In response to your question, We cast carved /cnc models and RP
models daily. Very fine thin lettering and lines that are deep can
problematic. We sometimes have this problem with lines/ lettering
that are in the.03 mm category and not at all in the.4mm category.
What we do to reduce any possibility of error is to not use any kind
of wax wash /soap/alcohol on the machined waxes… further more, we
use high pressure air blasting ( air gun with a reduced nozzle) to
clean out and dry any small grooves/ lettering from the wax before
attaching the wax to the tree.
Our investment and water is weighed on digital scales for accuracy
and sometimes we use a 38/ 100 mix to have stronger investment on
carved models. That is also why we cast models for our customers
individually in their own flasks at the correct temperature for the
I suspect that if you are having this problem at.4mm that there may
be some water/ soap in the grooves before inversting which is
weakening your mixture just enough in that area.
I would suggest cutting the depth to 1/2 mm or less as deeper is
totally useless and may cause issues in those same areas if a rubber
mold is made. I hope this helps.
Racecar Jewelry Co. Inc.
We do casting /finishing from small to large pieces for people in