Hi,
Thanks for the suggestions. I think I'd like to stay with steel as I'm planning on covering the stand with a nice finish plywood and am going to use rare earth magnets to attach to the frame. Saw someone else do it that way, and its pretty nice, more mobile too.
There are always tons of people in my area looking for stands, so I'm thinking that if I like it, I could do this on the side to pay for some of my toys. I've been looking at some of the other steel stands in the net, and saw where someone had made a 230g stand out of 2 x 2 x 1/8", so I'm guessing its strong enough. From what I've read though, Mig doesn't give the weld depth that stick does, correct? However, if I'm using 1/8", that might not be a problem, and I'd probably end up burning through the 1/8" with the stick anyways?
Any idea on where I could find information on deflection over a span of 48" using either angle or tube? The entire 1200# would be supported on the rail of the frame, and not distributed across the entire area of the tank bottom, unlike acrylic tanks which are flat bottomed. Therefore, much deflection would lead to stress on the glass, with the expected results.
Another reason why I was thinking that perhaps 3/16" might be better?
Oh well, any advice is greatly appreciated.
Hi badpacket,
I'm not an engineer, so I can't help you with deflection, but according to LRFD, Load and Resistance Factor Design, for TS 2 x 2 x 1/8" spanning 48" and laterally supported, the maximum uniform load would be 4000 pounds per each 48" length. If a 3/16" wall is used, it increases to 6000 pounds. Note that this is based on electric resistance welded tubing with a minimum yield stress of 46 ksi. The stress values may vary depending on the ASTM specification and grade of material. Here's a link to the Steel Tube Institute of North America, which lists LRFD tables for 46 and 50 ksi minimum yield stresses for rectangular and square tubing. Scroll down to page 35 for the 46 ksi version:
http://www.steeltubeinstitute.org/pdf/brochures/LRFD_Beam_Load.pdf
badpacket,
Once you figure out your frame with legs and all that, a small L1x1x1/8 angle mitered at the corners would frame out the top nicely to keep the tank from sliding off until you get it full of water. Keep in mind you will want to weld this onto the frame and have it supported for it's entire length, it is only to cap off the top and give a lip.
just a thought,
John Wright
You should check how carefully that tank needs to be supported. Glass is a reasonably strong material. Assuming that continuous support is necessary you will either have to provide camber (upward bend) so that the member loads to straight or some cushioning between the tank and the frame. Otherwise as the frame deflects you will wind up supporting the corners more than the middle. I would lean toward the cushion, it's simpler.
Tables of deflection of uniformly loaded beams can be found in the AISC manual for steel construction if I remember correctly and also textbooks on steel design and sometimes in handouts from steel suppliers. Google for it I bet it's here someplace.
Any welding process that you are familiar with will do a fine job of this. It seems though that there is not a process that you are truely familiar with, therefore some practice may be in order. I do not recomend a project that involves supporting a half ton or more of water and expensive fish over that expensive carpet and perhaps the neighbors kids as a learning exercise.
Bill