WarmGlass.com

I am about to make my first fused glass kitchen backsplash for a client and am hoping for some advice. I use float glass and the piece will be either one piece of 72cm by 70cm or the same size produced as 2 panels, either way they will be between 7 and 9mm in thickness. The panels will be textured so they cannot be toughened. I understand there is a special coating that can be applied to the back just in case the piece breaks which stops the pieces all falling off. The hob is a ceramic electric hob so there won't be any naked flames being pushed up against the glass by a wok or other big pan. I have considered ordering a custom made backing piece of strengthened glass and then fixing my panels to that, but after some consideration can't see any real benefit plus it would add to the overall weight of the panel making it heavier for mounting on the wall as well as increasing the cost of the piece. Any suggestions on glues/fixing etc. Anything else I need to think about? Thanks in advance. Gen

You are making this too complicated. Thinset will keep the glass from falling out in case it should break. Drywall is never flat. Thinset should be able to compensate for this. Be sure to use a thinset recommended for glass. Thinset shrinks as it sets, so lower contraction formulas are recommended.

BTW I routinely temper (toughen) kiln cast float glass. But I would not bother to toughen a backsplash that is installed like tile.

I have a shower stall at my home that has 3 walls tiled with annealed enameled 10mm float glass 3" x 6", 1 wall made of tempered kilncast float glass, and a tempered textured float glass frameless door.

What is the substrate for your panels? (i.e., what are you installing them on? drywall? lathe & plaster? Plywood? Concrete? Brick? Stone?) If I'm putting glass tiles in new construction, I'll ask for either a mortar bed or cementitious backerboard (in the UK this is probably called Hardieboard) instead of drywall as substrate. Either will likely be flatter and more stable than drywall.

If I'm adhering the panels to the substrate, as Bert said, I'll choose a thinset mortar especially formulated for glass. Glass thinset usually contains copolymers to increase elasticity, and it can be applied smoothly, which looks better through transparent glass. It's also bright white, again because it will be visible in the result. (BTW, when I'm showing samples of glass intended for tile, I always show them against white paper--it gives a more accurate idea of the appearance when set)

If the panels are actually embedded into the wall with thinset, they become part of the wall, and are no more dangerous than ceramic tiled walls.

HOWEVER...you're setting relatively large, thin glass panel(s), not tiles. Most glass thinsets are designed for tiles up to 15x15cm; larger than that and there is a risk of cracking the panel as the adhesive sets, particularly if your thinset application must compensate for a less-than-flat substrate. It's certainly not an impossible task, but you should contact the manufacturer of your thinset for advice. They may suggest you reduce the size of individual panels.

It's also possible to set large panels mechanically, with the same fasteners used by glass/mirror installers. You might want to check with a local glass shop, one that routinely installs such things, for help.

Thank you Bert and Cynthia for you really usefull advice. I will clearly need to do some more research into Thinsets once everyone opens again after the New Year. I will keep you posted on how I get on.

Gen

Tech super flex is probably the best product out there. They have regular thinset, full flex and super flex. Super flex cost the most but has the most give as it was designed for softer substrates which have more movement than wonder board.
Bob

Are you in the UK, Europe, North America? It affects the answers that are relevant.
Will the splash back be clear or opaque? That affects the answers too.
Any adhesive you use will take the place of any anti-splinter compound for the back.

Tec includes a warning in the spec sheet about using Super Flex with glass tiles larger than 6" x 6".

http://media.hbfuller.com/documents/Sup ... 92_393.pdf

Tony

Do you think it would be better to make the panel a bit thicker eg 10mm thick, instead of 7mm thick? Will this make a stronger panel (assuming I get the firing schedule right!)?

Mapei makes a product for this but I do not have the info on this computer. email me for info. Otherwise I will try to post from my shop computer.

Thank you everyone for your advice. With all my investigations I found two local companies who specialise in all sorts of large scale glass installations. One of them sold me a tube of CRL ever grip mirror adhesive and the other one gave me a tube of Otto SEAL S50 Crystal Celar silicone adhesive/sealant. Both companies considered a glass panel of the size 70 by70cm small compared to the sort of scale that they work in, so I feel reasonably confident in their advice. I am going to make a 50 by 100cm panel in my own kiln and then fix it in my own kitchen as a backsplash so that I've done a full test run before fixing the 70 by 72cm panel for the client. It's all a bit scary but I've got to stretch my skills and this is certainly ticking that box! I'll provide an update once I've finished.

Wonderful! I think that was a good choice--I was really worried about the rigidity of the thinset.

I have finished and installed a 2 section prototype in my own kitchen and so far it is doing well! The panel is only 2cm away from the stove top rather than the 10cm recommended. When the large hob is on, the glass does heat up but so far this hasn't been a problem. I didn't go for any kind of backing or opaque powder on the panel so it is transparrent in places but not enough for it to be a problem even with some variation in colour on the wall behind. I was going to post an image but I can't figure out how to do this! So I start the big one on Monday with installation scheduled for Friday.