kiln casting with metal... please help!

[froggee501]

Geri - I don't understand how I could get a 3 dimensional object out of enameling though, without forming the flower out of metal first... and the project MUST be cast, in order to meet class requirements.

And yes, this is a jewelry/metals class. The teacher has only done very minor things in glass (setting cabs and making simple beads). However, one of my goals for this semester is to incorporate glass into everything that I make. The project is supposed to be two different metals, but because of my goal, I got special permission from Fitz to use glass as one of my "metals". The ONLY two ways we are allowed to attach the bicolor pieces are to 1. solder them on or 2. cast one directly onto the other.

Also, I'd like to keep my project completely silver and glass... therefore the copper foil method is prolly out.... Not to mention the fact that I'm not sure that she'd like that, plus it means that I'd have to form my glass in two pieces. As far as I know, casting the glass into place is my only option if I go through with this glass/metal thing, and I will.

that casting may not be the best way to do what you want to do.

Brad - yeah, This thread is really helping me realize this... However, for the same reasons that I told Geri, plus the fact that I'm a stubborn idiot at times, I'm going to do it. Just need to know what specifics will give me the best chance at success.

Bert - so are you recommending that do this, including the 3-D sculpture part, using enamels? I was hoping for something I have, that would be a little more cost effective, but if it's the best thing to use...

[Geri Comstock]

Geri - I don't understand how I could get a 3 dimensional object out of enameling though, without forming the flower out of metal first... and the project MUST be cast, in order to meet class requirements.

And yes, this is a jewelry/metals class. The teacher has only done very minor things in glass (setting cabs and making simple beads). However, one of my goals for this semester is to incorporate glass into everything that I make. The project is supposed to be two different metals, but because of my goal, I got special permission from Fitz to use glass as one of my "metals". The ONLY two ways we are allowed to attach the bicolor pieces are to 1. solder them on or 2. cast one directly onto the other.

Also, I'd like to keep my project completely silver and glass... therefore the copper foil method is prolly out.... Not to mention the fact that I'm not sure that she'd like that, plus it means that I'd have to form my glass in two pieces. As far as I know, casting the glass into place is my only option if I go through with this glass/metal thing, and I will.

that casting may not be the best way to do what you want to do.

Okay, here's another idea...how about using an inlay technique for attaching the glass? You can cast the glass pieces separately and then inlay them into a flower form made from soldering bezel wire onto the leaf in the shape of the flower.

Here's a photo from a "secret place" (LOL...it's just not available except directly through this link) on my website of my first implementation of the glass inlay on metal technique. The glass in this piece was fused instead of cast, but it could have been cast.

The idea behind the inlay technique is that you solder walls onto the leaf to create the areas in which to inlay the glass. My suggestion is that you cast the glass first and them make the silver part of the inlay to fit the glass, rather than trying to do the inverse.

Here's the link:

http://www.comstockartglass.com/Bert/Pin_Small.jpg


Good luck -

Geri

[Geri Comstock]

Here's an addendum to this now that I've thought abut this a bit more...

Rather than using bezel wire to make the compartments for the glass, I may have used a heavier gauge sterling silver. At least that's what we were supposed to do. LOL. I learned this technique from past president of the Society of North American Goldsmiths, Don Stewart of Canada. He uses this with materials other than glass in his work. It's amazing.

Anyway, another thought I had is that you might want to make a separate baseplate for the flower, to which you solder the inlay compartments. Then you could attach solder the inlay piece to the leaf with a bit of wire to support it and hold it above the leaf. It would be
an effective presentation for this piece, if it meets the requirements.

Good luck!

Geri

[froggee501]

(This is the reply to before the added post...)hmmm.... that's a really good idea, I'm just not sure if it will meet the requirements... I'll talk to Fitz on Monday though, and see what she has to say... That's sounding like the best idea yet.

This picture is my interpretation of your suggestion... sorry for the shoddy picture, I'm not a Paint arteeeeest! the arrows point to where I would curve the bezel wire over to make sure it's held more securely...
http://www.geocities.com/red_tomato501/ ... ahaha.html

[froggee501]

Okay, it sounds like (in your added post) that I should make each petal separate? And then inlay them? If I were doing that, then I might as well fuse cabs for the petals.... I need to do something that is distinctly casting, that can't be done another way. I may be able to get away with casting a whole flower and setting that into a soldered component, but that's pushing it... Inlaying cabs (fused or cast) would be too much like just setting a stone.

[Geri Comstock]

Using an inlay technique, you don't set (bend over) the metal over the glass pieces. You leave the wall intact, standing at a 90 degree angle to the base plate. You glue the cast glass pieces in with a glass to metal glue. If you've never set cabochons before, you'll find this inlay tehcnique far easier than trying to set each piece of glass.

