new plywood project.

[Backfromthedead]

ok so about a month ago i got this tank. after extensive buffing, cleaning, patching several cracks with acrylic, and creating an ornate 3d background i finally filled it with water. leaks. put in another patch. more leaks. it seems the back bottom seam of this tank is just beyond hope of repair. it keeps opening around the bottom and developing small leaks.

ive become very frustrated with the tank quite honestly. but also see an opportunity. the funky shape of the tank ive never really loved but i do love a bowfront. so why not make two bowfront plywood tanks out of the front and rear pieces, which are both 3/4" acrylic and have no cracks at all.. i could do any footprint i wanted too. im pretty excited thinking about it but have never done a plywood tank before.

for those of you that have, how difficult would it be with this curved front? is it even possible? the front piece is 7' and the back is 6'. maybe a 300 gallon out of one and a 250 with the other?

 

[Zanson]

you could also rip the bottom off, and reattach it with acrylic cement (what ever that stuff is called)

bowfront with plywood would be interesting, you would most likely need to find a way to warp the wood like the bow front acrylic. that in itself would put more strain on the wood i would think so im not sure how well it would hold up long term since the pressure from the water is pressing out with the convex structure.

 

[Backfromthedead]

you could also rip the bottom off, and reattach it with acrylic cement (what ever that stuff is called)

bowfront with plywood would be interesting, you would most likely need to find a way to warp the wood like the bow front acrylic. that in itself would put more strain on the wood i would think so im not sure how well it would hold up long term since the pressure from the water is pressing out with the convex structure.

ive kinda been brainstorming that too. what do you think of this stuff?

http://www.roberts-plywood.com/half-rounds.html

would 5/8" thick cut it?

 

[wannadivesteve]

ive kinda been brainstorming that too. what do you think of this stuff?

http://www.roberts-plywood.com/half-rounds.html

would 5/8" thick cut it?

I'm thinking half rounds are pre-bent to a possibly worse curve than bending straight plywood might be as far as matching Your curved acrylic. Or are you thinking of using your half rounds as the ends ( that could look kind of sharp if you could make it work).

My vision of this is to get those front and back sides off, figure out what size you want to make it, and trace your tops and bottoms in plywood and cut the curves you need, then find a woodworker who would bend some solid 1"x4"s (1"x3"?) to match your top and bottom plywood and add those to complete the top and bottom frame. You'd still need to deal with the ends and end frame pieces. Either that or learn about bending wood. I could be completely wrong but I think bending plywood might not be the best of ideas. I am not a wood worker, but I think bending wood involves a pipe, a bunch of steam, and a lot of clamps. Someone who already does it might be able to do it fairly readily.

I hope this makes sense. We could be thinking of totally different patterns.

 

[Backfromthedead]

I'm thinking half rounds are pre-bent to a possibly worse curve than bending straight plywood might be as far as matching Your curved acrylic. Or are you thinking of using your half rounds as the ends ( that could look kind of sharp if you could make it work).

My vision of this is to get those front and back sides off, figure out what size you want to make it, and trace your tops and bottoms in plywood and cut the curves you need, then find a woodworker who would bend some solid 1"x4"s (1"x3"?) to match your top and bottom plywood and add those to complete the top and bottom frame. You'd still need to deal with the ends and end frame pieces. Either that or learn about bending wood. I could be completely wrong but I think bending plywood might not be the best of ideas. I am not a wood worker, but I think bending wood involves a pipe, a bunch of steam, and a lot of clamps. Someone who already does it might be able to do it fairly readily.

I hope this makes sense. We could be thinking of totally different patterns.

yeah i see what youre saying. no i was gonna use the half round for the front but noticed they dont have any sheets for a corresponding size diameter that would match my tank. im trying to find exactly what diameter im looking for but cant remember the equation from trigonometry class lol.

what if i just doubled up on 5/8" or 3/4" plywood?

 

[wannadivesteve]

yeah i see what youre saying. no i was gonna use the half round for the front but noticed they dont have any sheets for a corresponding size diameter that would match my tank. im trying to find exactly what diameter im looking for but cant remember the equation from trigonometry class lol.

what if i just doubled up on 5/8" or 3/4" plywood?

I just saw that apparently plywood can be bent by steaming or soaking. I was worried about weakening the glue already in the plywood.

It'd take some time and some extra wood to make a form that matches the curve of your tank, along with a lot of clamps. Maybe you could curve/bend a couple 3-4 inch wide lengths of 5/8ths and laminate them together for extra strength?

I saw a kerfing method that looks real easy but it would really reduce the strength of the plywood. There are bending instructions on the web. You'd be taking a bit of a chance. I'm assuming that your front and back acrylic panels were already curved on a form and will want to keep their shape so it might be a matter of just making the frame strong enough so they don't pop out of place and create leaks. If that's the case the biggest issue would be getting a good seal between the acrylic and the epoxied plywood.

 

[Backfromthedead]

i wonder if i could bend the wood on the acrylic pieces themselves to get a precise fit

 

[Zanson]

i wonder if i could bend the wood on the acrylic pieces themselves to get a precise fit

assuming you leave the bottom and top acrylic attached for structure, then you probably could assuming you are not heating the wood. but if you remove the top and bottom acrylic, and just have the curved panel. that panel will give a bit with weight and everything will be off.

 

[monkeybike]

It doesn't seem to be that drastic of a curve. I would laminate 2 sheets of thinner ply formed over a matching curve. Use titebond applied with a roller. I would mark off the size of your window opening and blow screws all around inside the area to be cut and clamps around the outside of the window cut area.

 

[Backfromthedead]

assuming you leave the bottom and top acrylic attached for structure, then you probably could assuming you are not heating the wood. but if you remove the top and bottom acrylic, and just have the curved panel. that panel will give a bit with weight and everything will be off.

i actually have a jig that i made out of plywood to build the 3d background for the tank. it matches the curve of the tank. probably just use that.