My idea for a DIY plywood aquarium

[Big Fish Freak]

If the 6" border at the bottom is veneer (and I consider moulding to be basically veneer), then for determining glass thickness it's still 48 inches deep. That's because veneer isn't reinforcing the bottom and the glass at 48" depth is under unreinforced pressure. If on the other hand it's really strongly built to restrain the glass (not simply cover it), that is, the border is physically supporting the glass against pushing out, then the "effective" depth is 42". That reduces the thickness needed to 23mm, (although not 19mm.)

I believe that adding a vertical piece of wood dead center that strongly reinforces the center has the effect of reducing the pressure on the glass as if it's half as wide. That would reduce the 23mm to 17mm. I can't tell you exactly how that has to be done in order to get that effect. I know that people have built large deep tanks and used that method to have tall, rectangular windows with relatively thin glass by keeping the width to a minimum. For example, if you had two 4' by 4' pieces of glass, built them into the tank correctly and had a strong 6" border at the bottom, you could probably use thinner glass like 17mm.

People of course often don't want that strip because it breaks the vision. Personally, I would opt for a longer or wider tank with less depth because I prefer no obstructions. Ultimately, unless you need the depth, it tends to be the choice people make. Four feet deep of course also adds a serious issue in terms of cleaning and maintenance.

So what if I cut down on height, but added width? So, instead of 8'x4'x4' I went 8'x5'x3'..Would that affect glass thickness in a positive way, negative way, or make no difference? I am thinking that with this build, I may want to go less tall as the fish is a top dwelling fish, and once he is out of there I want to put some nice rays in there so wider is better than tall all the way around in this case...It adds some extra cuts but I could just have HD cut them down to 3'x8' sheets for free and then I have the same amount of work to do..I will just have to buy an extra piece of plywood is all..

So if I did an outside "trim" it would basically add no structural support..What if I framed the inside of the tank with 2x4s? that would surely add support and stability to the tank. Would that help reduce the outward pressure of the glass? Or would I have to frame the outside of the tank with 2x4s to do that?
I am starting to understand this more and more every time we discuss it and I will get it eventually..I typically have to see it to understand it, so I am building small mock-ups out of cardboard to understand what you are telling me..haha

I am so ready to get started on this build!!.and since the overall end project is going to end up here at the store, the store is going to be paying for the first two builds..

Let me know what you think.

 

[sashimimaster]

Im interested to see how the Ames Blue works out. It was on my list of potential sealers but I decided against it because I didn't think it was thick enough. There is a thread comparing different types of sealers (maybe a sticky).

 

[Big Fish Freak]

The Ames should do pretty well..I will have to find that thread and check it out..I already have a call into them, waiting for a call back, on whether or not I can safely dye it black cause I don't like the blue..I thought about another brand but it will cost me half the price of the product just to ship it to me and that seems like an unneeded expense at this point..If I can dye it cool, if not, I will figure something out..maybe if it is too thin i can figure out a way to thicken it up without compromising waterproofing ability..

I was thinking about maybe doing an epoxy coat over my Ames Blue, but it's technically an unnecessary step and will cost more $$ so I will make that determination later..If it comes down to it, I may just scrap the Ames and go with one of the other brands...I'm fairly confident in the Ames though from reviews I read and talking to someone at the company, but only the finished product will tell the truth..

 

[wednesday13]

Ames blue max is often used on cement ponds/fountains...it is fish safe and has already been proven to work on wood by other members. The member "Tobeinchrist" (not positive on that spelling lol) has had a 400gal up with it for around/over a year now. I use it all the time for painting tank lids, basement walls or wood i dont want to get wet/rot. Would i ever use it on a tank....no lol... the product never dries...and full submersion of a waterbased paint ensures it never will. On "dry" applications the ames remaines a dark transparent blue and stays very tacky. My basement walls are still sticky after 2 yrs of application. On "wet" or submersed applications the ames turns light blue and gets soft. You can pretty much scratch it off with ur finger when its around water if u want too. Can it work...sure...for how long is the question. Far more options out there for a better outcome and life of the tank. You can paint a black base coat to darken the blue ames but once its submerged i imagine itell lighten up anyway. Painting epoxy paint over rubber waterbased paint will not work either. For one, the paint wont stick and as the rubber paint flexes the brittle epoxy paint will flake off.

Sent from my SAMSUNG-SGH-I747 using MonsterAquariaNetwork App

 

[Drstrangelove]

So what if I cut down on height, but added width? So, instead of 8'x4'x4' I went 8'x5'x3'..Would that affect glass thickness in a positive way, negative way, or make no difference?

That would reduce glass thickness needed for a 2.5 safety factor from 28mm (4 feet high) to 19mm (3 feet high.) You'd lose 6% total gallons but gain 25% more footprint. So, if you don't need the extra height, it's got lots of plusses all the way around.

So if I did an outside "trim" it would basically add no structural support..What if I framed the inside of the tank with 2x4s? that would surely add support and stability to the tank. Would that help reduce the outward pressure of the glass? Or would I have to frame the outside of the tank with 2x4s to do that?