I hope this meets your teacher's requirements. What's his/her full name? I ask because I'm wondering if I know them either in person or by reputation from my years in the jewelry world.

Best -

Geri

[Geri Comstock]

Okay, it sounds like (in your added post) that I should make each petal separate? And then inlay them? If I were doing that, then I might as well fuse cabs for the petals.... I need to do something that is distinctly casting, that can't be done another way. I may be able to get away with casting a whole flower and setting that into a soldered component, but that's pushing it... Inlaying cabs (fused or cast) would be too much like just setting a stone.

You can cast the flower all as one piece, if you want to do it that way and inlay that.

I'm having trouble helping you more effectively because I don't quite understand the assignment from your posts.

Geri

[Geri Comstock]

Here's another thought. Renee Lalique made some incredible cast glass and metal jewelry that couldn't have been made any other way than casting the glass. Perhaps you can find a reference to some of it in a book or on the web to see an example of his work.

Good luck!

Geri

[charlie holden]

Just to follow up on ancient history: if you do want to look for some lead crystal it is made by Schott in optically clear and Gaffer in colors. You have to get softening points and annealing points from the manufacturers or retailers.

I've also had a thought about your aproach. You may have more success casting the glass first, cold working it if needed then reinvesting it. When you reinvest the glass you could also add an open faced mold of the leaf. Then bring the glass and leaf mold up to abot 1000 F. At this temperature the glass won't thermal shock but it won't deform either. You could pour silver onto the open mold and it should bind to the glass where they come in contact. You still have the problem of whether they stay together as they cool.

I don't know if this will work or not. I do know that many people electroplate metal onto glass and some spray it on while it is molten. The metal binds permanently and the glass doesn't break. Extending the metal out away from the glass to support itself would be what you are after.

Michael Glancy electroplates:

http://www.barryfriedmanltd.com/artists ... glancy.htm

I believe, though I'm not sure, that Alex Bernstein sprays metal hot:

http://www.bluespiral1.com/bernstein-al ... alextm.htm

good luck

ch

[rosanna gusler]

wow charlie, thanks for the links. rosanna

[Bert Weiss]

The reason I think you should look in to enameling frits from Thompson is that they are formulated to be compatible with silver. If indeed they are, you might be able to cast in the pate de verre style with them. This frit isn't cheap but no other kind of frit or glass is likely to work as long as it is "stuck" to the metal except maybe with flexible glue.

Expansion coeffecients are something that you need to learn about if you want to join any 2 materials.

[froggee501]

leaf is cast in 50/50 alloy between fine silver and copper... hopefully more compatible than straight silver, but teacher wouldn't cast in straight copper for fear of splatters.

Will be casting on Sunday, then will oxidize, and polish vines and leaves and back.

picture can be found here:
http://www.wetcanvas.com/forums/showpos ... ostcount=9

[froggee501]

according to http://www.warmglass.com/COESummary.htm#metal (thanks Brad!), copper has melting point of 1981 and silver has melting point of 1764 (degrees in Farenheit). For a 50/50 alloy, is the melting point then the average of the two, or 1873? not sure that this is right, and not sure I'll get an answer in time... but if someone knows, that would be much appreciated, even if just for future reference.

Emma

[AVLucky]

copper has melting point of 1981 and silver has melting point of 1764 (degrees in Farenheit). For a 50/50 alloy, is the melting point then the average of the two, or 1873? not sure that this is right

Sterling silver, which is 92.5% silver and 7.5% copper, has a melting point of 1640 F. Coin silver, which can contain between 10-20% copper, melts at a lower temp than sterling. Both of these alloys have a melting point that is lower than both of their component metals. I don't know a formula for figuring these out, but I'm pretty sure averaging won't work, based on the info for the 2 alloys I mentioned.

[Pam Hrycyk]

Will be casting on Sunday, then will oxidize, and polish vines and leaves and back.

Any news on the casting yet?

[froggee501]

Sterling silver, which is 92.5% silver and 7.5% copper, has a melting point of 1640 F. Coin silver, which can contain between 10-20% copper, melts at a lower temp than sterling. Both of these alloys have a melting point that is lower than both of their component metals. I don't know a formula for figuring these out, but I'm pretty sure averaging won't work, based on the info for the 2 alloys I mentioned.

yeah, I found all that.... after my stuff was already in the kiln.... *sigh*

Any news on the casting yet?

came home from school, started chipping away at investment, and have reached fossilized rock.

doesn't help that the end of the marking period is this thursday.

Yeah, I'm feeling a little bitter at myself right now.

http://www.geocities.com/red_tomato501/ ... ygrrr.html

[watershed]

Just to pile on.

I still don't understand how the glass goes through, from what direction, and/or what shape the glass wiill be. I could do it hot, but you'd have a pile of fire scale to deal with.

