Idea for Reinforcing Plywood Panels

  • We are currently upgrading MFK. thanks! -neo
K

Karl424

Feeder Fish
Jan 15, 2010
2
0
0
England
I want to build a plywood tank 60x15x30.

According to GARF they do not advise building above 24 height if going longer than 60 inches.I assume this is to do with the wood flexing i have come up with a solution.

2 x 12mm plywood panels.
10mm steel rods.

If you cut out a 5mm groove down the length of each plywwod sheet inserted steel rods at various intervals and glued the 2 panels together you would have 1 panel reinforced with steel.

Good idea? Can anybody see anything wrong with this plan?
 
I would either
a# use thicker ply
b# use external framing for support or
c# fiberglass both sides to create a sandwich.

My tank is 106" x 48" x 41". Built with 1,1/4" ply(32mm), no external framing but fiberglassed both sides with no bowing at all.
 
I agree with greenterra. I don't think the steel rod idea is going to work.
 
I think the steel rod could help, but I think it would be a lot more work and not get you any added benefit. I agree with the others, just use thicker plywood or ad additions wood supports on the exterior.
 
With proper bracing along the top and maybe even an exoskeleton using just 2x4s (which is probably overkill) I don't think GARF is worried about the plywood flexing. I think they're more concerned with the thickness of glass and the chance of a higher probability of failure. As awesome as GARF is with all of its resources I think they tend to stay on the safer more conservative side when it comes to building plywood tanks. Just my thoughts on the matter.
 
My friend used steel threaded rod across the top of his 26 ft long 2600 and on the smaller 2200. Works fine. Ugly as crap, but works nonetheless.

Check out my 90 Gallon Expansion thread to see how I'm doing the exoskeleton framing. Same thing could work on longer, narrower tanks.
 
Thanks for the input i don't think i explained clearly it is not 1 steel rod.

The steel rods would be sandwiched vertically at intervals between the plywood sheets.

Exterior bracing is not an option as space is limited think i will go with just thicker plywood.
 
Karl424;3791179; said:
I want to build a plywood tank 60x15x30.

According to GARF they do not advise building above 24 height if going longer than 60 inches.
Click to expand...

I know of at least one plywood tank that was 42" tall that had no bracing, not even fiberglass reinforcement. It was made from 3/4" plywood sealed with epoxy paint. Flexed badly but has held water for over a decade and was even moved across town once.

This tank did not have a viewing window, however, so the flex was not an issue.

Still, given your space concerns I would encourage you to use fiberglass reinforcement. You'll get more rigidity than your solutions offer and at less thickness.

Not fun to work with but the right choice in this case I think. I would use a cheaper polyester to save on costs.

And remember, while fiberglass matt is cheaper than fiberglass cloth and roving, it takes more resin to wet it out so there are basically no cost savings. I believe there are online calculators that help you figure this out.
 
I think there are basically two main ways to reinforce the plywood panels.

1. Frame the outside of the tank with 2 x 4's and then attach the plywood panels. This is the idea similar to how walls for homes are constructed.

2. Put internal bracing inside the plywood tank. I have seen examples where nailers have been used.
 
You must log in or register to reply here.
MonsterFishKeepers.com
Top Bottom