Jodi McRaney RushoOne of the really cool parts about this blog is I get asked a lot of really great questions, some of which I even know the answers to. Since the answers may help others as well, I’m posting them here. If you have a question, don’t be shy, send it on over! (I have left off the names of the question senders for privacy. If you sent a question and would like attribution and a back link, let me know!)

  • Q: I am so happy to have found your site and look forward to learning more about & experimenting with recycled glass. I do have a question… Can you mix different colored bottle glass together, like the dark  blue sky vodka and the light blue sapphire gin bottles, in a pot melt? I’m not sure if all bottle glass is the same or if there is a compatibility problem.
  • A:  Yes, you can mix different color bottle glass together in a pot melt.  Everything I’ve read about COE is that it is directly related to surface tension, different glasses have different COE’s which shrink at different rates as they are cooling, which is what causes the breakage as you fuse different COE’s.If you eliminate the surface by crushing the glass very small, or in a potmelt, where the surface become homogenous, you create a new glass with a unique COE.  I’ve done it successfully for a long time and had no problems.

    If the color is too intense (sometimes happens with cobalt), you can also add broken tempered window glass to the mix and it works as well.

  • Q:  if using a stainless steel mold i have to pick holes in the mold? and must stainless be 18/10?
  • A:  If your stainless mold has steep sides, it is a good idea to poke holes in it.  If you are slumping over a stainless mold, you can raise it up off the shelf and not poke holes.18/10 stainless works the best, it is the most durable.  Other kinds work too, you won’t be able to use them as long.  Make sure all stainless molds have a very good coat of kilnwash and clean off the mold and make a new kilnwash coating for every firing.

    I am very fond of buying old stainless bowls at the thrift store and using them as molds.


  • Q:  So, where does one buy a rock tumbler for polishing?  This tech tip was great!
  • A:  The smaller one I bought from here:  they also carry the larger ones.The larger one I got from, which is also Rockpick Legend on 10th S. and Main street in Salt Lake City, UT.

    Not a cheap toy, per se, but mine have paid for themselves many times over.  I can polish small sculptures (up to brick size) in the larger tumbler.


  • Q:  I have an opportunity to pick up a FREE tempered glass table top. I haven’t done any work with tempered glass.  I just started messing with bottle slumping as my first experience in recycled glass.
    I have no clue as to a firing schedule for this type of glass.  I’m assuming I  would have to use a glass saw to cut it up. I don’t even have an idea as to what I should make  out of it.
    Recommended Books or DVD’s or is it trial an error?
  • A:  Go ahead and get the table if you can get it home.  It’s probably really heavy!Thick tempered glass is really useful.  If you want to do any casting, it’s my first choice.

    DO NOT, DO NOT, (please!) try and cut it with a glass saw.  It will explode into a million pieces and those pieces WILL travel several feet with great force.

    Get it, put it on a big clean tarp or piece of fabric, clean both sides and around the edge as well as you can.  Wrap the tarp over the table, tape it shut if you wish.

    Use a spring loaded center punch and punch the corner.  Sometimes it takes a couple tries.  The table will break into small pieces.  Unwrap and store in clean, lidded buckets.

    The chunks can be used in pot melts mixed with bottle glass (yes, really!).  Or, put into plaster/silica molds and fused into solid sculptures.  Or, spread it out on a shelf, fuse it and it will bead up into round jewels for stained glass work.

    You could even put one chunk in each of the little pendants of the molds I’m giving away and make pendants!

    I’m not sure about books or DVD’s, I’ve never found any.    SO, I’m working on one now, and there will be blog posts in the near future about casting which will help you tremendously!