What would be cool, is a 3 layer thingie. Glass leaf on back and front, silver between. Trickier than hell, but very cool.

You do lampworking, I gathered from one of the posts. Could you do most of this out of boro, and or finish it on the torch? Back to my 3 layer burrito, make the back leaf with a stub that fits through the hole, then attach the front leaf, while not scaling the silver etc....

Or if "Pickle" will clean the scale, then scale away. just don't melt the metal.

As for expansion, both copper and silver are acceptable metals for inclusion in glass, though your alloy may not be. And you threw in Moretti, which throws everything I know, out the window.

Greg

[Lauri Levanto]

This thread hs been the most thrilling adventure story
I have read for a long time.

Can't wait for the next episode
-lauri

[Chris Rogahn]

Emma,
I just started reading this thread, I hope this doesn't come too late for you.

When I read your description and saw your diagram on the Wet Canvas Site, my first thought was (given the thickness of your metal casting, and the shape and thickness of your glass) to keep them separated. The glass can still be fused through the hole, the stem just needs to be slightly smaller than the opening through your silver casting.

Here's the way I would make my first approach at this:
1. Cast your front flower and back leaf shape separately - If I remember correctly you want to do these as Pate De Verre. This will add a step (as opposed to regular casting), but I think will give you a nicer end product.

2.The front flower will need to have a "stem" (the part that will pass through the silver casting). I would clean up the front flower, make an appropriately sized (just barely smaller than your opening in your casting) "stem" from sculpty clay (several times longer than the actual needed stem length) and re-invest face down. After removing the clay, fill with the same frit as you used (or a piece of appropriate glass rod) and re-fire. Clean up the flower with stem, place face down, put the silver casting over your flower and mark where the stem protrudes up through the casting. Grind back the stem to just about the same height as the opening.

3. Invest the flower part again face down (shallow this time, not covering the back of the flower, just enough to keep the shape and details of the front of the flower).

4. Around the inside of the hole in your silver casting you will need to paint a layer of strong "Bead Release".

5. Position your glass leaf on top. Depending on the surface of the back of your silver casting, you may need to either coat any protrusions with bead release or if it's realtively smooth, a piece of thin-fire cut to the leaf shape may work. Basically anything to keep the metal and the glass from adhering to each other.

6. Fire. With good temperature control, you should be able to tack fuse the back of the leaf to the stem. Even with good temp. control and slow, long firing, you may lose some details on your leaf.

7. Carefully, carefully anneal. Remember that part of the glass is in a mold, part shielded by the silver and part exposed to the elements.

8. Soak the piece (start with water) to remove the bead release.

The main problem I can see with this is that the flower and stem could potentially spin. This could be solved by the shape of the stem and or small bumps (decorative elements) on the leaf side (outside the shape of the leaf) that would keep the glass in place.

The other problem could see is if the firing is too hot, the silver casting could slump down into the front flower and again become adhered (you may have to use a separator there as well).

I just had one more thought. You may be able to use a "flux" between the stem and the back of the leaf to lower the temp needed to fuse the two pieces together. Maybe someone else can guide her to an appropriate product? I was thinking "Back Magic" or the Sunshine Ferro product?

I hope this helps (please remember I haven't actually done this, so this is all just theory from my head)!

Chris Rogahn

[froggee501]

Just to pile on.

I still don't understand how the glass goes through, from what direction, and/or what shape the glass wiill be. I could do it hot, but you'd have a pile of fire scale to deal with.

the flower petals were facing down, and the glass leaf was above the metal, and there was a sprue attached to the top of that, which curved out into a bowl to hold the glass. Therefore, glass went bowl --> sprue --> leaf --> through hole in metal --> flower petals. (Ideally, not actually.)

What would be cool, is a 3 layer thingie. Glass leaf on back and front, silver between. Trickier than hell, but very cool.

You do lampworking, I gathered from one of the posts. Could you do most of this out of boro, and or finish it on the torch? Back to my 3 layer burrito, make the back leaf with a stub that fits through the hole, then attach the front leaf, while not scaling the silver etc....

That would be a way of doing this... However, my torch doesn't get hot enough to melt boro, or even bullseye easily. Also, that would not have fit the requirements of my assignment, as I needed to have two cast pieces (in my case, 1 metal and 1 glass). And fine silver doesn't scale (although my silver copper alloy does, 'cause of the copper)

Or if "Pickle" will clean the scale, then scale away. just don't melt the metal.

I definately melted the metal...

As for expansion, both copper and silver are acceptable metals for inclusion in glass, though your alloy may not be. And you threw in Moretti, which throws everything I know, out the window.

lol... my alloy may have been okay to put IN glass, but it definately melted before my glass did... the alloy had a lower melting point than the glass! And Moretti is pretty much all I really know well in glass! It has a COE of 104...

Greg