Like many jewelers who tried Formlabs resin wax, we were seduced by the results. However, it was necessary to adapt the given procedures somewhat to arrive at a result close to perfection. This is how we did it.I
In July of last year Formlabs has put on the market its new resin containing 20% of wax in order to correct the major defect of classic castable resins namely the creation of ash during melting.
Moreover, this new resin not to be processed after UV printing offers another considerable advantage in saving production time, at least in theory.
In theory, because if we stick to the burnout plan proposed by Formlabs, the most classic, and its postcure procedure, it is clear that the ashes are still present.
This resin is not so disappointing, far from it. Its original tougher consistency compared to the previous one (the blue) makes it not only easier to shape once cleaned, but undoubtedly offers better characteristics for melting.
A truly calcinable resin should behave exactly like a classic wax. Is it correct to use this qualifier for wax resin?
To get the most out of it, it is necessary to deviate somewhat from the Formlabs plan and procedure. This article is therefore intended to report some conclusions from our workshop tests.
Nana korobi ya oki (seven falls, eight getting up)
Saïd Ibrahim, our caster in Brussels (castinghouse) carried out numerous tests with the jewelery resins of Formlabs and the difficulties encountered were numerous. From the outset, two options seemed to offer us to solve this puzzle: change the oven program and / or develop a new postcure procedure.
The burnout program.
As shown in the graph below, for a successful melting of the wax resin it is necessary to increase the T ° of the melting phase to 850 ° C. In addition, as the drying phase of the plasters is also warmer, it is necessary to adopt more resistant ones under penalty of seeing them crack.
This process also allows successful melting for the first calcinable resin of Formlabs.
The major disadvantage is of course the consumption of electricity, which for us is doubly penalizing because our second workshop is in Tunisia and the energy is much more expensive.
The postcure process.
Although Formlabs does not consider it necessary to have to UV treat its resin wax, it seemed worthy of us to still apply a drying phase to harden it, the nerve of the problem being precisely at this level .
Unless you have unlimited time available, the use of nail drying equipment is strongly discouraged given what we have been able to experiment.
To obtain a sufficiently hard resin in a reasonable time of 7 to 8 hours, it is necessary to increase the power of the UV either by self-manufacturing its LED box (as we did) or by obtaining one at Formlabs.
Another solution is to enjoy a strong and constant sun like that of Tunisia and it is guaranteed that the resin hardens in much less time. We are lucky to be able to count him among our team.
Our tests to come.
Although we are able to process Formlabs’ castable resins in such a way that the cost and production time are quite acceptable, we continue to test new procedures to determine if it is possible to use these resins without over-consumption of electricity or addition of UV drying time, as is customary for conventional waxes.
The track we are currently following in our Tunisian workshop, with Ryadh Kochbati, master caster -blind and deaf- (meet Ryadh here) is that of a precise handling of the pump during casting. Ryadh is trying to develop a gesture that allows ash extraction just at the right time. It is difficult to describe it in a few words here, surely we will do an article with hopefully an explanatory video in the near future. The current results are very encouraging and make us think that the Formlabs wax resin is really calcinable.