inconsistant casting quality w/emerald

A lost wax capable resin tuned for 30 - 70 micron slice thickness
jbdesigns
Newbie
Newbie
Posts: 8
Contact:

inconsistant casting quality w/emerald

Post#1 » Sun Dec 11, 2016 5:41 pm

Greetings all,

I have been reading some of the topics and commenting but thought I would start a new topic with all of the details of my issue.

Purchased a new b9 creator appx a month ago. Before we made the purchase we did some test casts of various b9 resins from the b9 distributor in California and also from a friend with a machine who resides in NYC.

Back story : We initially had attempted to cast resin prints over the past several years with bad results. Finally we determined it was out burnout process, we set up a small kiln with a programmable timer built in it. With the new oven and burnout set up we received 4 different samples from the b9 distributor. We cast these items all in the same flask so the burn out conditions were consistent.They all came out perfect! One variable we were not in control of was the curing process, time these items were on the shelf before we received them. Recently we were told they were on the shelf for appx a week or two.

Also previously we received some printed ( simple bands) from a colleague in NYC from his b9 creator he used the red resin. First cast of this lot was using our old burn out method it failed with a very very rough surface that was internal not external on the original design.
The second attempt was with the same wax weeks later using the new burnout kiln and program and it came out perfect.

Current situation

We received the machine set it up got it running, printed our first designs and cast ! One of the designs was cast in platinum so we used a platinum investment it came out good. Second item was a small / simple canoe paddle. Appx .75 inch in length very thin. this item sat on the shelf for appx 1 week give or take a little. This item cast perfect in sterling silver using standard investment process ! whoot whoot we were so happy !! Now on to real business. Printed more items to be cast, these items were cured at the same "recommended" time as the paddle. All items were very small in size (not heavy) they were printed one day and invested the next. same investment process, same burnout as the previous successful castings and they failed :( pictures attached We then were told to increase the curing time as one of many ways to try and eliminate the issue. We did this and the casting failed again twice.

The reason we chose the b9 creator was to avoid all the issues that we are now up to our ears with. I am now hearing that we may have to put our prints into a toaster oven at 200° for a while? use platinum or simular investment ? What else ? How do we remedy this situation ?

Any help would be appreciated.

Thank you !
Attachments
2016-12-06 11.34.17.jpg
2016-12-06 11.34.55.jpg
2016-12-06 11.34.59.jpg

User avatar
Robert Howle
B9 Creator
B9 Creator
Posts: 6629

Re: inconsistant casting quality w/emerald

Post#2 » Mon Dec 12, 2016 11:59 am

If your castings were good and now bad u have to figure out what is different. Cast the green several times a week for myself and other stores. No issues.

Must have, Cure, air flow in oven, and high end temp must be reached (1350) or exceded.

First thing I would do is go to 1425F on the high end of the burnout. If u are using the B9 model cure u only need to cure for 2 to 6 min depending on weight of the print. If u don't have a good uv light box then heat cure takes 1 hr at more than 200 F (approx.340 F). Don't know where u got that number. U also have to ramp up when heat curing. U can crack the prints.

Robert Howle
Dance like nobody's watching!

jbdesigns
Newbie
Newbie
Posts: 8
Contact:

Re: inconsistant casting quality w/emerald

Post#3 » Tue Dec 27, 2016 1:12 pm

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

User avatar
akgold
B9 Wizard
B9 Wizard
Posts: 2101

Re: inconsistant casting quality w/emerald

Post#4 » Tue Dec 27, 2016 5:08 pm

jbdesigns wrote: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.
I'm so far behind I think I'm First !!

jbdesigns
Newbie
Newbie
Posts: 8
Contact:

Re: inconsistant casting quality w/emerald

Post#5 » Tue Dec 27, 2016 6:10 pm

We are currently using R&R Ultra but agree satin cast/ ultra cast... its all the same I have used both over the past 25+ years and have never had an investment related problem. We are curing in the B9 curing box for avg 4 minutes. Oven is vented and the flasks are raised from the bottom by at least 1/2 inch. I talked to a consultant today who does not sell b9 or any of its resins, he suggested putting sugar in the water that we use in the curing box ?? He had a really long technical (over my head) explanation as to why. Anyway for now we are continuing to work on the curing effect and will set the oven to reach 1450. Which leads me to a question: at these temperatures 1350/1450 how does 100° make a difference ?

