Not logged inAmerican Welding Society Forum
Forum AWS Website Help Search Login
Up Topic Welding Industry / General Welding Discussion / Tube steel and welder suggestions
- - By badpacket Date 07-07-2004 01:48

Hi All,

Just bought a house and finally have room for all sorts of tool to hurt myself with. I am currently looking at building a stand for a 100g aquarium, which will end up weighing in the neighborhood of 1200# easily. As the last time I did any welding was in highschool, I'm wondering what would be the recommendations for this project?

Any suggestions on what type of square steel stock to use? Aquarium is 60"L x 20"W. Since its glass, beam deflection needs to be minimal, however I'd still like to avoid having a 'leg' in the center of the front of the stand if possible. I guess it easier to ask it like this. I need to make a table that will support 1200#.

As a rusty novice, I am imagining that stick welding would probably give someone like me the better, deeper weld?

Thanks in advance. I'm looking at the Hobart's BTW.
Parent - - By pjseaman (**) Date 07-07-2004 04:48
I would go for a mig maybe a millermatic135 or if 220volt service is available a millermatic 175. These models have similar cousins in the hobart brand as they are relative companies the technology will be close to the same. As for the aquarium stand probably 1/8" wall 1" square would do the job nicely maybe make the upper rail of angle for a lip for the tank to sit into. you could make some scroll work out if 1/4" or 1/2" rod to add a decorative touch. BTW I have a millermatic210 with spoolgun for Aluminum and if the ability to weld aluminum strikes your fancy this is the machine I would start with. Mig has the shortest learning curve and you should be up to speed in no time.
Just one opinion,
pjseaman
Parent - - By badpacket Date 07-07-2004 06:23

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.

Parent - By swnorris (****) Date 07-07-2004 15:01
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
Parent - By jwright650 (*****) Date 07-07-2004 16:01
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
Parent - By billvanderhoof (****) Date 07-08-2004 05:43
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
Up Topic Welding Industry / General Welding Discussion / Tube steel and welder suggestions

Powered by mwForum 2.29.2 © 1999-2013 Markus Wichitill