A Crafts Community For Craft Ideas & DIY Projects - Craftster.org
Help | About | Contact | Press | Advertise | Terms | Site Map
Welcome, Guest.
Please login or register.
Random Tip: Please remember to SEARCH before asking a question that may have already been answered. Thanks!
Total Members: 299,180
Currently Running With Scissors:
619 Guests and 25 Users
Home Craftster Community Crafting Articles Craft Tutorials My Craftster Crafting Calendar City Guides Craft Shop


Pages: [1] 2  All
Jump to page:
  Show Images Only     Send this topic  |  Print  |  Bookmark  
Topic: Casting a Glass Ring  (Read 2121 times)
Tags for this thread:  Add new tag
Share the love... Pin it Submit to reddit add to Wists
1+
 
magpie0816
« on: June 01, 2008 06:05:36 PM »

Hello all. I found an old resin ring of mine that I would like to attempt to make a mold of in order to cast some glass rings out of some recycled glass. I have a glass kiln and fuse quite a bit, however, I have never done any casting...and have never made a mold of an item expressly for that purpose.

Can anyone help me figure out the best way to do this and the proper materials to use? My kiln only goes up to 1800 degress - so firing a ceramic mold myself wouldn't be an option - I don't think.

If anyone has kiln casting experience...I would greatly appreciate the advice. Thanks!


THIS ROCKS   Logged

One of a Kind Fused Glass Jewelry
Shop Dye Lot Collective http://www.dyelotcollective.etsy.com
http://www.dyelotcollective.com
PinkyK
Friend of Craftster Friend of Craftster

Offline Offline

Posts: 4999
Joined: 25-Jul-2005


View Profile WWW
« Reply #1 on: June 02, 2008 07:27:35 AM »

I hope someone has an answer because I'd loooooove to do the same thing!  Grin

Have you checked any of the glass suppliers for a mold?
THIS ROCKS   Logged

menty666
« Reply #2 on: June 02, 2008 07:31:49 PM »

I've never actually done it, but if I were to try it, I'd try this....

Start with a two part mold made of silicone or that pink stuff Michaels sells for mold making.  You'll be making a wax copy of your ring in this.    There's a decent how-to here: http://www.instructables.com/id/Two-Part-Silicone-Casting/

From that mold, you'll want to make a wax copy of your ring.   Paraffin works great for stuff that doesn't have a lot of detail to it.   Use a double boiler to melt your wax rather than direct heat because otherwise you have a really good chance of causing a wax fire.  NOT something you want.  Pour your wax into the mold (you did leave a channel to pour, right? Smiley)

Time to make another negative mold.  This time make it out of plaster and silica.   The silica is the refactory material that will allow the plaster to survive long enough to make your mold.   Ceramic supply shops will have it.  Please be sure to wear a n-100 respirator with this and work in good ventilation as it's a respiratory hazard.   You'll be making your two part plaster/silica mold around your wax ring making sure to make a couple of registration points to re-align the mold after separating it.  I believe Bullseye Tech Tip Sheet 5 (boxcasting) has a formula for figuring out how much of plaster, silica, and water to use.   It'll do for what you're doing here.

Once done, separate the mold and steam the wax out of the halves.

Place the mold back together and bind it with high temp wire and set it into the kiln on your shelf with the pour channel facing up.   

Now here's the tricky part  Smiley   Find a flat terra cotta saucer preferably with a hole already in the bottom.   Fill this with enough glass to fill your mold.  You'll have to do a little volume math here, and you're on your own, but I think Bullseye has a tech tip sheet on this.    You'll follow a full fuse schedule to ramp up slowly up through 500 to dry out the mold a bit, but then follow the normal schedule up to the full fuse point.   You'll want to do some holding and babysitting at that point to see when the glass has left the saucer and flowed into your mold.

You'll need a little cold work to clean up the flash on the molded piece, but it should work.

"Simple" huh?  Smiley

If someone's got a quicker way I'm all ears.

THIS ROCKS   Logged

magpie0816
« Reply #3 on: June 04, 2008 06:13:31 AM »

Very helpful post. I had been bouncing around a few ideas on the molds etc...but hadn't thought of the plaster and silica - I was more thinking ceramics...but this is much more user friendly.

Making wax copies would also make sizing easier - in that to make larger sizes, I would just shave off wax from the inside of the copy before making the negatives.

Also, great suggestion on the saucer...for some reason, I was only thinking terra cotta pot - which would be too high for my kiln.

Question - because it is a closed mold - do I need to drill any holes in the mold to allow for air to escape OR is that all ok because I would be using the saucer to slowly "melt" in the glass - forcing the air out of the top as it pours in?

So glad you posted this...I have been scouring and reading the warmglass.com board - and, to be honest, am no where NEAR that advanced - and was a little shy about posting my newbie question.

