900 gallon plywood shark tank build

[dingodan]

So some of this is already in another tgread i created but it was more about me asking what materials to use. Now that ive decided to go with a stacked 2x4 frame followed by oak plywood, acr epoxy fiberglass and sweet water paint top coat(s), here is the build so far. I obviously can't change what ive done but if anyone has suggestions moving forward i am happy to hear em. For the top bracing ill be putting in 3 2x4 braces lag bolted across the top that will then be eurobraced with 3/4 plywood. I also plan to use 3/4" glass for the front panel. Inside dimensions of the tank are 126"' by 50" by about 38" tall (29" water depth). Those overflows are actually pool skimmers that will be piped directly to the intake of my pumps. There is no sump but the output of my skimmer will be above the tank, so think of it like the skimmer is the tank and the tank is the sump if you want.

 

[dingodan]

Max bond non sag epoxy on the corners and screw holes

 

[dingodan]

Next step is fiberglassing corners before fiberglassing floors and walls

 

[dingodan]

You cant see in the pics but there are also small sections with no 2x4 backing to allow for bulkheads. A Total of 10 lag bolts were used to secure the bottom 2 layers of 2x4 into the bottom joists (2 on each and and 3 on the front and back).

 

[tlindsey]

Next step is fiberglassing corners before fiberglassing floors and walls

 

[twentyleagues]

Yeah you ain't kidding!

 

[dingodan]

One thing i need to give more thought to is the sweetwater paint colors. I want the bottom to look like sand and the back to look like the ocean so i plan to use their light grey on bottom but for the walls i need a bit of green for it to look realistic. I can buy their light blue and their light green but i only need a bit of green to tint it and at almost 100 buks a can its a pretty expensive tint. Cant seem to find any info about adding common epoxy coloring powder to epoxy paint but it would be alot cheaper if i can

 

[fishhead0103666]

I always say there needs to be more saltwater monster keepers.
Very excited to watch as this continues, you have my attention.

 

[dingodan]

Id also like to know how perfect the screw holes need to be filled. The non sag epoxy does sag a tiny bit so the tops of all the screw holes are all indented a bit still. Not to the point you see the screws but maybe 1/8" deep tops. I find it hard to believe this matters much considering i am fiberglassing over everything but if someone knows something i dont please share.

 

[twentyleagues]

Id also like to know how perfect the screw holes need to be filled. The non sag epoxy does sag a tiny bit so the tops of all the screw holes are all indented a bit still. Not to the point you see the screws but maybe 1/8" deep tops. I find it hard to believe this matters much considering i am fiberglassing over everything but if someone knows something i dont please share.

I don't know the answer to that, but in most builds I have seen they either Bondo over or wood filler over the screws. I always assumed it was a possible weak spot so you would want it as reinforced as possible. I could imagine under all that pressure water some how finding a way past the epoxy could use the screw threads to make an escape.....but if it gets through the epoxy aren't you kind of boned anyway?