Thank you Robert,
The temp was suggested by a b9 distributor. I am now being told that they use the R&R plasticast investment on all of their b9 resin castings. Seems the resins are not " standard investment and procedure castable" We are now undergoing hours of testing and trial and error which is what we were hoping to avoid by buying this machine. At the moment we are zeroing in on curing time/ shelf time/ and perhaps the bench time( for the invested flask) prior to burnout. Our oven reaches 1350 with no problems. our burnout program is as standard as they go. a couple hours at low temp then a slow ramp up to 1350 over 7 hours and hold for 3 hours then ramp down to our casting temperature.
Whats the deal with Asiga's superwax ( yellow) that they are promoting now ? melts like wax ?http://protoproducts.com/Catalog.php#!/ ... y=14185012
Sorry but who ever told you that you have to switch investments is just grasping at an answer.
So they use R&R that is fine because that is probably what they have always used and can only speak to it's success.
I use satin cast like I have been with wax for the last 37 yrs of casting. I have only had a few problems with bad castings and that was due to poor curing I am sure of that.
If your still having casting problems 1350 won't cut it, your oven needs to go to 1450 for a complete burnout held for minimum of 2 hrs. and then ramp down to cast temps. I don't care which resin your using the common link to bad castings across the board is basically due to poor curing of resins and not letting the investment sit for a specific length of time. Like a minimum of 3 hours outside the bell jar.
Unless your using Platinum casting investment then I don't think it would matter if they are even cured
that investment is hard as cement and has to be divested using acid. Too much work for me unless your casting platinum and you already have all that is needed to do that.
Burn out ramping is subjective by all I have read but if I were to do a study of the results from just this forum I would venture to say that ramping from room temp to 1450 doesn't have to do with much, rather the air flow for eliminating ash is the key.
So that said I don't have anything to cause increased air flow I just have piece of asbestos set in the bottom right hand corner of the door ( when the door closes it is spring loaded to close tightly all over due to heat expansion) and I also make sure my cans sit at an angle with 1/4 inch asbestos under cans so there is free area under cans to allow flow.
I think the one thing a person offered here to prove that ramping is probably not that big of deal is to put cans in a preheated oven I think it was 800 deg F. for about 3 hrs and then go to 1400. Not sure about that I have yet to try it.
If you haven't got a good curing lamp like the box B9 already sells then you will have to make sure the resins are cured using Heat at no more than 300deg F. ramping up for approx 2 hrs. (like Robert says) and then let cool inside kiln to room temps or the resin will crack. Takes too long if your in a hurry.