I am going to start to gather the supplies...maybe I will photograph my progress as I go and post my experience here.
« Last Edit: June 04, 2008 06:18:02 AM by magpie0816 » THIS ROCKS   Logged

One of a Kind Fused Glass Jewelry
Shop Dye Lot Collective http://www.dyelotcollective.etsy.com
http://www.dyelotcollective.com
magpie0816
« Reply #4 on: June 04, 2008 07:32:42 AM »

I acutally think I answered my own question on the air hole...I could make sure there is a second/third small hole, next to the pour hole for the air to escape while it is filling up...right? Like in this vid...

http://www.instructables.com/id/Mold-Making---Mass-Casting-Complex-Parts-with-a-p/
THIS ROCKS   Logged

One of a Kind Fused Glass Jewelry
Shop Dye Lot Collective http://www.dyelotcollective.etsy.com
http://www.dyelotcollective.com
menty666
« Reply #5 on: June 05, 2008 12:09:37 PM »

I'd put in a vent or two.  Hollow stir rods are a nice thin diameter.

If you do do it, take and post the pictures, I'd love to see how it went for you.

OH...and from what I've read elsewhere, the italian terra cotta saucers vs. others (mexican? dunno) tend to hold up better in the kiln.  But you're still not going to get more than one firing out of it because that much heat wrecks it.
« Last Edit: June 05, 2008 12:13:43 PM by menty666 » THIS ROCKS   Logged

nvl
« Reply #6 on: June 14, 2008 12:46:30 AM »

I actually teach an entry level glass casting glass at Wired Designs Studio in San Antonio, TX. The class is 2 days and it would be difficult to cover all the necessary steps in a quick post but there are a few things to keep in mind which I have not already heard in the posts above
•   You most likely will not be able to make a mold of you ring directly in plaster with out ruining your ring and creating a poor mold. Your first mold should be made of alginate or hydrogel. This will provide you a temporary negative mold which you use can create a positive wax image. Using the wax version of your ring you can then make a plaster silica mold and steam the wax out. This flipping back and forth between positive and negative is what confuses people most.
• You can also alter the wax by carving into it before you make the plaster hold, just be careful to avoid creating undercuts
• Be sure your plaster mix includes 50% silica or some other agent that will provide strength that the temperatures you will fire to (apx 1150f for coe 90 If you use just plaster it will crumble at high temperatures and. that would be bad...
• The plaster mold is made using a fair amount of water so allow for plenty of time for the mold to dry or compensate of this in your firing schedule by holding for a sufficient amount of time between 200-400F
• Check Tip Sheet number 5 on the Bullseye Glass website, it covers some good info on mold making
• Be sure to accurately measure the amount of glass for your mold. The simplest method I have used for this is water displacement
• Make sure your mold is impeccably clean... anything left in your mold will end up in your ring. I like to spray my molds out with compressed air before filling them with glass.
• hmm what else... if you can take a class somewhere there are lots of little steps and missing any one can screw up your whole project. Most castings are thick the can take days to fire/anneal and that's a lot of time to waist if something goes wrong.

It's a bit late at night so I hope I have made at least some sense. Best of Luck…
THIS ROCKS   Logged
nvl
« Reply #7 on: June 14, 2008 12:54:41 AM »

oh... on the terra cotta pots your are absolutely right to avoid those made in mexico. Pots made in the US, Canada or Italy are all fine.

If you are going to use a two part mold I would absolutely put a small (toothpick sized) whole in the bottom for the air to escape.
THIS ROCKS   Logged
menty666
« Reply #8 on: June 16, 2008 06:24:29 AM »

I'm glad I wasn't totally off base with my advice Smiley
THIS ROCKS   Logged

magpie0816
« Reply #9 on: June 16, 2008 03:59:53 PM »

• hmm what else... if you can take a class somewhere there are lots of little steps and missing any one can screw up your whole project. Most castings are thick the can take days to fire/anneal and that's a lot of time to waist if something goes wrong.

VERY helpful...thanks for the tips and process. What do you think the anneal time would be on that size ring? It's not super thick...
THIS ROCKS   Logged

One of a Kind Fused Glass Jewelry
Shop Dye Lot Collective http://www.dyelotcollective.etsy.com
http://www.dyelotcollective.com
Threads you might like:
Pages: [1] 2  All Jump to page:
  Send this topic  |  Print  |  Bookmark  
 
Jump to:  



FacebookTwitterPinterest
only results with images
include swap threads
advanced search



your ad could be here!

How-To Videos
I-DIY Surrealist Gingerbread Cookie Art With Maayan Zilberman
How to Make Gummy Bear Popsicles
Chilled Affogato Float Recipe
How to Make Cherry Garcia Popcorn
How to Make Rocky Road Fudge
Latest Blog Articles
Handmade Gift Ideas: Hippogriff
Handmade Gift Ideas: Exploding Needle Box
Handmade Gift Ideas: Japanese Shibori Dyeing

Comparison Shopping




Support Craftster
Become a
Friend of Craftster

Buy Craftster Swag
Buy Craft Supplies
Comparison Shopping

Craftster heartily thanks the following peeps...
Moderators

Follow Craftster...






Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC
SimplePortal 2.3.5 © 2008-2012, SimplePortal
Valid XHTML 1.0! Valid CSS!

Copyright ©2003-2014, Craftster.org an Internet Brands company.