Large Vat construction ideas

I did look at Sanitred, and my first inclination was to use the Rubbermaid tanks. with Sanitred the issues was that for all of the steps and prep work that had to be done I could have just gone with Fiberglassing the frames. I still have them on my list of alternatives along with a few others that I will try if the first coatings don't work.

The problem with stock tanks in general are that they only come in dark colors, and odd/round shapes. The dark colors will not work as they will suck up too much heat in the summer and reduce the upwelling light that many corals love. I may use the stock tanks in the winter to collect heat in my makeup water to help with heating, but not for the coral tanks. Another is that i would lose about 33% of my growout space if I went with round tanks instead of square.
 
<font color="99CCFF">
dont forget to use fine weeves to fiberglass these vats
<img src="http://www.goldencards.com/database/cards/friendship/hello/01.gif">
 
You should see if OSB works as well as marine grade plywood. I would take into consideration the strength when wet. You will have high moisture and some leaks along the way so you might look into it.
 
From what I understand OSB makes a little more sense than regular plywood, mostly becuase there is more glue, but marine plywood would be a better choice. It is also much more expensive, and I believe OSB will work pretty well. I am painting it all around and that should help as well.

I will be using a fibreglass tape (very fine weave) to seal the seams of the epoxy tank and a thick rubber/fabric tape to seal the seams of the other tank.

I should have some results of the both by the middle of next week. I should get delivery of both coatings by the middle of this week, and will set things up to work on them this coming Saturday. I will let ya know soon how things are turning out.
 
If you buy those 48x44x30 bins often used at LFS at wholesale price and in volume the prices should be well below your price goal.
 
Hi Raaden, I'm about a year behind you with a similar project in a colder climate. It's great to have pioneers like yourself go before me so I can learn at your expense. :) The free exchange of information will certainly help us all. I'll try to share my experience while I pick your brain.

Have you experimented with the shadow cast by a 30" deep vat vs. a shallower vat? Are you planing to have a raised growing platform, or live rock base?

Will OSB stand up to humidity compared to regular fir plywood? From my experience (using it under commercial tanks), it tends to "flake off", fall apart, and bow. It also seems to be less tolerant to salt exposure. Up here in Canada, 3/4" fir plywood is about the same price as OSB ($27.00/sht).

I have used teak and mahogany (marine grade) plywood ($175.00/sht) for tank and vat construction, but have found (good one side) 3/4" fir plywood to be adequate and a world cheaper. The vats I have made have been between 12 - 24", so a eurobrace was all that was necessary (no external frame). The 12" deep vats required no bracing and had no significant bow.

With our cold climate up here, we can't use pressure treated wood, as ventilation is limited during winter months. Is cedar, cypress, or ponderosa pine an affordable option down there?
 
I checked out all sort of bins and pool, and even though the pool idea was somewhat successful I don't feel comfortable enough with them long term to use them.

Shadows shouldn't be too much of an issue inside the GH as the covering does an excellent job of diffusing the light coming into the GH. I can stand with my back to the sun and hardly make out a shadow in front of me. In addition the tanks (with one exception) will be very light in color and should create some good reflection inside the vats further reducing any potential for shadows.

The reason for the depth is twofold. I am going to have a 6" sand base, then another 6 inches of live rock and macro algea, and the next foot or so will be for the corals to use. The other reason is that I want to have as much volume as is reasonable to help with chemical and temperature stability.

OSB I hope will be able to stand up to the humidity pretty well. I have sealed the non waterbearing sides with a good exterior grade paint and will be using an epoxy on the rest of it, so I hope that there won't be much area for the water to seep in. OSB, atleast around me is very cheap (~ $5-6/sheet) which is one plus, and will warp far less than plywood. I have seen some issues already with pieces flaking off, but once it is sealed I don't think this will still be a problem.

I would stay away from oily woods like teak as most coating will not stick to them unless they are stripped first and you don't want to get those chemicals anywhere near your tanks. Marine grade glue is great but eventually the plywood will separate.

