Granite Island

[kiwi]

I need to know your opinion. Would 2" 14 GA box tubing be sufficient to support a 44" piece of granite for a kitchen island? The island will be fully supported similar to the structure of a welding table. Any thoughts would be greatly appreciated.
Thanks,
Nick

[Jim-TX]

I wouldn't hesitate. The attached pic is a conference table that I built the frame for. It's 2x2x14 ga for the top frame and legs and 1.5x1.5x14 ga for the lower support. The top frame also has 2 pieces that run across the short way to support the granite. That granite top is about 4 ft x 6 ft. The table is rock steady. The table is located in the granite seller's showroom. BTW, the blue chairs have been replaced.

[kiwi]

I wouldn't hesitate. The attached pic is a conference table that I built the frame for. It's 2x2x14 ga for the top frame and legs and 1.5x1.5x14 ga for the lower support. The top frame also has 2 pieces that run across the short way to support the granite. That granite top is about 4 ft x 6 ft. The table is rock steady. The table is located in the granite seller's showroom. BTW, the blue chairs have been replaced.

Thanks Jim....WOW that was fast!!

[kiwi]

Very nice work I might add!!

[Portable Welder]

I think that would give you a good sturdy surface, No problem as long as you have good welds.

My back ground is 20 years of doing this type of work, building and designing things.

I would however design some leveling pads that screw into the bottom of the legs to keep it from wobbling.

[MTBob]

I think that would give you a good sturdy surface, No problem as long as you have good welds.

My back ground is 20 years of doing this type of work, building and designing things.

I would however design some leveling pads that screw into the bottom of the legs to keep it from wobbling.

Portable Welder (or anyone else): On this kind of box frame design, what methods do you use to get the legs parallel and cross members perpendicular to one another? Also, when tacking a leg to the cross members how do you keep a tack weld on one side from pulling (tilting) the leg when the weld cools? Any tips would be appreciated.

[Bodybagger]

Put diagonals on it to prevent racking. Otherwise, a failure mode like this may happen...

http://www.youtube.com/watch?v=sEaqfpqLBK4

Without diagonals, you are relying on every conection to be a moment connection, and this makes the welds between legs and the top horizontals a critical weld.

Addition of one diagonal in each plane defines a rigid shape relying only on pinned connections.

In the video above, the structure racked just a little bit from the impact and this overloaded every connection because they were not moment connections. Scale that down and imagine hitting your counter with a hand truck or maybe during a "heated family scuffle."

Here's another failure due to lack of diagonal bracing or moment connections (you've got to have at least one)...

http://www.youtube.com/watch?v=tAOVkKWNfdo

[Portable Welder]

Theres nothing complicated about this, Use a flat table and a square no other braces needed unless for temporary use.

Just tack the unit together and keep checking things.

The bottom of the legs will warp in slightly maybe an 1/8" at most.

Use a bottle jack to spread them back out if its that criticle.