Thank you

User avatar
akgold
B9 Wizard
B9 Wizard
Posts: 2101

Re: inconsistant casting quality w/emerald

Post#6 » Tue Dec 27, 2016 9:17 pm

for the same reason you go to 1350 instead of 1250
I imagine it's a tipping point where that extra 100 deg does the trick.
I'm so far behind I think I'm First !!

User avatar
Robert Howle
B9 Creator
B9 Creator
Posts: 6629

Re: inconsistant casting quality w/emerald

Post#7 » Tue Dec 27, 2016 9:50 pm

Curing, air flow, and high end ramp at (I recommend above 1350) 1350+ . This is all it takes.

I have been casting all the B9 resins (except black) since August of 2013. Only Satincast, water, and a broken arm casting machine. It doesnt' take tricks or magic.

As far as buying the B9 and the castable resins to avoid issues, then do what is recommended and u should be fine (not complaining here). As far as the question about the extra 100 degrees, why do u even ask. The recommended temps are there for a reason.

As far as sugar in the water, wow, dont' get it. The only reason u cure under water is because oxygen inhibits curing. I have cured under mineral oil (baby oil) and water with identical results.

If u sand, file or do anything to "break" the surface of a cured print, then do the curing again. U can expose uncured resin.

All things required for good casing with any "castable resin" are critical to a good outcome.

Before I can help anyone with casting issues I would have to know more about your proceedures (spruing, etc.)

Wax is so forgiving, that anyone can cast it. Resin requires more attention to details, even though there are only a few things to deal with.

Post pics of your casting failures with the sprues and button in place. This will really help with input from the hundreds of users casting the Emerald and yellow resin daily, including myself.

Robert Howle
Dance like nobody's watching!

badbrando
B9 Maker
B9 Maker
Posts: 94

Re: inconsistant casting quality w/emerald

Post#8 » Wed Jun 14, 2017 4:47 pm

I can add some here, I have placed a dry flask of models into a 900* oven and then ramped directly to 1500 because one can with another resin in the oven required that treatment and the emerald went along for the ride in a different can. The emerald resin did fine with that abuse.
Another thing is that i don't think over curing is a thing. I cure the crap out of everything because why not? If you have time cure it more.
The other thing is that using a thicker investment mix is a stronger mix if that helps. But curing is most important and then high temp to burn off any ash, I also use air vents to blow or vacuum the ash before casting.

Aaron RMW
B9 Maker
B9 Maker
Posts: 136

Re: inconsistant casting quality w/emerald

Post#9 » Thu Jun 15, 2017 9:43 am

100 degrees can make the difference between reaching burning point and just getting the material to break down and still leave some ash and not fully burnt material behind. Exceeding the burning temp is making sure that all material is completely reduced as much as possible. Just like 10 degrees can be the difference between solder flowing and not flowing, or a book spontaneously igniting due to a 3 degree difference (f 451). It's Physics and Chemistry. At specific temps certain things happen to certain materials. One of the things that can have an effect on those temperatures is elevation, so while some people might get away with 1350 because their conditions make that above the burning point, but if your conditions don't you go higher. you might be able to work it back down by 25 degrees at a time until you find where you start getting failures of burnout, then go back up by 5 or 10, or just do 1450 because you know it will def be enough and the heat won't damage the investment if it is designed to take even hotter. but as others have suggested this could definitely be curing related. We just cast this piece that was cured using the b9 curing oven using a ramp to 1350 and R&R ultra-vest investment, we may have done a coat of spray paint, not sure.
Attachments
IMG_0008_18.JPG

Return to “B9R-3-Emerald”

Who is online

Users browsing this forum: No registered users and 1 guest

Close Menu Shop Forum