Projet 1200 - FTX Cast Burnout Tests

[bford903]

By the way, about the divesting liquid, how well does it work and is it expensive? I was doing mechanical divesting of Formula and I cannot say that it can win any stars in the favourite activities competition. -LOL! I feel the same way. I felt like a paleontologist removing rock from a new fossil specimen. My guess is the rough surface quality may be caused either by residual ash left over in the cavity when pouring the metal, or the cavity walls are cracking and breaking during the expansion of the material. I've consulted a few people who theorize the photopolymers may be interacting chemically with the investment during burnout, causing the rough surface textures, but I'm not sure how to confirm that.

Here's some info on divesting from Ganoskin:

Removing the castings from the investment can be a challenge. The investment, which is baked at very high temperatures, turns into a glass-like substance that can be difficult to separate from the cast pieces.
Most manufacturers use hydrofluoric acid, which is extremely dangerous and must be handled with utmost caution. Always use rubber gloves, a rubber apron, and a respirator that filters small particles from the air.
A small shop may wish to consider a safer devesting agent for platinum investment as a substitute for hydrofluoric acid. Ask your tool supplier; there are many brand names. You can also mix your own substitute using the following formula (percent- ages are given by weight): 25 percent sodium hydroxide, 25 percent potassium hydroxide, and 50 percent deionized or distilled water. (The sodium hydroxide and the potassium hydroxide should be in pearl or flake form.) Combine all three solutions in a stainless steel container, and heat (do not boil) for 25 to 40 minutes. Be careful mixing, since the three ingredients will naturally heat up when combined.

Here's a link to a safer divesting solution but it's still a bit pricey. It's a hazmat item so shipping will be more expensive as well: http://www.ishor.com/casting/investment/safe-d-vest-investment-remover


I usually soaked it in the divesting solution until the investment started to loosen up, then put it in an ultrasonic. Repeat until all investment is removed. Make sure you have good ventilation in the area you're divesting.


@survivalist
I've always used Castaldo for my molds. It's pretty durable stuff in my experience. Haven't tried any of the alternatives.

[linamvr]

Hello all

Finally I have been able to cast FTX green without porosity.



The process is to cast as if you where casting platinum. The secret lies in the investment and its expansion capacity. To get a good expansion capacity ( to avoid internal fractures), you need to use Phosphate bonded investment.

In countries where you cant find this in jewelry supply stores, look for this in dental supply stores because it is the same investment used for dental casting.

I used the fastfire 15 from Whipmix and the process I followed was the following.
http://whipmix.com/product/fastfire-15/

1. Prepare the investment as per instructions (per 100 grams, 27 mils of the binding liquid sold with the investment). I did not add any water. Be very quick while mixing since it gets hard very very fast.

REMEMBER TO PREHEAT THE OVEN AT 730 DEGREES CELCIUS

2.Vacuum the investment mix

3.Put some tape around the top of the flask because while vacuming it rises a lot. Use liner inside the flask . (liner is sold by Whipmix - and it is an asbestos paper to control thermal expansion.
Pour the investment mix and vacuum the flask again.

4.It will become very hot while it hardens due to a chemical reaction of the mix

5.Hold still and dont move the flask for 20 minutes

6. Put the flask in the oven (remember you had preheated it!) fo 1 hour and 15 minutes at 730° celcius

7. Lower temperature to your metals recomended casting temperature (ej. white gold with palladium at 490° C) and stay at that temperature for 30 minutes

8. Cast (I use centrifuge)

10. The investment gets very hard , I used a hammer to help me crack it. If you need, buy the investment remover also sold at dental supply stores.



The results are great, hope you get as good a result as well. I will post pictures soon



Lina

[survivalist]

@bford903 What exact product from castaldo have you been using ? There is many choices from castaldo namely ;

LiquaCast®

LiquaCast®Long-Life™

LiquaGlass®

LiquaFast ICE®

[bford903]

@bford903 What exact product from castaldo have you been using ? There is many choices from castaldo namely ;

LiquaCast®

LiquaCast®Long-Life™

LiquaGlass®

LiquaFast ICE®

I was using LiquaCast. It's a light pink color.

[tato887]

thanks very much for your help linamvr, but i have some questions, i saw some products in whip mix, and one product is call ceramigold and is a phosphated investmens ypou try whit this produc ??

[B-3]

Did you ever build an an external curing chamber? If so what did you use?

[STL Summit Co]

Hello all,
I've been attempting to print and cast using the projet for about a month now. As many of you have mentioned, I've found the CAST resin to be pretty unreliable. I am particularly frustrated by the lack of information from the companies that sell these machines and resins. They have been almost no help. Thank goodness for forums like these. I plan to try the previously mentioned steps which include the phosphate bonded investment but I've never used it before. Are there any risks of contamination from the gypsum based investment being mixed using the same equipment? Also, does the FTX green require the same type of extended curing times as the CAST? Or, is it not an issue because of the strength of the investment?

Thanks in advance,

Tina

[LinerArt]

Hi all,
if this thread is still alive, we're a small jewelry design company in Saint Louis, MO with a Projet 1200 printer. We've been having nothing but trouble with this ... printer practically from day one. The fact that none of these materials are actually truly cast-able (contrary to what the company falsely-advertised) has been the main issue. So the question is, does anyone know or can recommend another 3D printer alternative, that is comparable in price (under $5000) and can produce decent quality prints out of materials that are truly easily cast-able?

Really appreciate your help!

[awerby]

No plastic resin materials cast as easily as wax, which melts and flows out of the mold instead of sticking in there and burning, but some cast better than others. If you need a machine that builds models in real wax, the only one I know of is the Solidscape, but that's outside your budget range. I've had good luck with the B9 Creator, which uses a resin that burns out pretty well. It helps to use Plasticast investment, which can tolerate a little more heat than normal investments, and to introduce a little extra air into the kiln at the last stage of the burnout cycle. You might try that with your Projet models before giving up on it. But if it still doesn't work, I've got an extra V1.1 B9 I can sell for $3k.

Andrew Werby
www.computersculpture.com

[LinerArt]

Hi Andrew, thank you for your input! We've sent you a message through the messaging option, let me know if you received it. We wanted to discuss the B-9 that you've got.

You can email to: linerart at gmail.com