Is this going to hold
 

so i got a 428 gallon 84x42x28 and my buddy is making a stand out of 1 1/4 square tubing going to have 6 legs so it will be 3.5 ft to each leg with 1 inch plywood on top is it going to be enough to hold the 4000 pounds or so only going 28 inch tall so it can fit in a door with out having to come apart made like all the rest of the stands with a top and bottom with 6 legs going up

what size wall will the tubing have?

3 1/16

I would use at least 1 1/2" x 1 1/2" x 3/16 (.188) HSS if not 2 " x 2".

yup and This guy would know

Without going into too much detail I ran half the frame with half the weight using A36 steel in the size you're planning and you barely get a safety factor of 2, typically for this application I like to see 5 or more. 2" with a .25 wall will give you close to 5 following the same stand design/layout.

HTH

http://i11.photobucket.com/albums/a1...elps/Part2.jpg

If you are using 2x2x.250w HSS the grade would either be a G40-21 350W or an A500 GR C . This would increase your safety factor and possibly enable him use a lighter wall thickness.

A36 HSS? Dude, where you gettin' steel from?

I ran some similarly technical tests and determined this would not work:

http://diyfamily.files.wordpress.com/2009/11/table.jpg

A36 is the most common and readily available steel grade used in structural fabrication.

If it is possible go with 2 mid supports splitting the tank length into 3rds.