Ply Wood Tank Help

OK as far as the cuts you first set the table saw on 45* and rip them end to end. Then you use the miter saw.
Here are some pictures sowing spreading the epoxy.

 

Got it Thx. Looks like you used fiberglass on top of your mitered braces as well? How many coats of resin do you apply 3-4? Do you also go over all the corners with silicone?

 

DON'T PUT SILICONE ANYWHERE YOU WILL COVER WITH EPOXY! The epoxy won't stick to it. Of course putting silicone on the epoxy is fine -thats how it's done. But the revers is not true.

2-3 coats is fine. The thicker the better. Thats not my tank, but he got a package that came with the fiberglass so he used it... Not necessary, especially with the 45* pieces, but anything to add to the strength. You may need to sand between coats, but I'd contact the manufaturer of the resin to make sure. Not all need that.

You can see that these tanks are meant to last a lifetime. With Glass, you are limited as to how much you can do to lengthen the life/minimize the risk of failure. But with plywood, it's as good as you build it. So building it well is important IMO.

 

Sorry for not being more specific, but I meant after. I still think in my specific case I won't need the extra reinforcement. Lots of other people have had 20yrs or more success without it. Mine being stuck in a concrete enclosure should be fine. I will probably do 4 coats of resin and then seal with silicone. Should be about bullet proof at that point anyway. I do see your point for sure, and if this was a free standing tank I wouldn't hesitate to do it. Will probably use some fiberglass though.

 

You won't need any silicone other than for the glass...

As far as the 45*'s go, theoretically, you could even use quarter-round moulding. Just something to change that tension seal into a compression seal. Then you wouldn't even need to rip them... It's already done for you.

 

That is an excellent solution, I will do that. probably would only need to put liquid nails to hold them in place? Jason, what to you use as a top brace? I have seen tension rods or one wood brace across the top from front to back. My concern with that is that it would block some light from getting to the tank.

 

I used 1x6 pine and created a eurobrace around the top. Nothing spans the tank.

I'd use finishing nails and glue. The only problem with the quarter round will be the vertical pieces... To get them to fit would require routering the ends with a quarter round bit. Or you could see if they have non round moulding...

 

I'm not sure I understand how that keeps your tank from expanding front to back?

 

Well, in the first plce, the plywood frame you'll build is FAR more resilient than glass and that will add to the rigidity. (See zero edge tanks with NO bracing -it's not needed because the glass is so thick) So flexing would already no be too much of an issue. Then add to that the strength of the epoxy resin, which we've already discussed in this thread, and you have a tank that should be strong enough (Obviously you still need to have glass the correct thickness, but hypothetically this will be less than any other glass tank -even without bracing due to the already mentioned factors, but also the fact that the glass does not sit on the bottom of the tank, and so doesn't "feel" the pressure at the highest point -the bottom corners of the tank.) But for added piece of mind, I added euro bracing which adds to the tension of the tank, tieing the top front panels to the top rear, and the same for the sides. It basically ties easch top surfact to EVERY other top surface, reducing bowing. It's used extensively in aquarium building.

 

My tank will be 36" high. I may just add like an adjustable tension rod at the top for added insurance and that won't block any light to speak of. How many of these tanks have you built and how long have they been running?