200g Cantilevered "In-Wall" Plywood/Glass Tank

[dougwilliams]

Just thought I'd share some of this with you all-

I'm in the process of designing a new tank - and luckily have the room available in my house. So I'm going semi--in-wall, and building a 200g tank that will cantilever out of the wall - sort of like a bay window. It will be a fiberglass/epoxy over plywood tank. It's not entirely done design-wise (so there is still some more bracing etc scheduled to go in the plans). But I do have the wood sitting in my garage just waiting to be cut :) (And an old laundry room wall waiting to be hacked into as well).

There will be a light rack above (havent worked on that much yet) - and an access panel also on the front/top for easy front side access.

Similarly, as the tank and stand are "one" (I'm not building a tank and putting it onto a stand) - the sump is also integrated into the stand (backside). Thats why the plywood sheathing/stand reinforcement is on the backside (which also allows an otherwise natural wall line on the front side with standard wall sheathing etc).

Plumbing is done in my head - but not drawn up yet - in summary - its an external overflow on the back (slots will be added across the back/top), and main flow will be provided by CL system.

Questions/Comments/Critiques welcome....

(PS - Colors are just that way to show individual pieces better - all is standard as described above)...


http://i119.photobucket.com/albums/o125/dougwilliams/tank13a.jpg

http://i119.photobucket.com/albums/o125/dougwilliams/tank13b.jpg

http://i119.photobucket.com/albums/o125/dougwilliams/tank13c.jpg

[WarrenG]

I don't really see a reason to make the tank and stand all one piece. It's not needed for strength-the 2x4's in the wall and cantilevers will be what supports the tank's weight.

A separate tank allows for more versatility in case you need to remove the tank for some reason, or replace the tank. The amount of side view area will be much less than if you used glass or acrylic for the tank (no need for those view-obstructing corner braces).

I had a tank in this same position in a wall (projecting out about 8") but didn't bother with the cantilevers. I just made a nice-looking stand for the part that projected from the wall.

Instead of a fiberglass lining for the plywood, you might use relatively thin, and inexpensive acrylic or black polycarbonate sheet. The smooth surface is easier to clean, and it may be easier for you to construct the tank.

[DgenR8]

That looks like one heck of a project, Doug.
Following along to see how the finished product looks. ;)

[nullcable]

What epoxy and brand of epoxy would you use for this?

Thanks!!!

--nick

[dougwilliams]

Ok - I think almost all of the issues WarrenG brings up are related - so answering one doesnt really make sense - have to look at the answers to them all -

First, I would rather have an in wall tank, not a tank on a stand in the room. Originally I was going to go a pure single viewable pane in-wall, most of the reason being I dont want to take up floor space in the room the tank is viewed from. I have lots of space in the "fish room" where the tank and stand will primarily reside.

Agreed that if I used a separate tank and stand approach I would have flexibility to move it around or remove it. I dont have anywhere else in my house that I would want the tank though - and once the tank is set up I see little reason to move it.

On the other hand- if I went with a full glass or arcylic tank I would have full visibility and no corner braces. For right or wrong, I'm looking at my approach as an advantage over a single pane in wall - so I do get some side visibility.

If money were no object Id get a curved piece of glass or acrylic and essentially have a bof front that cantilevers into the room. That would be cool. But I think that would be an order of magnitude more than what I'm spending now.

Hmm - but that does give me an interesting idea- not sure if its possible (or if I'd try): just have plywood bottom and top(brace) and essentially dowel or wedge a piece of acrylic or galss between the two - so there wouldnt be corner braces. And if that could be done, than you could also do an angled back pieces in place with no wood braces. Hmm- not sure if I'd be that courageous to try - but I'll sketch it up and add some pics just to illustrate the idea.


Also - I was considering just lining the plywood with thin acrylic/polycarb sheets. I guess in general I dont trust that as much (leak wise) as epoxy/fiberglass. Plus, the fiber/epoxy adds structural integrity to the tank.

And I dotn have to make the tank/stand/sump integrated - but then - why not? It seems to save on material and I dont see mcuh downside. The sump I'm most likely to de-integrate...but we'll see.



(Thanks Larry - should be interesting...)

Null- as for epoxy - I'm not going with west systems or anything branded. Epoxy is basically a comodity item in the industrial world and you just order formulations which are virtually standard. If you do it that way you order up some 821 or 322 or whatever number the company calls it - and be done with it. I'n high volumes around 10 gallons or so I see prices around $30 a gallon (shipped) - which lets me do my tank, fish and laundry room floor and the garage floors as well.

[BeanAnimal]

Doug,

The problem with the "just order some epoxy" concept is pretty simple and also holds true for polyurethane. The "blends" are what are proprietary. So yes there are "standard" formulations that many resellers can get their hands on.... but the good stuff is usually a closely guarded blend that is either patented or unpublished.

Moar Poly is blended by Hess or Stepan. The raw chemicals come from DOW. There are hundreds of not thousands of companies that send Hess or Stepan their "blend" recipes... those recipes are not shared. Hess and Stepan just produce the product and ship it. Epoxy is pretty much the same. You can't call Hess or Stepan any buy polyurethane unless you are buying 100,000 pounds or more and have a recipe....

That means you need to go through a retailer or wholesaler to get your epoxy. Because there are no real standards you will have to find a blend that meets the characteristics you are looking for. (likely food or potable water compatible and also UV stabalized).

If you DO find a good source for a suitable product, please do let the rest of us know. I have sources for polyurethanes, but never looked into epoxy in great detail. The thousands of pounds of epoxy that I have used were resold throug Seka and several other industrail chemical grouting suppliers.

Bean