I am not sure if you can get it, but there is a new type of pressure treated wood that is non toxic and hazardous, it is a bit more expensive but well worth it if you ask me. It is strange because when I went to buy some I didn't believe it was pressure treated because there was no discoloration and the wood was still somewhat damp. If you can find that I would look into it as pressure treated is definitely the way to go for any bracing you may need.

The more exotic woods are very expensive comparatively around me and would have meant a 2x or 3x increase in price.

P.s. Mr. Wilson have you looked into the bubble greenhouses that they are using in Canada for insulation. It seems like a great idea but I wonder how they fare in comparison with regular poly greenhouses.
 
The liquid soap insulation & shading systems haven't really caught on up here yet, so I don't know how much is function, and how much is gimmick. I'm also not sure how long it would take to pay itself off. It's certainly an interesting idea. Here's a link for those who haven't heard of it. http://www.sunarc.ca/english/home.html

There isn't a lot to it, just a temperature controller hooked up to a delivery pump and reservoir of soapy water. A second solenoid runs freshwater through the system to remove the foam.

They claim it will cut heating costs in half, but they are comparing that to having no other means of trapping heat at night. I don't know how liquid soap insulation would compare to having foil insulation rolled out at night (manual or automated).

You are wise to use cheaper paint for the outside of your vats. The epoxy is only important on the inside.

That's really cheap for the OSB. I see why you went that route.

I think we have a "non-toxic" alternative to pressure treated wood up here that uses copper instead of arsenic and cyanide. Just don't use it in your vats. :)

I see what you mean about the lack of shadows in the GH. Good information.
 
I just bought 3 48X44X30 200G white, food-grade vats from Marine Center for $225. If you buy 7 they will cost you just $150 each. I wish I had more room because I would have bought all these out but my operation can only handle 3. Oh, BTW, the price includes shipping these monsters!

Here is a link and description from Marine Center.

These are new, never used, and we're giving these away compared to what they cost newâ€" and these ARE new! These are the corrugated "vats" used in leading livestock facilities worldwide. Made from white food grade, indestructible, high-density polyethylene. See specifications and prices below. These are virtually indestructible they can easily be drilled with a hole saw for system connections. There is no better, more durable and easier to work with alternative for livestock holding systems.
http://www.marinecenter.com/rocks/equipment/sump200gallon7lot/
 
Those bubble greenhouses are certainly interesting, but with no mention of cost on the site I am wondering just how expensive they are.

Those food bins would be great for a sump or water mixing tank, but for growout they are quite expensive (not as expensive as fiberglass :D ). The cost per sf of growing space on those is ~$12.5 vs the vats that are being made I am looking at ~$5.5. I did see a few used for food service by looking in some business classifieds that were around $85 and that brings it down closer but then I would have to build stands for them which brings the price back up.

Overall I am quite happy with the first round of tanks and the second round (which I will start in the next couple of weeks) should be even better as there are quite a few new epoxies that I have just found that should make the new ones even better.
 
If you're still in R & D mode, you should look into two part urethane (polyurethane) coatings as well. The "epoxy" that I have been using for the past few years is actually one of these. It gives you a marine grade, hammer-tough finish.

This isn't where I get it from, but it's a good description of what it does.
http://www.epoxyproducts.com/lpu.html
 
I have a feeling I will always be in R&D mode, atleast until I run out of space to put the tanks into. Then I will just have to start expanding :p

That site is one of the ones that I did some research on and they have one of the products that I am going to try on the next batch. Apparently when I did my first batch of research I missed quite a few great products.

Epoxies are not at all what they used to be (and most of this is due to those crazy Euros leading the field in this one). No toxins, no carcinogens, and no long term leaching, easy roll on applications. It is making me reconsider that 400G in wall tank I have always wanted.
 
Making plywood display tanks isn't that hard. The glass panel is pushed against a plywood frame from the inside out, so the silicone is more of a gasket, than an adhesive.

You can have the glass overlap the front wood panel (cut-out) by 6" so you have a huge bonding area to work with.
 
Back
Top