Have you tried gluing granite?

[Questor]

A friend gave me a beautiful granite mortar and pestle as a gift. Part of it was broken in transit and I'd like to repair it. Can you recommend a good glue that will work? Structurally it's a rod made of granite that will be used to crush spices in a bowl, so there will be stress applied to it.  Thanks.

I'm thinking slow setting epoxy for maximum strength, but I've come to learn that selecting glues is no small decision and some are definitely better than others, depending on the application.

[Tommyt]

I have a granite mortar and pestle
 I JB welded the Pestle it broke about midway here is what I have
Pestle the Pipe section is what broke in two and it held fine so far

[Questor]

Thanks. I'll give that a try.

[GRIMJIM]

Try contacting a granite counter top company. They put build ups on counter tops with some kind of special glue. If you go to the shop, they might even fix it for you for nothing or you can give the guy a couple of bucks.

[Questor]

Well, I went to the hardware store and I thought the clear gel epoxy would be the best option. They didn't have JB, but this Devcon looks OK. It has a nice feature where one half of the epoxy is blue. When you mix them, the color turns clear to show that you mixed it thoroughly. Nice touch. It's the slow setting stuff that sets strong.

[Squib]

does it work without a porous/rough surface? 

[Questor]

Yes, but it's supposed to. I found a nice chart on one of the glue packages at the hardware store. It was a matrix of gluing one material to another. Masonry and stone are best glued with epoxy. The interesting thing about this Gel epoxy is that it's the strong kind, but the manufacturer claims it cures to full strength in an hour. I let it sit overnight, then sanded off the excess and I wouldn't notice the hairline of the repair unless I look for it.

The important thing is that it be able to withstand the pounding. I seasoned the mortar and pestle this morning by grinding rice repeatedly until the powder was white. This took a bit of pounding and the repair seems to be OK.

My experiences with using the right glue are that the piece may break again, but never in the same place that that the repair was made.

[slim rem 7]

 well this ain t granite, but gun related.. i tried the strongest mix of j b weld i know how to make on a scope
one time [against my mentors advice ,i might add..] i ll carry a scar right between my eyes until i die for my trouble..it works on a 22 but not an 06..slim

[Questor]

SlimRem7:

My target 45 has a Doktor sight on it, which uses a mount that replaces the iron sight. The screws sheared off and I sent it to Larry's Guns in Maine for repair. They did replace the screws, but also bedded the sight base with epoxy to help prevent the problem from happening again. It's neat the way they did it. They color the epoxy so it matches the gun.

[pmeisel]

Used to be a sailboat racer.  We break things.  Most of them we fix with West System brand epoxy.

There's a knack to it, read the instruction manuals, but it should work.