Today I’m answering reader questions about diamond drill bits, hole saws, melting glass insulators and custom molds.  If you have a great glass question, send it over to us through the About/Contact page.  All personal details have been removed for privacy.

Q:  Help! I’ve been buying hollow core drill bits from various places used for drilling holes in recycled bottles. I use water an have used both a drill press and hand held dremmel. I also drill in pulses to allow water to cool the bit. Some have worked well and some wear out immediately. Can you recommend a brand of bit that is reliable? I don’t mind spending a little more. I want quality at a reasonable price. I appreciate the help. I haven’t seen any advice on glass forums on this topic. Thanks.

A:  For hole saws, my favorite so far has been this set:

I’ve been using them to cut circles out of bottle bottoms and glass plates.  So far, they have been up to 20ish holes each and haven’t worn out yet.

I’m not as happy with my smaller drill bits, I’m ordering these next, I’ll keep you posted how they are durability wise.

Hope that helps!

Q:  Also want to melt a glass insulator flat and see how it looks. The glass in an insulator is very thick, so not sure what firing schedule would be best. Open to your suggestions.

A:  I have melted insulators, they melt smoothly and behave more like art glass than float/bottle glass. I haven’t melted one all the way flat though, so that may take some experimentation. I would probably do take it to 1500 and hold for 15 minutes as a start. Do you have one that could be broken up and tests run on the pieces?  I’ve added this to my list of experiments/tutorials.

Q:  If I am having to press hard on my glass with the cutter, does that mean my blade is dull? I have no idea how old the cutter is….

A:  Pretty much, I’d get a new one, you’ll be so happy with how easy it cuts. I’m a big fan of Toyo cutters, I’ve had several and they last forever!

Q:  I signed up for your mold making class but I was wondering if you make custom molds. I’m not sure that I will be able to make molds in time for what I want to do.

A:  We do custom molds, they are (of course) one of a kind, so a bit more expensive.   Typically we make the positive of the design in the size you specify, then make the glass mold. After firing, we do a glass test and send photos, if it looks good, we send the invoice + shipping and send it off to you.  To get a final quote, please let me know what size of mold you are looking for.  It takes about 2 weeks to complete a custom mold order for one or two molds.