DIY Stand: Span 6ft with 2X8?

[spence15610]

It sounds like more work for less strength is what I was saying and it is 1/4" thick walls on the rectangle tube not flimsey at all and the beem I used sets on the corner post so it is where the strength is I could remove the front wood all together and still have the same strength it would just be ugly, but you debate it how ever you want. By the way have you checked out the new Ford trucks with the sandwiched wood frames - super super duty

 

[RocketEngineer]

I think the bottom line in any stand design is what is the builder trying to create? A stand for a display tank to be seen in a living space? A support structre that will be sitting out of view? A rack to support the tank, the sump, and all the other equipement?

Steel vs metal: Steel is stiffer but heavier and more difficult to work with. Wood is more flexable and therefore takes a larger volume of material to get the same strength. It is relatively easy to work and can be picked up at any local lumber yard, HD or Lowes.

This thread was about could a 2X8 wooden beam span 60" with only end supports and the answer is YES it can. It will deflect 0.07" (~1/16th of an inch) under that load.

Just my two cents.

 

[Satori]

Wow, after reading this thread, maybe I under-built my 180g stand. :lol:

Sure, it's steel, but it's only 1" square tubing with 1/16" wall thickness. The whole thing only weighs about 25-30 pounds.

As mentioned, a single 2x4 will hold plenty as long as the corners are built right. It's not going to bow down in the middle since glass can't bow down and keep pushing it. Heck, most tank manufacturer's stands are only built out of 1/2" or 3/4" particle board, not so much as a single 2x4. I built my old 55g stand completely out of 3/4"x4" wood with no center support.

 

[spence15610]

Also as a structural engineer for a living I would have to say I know materials and load bearings pretty well and have seen what can happen with wood under load compared to metal

 

[spence15610]

very nice and strong stand Satori

 

[Satori]

Coming from a structural engineer, that means a lot to me! thanks.

 

[Rhodophyta]

To concentrate on the specific question starting this thread, yes you could replace the back 2 x 4 with a 2 x 8. but then topping the other 2 x 4's with a 2 x 4 would not work out exactly because of nominal sizing. i. e. a 2 x 4 is actually a 1.5 x 3.5 and a 2 x 8 is actually a 1.5 x 7.25. The 2 x 8 would stick up .25" higher.

One way to solve this is to simply stack on the back also instead of replacing the original 2 x 4. You could still remove the center leg in back. Screwing on some 1/2" or 3/4" plywood 7" or wider to keep the boards together should work fine. Another way would be to saw or plane off 1/4" from the 2 x 8. Or rip some 2 x 8 into actual 1.5" x 3.75" stock.

 

[anative]

Thanks everyone for all the feedback and ideas. From reading through all of the responses it sounds like there a few different ways to go which is great.

Jon