Resin cracks while heat curing

A lost wax capable resin tuned for 30 - 50 micron slice thickness
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panastation
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Resin cracks while heat curing

Post#21 » Mon Nov 24, 2014 1:54 pm

I know i should ask this in another post but since i alredy have ure awesome attention here** might as well ask.
ok here are my flask size specs . 108mm diameter by 60mm height
and a pic of my last cast.. i still cant get that nice burnout...maybe i nned to raise temps . what do u guys sugest,
im thinking there might be ash or something... has anybody tried to blow air or vacum their hot flask before casting.
just a thought maybe a steel tip adapted to a vacum . or maybe im just not getting the right burnout.


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Robert Howle
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Resin cracks while heat curing

Post#22 » Mon Nov 24, 2014 4:20 pm

Looks like u have uncured resin and also maybe lots of ash. U can vent by running a small diameter wax to the highest pt in the flask and after burnout blow air form the opening in the base left by the small diameter wax tube and flush out the ash. If the uncured resin has reacted or broken down the investment then this may not help. All of us use to have to "vent" the old viper models back in the early days.

How are u curing your models after printing and for how long?

Robert Howle
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panastation
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Resin cracks while heat curing

Post#23 » Mon Nov 24, 2014 4:57 pm

hey robert

i usually leave them for more than 6 hours sometimes overnight. I quit speed curing in kiln because of cracks and flakes,
if im not doing wax disc i sometimes leave them out in sun for a few hours and this is after i uv cured them in box.
Something u said about the heat not reaching center made me re think my kiln temp hold times. Ure right 2 hours is not enough for the size...maybge for a 2 by 2.5 inch but this disc is diff...il try raising temps to 1400 for 3 hours. Maybe blow ash out and see from there.

i bought that cheap salon uv light thats recomended in wiki,, i have 2 of those held together by a giant rubber band.

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Question ----have u ever tried jumping from 300degrees ---full ramp to 1400 degrees..and see if wax burns out before it can expand and such.

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Robert Howle
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Resin cracks while heat curing

Post#24 » Mon Nov 24, 2014 6:43 pm

I use the nail boxes too. No shoudl go to 600 for at least 1 hr to allow the models to break down. Need to make sure the temp in oven is what the thermocouple is reading they can be off by 50 degrees F. need to calibrate oven to make sure u are getting to 1350 for 2 to 3 hrs. Air flow is important also. Smaller ovens have just one small hole in the door an on top.

Robert
Dance like nobody's watching!

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TAJS
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Resin cracks while heat curing

Post#25 » Wed Nov 26, 2014 10:46 am

In regards to casting, I try sprue up my models where the resin can drain out. I try to avoid having areas where the resin has to just "burn up"...I think this is where the ash residue is, thus casting issues with pits and porosity. Just my 2 cents. HTH

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panastation
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Resin cracks while heat curing

Post#26 » Wed Nov 26, 2014 1:34 pm

i doubt very much resin drains out like normal wax does. My error is so close to being figured out. Ive seen resin burn through my kilns front window and its it more like a black charcoal than wax flowing. flsdk size and hight temp hoild times are the trick here. ill keep testing stuff out. thanks for input

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