Somewhat On Topic - Aluminum (or other) to Granite

I need to glue two large pieces of granite together at the edge.

I will not need to see the bottom of either part so I want to make a large overlapping "plate" to span the "crack" and hold the two pieces together.

The edge is about 30" in length and I figured an 18" square "patch" or "plate" below glued to both sides would work. The material isn't thick enough to use lag bolts and a plate.

...Thinking either construction adhesive or Gorilla Glue.

I'll put the plate on from below and press it up using bracing. I'll have a lot of weight on top to keep the pressure constant overnight or longer.

I'm thinking of using an aluminum plate simply because it's easy for me to get and easier to move around.

Any suggestions or thoughts?

Regards, Joe Agro, Jr. (800) 871-5022

01.908.542.0244 Automatic / Pneumatic Drills:
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V8013-R
Reply to
Joe AutoDrill
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I would use plywood and epoxy.

i
Reply to
Ignoramus21417

My first thought is, good luck!

Aluminum has three times the thermal coefficient of expansion as that of granite. If this is an indoors application, and if the place where you do the gluing is roughly the same temperature as the place where you will use it, you probably won't have a problem. If the temps are much different, the aluminum will try to shear off of the granite.

It's difficult to glue anything to aluminum without preparation. A thin layer of aluminum oxide begins to form within a few seconds of cleaning it, and it's a very weak layer.

Epoxy is used for gluing granite and other masonry materials, but a strong epoxy often is brittle and the shearing problem will be worse. The construction adhesive you're talking about is, I think, recycled chewing gum , and it's less susceptible to brittle shearing but it's also a lot weaker. I'd call the maker of Gorilla Glue before even considering the use of it here. It's fairly reactive (a moisture-curing polyurethane) and I'd want to know how it sticks to these materials. I always ask for an engineer when I make those calls, and I eventually get one. Elmer's makes the same product under a different name, so I'd call them first.

We'll keep our fingers crossed for you. d8-)

Reply to
Ed Huntress

Why not avoid the thermal expansion problems you will have with aluminum and use a couple (or 2.5) of (easily available, inexpensive) granite floor tiles? If you really want a good joint, drill both sides and dowel them as well as gluing (stainless steel dowels, probably. Pick size to suit thickness.) Neither construction adhesive nor gorilla glue are particularly suited to granite, nor in any way to making two pieces of granite act like one (and if you don't need them to act like one, why bother gluing at all?) Various types of epoxy are far better suited to that purpose.

Reply to
Ecnerwal

...

Granite counter tops are epoxied at the seams. Check with your local fabricator. Bob

Reply to
Bob Engelhardt

how much flexing does it have to prevent? if you just want it to stay together when it's laying on something, some ge silicone 2 would work well. put zigzags of silicone (since it's air cured, you don't want to prevent air movement into the middle) on the Al, press together, and leave sit without movement for 24 hours. it's pretty good for sheer resistance, and very good for pull apart resistance.

i use it for gluing glass to metal all the time, and the bond can be stronger than the glass.

regards, charlie

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Reply to
chaniarts

You broke your kitchen counter?

Certainly a color matched epoxy would seem the be the appropriate material to use, and a counter fabricator should have it available. I wouldn't glue a plate to the bottom, due to the expansion issues others have noted. I would look to place a support under the crack however and wood with a buffer of wax paper ought to be fine.

Reply to
Pete C.

This website might be helpful...

Pete

Reply to
Pete Snell

Thank God, no. The previous owner essnetially has a floating island of granite pressed up against an anchored countertop. It looks seamless, but alas, there is a seam. It opens whenever someone leans on the "island" hard enough.

I'm not so concerned with it looking seamless as I am with it not moving around as the "island" really isn't totally disconnected either. It has a real wood veneer on the far side that flexes and buckles when the thing moves too far.

...I'm too lazy to disassemble the whole thing enough to anchor it to the floor so I figured I'd just tie the moving top to the non-moving top as best as I could.

Reply to
Joe AutoDrill

Ooh... Forgot about that site.

Thank you.

Reply to
Joe AutoDrill

Ok, then the answer is very simple - silicone caulk. Bathroom vanity tops are normally anchored solely in this way with caulk. Lift the floating island and apply some dabs of silicone adhesive caulk around it's supports, apply a bead of caulk into the gap between sections and lower and press everything back into alignment. Let the gap caulk squeeze to the surface and cure, then trim it off flush with a razor blade. Use color matched caulk.

Reply to
Pete C.

It is usually the case that the bed for a granite plate is flat and level, and the joints are aligned by that lower support; it gets complicated if you put an aluminum strap into the mix.

Why not just grout the joint, or use epoxy? Where's it gonna go that the aluminum would be of benefit?

Reply to
whit3rd

Aw, just spackle that puppy and slap some granite paint on it. It'll last for awhile.

-- That is what learning is. You suddenly understand something you've understood all your life, but in a new way. -- Doris Lessing

Reply to
Larry Jaques

I have done a bit of stone-to-metal and stone-to-stone gluing. Not aluminum I hasten to add.

1) Gorilla glue is worse than useless. 2) Polyurethane construction glue which does not foam was OK but a pain to work with due to its high viscosity. 3) Epoxy works well *unless the piece is exposed to sun for prolonged periods*

Michael Koblic, Campbell River, BC

Reply to
mkoblic

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