Best Glue or Adhesive for tank stands (doubling up 2x lumber)

[Tuffloud1]

I agree and iam a master carpenter and wood worker

Which good old-fashioned wood glue do you recommend? Tight bond one or tight bond 2 or tight bond 3?

 

[danoo]

Ok I just did a little test of deflection between plywood and dimensional lumber.

The contenders: Two roughly ~31" x 3/4" x 15/16" pieces of wood.

In one corner we've got our trusty Douglas Fir dimensional lumber, cut down from a 1x4. This lean, mean stick of wood comes in at 153g.

In the other corner we've got ultra high quality 3/4" baltic birch plywood, interior grade. This beautifully engineered piece of wood comes in at 231g.

Let's put them to the test with a 25 pound weight right in the middle and measure the deflection.

And the results:

I'd call it a push within the margin of error. But of course, the dimensional lumber is getting similar results while being lighter and cheaper, and pre-cut in the dimensions you want it.

 

[Tuffloud1]

Ok I just did a little test of deflection between plywood and dimensional lumber.

The contenders: Two roughly ~31" x 3/4" x 15/16" pieces of wood.

In one corner we've got our trusty Douglas Fir dimensional lumber, cut down from a 1x4. This lean, mean stick of wood comes in at 153g.

In the other corner we've got ultra high quality 3/4" baltic birch plywood, interior grade. This beautifully engineered piece of wood comes in at 231g.

Let's put them to the test with a 25 pound weight right in the middle and measure the deflection.

And the results:

I'd call it a push within the margin of error. But of course, the dimensional lumber is getting similar results while being lighter and cheaper, and pre-cut in the dimensions you want it.

Ha ha ha ha!!

Love it!

That’s awesome, nice work and thank you for doing all that.

 

[ca1ore]

So you think I'd get better resistance to deflection with the 3/4 plywood Titebonded to the 2x8 than a 1x8 Titebonded to the 2x8?

I do, yes. Plywood is often used to scab house joists. In fact I have used it to help mitigate floor deflection under my larger tanks. Use glue and screws though. The other advantage of plywood is that it starts out flat and stays that way. As to the ‘test’ above, I’ve found that as the samples get larger, the differences do as well. When I was building the stand shown above, I stood on the 8’ length without any span support and had my son judge defection. Dual 8” ply didn’t deflect at all, a single 2x8 deflected about 1/4”. OK, maybe it’s a distinction without a difference. Folks have been making stands with dimensional lumber since the dawn of time, I just like trying new stuff and thinking outside the proverbial box. I think either choice you make will suffice. 260 just isn’t that big (plus if you measure actual volume you’ll likely find you’re closer to 220).

 

[Tuffloud1]

Reporting back, I sistered on a Doug Fir 1x8 to the 2x8 by gluing with Titebond 3 and screwing a bunch of screws. Let it cure for almost 3 days.

Just filled the tank back up.

The deflection is now almost non-existent at 1/32 of an inch in the middle.

I’d say it worked.