500g Reef Tank Build Saga: A Guide on What Not to Do
- Thread starter h2so4hurts
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fwiw, the community, as a whole, doesn't progress when people don't take risks by trying something new, and, we certainly don't learn anything if said "chance takers" don't share their methods and results.
you're a good man, Charlie Brown, and, I'm tagging along as well.
-cap
you're a good man, Charlie Brown, and, I'm tagging along as well.
-cap
h2so4hurts
Active Member
Exactly. I'm not going to blame internet misinformation for this debacle... But it certainly contributed
. So, hopefully I can add a little knowledge about what doesn't work so others can learn from my somewhat expensive mistake(s).h2so4hurts
Active Member
Oh no…This thread was featured in an R2R email the other day. I better not screw this up…
I ended the las post by saying I ordered all the materials for the build and loaded up my car (my wife’s car) with a bunch of wood for the build.
But based on the replies to the first post I think it’d be a good idea to back up a bit and talk about some of my early decisions about the build.
I wanted at least a 30” viewable area and most of the threads I read on-line said ¾” plywood was good to about 36” water height, so I settled on a 35” water height just to play it a little safe. The sketch-up design was originally based on using a 39” glass panel, 1.5” of overlap on the window frame, but when I went to get quotes for glass, glasscages was all out of low iron glass (and wasn’t very helpful about identifying when they might get more in, just FYI) and all of the local glass shops wanted $4000+ for the dimensions I was looking for (37x39, 96x39, ¾” LIG). Combined with the other materials cost, that would have put the project around $5000 at which point I might as well have just built an acrylic tank, or bought one online. But since I had already decided I was going to do a plywood tank I contacted the local Acrylics Wholesaler (Piedmont Plastics, they’re a national distributor, very easy to work with and have great prices!). Their price on the panels I needed was $2100 (because I had to buy full sheets, so I had half a sheet I didn’t need, oh well, it was still half the price of glass). Before I pulled the trigger on the order I searched around to find out the best way to glue an acrylic window into a plywood tank. The results are a mix of Dowsil 795 and 3M 5200, so I thought, great, this will work!
I ordered:
Acrylic panels: front window, 1.5” acrylic, side window 1.25” acrylic - $2100
TotalBoat High Performance Epoxy: $200
¾” Baltic Birch Marine Grade Plywood: $500
4oz Fiberglass Mat: $100
3 quarts of black pond shield: $200
12 tubes of black 3M 5200: $240
5lbs 2.5” deck Screws: $25
5lbs 4” deck Screws: $25
5lbs 1.25” deck screws: $25
Flat black exterior enamel paint (For the outside of the tank): $25
JB Weld wood filler epoxy: $50
Various 2x4's, 2x6's, 4x4 posts: $200
6 tubes of Loctite PL Premium Construction Adhesive: $32
The water-proofing method I chose was not to just use straight pond armor like so many other plywood builds. There are a number of threads, you can look for them, that call into question the long term durability of pond armor and I wanted to be sure this wasn’t ever going to leak (LOL!) so I built it like a canoe and watched a bunch of videos on youtube about “how to fiberglass you boat” it was actually pretty easy once I got it all going, and satisfying. The key to fiberglassing though is air bubble removal. If you decide to fiberglass a tank, definitely invest in some quality fiberglass rollers, otherwise you’ll get air bubbles that will pop eventually. Now, the pond armor instructions do say to line all your seams with chopped matt (This is not a structural mat, but it’s easier to get bubbles out of it) but pond armor in most cases is colored, so you’re never really sure if you got the bubbles out. This is why I basically just chose to use it for “color”…because I was making 100% sure this thing never leaked.
All of the supplies arrived and I stacked everything up nicely in the garage before I made my cuts. Just look at that beautiful pile of "almost" tank!!
I busted out the miter saw, made all my cuts and assembled the body of the tank.
Everything was screwed and glued, because I was making sure it was a tank (a tank tank)! And it wasn't going to be my problem to break down if I ever moved, so why not!! (This is called foreshadowing..)
Just look at that beautiful frame! It's just like I designed it! And this is where I thought I was going to get really smart. Moving this thing around was already turning into a giant pain in the butt, so I figured, why flip it over to put the bottom on when I can just put it on the top!!! So I laid down the bottom plywood, happily gluing and screwing it down...
