Glue and Ovens

Paul Tarlow · Post by **Paul Tarlow** » Mon May 05, 2003 10:49 pm

I think I remember someone posting something about a glue technique for metal to glass that involved using an oven to cure the piece...but I can't remember.

Does anyone remember this?

Thanks,
Paul

Ann Demko · Post by **Ann Demko** » Mon May 05, 2003 11:00 pm

I remembered looking through the gallery and finding some pieces by Stacy Street, a fellow Ky. artist, anyway she attached glass to glass with Loctite UV glue and heated it in an oven for 1/2 hr @ 2oo degrees. Don't know why it wouldn't work with metal also. Ann Demko

Ron Coleman · Post by **Ron Coleman** » Mon May 05, 2003 11:05 pm

http://www.warmglass.com/cgi-bin/wgarch ... read=84953

Lynn Bishop · Post by **Lynn Bishop** » Tue May 06, 2003 11:30 pm

After a suggestion from someone who had talked to the manufacturer, I started curing mine at 150 degrees for 4 hours...or 28 when I forgot to take them out the previous night. When I try to break off the findings, I find the plating separates from the metal instead of breaking off from the glass or metal. Lynn Bishop

Paul Tarlow · Post by **Paul Tarlow** » Wed May 07, 2003 12:36 am

Does anyone know if this is a Locktite specific technique (the oven thing) or does it work with other epoxy?

Tony Smith · Post by **Tony Smith** » Wed May 07, 2003 6:14 am

Most epoxies will work with an accelerated cure by using an elevated temperature... they just don't advertise it. Loctite is an industrial epoxy where the users are concerned about acheiving maximum strength consistently, so they make this information available.

Tony

Kitty · Post by **Kitty** » Wed May 07, 2003 6:42 am

you can dissolve the epoxy in acetone, and spare yourself the grunt work. sometimes i glue up sterling on earrings and the metal shifts, so the acetone soak overnight takes care of the problem. i'm using 2-Ton by Devcon, and NOT their 5-minute version ... it's nice to have some little jars, like spice jars, around for the acetone treatment. Kitty.

Paul Tarlow · Post by **Paul Tarlow** » Wed May 07, 2003 7:46 am

Tony Smith wrote:Most epoxies will work with an accelerated cure by using an elevated temperature... they just don't advertise it. Loctite is an industrial epoxy where the users are concerned about acheiving maximum strength consistently, so they make this information available.

Tony

So does the elevated temp just speed the process -- or does it make the bond stronger?

Tony Smith · Post by **Tony Smith** » Wed May 07, 2003 8:56 am

If you look at the curing curves that are available on the Loctite site under their tech bulletins, http://www.loctite.com/datasheets/tds/H ... E-30cl.pdf
you'll see that epoxy cured at room temperature achieves 100% strength after 24 hours (this is for the E-30CL epoxy that I use). They don't show the curve for the elevated temperature cure, but it achieves 100% strength after 2 to 4 hours.

My guess is that the high temperature cure accomplishes a couple of things: It drives out any moisture or volatiles that might be in the air or on the surface of the glass, and it cures the epoxy thoroughly so that the core of the bondline is as strong as the surface. As with any catalyzed adhesive, thorough mixing is very important.

One other thing to note from the spec sheet is that at elevated temperature, the epoxy loses its strength. At 200Â°, it only has about 12% strength. So another way to take apart an epoxy joint is to heat it to 200Â° and pull it apart while hot. It regains this strength when it returns to room temperature, and if held at an elevated temperature for an extended period (>500 hours) it can achieve strength in excess of 150% when returned to room temperature.

Tony

Terry Ow-Wing · Post by **Terry Ow-Wing** » Wed May 07, 2003 1:03 pm

will this heat method work with the 5 minute epoxy - which is what I have on hand.

Thanks -
Terry O

Tony Smith · Post by **Tony Smith** » Wed May 07, 2003 1:07 pm

I believe all Loctite epoxies reference the accelerated cure at temperatures up to 200Â°... it probably works with other brands as well. It's easy enough to test it and see.

Tony

Kitty · Post by **Kitty** » Wed May 07, 2003 1:26 pm

Paul -- the heat cure makes the bond substantially stronger. i was having problems with the sterling popping off the glass before i found out about the heat cure. i was so frustrated with the breakdown of the bond, and had been thru so many glues, i finally called Devcon and asked them about it. this was about 2 years ago, and since then i haven't had any more problems, so yeah, it makes a huge difference. Kitty.