600g DIY plywood build
- Thread starter DIFish
- Start date
How is this thank doing? Any issues with bowing ? I'm looking into building an 8'x4'x3' and debating whether I need 2x4 framing/bracing or if using plywood bracing alone is enough
Over 5 years in now and the tank itself is doing great. No signs of material fatigue / bowing. Maintenance has been remarkably minimal. Keeping complementary fish has been a bit of a problem but the arrow and the stingray are doing excellent.
Updating with some unfortunate news. For the last few months or so I have been noticing an issue with the top bracing on the tank starting to fail. Looking over some of the original pictures it is clear I did not apply the epoxy correctly to the top bracing and it has rotted out from the humidity, and completely came apart leaving the tank with no top bracing. Sadly this could have been completely avoided and is definitely not where I thought the point of failure would be.
Surprisingly enough, the tank is still completely water tight, but is now showing significant bowing on the backside, as well as having exposed wood. I am calling this negligence in my epoxy coating rather than a design failure, as the tank would still have no bowing if the supports were not rotted out.
I am still completely confident on the initial design, and am actually impressed with how well it holds up with literally 0 top bracing after 7 years. Currently making plans to completely rebuild next month. There are a lot more plywood builds to learn from now, but I think I am going to stick to the original design with some small improvements as there were zero issues until now. I will post updates as they happen, and explain any changes I make vs the previous build.
Surprisingly enough, the tank is still completely water tight, but is now showing significant bowing on the backside, as well as having exposed wood. I am calling this negligence in my epoxy coating rather than a design failure, as the tank would still have no bowing if the supports were not rotted out.
I am still completely confident on the initial design, and am actually impressed with how well it holds up with literally 0 top bracing after 7 years. Currently making plans to completely rebuild next month. There are a lot more plywood builds to learn from now, but I think I am going to stick to the original design with some small improvements as there were zero issues until now. I will post updates as they happen, and explain any changes I make vs the previous build.
Terrific build and a very interesting thread; I wish I had found it long ago.
It's a shame about the top bracing. That has always been a difficult spot for me on my plywood builds. It's tough to make sure that you are applying the epoxy as carefully as required, regardless of whether you work from outside the tank or get right inside. Hard to reach, hard to see properly, just a PITA.
Are you planning on sanding the interior and applying more Pond Shield? Or trying something else? I recently had an unfortunate accident with one of my builds; the tank was empty and while doing some work on and above the top of it I knocked over several sharp-edged tools into it, damaging the epoxy bottom to the point where wood is visible in a couple places. I was going to re-coat with epoxy, but I have a large sheet of EPDM pond liner which is big enough to cover the entire inside of the tank; I'm thinking I may "upholster" the inside with this, likely with two layers on the bottom to resist damage from large rocks, etc.
Looking forward to your progress with this re-finish/re-build. Judging from your build thread, you work about 10 times faster than I do, so I can afford to wait...
Good luck!
It's a shame about the top bracing. That has always been a difficult spot for me on my plywood builds. It's tough to make sure that you are applying the epoxy as carefully as required, regardless of whether you work from outside the tank or get right inside. Hard to reach, hard to see properly, just a PITA.
Are you planning on sanding the interior and applying more Pond Shield? Or trying something else? I recently had an unfortunate accident with one of my builds; the tank was empty and while doing some work on and above the top of it I knocked over several sharp-edged tools into it, damaging the epoxy bottom to the point where wood is visible in a couple places. I was going to re-coat with epoxy, but I have a large sheet of EPDM pond liner which is big enough to cover the entire inside of the tank; I'm thinking I may "upholster" the inside with this, likely with two layers on the bottom to resist damage from large rocks, etc.
Looking forward to your progress with this re-finish/re-build. Judging from your build thread, you work about 10 times faster than I do, so I can afford to wait...
Good luck!Thanks and Completely agree with it being the toughest spot to epoxy. Originally I thought it was coated enough to last but obviously the humidity had other plans. The rotted/ruined wood covers most of the top of the tank, and looks to slowly be penetrating further so I unfortunately think a completely new tank is in order. I would have to cut off the top inch or two and redo from there, but honestly would have concerns about the structural integrity.Terrific build and a very interesting thread; I wish I had found it long ago.
It's a shame about the top bracing. That has always been a difficult spot for me on my plywood builds. It's tough to make sure that you are applying the epoxy as carefully as required, regardless of whether you work from outside the tank or get right inside. Hard to reach, hard to see properly, just a PITA.
Are you planning on sanding the interior and applying more Pond Shield? Or trying something else? I recently had an unfortunate accident with one of my builds; the tank was empty and while doing some work on and above the top of it I knocked over several sharp-edged tools into it, damaging the epoxy bottom to the point where wood is visible in a couple places. I was going to re-coat with epoxy, but I have a large sheet of EPDM pond liner which is big enough to cover the entire inside of the tank; I'm thinking I may "upholster" the inside with this, likely with two layers on the bottom to resist damage from large rocks, etc.
Looking forward to your progress with this re-finish/re-build. Judging from your build thread, you work about 10 times faster than I do, so I can afford to wait...
Sorry to hear about your damage to the epoxy coating. I would hope that you could just coat those areas as a spot fix? I have never attempted a liner but am sure they work well if done right.
Current plans are a full
rebuild, making use of new knowledge and properly using epoxy. I will be reusing the same glass panel, but other than that it will be a whole new tank. Am also on a bit of a time crunch as the tank is actively getting worse but I think it can be fully rebuilt in a few weeks. Will also be taking the opportunity to rework the filtration system and add some more fish as almost all the original inhabitants are long gone.
When you redo the build try reinforcing all exterior edges/supports with steel. A thin mounting bracket running the length of every stress point would prob last the rest of your life.
Awesome built, bummer to see the update but great to hear your planing the 600 2.0 lol, can't wait too see the progress
DIFish
Excellent build start to finish! Great pictures as well!!!
The only improvement I would recommend would be to add a layer of fiberglass and epoxy over the interior as well as a few inches over front opening.
Then paint this blue with your pond liner material.
This will add immense strength to the plywood frame as well as great weather proofing.
Do you have options for rehoming your fish while rebuilding?
I see that small indoor pools are available and many use them as stock ponds. May be a good safe option while you rebuild!