And then to my horror realized that if I flipped it over, the window was going to be on the wrong messing side. I'm sure everyone has been here, where you feel your heart start beating out of your chest because of the colossal idiotic "smart" mistake you made? Or maybe that just happens to me. So, because I idiotically glued and screwed it in already, taking it off was going to be a giant mess, and, I was home alone with no help to safely get that 150lb sheet of 1" plywood off the bottom, so, I busted out the crowbar and frantically tried to put the window on the right side of the tank.
Success!!
I finished laying down the rest of the decking and decided to call it a night, because I had made enough mistakes for one day, and I wanted to save the other mistakes for later.
I'm sure you're thinking, "Man, this guy is an idiot." Don't worry. It gets better.
I ended the las post by saying I ordered all the materials for the build and loaded up my car (my wife’s car) with a bunch of wood for the build.
But based on the replies to the first post I think it’d be a good idea to back up a bit and talk about some of my early decisions about the build.
I wanted at least a 30” viewable area and most of the threads I read on-line said ¾” plywood was good to about 36” water height, so I settled on a 35” water height just to play it a little safe. The sketch-up design was originally based on using a 39” glass panel, 1.5” of overlap on the window frame, but when I went to get quotes for glass, glasscages was all out of low iron glass (and wasn’t very helpful about identifying when they might get more in, just FYI) and all of the local glass shops wanted $4000+ for the dimensions I was looking for (37x39, 96x39, ¾” LIG). Combined with the other materials cost, that would have put the project around $5000 at which point I might as well have just built an acrylic tank, or bought one online. But since I had already decided I was going to do a plywood tank I contacted the local Acrylics Wholesaler (Piedmont Plastics, they’re a national distributor, very easy to work with and have great prices!). Their price on the panels I needed was $2100 (because I had to buy full sheets, so I had half a sheet I didn’t need, oh well, it was still half the price of glass). Before I pulled the trigger on the order I searched around to find out the best way to glue an acrylic window into a plywood tank. The results are a mix of Dowsil 795 and 3M 5200, so I thought, great, this will work!
I ordered:
Acrylic panels: front window, 1.5” acrylic, side window 1.25” acrylic - $2100
TotalBoat High Performance Epoxy: $200
¾” Baltic Birch Marine Grade Plywood: $500
4oz Fiberglass Mat: $100
3 quarts of black pond shield: $200
12 tubes of black 3M 5200: $240
5lbs 2.5” deck Screws: $25
5lbs 4” deck Screws: $25
5lbs 1.25” deck screws: $25
Flat black exterior enamel paint (For the outside of the tank): $25
JB Weld wood filler epoxy: $50
Various 2x4's, 2x6's, 4x4 posts: $200
6 tubes of Loctite PL Premium Construction Adhesive: $32
The water-proofing method I chose was not to just use straight pond armor like so many other plywood builds. There are a number of threads, you can look for them, that call into question the long term durability of pond armor and I wanted to be sure this wasn’t ever going to leak (LOL!) so I built it like a canoe and watched a bunch of videos on youtube about “how to fiberglass you boat” it was actually pretty easy once I got it all going, and satisfying. The key to fiberglassing though is air bubble removal. If you decide to fiberglass a tank, definitely invest in some quality fiberglass rollers, otherwise you’ll get air bubbles that will pop eventually. Now, the pond armor instructions do say to line all your seams with chopped matt (This is not a structural mat, but it’s easier to get bubbles out of it) but pond armor in most cases is colored, so you’re never really sure if you got the bubbles out. This is why I basically just chose to use it for “color”…because I was making 100% sure this thing never leaked.
All of the supplies arrived and I stacked everything up nicely in the garage before I made my cuts. Just look at that beautiful pile of "almost" tank!!
I busted out the miter saw, made all my cuts and assembled the body of the tank.
Everything was screwed and glued, because I was making sure it was a tank (a tank tank)! And it wasn't going to be my problem to break down if I ever moved, so why not!! (This is called foreshadowing..)
Just look at that beautiful frame! It's just like I designed it! And this is where I thought I was going to get really smart. Moving this thing around was already turning into a giant pain in the butt, so I figured, why flip it over to put the bottom on when I can just put it on the top!!! So I laid down the bottom plywood, happily gluing and screwing it down...
