CyclistMT
More Idiot Than Savant
When I was researching building a plywood tank I couldn't find a lot of resources to look to. So, in addition to my post, here are a couple others to get you started if you're thinking about trying this.
Instructions for plywood tank construction
scchase's build thread
jcanute build thread
Sean : EbN build thread
I'm no stranger to glass tanks and used to work at a LFS that manufactured all of the tanks we sold. I have built several glass tanks and was not afraid to build another, but when I started to estimate the cost to purchase pre-built or build my own, I began to consider other options.
The size and shape of the tank I wanted would require a custom build and it quickly became very expensive. The tank I wanted would be 48L x 24H x 32W. This would require fairly thick glass. At a minimum, a tank of these dimensions should be built with 1/2" glass on all sides and 3/4" for the bottom. Additionally a strong cross brace or a well designed Euro brace would be required. Just to purchase the glass I guessed it would be in excess of $600.00 and to have it custom built and shipped, well over a $1000. There are no custom tank builders near this piece of Montana.
I didn't even want to think about how heavy a glass tank of this size would be. Acrylic wasn't an option for me as I've never worked with the material on this scale and wouldn't trust in my ability to construct it.
For me, that left a plywood/glass option only. I have reasonable woodworking skills and can wield a paint brush with the best of them so I figured I could get the job done. All tolled I have around $420 in to this build. I know, some will say that the cost of the tank is one of the least expensive investments in a reef tank. That may be true but you've got to try and save somewhere right? I am also going with 100% DIY rock and with a careful selection of good quality equipment I figure I will have $3000 or at most $3500 before livestock. With an all glass or acrylic tank and live rock, I would be well over $5000.00. That $1500+ I've saved will buy some nice corals and fish.
After much research I decided that I would trust in the epoxy to provide enough of waterproofing without using fiberglass. Many people talk about using fiberglass when building these tanks and you can see examples of that in the posts above. I have a strong feeling that most of them do it to enhance structural integrity of the tank and maybe they need to because of the massive sizes they build. I have never worked with fiberglass either and I didn't really want to hassle with the mess. Once the tank was constructed, I had no worries about structural integrity. With 3/4" plywood, Euro bracing and only 4' in length I am not worried about any kind of deflection at all. I used 3/8" glass for the front and side viewing panels because that's all that's necessary for the 24" height. The plywood is taking the pressure load here so it allowed me to reduce the glass thickness from what would be necessary in an all glass tank.
I used hemlock plywood I found at Lowes because it came in precut sizes that would work for me and was sanded on both sides. This saved me the hassle of filling in imperfections and minimized the cuts I needed to make. It was a little more expensive this way over a 4x8 sheet of plywood but it saved me a lot of hassle. I didn't even bother looking for marine grade plywood as suggested at some sites as I figured it would require special ordering at best and if the epoxy is applied correctly, water should never reach the wood anyway.
Here is my materials list and approximate cost:
Plywood- $120.00
Epoxy- $100.00
Glass- $150.00
Screws, filler, silicone, Liquid Nails- @$50.00
I don't have my receipts in front of me but that's in the ballpark.
If you've stuck with me this far and are interested in trying a project like this for yourself, let me offer this word of warning. If you've never picked up a saw in your life, this will be a very difficult project. You should have some basic workworking knowledge like how to square a corner and that you need to drill pilot holes before inserting screws. If these are foreign concepts to you, this project might not be up your alley. FWIW.
Plywood you can get at your favorite lumber yard or box hardware store.
Epoxy can be found at local paint stores but if you try to find anything even remotely out of the ordinary in Billings, MT you're usually met with a blank stare. I didn't even bother to try and just ordered mine from Aquatic Ecosystems. They have a variety of colors as well.
Glass can be custom cut at any glass shop but call around. You will get many different price quotes. The bigger glass shops will usually be cheaper as they deal in much lager quantities. I was quoted twice the price for my glass from one shop with only ground edges. Where I ended up buying it, not only was it half the price but they beveled the edges too.
For filler I used Dap Plastic Wood. Once cured, this is very strong stuff. It took a lot of elbow grease to sand it down. I used this in the corners to ensure a uniform surface for the epoxy coating.
For screws I opted to use stainless steel deck screws. Probably not necessary as again, no water should be getting to them anyway but it gave me a little more peace of mind. I found them at Home Depot. I used 2 1/2" x 10. In retrospect I wish I would have used a smaller gauge and length. Even with pilot holes I got some bulging but it wasn't bad enough that I'm worried about it. Perhaps my pilot holes weren't large enough but I think a smaller gauge would be better suited since you are fastening into plys and not solid wood.
For silicone I used GE 1 Window and Door 100% clear. I kind of wish I would have sprung for black silicone though. Ultimately black would probably be less noticeable. I don't know if GE makes an aquarium safe black but I think you can buy black silicone at Aquatic Ecosystems as well.
Ok, on to some pictures.
I pretty much followed the Garf instructions. Sides on top of bottom, Liquid nails between the wood interfaces, and screws about every 2 inches.
Epoxied and outside frame painted:
The epoxy is not a smooth as it could be but it was 90+ degrees when I did it so it's not perfectly pretty but functional. Rock will probably cover most of it anyway.
Preparing to install glass and front panel glass installed:
After both glass panels were installed it sat in my garage for about 3 weeks with water in it. No leaks!
And now, in its final resting place. Obviously I still have trim work to do and please ignore the light. I was just playing with it. The tank will be lit with real MH reflectors.
