I have been trying to generate a dependable workflow for the new castable resin. So far my results are mixed. The castings have a good deal of texture - but not horrific.<img src="http://www.garysnyderjewelry.com/data/uploads/DrakenCastable1.jpg"/><br><img src="http://www.garysnyderjewelry.com/data/uploads/DrakenCastabe2.jpg"/> <p>
My kiln has no venting (table top furnace), so I burn out with the door cracked open.
schedule is (note my controller doesn't understand ramp rates, it ramps over a period of time)
room to 300F over 15 minutes
300F for 45 minues
300F to 700F over 15 minutes
700F for 1 hour 45 minutes
700F to 900F over 15 minutes
900F for 45 minutes
900F to 1650 over 15 minutes
1650 for 4 hours
1650 to 975F over 15 minutes
Hold at 975 till cast.
Using plasticast w/bandust in a 3.5" flask, cured for4-6 hours and soaked for one minute before loading into the kiln at 300F,
I have been having a lot of trouble getting reliable prints. Lots of failures. In Ron's posting on mj castable he pictured an array of rings with all cracked in the same spot - I've experienced exactly this with the draken resin.
All 4 rings cracked in exactly the same spot. <img src="http://www.garysnyderjewelry.com/data/uploads/DrakenCastabe3.jpg/>
I don't see how it could be a peel issue, due to the way the rings are supported, but I here to learn.
Exposure times are about twice what I need for MJ SR Yellow - my times don't compare to ron's because I'm using a stock viewsonic projector in slot 3, and my times are generally about twice what ron uses with his rig.
I've also experienced a lot of separating from supports, print throughs and fill ins. , etc. it's tough to hone in on optimal exposure.
I'm using one of the clear sided vats - which has served me so well I'm afraid to put the new yellow sided vat into use. No problems with sticking to the build plate, but frequent problems with model separating from the supports.
I cure under a uv led array, and have had no issues with crazing or cracking during/post cure. Only during printing.
I'm not sure if the texture in the castings is due to burnout, or if the texture is in the models to begin with. I will start experimenting with pre-finishing the print before spruing and see how that works out.