And then to my horror realized that if I flipped it over, the window was going to be on the wrong messing side. I'm sure everyone has been here, where you feel your heart start beating out of your chest because of the colossal idiotic "smart" mistake you made? Or maybe that just happens to me. So, because I idiotically glued and screwed it in already, taking it off was going to be a giant mess, and, I was home alone with no help to safely get that 150lb sheet of 1" plywood off the bottom, so, I busted out the crowbar and frantically tried to put the window on the right side of the tank.
Success!!
I finished laying down the rest of the decking and decided to call it a night, because I had made enough mistakes for one day, and I wanted to save the other mistakes for later.
I'm sure you're thinking, "Man, this guy is an idiot." Don't worry. It gets better.
Last edited:
Ohh.... I winced when I saw the word plywood. I know some do but not for me I don’t think. Props though. I’m scoping an 1800g build at present having been away from the hobby for 18 years. Lot of changes and new equipment/methods. I’m a eco and prefer to build if I can ..... just finishing my 7 year self build project - passivehause, 3 storeys,550 sq mtrs with a roof garden. The tank is part of my 2nd fix build up as I plaster out (not told the wife yet..... but she’s asking too many questions about the amount of research I’m doing) and thinks my next project is making the front door.... well that is a priority before the tank..... but I think the tank will come before the kitchen ( will make do with a makeshift for a bit) I mean a man has to get his priorities right every now and again. Haven’t mentioned to her yet the fact that I’m already scoping the glass from the guy who supplied my glazing.....which I’ve just finished installing. She wants a move date and I’ve moved onto my tank build.... oops.
Now this takes me back in time..... looks like how I started off my house build! Good on ya.Oh no…This thread was featured in an R2R email the other day. I better not screw this up…
I ended the las post by saying I ordered all the materials for the build and loaded up my car (my wife’s car) with a bunch of wood for the build.
But based on the replies to the first post I think it’d be a good idea to back up a bit and talk about some of my early decisions about the build.
I wanted at least a 30” viewable area and most of the threads I read on-line said ¾” plywood was good to about 36” water height, so I settled on a 35” water height just to play it a little safe. The sketch-up design was originally based on using a 39” glass panel, 1.5” of overlap on the window frame, but when I went to get quotes for glass, glasscages was all out of low iron glass (and wasn’t very helpful about identifying when they might get more in, just FYI) and all of the local glass shops wanted $4000+ for the dimensions I was looking for (37x39, 96x39, ¾” LIG). Combined with the other materials cost, that would have put the project around $5000 at which point I might as well have just built an acrylic tank, or bought one online. But since I had already decided I was going to do a plywood tank I contacted the local Acrylics Wholesaler (Piedmont Plastics, they’re a national distributor, very easy to work with and have great prices!). Their price on the panels I needed was $2100 (because I had to buy full sheets, so I had half a sheet I didn’t need, oh well, it was still half the price of glass). Before I pulled the trigger on the order I searched around to find out the best way to glue an acrylic window into a plywood tank. The results are a mix of Dowsil 795 and 3M 5200, so I thought, great, this will work!
I ordered:
Acrylic panels: front window, 1.5” acrylic, side window 1.25” acrylic - $2100
TotalBoat High Performance Epoxy: $200
¾” Baltic Birch Marine Grade Plywood: $500
4oz Fiberglass Mat: $100
3 quarts of black pond shield: $200
12 tubes of black 3M 5200: $240
5lbs 2.5” deck Screws: $25
5lbs 4” deck Screws: $25
5lbs 1.25” deck screws: $25
Flat black exterior enamel paint (For the outside of the tank): $25
JB Weld wood filler epoxy: $50
Various 2x4's, 2x6's, 4x4 posts: $200
6 tubes of Loctite PL Premium Construction Adhesive: $32
The water-proofing method I chose was not to just use straight pond armor like so many other plywood builds. There are a number of threads, you can look for them, that call into question the long term durability of pond armor and I wanted to be sure this wasn’t ever going to leak (LOL!) so I built it like a canoe and watched a bunch of videos on youtube about “how to fiberglass you boat” it was actually pretty easy once I got it all going, and satisfying. The key to fiberglassing though is air bubble removal. If you decide to fiberglass a tank, definitely invest in some quality fiberglass rollers, otherwise you’ll get air bubbles that will pop eventually. Now, the pond armor instructions do say to line all your seams with chopped matt (This is not a structural mat, but it’s easier to get bubbles out of it) but pond armor in most cases is colored, so you’re never really sure if you got the bubbles out. This is why I basically just chose to use it for “color”…because I was making 100% sure this thing never leaked.