If the outside is really only trim, then it adds no significant support, but you can build support at the bottom, sides and top. It's just a design preference as long as the tank is built to hold properly. I'd take a look at the many builds people have posted, take a crack at designing yours, then post it for review.

 

[Big Fish Freak]

Ames blue max is often used on cement ponds/fountains...it is fish safe and has already been proven to work on wood by other members. The member "Tobeinchrist" (not positive on that spelling lol) has had a 400gal up with it for around/over a year now. I use it all the time for painting tank lids, basement walls or wood i dont want to get wet/rot. Would i ever use it on a tank....no lol... the product never dries...and full submersion of a waterbased paint ensures it never will. On "dry" applications the ames remaines a dark transparent blue and stays very tacky. My basement walls are still sticky after 2 yrs of application. On "wet" or submersed applications the ames turns light blue and gets soft. You can pretty much scratch it off with ur finger when its around water if u want too. Can it work...sure...for how long is the question. Far more options out there for a better outcome and life of the tank. You can paint a black base coat to darken the blue ames but once its submerged i imagine itell lighten up anyway. Painting epoxy paint over rubber waterbased paint will not work either. For one, the paint wont stick and as the rubber paint flexes the brittle epoxy paint will flake off.

Sent from my SAMSUNG-SGH-I747 using MonsterAquariaNetwork App

Do you think it's possible that it not drying could be a humidity/moisture issue? I talked to a couple Ames reps just an hour ago and both told me that Blue Max dries..they did tell me however that tank maintenance is crucial because different microbes and microorganisms (i'm assuming he means algaes and such) eat at sealants..
They told me 2-3 coats should do the trick..
i may look into other options...there is a thread on here (sticky i think) that listed someof the better waterproofing agents and Blue max was near the top so it can't be that bad..

 

[Big Fish Freak]

That would reduce glass thickness needed for a 2.5 safety factor from 28mm (4 feet high) to 19mm (3 feet high.) You'd lose 6% total gallons but gain 25% more footprint. So, if you don't need the extra height, it's got lots of plusses all the way around.

That might be the route I take for this build then..I will probably still get tempered glass, just to be safe..
I can deal with a 6% gallon loss and a 25% footprint gain..I love wide tanks..

If the outside is really only trim, then it adds no significant support, but you can build support at the bottom, sides and top. It's just a design preference as long as the tank is built to hold properly. I'd take a look at the many builds people have posted, take a crack at designing yours, then post it for review.

I will do that..either sketch somethin up on the cpu or will use my cardboard models..lol

So now, with a sheet of plywood only being 4' wide, how do I add that extra 12" on the bottom panel? Common sense tells me wood glue and clamps but is that doable for this situation?

 

[Big Fish Freak]

Okay, so I did a mock up of what I am thinking of doing support wise on the inside of my tank..I only did one side as I only was using the paint program that is standard on the cpu and it was making me very angry...just imagine that everything lines up correctly and that it applies to all 4 sides of the tank..lol
obviously the red boxes are vertical supports and the greens are horizontal..I'm not 100% sure how I would get those screwed together through the ply, and another 2x4 but I suppose they make screws long enough to reach...
I'm thinking that this is going to be the overall strongest build, especially with the braces over the top...let me know what you guys think...

And also, I remember looking at a thread here that was comparing different waterproofing types and brands, it was actually Where I got the idea for the Blue Max, and I have no idea where I saw it...does anyone happen to know or have the link to that thread? I want to have a backup ready just in case I decide against the Blue Max.. I have seen some pretty good results with ACR MAX but does anyone know where to get it other than off ebay? Can I buy it in a store somewhere?

 

[coolkeith]

To join the plywood bottom, you'll probably need to use 2 layers of plywood.

Max ACR from Polymer Products can only be purchased on EBay. I've ordered from them a few times already. MAX BOND THIXOTROPIC is also a good product to use to get water-tight plywood joints, to bond/seal screws in the screw holes, and to laminate pieces of plywood together.

In my current build, for the front frame where the glass will be siliconed to, I laminated 3 layers of plywood together with Max Bond. At 1st I was just going to use 2x4's for the front frame, but I learned that 2x4's weren't straight enough for my liking. Also have 2 layers of ply on the bottom and sides. I just used Titebond III wood glue for that though. The tank size is 10x2x2.

 

[Big Fish Freak]

To join the plywood bottom, you'll probably need to use 2 layers of plywood.

Max ACR from Polymer Products can only be purchased on EBay. I've ordered from them a few times already. MAX BOND THIXOTROPIC is also a good product to use to get water-tight plywood joints, to bond/seal screws in the screw holes, and to laminate pieces of plywood together.

In my current build, for the front frame where the glass will be siliconed to, I laminated 3 layers of plywood together with Max Bond. At 1st I was just going to use 2x4's for the front frame, but I learned that 2x4's weren't straight enough for my liking. Also have 2 layers of ply on the bottom and sides. I just used Titebond III wood glue for that though. The tank size is 10x2x2.

By 2 layers do you mean staggering the bonds? e.g. , the bonded side in front on the bottom layer, and the second layer having the bond in the back? And where can I buy MAX BOND THIXOTROPIC?