Granite is apparently a bad idea...

[clevinski]

Hi...

I've been concerned about making welds on material clamped directly to my welding table; for example, making a plug weld that might end up welded to the table if I burn through. I had read here that one solution is to use copper, or even better, some sort of stone under the piece being welded. I didn't have any copper, so I got a few 9 mm thick granite tiles (yes, real granite) from a buddy of mine in the kitchen trades and tried that.

Big mistake.

The granite cracks, crumbles and actually adheres itself to the weld. (If anyone is looking for someone to weld steel to granite, I'm your guy. ) Well, live and learn.

What is the best material to use between your welding table and work?

 

[rtbcomp]

How about firebrick?

 

[migmag]

Don't use concrete either it explodes.........

Can't you just lift it off the bench with some bits of scrap??

 

[fingers99]

Copper is good. The more affluent TIGistas have been known to use ceramics. I've used firebricks in the past, but do make sure they are dry. Often migmag's suggestion will work fine, just depends on the shape of the workpeice.

I think you burn granite to make quicklime, which is really nasty stuff!

 

[clevinski]

Sure, I guess I could just lift it off with some scrap. I like the idea of the firebrick for some projects... I'll avoid the concrete. Thanks for the input...

 

[Justme]

I think you burn granite to make quicklime, which is really nasty stuff!

No thats chalk or limestone.

Justme

 

[clevinski]

I think I have to find myself a copper plate, at least for anything that I want to clamp flat to weld. I can't see clamping a flat frame to firebrick, for example. However, I'm going to buy some firebrick too, since I think it would work very well for odd shapes, maybe even to position odd shapes for welding.

The only thing that I'm sure the granite makes when you heat it is a mess...