All of the supplies arrived and I stacked everything up nicely in the garage before I made my cuts. Just look at that beautiful pile of "almost" tank!!
I busted out the miter saw, made all my cuts and assembled the body of the tank.
Everything was screwed and glued, because I was making sure it was a tank (a tank tank)! And it wasn't going to be my problem to break down if I ever moved, so why not!! (This is called foreshadowing..)
Just look at that beautiful frame! It's just like I designed it! And this is where I thought I was going to get really smart. Moving this thing around was already turning into a giant pain in the ***, so I figured, why flip it over to put the bottom on when I can just put it on the top!!! So I laid down the bottom plywood, happily gluing and screwing it down...
And then to my horror realized that if I flipped it over, the window was going to be on the wrong messing side. I'm sure everyone has been here, where you feel your heart start beating out of your chest because of the colossal idiotic "smart" mistake you made? Or maybe that just happens to me. So, because I idiotically glued and screwed it in already, taking it off was going to be a giant mess, and, I was home alone with no help to safely get that 150lb sheet of 1" plywood off the bottom, so, I busted out the crowbar and frantically tried to put the window on the right side of the tank.
Success!!
I finished laying down the rest of the decking and decided to call it a night, because I had made enough mistakes for one day, and I wanted to save the other mistakes for later.
I'm sure you're thinking, "Man, this guy is an idiot." Don't worry. It gets better.
h2so4hurts
Active Member
Yes, priorities are important, and a couple of you have already hinted at one of the key lessons here. Glass is easiest for a plywood build, but I'll also give some tips for being successful with Acrylic! Just because I wasn't successful doesn't mean others can't be, just learn from my mistakes!
I’ve made a few mistakes myself. Who doesn’t. It’s what we learn from them that’s important. I had a 150g tank burst on me when my wooden frame it was on didn’t quite come up to muster ...... a good few years after installation. It was fairly heavily populated. Nightmare. Oh and I also had bursts on my concrete passive build ..... only a couple when I first started out and wouldn’t want to repeat that either. What a mess.
h2so4hurts
Active Member
That really sucks. Stick around so you can commiserate in my misery. It's always fun to laugh at yourself with friends.
Entomophage
Community Member
I'm sure I'm not speaking for myself alone when I say......update!?!?
h2so4hurts
Active Member
Haha, Monday! That's the only day of the week I have enough time to sit down and dig through all of the pictures!
h2so4hurts
Active Member
So let’s talk about lights!
The original tank used a light rack I built in 2014. It was a rapidled solderless build. In total it had 9 pendants each with 24 CREE XPG and XTE cool white and royal blue LEDs and was powered by two 300 watt meanwell drivers (one for each channel). It still produces a ton of PAR but I wanted something bigger and better for this build. I decided to go the DIY route again 1) because it’s slightly cheaper 2) if something on it breaks I can replace most components for dollars vs having to buy a new fixture 3) there aren’t any fixtures that can drop 200 PAR down 35+ inches 4) If you haven’t figured this out yet, I like building things.
I decided to go the MakersLED (http://www.makersled.com/ - check them out if you are interested in learning more) route this time over RapidLED, mostly because it seems like RapidLED is focusing on the horticulture side of things these days and they didn’t have bulk quantities of the LEDs I wanted in stock. I also decided to switch up my color spectrum a bit this time and went with a mix of royal blue, blue, neutral white and cool white CREE LEDs. I went with XPE LEDs this time because, while less efficient, they have higher penetration than XPG or XTE so I decided to make that trade off, but honestly it probably doesn’t matter. They’re all high quality LEDs. I have 6 pendants with 63 LEDs each, 40 Royal Blue, 12 Cool White, 6 Neutral White, and 5 Blue. Each pendant has it’s own 200 watt meanwell power supply and a MakersLED 5UP PRO Driver with 5 1amp LDDs (1 LDD per channel). You can see how I wired the channels together in the diagram below.
For optics I got Narrow (40 degree) and Wide (60 degree) Carlco lenses which are held into place by BJB solderless LED connectors. I chose these optics because I wanted one wider fixture at the back of the array to hit coral on high rocks, and then a narrow LED fixture in the front to punch down to the lower shelf and sandbed. All in all the MakersLED kit creates a very good looking fixture. It’s quality is way better than what I had previously DIY-ed with RapidLED kits.
