Special Glue Needed

Thank you for your help, Brave Sir. Your insight on the supreme importance of surface prep. is instructive.

To make the bond between granite and stone you can use thin set compound.

Comes in grey and white. Once applied to both sides, join and support in the right position until dry. (typical 1 day)

Epoxy compound does the job also. So does "bondo" (use the fiber reinforced one if you need to fill more than 1/4 inch ( or 6 mm)

The 2 component products have a shorter set time than the thin set. (powder + water)

Thanks for your help, much appreciated! I'm not sure about just what 'thin set' is though. Is this a brand name like 'Bondo'. I don't think Bondo will work for long because it will absorb moisture unless painted.

thin set is pre- mixed dry mortar that is used to tile, floors and wall tiles. You just add water to make a workable compound.

Googled the question.

Google said to ask here.

They obviously recognise a superior intellect.

Here's some additional information that you might like to read through:

http://www.globalspec.com/learnmore/materials_chemicals/adhesives/epoxy_adhesives

http://www.globalspec.com/industrial-directory/stone_epoxy_adhesives#moreinfo

A long time ago (40 years or so) I used to work the summers cutting natural stone, Amabel marble from the Bruce Peninsula Ontario. They used a polyester resin (think fiberglass) supplemented with a grey fill that was a close color match to the Amabel marble.

I still think it was actually grey body filler.

If it's a fairly clean break, ie not too much filler required, then consider Gorilla Glue, it's 100% waterproof and extremely strong.

I use it for heaps of projects and never have a failure. It expands as it cures, so it will fill small gaps, and it will also push the pieces apart if you don't prevent that from occurring. Dries to a mid tan colour.

If you would rather use an Epoxy, or the gaps are larger, then you can't go past JB weld. Dries dark grey colour .

Clean the surfaces well. Any quality exterior adhesive in a calking gun will do. I like silicone because it has good long-term water resistance, but others have worked for me.

Preparation of the surfaces are the most important thing along with the type of glue used. The biggest problem with gluing stone is that in some instances the bond between the glue and the surface is stronger than the stone itself. If the surface is not extremely clean a "substrate failure" can occur. This occurs when the stone fails in the stone adjacent to but not at the glue line. Sort of like gluing two pieces of wood together with a lot of saw dust on the boards. The glue initially holds them together but it then fails at the saw dust and board interface. This occurs in stone when the forces cause small stress chipping adjacent to the glue line. The stone breaks from this powdering and the bond fails.

If two clean boards are glued together on part of the surface of each, allowed to cure, and then broken apart-- if the break is at the glue line then that is glue failure; if the glue line is intact but the wood tore apart on one or both pieces, that is substrate failure, just as often happens with gluing stone.

Borden Chemical used to make an industrial adhesive for gluing gravel or "bank run" stones to plywood panels for "making walls of stones". The glue adhered to both stones to stones and stones to wood. I don't remember the product name but an inquiry to their successor, National Starch and Chemical, Bridgewater, NJ should help you in your search.

A great glue doesn't necessarily make for great, or even good, adhesion.

Good Luck, Old Salt

This stuff is awesome! Again, make sure the surfaces are clean, but with this stuff, it doesn't need to be super clean. Just scrub with a stiff brush and some Dawn dish soap. Make sure you rinse all the residue off.

This stuff holds well in wet conditions, but I wouldn't use it if the glued area will be constantly under water.

Here's the link http://www.homedepot.com/p/Custom-Building-Products-OmniGrip-1-gal-Maximum-Strength-Tile-Adhesive-OGA1/100284548

Epoxy should work. I repaired a corner of a concrete slab where I took the form off too quick. It has lasted for years and I can't tell where the repair is now.

Wow! What a response! Too many to reply to individually ---only because the replies would get a little monotonous! Thank you, thank you thank you to all.

I just don't get it.

We installed 27.000 square feet granite in 1997 and not one tile came lose.

3/8 thick

The only problem with thin set:

10 times cheaper than all epoxies

if the tile is dark, like e.g. a Jassberg (nearly black with silver gray) use grey thin set.

The white pigments can seep through the tile if not a dense type of granite.

They can "cloud" the surface.

You can work even with wet tiles (=asking for disaster with epoxy based solutions)

Want to see the work, PM me.

you can always try 'Plastic Padding'. clean the surfaces, and mix up the compounds, sticks anything to anything....I've used it.. awesome stuff.

FYI, Plastic Padding is a car body filler.