I still have a lot of work on the fish room....err fish closet so I'm many months away from water but I though it might be nice to share my project thus far.
Instructions for plywood tank construction
scchase's build thread
jcanute build thread
Sean : EbN build thread
I'm no stranger to glass tanks and used to work at a LFS that manufactured all of the tanks we sold. I have built several glass tanks and was not afraid to build another, but when I started to estimate the cost to purchase pre-built or build my own, I began to consider other options.
The size and shape of the tank I wanted would require a custom build and it quickly became very expensive. The tank I wanted would be 48L x 24H x 32W. This would require fairly thick glass. At a minimum, a tank of these dimensions should be built with 1/2" glass on all sides and 3/4" for the bottom. Additionally a strong cross brace or a well designed Euro brace would be required. Just to purchase the glass I guessed it would be in excess of $600.00 and to have it custom built and shipped, well over a $1000. There are no custom tank builders near this piece of Montana.
I didn't even want to think about how heavy a glass tank of this size would be. Acrylic wasn't an option for me as I've never worked with the material on this scale and wouldn't trust in my ability to construct it. For me, that left a plywood/glass option only. I have reasonable woodworking skills and can wield a paint brush with the best of them so I figured I could get the job done. All tolled I have around $420 in to this build. I know, some will say that the cost of the tank is one of the least expensive investments in a reef tank. That may be true but you've got to try and save somewhere right? I am also going with 100% DIY rock and with a careful selection of good quality equipment I figure I will have $3000 or at most $3500 before livestock. With an all glass or acrylic tank and live rock, I would be well over $5000.00. That $1500+ I've saved will buy some nice corals and fish.
After much research I decided that I would trust in the epoxy to provide enough of waterproofing without using fiberglass. Many people talk about using fiberglass when building these tanks and you can see examples of that in the posts above. I have a strong feeling that most of them do it to enhance structural integrity of the tank and maybe they need to because of the massive sizes they build. I have never worked with fiberglass either and I didn't really want to hassle with the mess. Once the tank was constructed, I had no worries about structural integrity. With 3/4" plywood, Euro bracing and only 4' in length I am not worried about any kind of deflection at all. I used 3/8" glass for the front and side viewing panels because that's all that's necessary for the 24" height. The plywood is taking the pressure load here so it allowed me to reduce the glass thickness from what would be necessary in an all glass tank.
I used hemlock plywood I found at Lowes because it came in precut sizes that would work for me and was sanded on both sides. This saved me the hassle of filling in imperfections and minimized the cuts I needed to make. It was a little more expensive this way over a 4x8 sheet of plywood but it saved me a lot of hassle. I didn't even bother looking for marine grade plywood as suggested at some sites as I figured it would require special ordering at best and if the epoxy is applied correctly, water should never reach the wood anyway.
Here is my materials list and approximate cost:
Plywood- $120.00
Epoxy- $100.00
Glass- $150.00
Screws, filler, silicone, Liquid Nails- @$50.00
I don't have my receipts in front of me but that's in the ballpark.
If you've stuck with me this far and are interested in trying a project like this for yourself, let me offer this word of warning. If you've never picked up a saw in your life, this will be a very difficult project. You should have some basic workworking knowledge like how to square a corner and that you need to drill pilot holes before inserting screws. If these are foreign concepts to you, this project might not be up your alley. FWIW.
Plywood you can get at your favorite lumber yard or box hardware store.
Epoxy can be found at local paint stores but if you try to find anything even remotely out of the ordinary in Billings, MT you're usually met with a blank stare. I didn't even bother to try and just ordered mine from Aquatic Ecosystems. They have a variety of colors as well.
Glass can be custom cut at any glass shop but call around. You will get many different price quotes. The bigger glass shops will usually be cheaper as they deal in much lager quantities. I was quoted twice the price for my glass from one shop with only ground edges. Where I ended up buying it, not only was it half the price but they beveled the edges too.
For filler I used Dap Plastic Wood. Once cured, this is very strong stuff. It took a lot of elbow grease to sand it down. I used this in the corners to ensure a uniform surface for the epoxy coating.
For screws I opted to use stainless steel deck screws. Probably not necessary as again, no water should be getting to them anyway but it gave me a little more peace of mind. I found them at Home Depot. I used 2 1/2" x 10. In retrospect I wish I would have used a smaller gauge and length. Even with pilot holes I got some bulging but it wasn't bad enough that I'm worried about it. Perhaps my pilot holes weren't large enough but I think a smaller gauge would be better suited since you are fastening into plys and not solid wood.
For silicone I used GE 1 Window and Door 100% clear. I kind of wish I would have sprung for black silicone though. Ultimately black would probably be less noticeable. I don't know if GE makes an aquarium safe black but I think you can buy black silicone at Aquatic Ecosystems as well.
Ok, on to some pictures.
I pretty much followed the Garf instructions. Sides on top of bottom, Liquid nails between the wood interfaces, and screws about every 2 inches.
Epoxied and outside frame painted:
The epoxy is not a smooth as it could be but it was 90+ degrees when I did it so it's not perfectly pretty but functional. Rock will probably cover most of it anyway.
Preparing to install glass and front panel glass installed:
After both glass panels were installed it sat in my garage for about 3 weeks with water in it. No leaks!
And now, in its final resting place. Obviously I still have trim work to do and please ignore the light. I was just playing with it. The tank will be lit with real MH reflectors.
I still have a lot of work on the fish room....err fish closet so I'm many months away from water but I though it might be nice to share my project thus far.