What was the damage? Well, for 1200 watts of LED power and the ability to push 200 PAR 36+ inches it cost me $3,700 and about 6hrs! of my time to assemble each pendant. Putting these fixtures together was more time consuming and back breaking than building the plywood tank, but the end result is amazing and I really love the color this fixture puts out.
One finished fixture compared to how the old DIY build looked below...no contest.
And did I mention these things are BRIGHT. This is one fixture at 85%!
I’m also really impressed with the simplicity of the MakersLED controller. It’s intuitive, simple to use, and just works. There’s no App for it, but it has everything you could possibly need in a simple push button interface. And at $49 to control as many lights as you can daisy chain together with audio cable makes it a steal in my opinion. So if you’re in the market for new lights and want to get your fingers dirty, I’d totally recommend a MakersLED build.
Next week I'll probably finish out with the build pics of the tank itself. We're getting to the really fun parts soon, where we'll dig into the "What no to do" parts of the guide. Some of you might have already picked up on those, or seen the flaws in my original design. If not, don't worry, I'll go into detail, and yes, in case you were wondering, this story does have a happy ending, eventually.
The original tank used a light rack I built in 2014. It was a rapidled solderless build. In total it had 9 pendants each with 24 CREE XPG and XTE cool white and royal blue LEDs and was powered by two 300 watt meanwell drivers (one for each channel). It still produces a ton of PAR but I wanted something bigger and better for this build. I decided to go the DIY route again 1) because it’s slightly cheaper 2) if something on it breaks I can replace most components for dollars vs having to buy a new fixture 3) there aren’t any fixtures that can drop 200 PAR down 35+ inches 4) If you haven’t figured this out yet, I like building things.
I decided to go the MakersLED (http://www.makersled.com/ - check them out if you are interested in learning more) route this time over RapidLED, mostly because it seems like RapidLED is focusing on the horticulture side of things these days and they didn’t have bulk quantities of the LEDs I wanted in stock. I also decided to switch up my color spectrum a bit this time and went with a mix of royal blue, blue, neutral white and cool white CREE LEDs. I went with XPE LEDs this time because, while less efficient, they have higher penetration than XPG or XTE so I decided to make that trade off, but honestly it probably doesn’t matter. They’re all high quality LEDs. I have 6 pendants with 63 LEDs each, 40 Royal Blue, 12 Cool White, 6 Neutral White, and 5 Blue. Each pendant has it’s own 200 watt meanwell power supply and a MakersLED 5UP PRO Driver with 5 1amp LDDs (1 LDD per channel). You can see how I wired the channels together in the diagram below.
For optics I got Narrow (40 degree) and Wide (60 degree) Carlco lenses which are held into place by BJB solderless LED connectors. I chose these optics because I wanted one wider fixture at the back of the array to hit coral on high rocks, and then a narrow LED fixture in the front to punch down to the lower shelf and sandbed. All in all the MakersLED kit creates a very good looking fixture. It’s quality is way better than what I had previously DIY-ed with RapidLED kits.
What was the damage? Well, for 1200 watts of LED power and the ability to push 200 PAR 36+ inches it cost me $3,700 and about 6hrs! of my time to assemble each pendant. Putting these fixtures together was more time consuming and back breaking than building the plywood tank, but the end result is amazing and I really love the color this fixture puts out.
One finished fixture compared to how the old DIY build looked below...no contest.
And did I mention these things are BRIGHT. This is one fixture at 85%!
I’m also really impressed with the simplicity of the MakersLED controller. It’s intuitive, simple to use, and just works. There’s no App for it, but it has everything you could possibly need in a simple push button interface. And at $49 to control as many lights as you can daisy chain together with audio cable makes it a steal in my opinion. So if you’re in the market for new lights and want to get your fingers dirty, I’d totally recommend a MakersLED build.
Next week I'll probably finish out with the build pics of the tank itself. We're getting to the really fun parts soon, where we'll dig into the "What no to do" parts of the guide. Some of you might have already picked up on those, or seen the flaws in my original design. If not, don't worry, I'll go into detail, and yes, in case you were wondering, this story does have a happy ending, eventually.
Last edited:
Daniel@R2R
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My Tank Thread
How's it going on this build? Super excited to follow!
