2 - After the 9 minutes I shake for another minute and put on the second tank with IPA for 8 minutes.
3 - After the 8 minutes I brush with a smooth toothbrush until I can see/feel that there’s no more resin.

4 - I let the object dry really good (normally is 10 minutes) so the IPA can completely evaporate and I can feel the piece and see if there’s any resin residue.

5 - I put the piece on the uv-cure machine (Meccatronicore) for 120 minutes 45° x3 times on Friday, x 6 times on Saturday and x6 on Sunday (for this last ring)

Do someone have any tip of what could i do wrong?

thx for your attention. Bruno, from Brussels.

way too long in the ipa, i swish for about 10 seconds in each tank then use an air compressor to blow off ipa and check if all uncured resin is removed, if not swish again then blow off with air, but do not soak in ipa. then cure for about 6-8 hrs. with that method were getting some pretty good castings

Thx a lot. I’ll try that way.

We recommend soaking for 5-10 minutes in each bath for optimal part cleaning. This shouldn’t adversely affect casting and washing parts for less time than that might not give excess resin enough time to dissolve off. This does vary a bit based on part geometry so if shorter wash times are giving good results, by all means keep using them, but it might not be applicable for all users.

Cure time is going to be the most important factor for casting. Most parts will need 6-8 hours of UV curing (using the nail units) and denser parts could need 10-12.

Why 6 to 8 hours of post curing now? On all your documents it is just 2 hours or more.

It does vary based on the cure chamber used and the geometry of the part. Using the nail salons, most parts should be cured for 6-8 hours.

all i know is that when i don’t soak the resins and cure for a long time, i get good casts, when i follow the instructions i get castings like the above pics. also i have been casting everything at 900 degrees and its working pretty well . That’s just what has worked for me

Looks like ash porosity. What burnout schedule are you following?

This piece was casted with others on a same casting tree (with different resin) and only this one wasn’t ok. I don’t know the exact schedule, i ll ask the founder.

I’ll try this so. thx a lot.

There’s your problem. There is a subject on this forum listing casting houses that know how to handle Formlabs material. Suggest you switch to one of those.