Molds are there better Molds?

[Teknoron]

Hey guys have question about molds for fusing glass. I have been using the standard molds, kiln washed with airbrush, several coats, kiln dried between coats, then as a double precaution I use the boron spray on top of the kiln wash. After each firing I have a soft brush I use to clean the mold and re add another coat of boron spray. 98.5% of the time my pieces pop out without issue. However are there molds that do not need to e kiln washed or sprayed? I ran across these graphite molds they use for glass blowing. He wasn’t sure about putting in a kiln but that I could pour the glass into the mold. Which at that moment I was thinking how it would suck to be picking molten glass from my body. I am thinking of making my own molds, something that is built like a tank or something I am not spending a lot of time recoating. Any suggestions?

[Morganica]

The graphite will break down in the kiln, after awhile, so it would be an expensive option.

The sturdiness of the mold doesn't have all that much to do with whether or not you need to recoat the release. But...are you talking about FUSING the glass in the mold or SLUMPING it? If you are fusing in a mold (i.e., casting), that's a very different deal--release in a permanent casting mold usually needs to be renewed every firing, especially if you're using stiffer glass that takes more heatwork (like whites and ivories).

The molds that don't need to be kilnwashed or sprayed are, almost by definition, not permanent. Those are the ones you build from refractory plasters, and they break down after X number of firings.

BN works for me in slumping temps but breaks down and gives uneven results in a fuse/cast. I know this isn't the case for other people--Colour de Verre I think recommends BN only--but it's sure been my experience. I will use it on top of a kilnwashed surface--it can eliminate rough glass textures--but not by itself.

[GlassCat]

Just used a Color de Verre mold for the 1st time. Followed the directions to the letter and still has a slightly stuck piece. I was able to get it out and maybe it was my fault and I didn't have an even coat of BN. What I don't like is the rough texture and spikes on some pieces even though I was very careful to use my "artist brush" and move all the frit away from the sides of the mold.

Thought I would try these but don't really think I have the time to mess around with them.

Carol

[JestersBaubles]

Just used a Color de Verre mold for the 1st time. Followed the directions to the letter and still has a slightly stuck piece. I was able to get it out and maybe it was my fault and I didn't have an even coat of BN. What I don't like is the rough texture and spikes on some pieces even though I was very careful to use my "artist brush" and move all the frit away from the sides of the mold.

Thought I would try these but don't really think I have the time to mess around with them.

Carol

I have used the jewelry molds. Every time I've fired them, I've had a couple of pieces that needed to be "heated out" (put back in the kiln with the mold upside down), and the edges are always sufficiently rough that I have to fire polish.

PITA!

Dana

[GlassCat]

Thanks Dana, good to know it's not just me. This is certainly not what I was lead to believe would happen. It's kind of a novelty and I wanted to give it a try but not impressed.

Carol

[Laurie Spray]

My thoughts......

When you use molds such as Colour De Verre's and follow their video on the application and firing the work great! Using MR-97 has eliminated any spikes for me and the glass just slides out. Once you have used it on a mold you can not go back to kiln wash and you need to remove residue with a stiff brush after each firing. They are really nice molds if they fit your needs.


As far as clay molds a good layer of kilnwash should last many firings without reapplying for slumping. No need for spray.

[Valerie Adams]

Back to the original question: I think you're working too hard with your molds. I bought several of my molds 10 years ago. Applied 3-4 coats of kiln wash and air dried. I've never recoated any of them, except for stainless molds. I never slump over 1150°; perhaps you're slumping too hot if your glass is sticking and/or kiln wash is breaking down.

[Larry Jacobsen]

I'm from Colour de Verre and our molds were being discussed earlier in the thread.

We only recommend two methods for priming our molds: MR-97 Aerosol Boron Nitride and Hotline Primo Primer. You can see videos about how to use the products at http://www.colourdeverre.com/go/primo and http://www.colourdeverre.com/go/mr-97 We have tested many primers and BN sprays. MR-97 and Primo are the only two products consistently work with our molds.

One person complained about casting spikes when using our jewelry molds. This must be very frustrating. I would hate to have to grind and fire polish these small, delicate pieces. To prevent casting spikes when using Primo, make a small trough in the frit about 1/4" deep around the edge of the frit body. As the frit melts and collapses, it the hot glass doesn't drag down the cavity's walls. One very rarely sees casting spikes using MR-97.

Again, we really want people to have great creative experiences using our molds. If you have any questions about using our products, please give us a call or drop us a email. You can find our contact information at http://www.colourdeverre.com/contact.php

Best,
Larry

[JestersBaubles]

I'm from Colour de Verre and our molds were being discussed earlier in the thread.

We only recommend two methods for priming our molds: MR-97 Aerosol Boron Nitride and Hotline Primo Primer. You can see videos about how to use the products at http://www.colourdeverre.com/go/primo and http://www.colourdeverre.com/go/mr-97 We have tested many primers and BN sprays. MR-97 and Primo are the only two products consistently work with our molds.

I used Primo with the molds. I watched the videos, read the literature, made the troughs... and still ended up with glass that stuck and had to be heated out of the mold, then ground (had to do the inside bails with a dremel) and fire polished.

Not really an issue now, since the one jewelry mold I had cracked the last time I heated it to get a piece out. (due to impatience, I know...). I only used the mold three time, so it was a fairly expensive learning experience for a handful of pendants.

Thanks for the thoughts, though.

Dana

[Brad Walker]

I used Primo with the molds. I watched the videos, read the literature, made the troughs... and still ended up with glass that stuck and had to be heated out of the mold, then ground (had to do the inside bails with a dremel) and fire polished.

Not really an issue now, since the one jewelry mold I had cracked the last time I heated it to get a piece out. (due to impatience, I know...). I only used the mold three time, so it was a fairly expensive learning experience for a handful of pendants.

Not really sure what caused the problems you had, Dana. Lots of people use these molds without having trouble. My experience has been that people have problems if they apply the Primo Primer too thin or fire too fast or too hot; from your description it's possible that that may have been what went wrong. Sorry you had the trouble, it's not normal for people to have to heat the molds because the glass has stuck.

[Teknoron]

I am actually fusing glass, using the jewelry molds and what ever others i can find. for the most part the kiln wash and the 1800 BN spray work great. my tops are nice and the sides are too, the bottom have a textured finish but for the most part they are the back of the piece, which does allow for great adhesion for the bail. I do know that if i let my kiln creep to around 1500 i do run a big risk of the piece sticking, mostly due to me being impatient. After i fire a mold I use my brush to brush away any loose bn then hit it with a can of air, i am a computer guy so i always have plenty around. I try to keep it around 1400 - 1450 to fuse any of the pieces with frit or glass i have crushed myself. think maybe i will try the bn 97 spray see if it works better than the 1800. I do not have a kiln sitter so i tend to get distracted esp since my kitchen timer no longer dings. Can not afford one however with the instructions that i have found, i think i can build one that will maintain the temp without the worry of it climbing and causing me grief.