Barnabie Mejia
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the anxiety of waiting for another post!!!! we need an update!
h2so4hurts
Active Member
Sorry guys, I missed my window on Monday to make an update. It's snowing tonight in NC so I should have some time tomorrow morning to get the next installment up while I wait for the snow to melt before heading into work
h2so4hurts
Active Member
Right so last time I posted about the lighting system I built for the the new tank which is basically the only part of this build that is still functional. So, not a total loss!! But for the actual plywood part of the build we ended with box completion and it looked something like this:
The next step in a plywood build is to use bondo or epoxy filler to fill all the screw heads and seam gaps. For this I used JB weld wood epoxy which is a really cool 2 part putty product. It's like play-doh. It's a lot of fun to work with. It took about an hour to fill all the screw heads and seams and the buckets say to wait 24hrs before it's fully cured (I think it says you can paint and sand within a few hours, but I wasn't in a huge rush).
The next step after gap filling is the fun part: Fiberglassing. A lot of people who build plywood tanks only fiberglass the seams because those are the areas where there is the most stress. I have read a number of threads about epoxy water proofing products eventually getting microfissures and leaking within the panels. I didn't want to deal with that so I just fiberglassed the whole thing. I figured it was only an extra day of work and a couple hundred dollars more, so why not. And if it works for a canoe, it should work pretty well for a fish tank. I created a nice fiberglassing booth in my basement
And started the process of fiberglassing the tank with the sheets of 4oz mat that I had precut to fit each surface of the tank. I did the horizontal and vertical seams first and then overlapped the full panel sheets with those afterward.
Fiberglassing is actually pretty easy once you get the hang of it. A few simple rules though:
1) Before wetting out the fiberglass, spread epoxy over the wood surface. This will enhance the wetting out of the fabric. The wood will take up some amount of the epoxy so if you don't do this you can get spots in the fiberglass that don't wet out well and you have to spend a lot of time working epoxy into them. You don't want to do this when you only have 20 minutes or so of working time, especially if you're trying to lay more than one layer at a time (I was doing 2).
2) If you're doing a big section, roll the sheet up and the roll it out from left to right while covering with more epoxy. I tried to put the sheet on once just as a flat sheet and it wrinkled badly. It took a good 10 minutes to get it smoothed out, rolling it out gives you more time to work out the wrinkles before moving on to the next bit and makes the process go a whole lot more quickly
3) Get a good fiberglass roller. Rolling the fiberglass is the most important step! While doing this you introduce a ton of air bubbles into the epoxy and the fiberglass. if you don't roll them out they sit under the glass or in the epoxy and can pop or crack in the future. This is how leaks happen, so be sure you roll all the air bubbles out to prevent this from happening
4) Try to avoid rounded corners <3/4". Rounded corners make it almost impossible to remove air bubbles. The fiberglass just slides over the curved surface and this is especially bad on small radius corners. Try to keep any rounded corners at 3/4" or more if you must have them. I had a few 2x4 edges in my build and those were 1/4" corners. It was impossible to get a bubble free adhesion of the epoxy and fiberglass (the fiberglass does not bend well at all at that radius).
Once the fiberglassing was done I added pond shield pond armor for color. The tins for this product are covered in labels saying that it is non-toxic but it smells awful. The boat epoxy had no odor whatsoever, Pond Armor STINKS. If you're doing this in your house, get some fans and open a lot of windows!
Next came adding the acrylic windows. I picked these up from the local acrylic wholesaler with a uhaul and had a friend from work help me install the main window. The wisdom online said to rough up the sealing surfaces with 60 grit sand paper and liberally apply 3M 5200. We got there eventually after a lot of grunting and covering ourselves in 5200. Take it from me, wrestling a 250lb piece of 1.5" thick acrylic into a box is NOT a good time! I clamped it down and braced it, waiting 7 days for the cure before I installed the side window myself
In this picture you can see in the corner that I left about a 1/2" gap between the edge of the box and the window. This was eventually back filled with 3M 5200 with the expectation that the 5200 on the sealing surface and around the perimeter gap would be sufficient to keep water in the tank.
The side window was much easier to get in, half the thickness, 1.25" and about half the length!
Then came adding the top bracing
Building the light rack
And testing out my artificial Sun!
And as a final step I added the spa flex, bulkheads and got my wife to help me paint the exterior with some flat black enamel paint!
And at this point we were ready to go to install the Monster, which will be the highlight of the next post. The build process after my window mistake went surprisingly smoothly. Maybe I should have seen that as a warning, but at this point I was blissfully ignorant of the excitement I had ahead of me.
The next step in a plywood build is to use bondo or epoxy filler to fill all the screw heads and seam gaps. For this I used JB weld wood epoxy which is a really cool 2 part putty product. It's like play-doh. It's a lot of fun to work with. It took about an hour to fill all the screw heads and seams and the buckets say to wait 24hrs before it's fully cured (I think it says you can paint and sand within a few hours, but I wasn't in a huge rush).
The next step after gap filling is the fun part: Fiberglassing. A lot of people who build plywood tanks only fiberglass the seams because those are the areas where there is the most stress. I have read a number of threads about epoxy water proofing products eventually getting microfissures and leaking within the panels. I didn't want to deal with that so I just fiberglassed the whole thing. I figured it was only an extra day of work and a couple hundred dollars more, so why not. And if it works for a canoe, it should work pretty well for a fish tank. I created a nice fiberglassing booth in my basement
And started the process of fiberglassing the tank with the sheets of 4oz mat that I had precut to fit each surface of the tank. I did the horizontal and vertical seams first and then overlapped the full panel sheets with those afterward.
Fiberglassing is actually pretty easy once you get the hang of it. A few simple rules though:
1) Before wetting out the fiberglass, spread epoxy over the wood surface. This will enhance the wetting out of the fabric. The wood will take up some amount of the epoxy so if you don't do this you can get spots in the fiberglass that don't wet out well and you have to spend a lot of time working epoxy into them. You don't want to do this when you only have 20 minutes or so of working time, especially if you're trying to lay more than one layer at a time (I was doing 2).
2) If you're doing a big section, roll the sheet up and the roll it out from left to right while covering with more epoxy. I tried to put the sheet on once just as a flat sheet and it wrinkled badly. It took a good 10 minutes to get it smoothed out, rolling it out gives you more time to work out the wrinkles before moving on to the next bit and makes the process go a whole lot more quickly
3) Get a good fiberglass roller. Rolling the fiberglass is the most important step! While doing this you introduce a ton of air bubbles into the epoxy and the fiberglass. if you don't roll them out they sit under the glass or in the epoxy and can pop or crack in the future. This is how leaks happen, so be sure you roll all the air bubbles out to prevent this from happening
4) Try to avoid rounded corners <3/4". Rounded corners make it almost impossible to remove air bubbles. The fiberglass just slides over the curved surface and this is especially bad on small radius corners. Try to keep any rounded corners at 3/4" or more if you must have them. I had a few 2x4 edges in my build and those were 1/4" corners. It was impossible to get a bubble free adhesion of the epoxy and fiberglass (the fiberglass does not bend well at all at that radius).
Once the fiberglassing was done I added pond shield pond armor for color. The tins for this product are covered in labels saying that it is non-toxic but it smells awful. The boat epoxy had no odor whatsoever, Pond Armor STINKS. If you're doing this in your house, get some fans and open a lot of windows!
Next came adding the acrylic windows. I picked these up from the local acrylic wholesaler with a uhaul and had a friend from work help me install the main window. The wisdom online said to rough up the sealing surfaces with 60 grit sand paper and liberally apply 3M 5200. We got there eventually after a lot of grunting and covering ourselves in 5200. Take it from me, wrestling a 250lb piece of 1.5" thick acrylic into a box is NOT a good time! I clamped it down and braced it, waiting 7 days for the cure before I installed the side window myself
In this picture you can see in the corner that I left about a 1/2" gap between the edge of the box and the window. This was eventually back filled with 3M 5200 with the expectation that the 5200 on the sealing surface and around the perimeter gap would be sufficient to keep water in the tank.
The side window was much easier to get in, half the thickness, 1.25" and about half the length!
Then came adding the top bracing
Building the light rack
And testing out my artificial Sun!
And as a final step I added the spa flex, bulkheads and got my wife to help me paint the exterior with some flat black enamel paint!
And at this point we were ready to go to install the Monster, which will be the highlight of the next post. The build process after my window mistake went surprisingly smoothly. Maybe I should have seen that as a warning, but at this point I was blissfully ignorant of the excitement I had ahead of me.
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