issues with moving a plywood tank?

[doughmonkey]

good morning monster fish people,
I have been stalking this forum from a far in preparation for a plywood tank build for my turtle. As far as the build itself, it will only be about 140 gallons and the reason for building it is because of the layout. Internal dimensions will be 36"x48"x20" high and will have glass on all 4 sides. I was able to salvage 2 leaky 55 gallons with 3/8" glass and cut down two of the sides to 36". The tank will have 3/4" ply bottom, and the sides with be doubled up and overlapped 3/4" ply. Then 6oz fiberglass with MAX ACR epoxy (doubled up on bottom), then pond shield over that. The sides with have not gaps between the glass. I know this might be overkill, but turtles have sharp claws and can be pretty abusive to there surroundings. it will have a coast to coast, with a bean animal to a 40 gallon sump
My big question is about moving the tank from the garage to the house. I have been having a hard time finding any discussion about this. I will brace the tank as much as possible to try and keep it from racking, but I like to over-prepare for projects before I even start them.
So really looking for any tips, tricks, ect. I'm not even sure if I have to worry about it, but like I said, I prefer not to go into a project without addressing potential issues.
Thank you in advance

 

[Backfromthedead]

Your plan sounds solid. Its obvious youve done a lot of research before even starting. jjohnwm is a plywood builder, he may have some tips that could streamline your design.

Ime the more bracing and reinforcement you put into your tank, the more simple moving it will be. With your design and since youre applying an entire layer of fiberglass i would personally have no problem handing the thing over to the most cut-rate of moving companies and still expect it to hold water afterwards.

 

[jjohnwm]

To be more concise...I am a paranoid plywood builder.

I always worry about this exact possibility, so while I build the actual box wherever it's convenient, I don't actually seal the interior or install the glass until the thing is situated where it will be living, just so that I don't need to worry about this. Having said that, I have moved several tanks over the years, sometimes across the basement, other times across the province, and didn't have any difficulties. An 8x3x2 foot tank that we moved from my place to a buddy's house, 300+km away, had held water for 8 or 9 years before the move, and continued to do so for at least another 5 years afterwards, maybe much longer.

I read a lot about "micro-fractures" forming in the the epoxy liner of a plywood tank, resulting in leaks, but have never had a leak that could be attributed to that mysterious cause. Some sources state that these microfractures occur along the seams, so I always put a healthy bead of silicone on all the interior seams after the tank is built and after the epoxy has been applied. After the application of the silicone, those corners can microfracture to their hearts' content and it won't matter.

I also worry a bit about microfractures occurring right in the center of panels, possibility as a result of slight "drumming" of the panels as pressure is released and then re-applied during water changes. I have no idea if this a realistic concern; I have probably done something like 5000 major water changes in plywood tanks over the past few decades...I change a lot of water...and again, no mysterious leaks have occurred which could not be traced to some obvious cause, never "micro-fractures".

You are obviously doing this build right, taking everything into consideration and planning carefully. Two completely separate treatments of two different epoxies, either of which alone should be adequate? Overkill for sure; I like overkill!

Epoxy is tough stuff; I have kept lots of big turtles in the past and never had them damage an epoxy sealing coat. I think you will be fine, but would suggest that you contact the manufacturer of Pond Shield to determine how well it will adhere to the MAX ACR, paying particular attention to the application time window within which the best adhesion will be obtained.

If you must move the fully-completed tank, why not temporarily attach a top, or at least several wide solid braces spanning the top opening, which will add immeasurably to the strength and rigidity of the whole thing? Once it is in place, remove them and seal the screw holes with silicone. You might be able to use the cut-out pieces from creating the window openings for this purpose. Keep us posted!

I'd say good luck...but with proper planning and careful execution, luck becomes much less important...

 

[doughmonkey]

Your plan sounds solid. Its obvious youve done a lot of research before even starting. jjohnwm is a plywood builder, he may have some tips that could streamline your design.

Ime the more bracing and reinforcement you put into your tank, the more simple moving it will be. With your design and since youre applying an entire layer of fiberglass i would personally have no problem handing the thing over to the most cut-rate of moving companies and still expect it to hold water afterwards.

thank you,
When I start the build, I will post up pictures of the progress. Obviously not a monster tank, but should still be a fun build. i dont have enough post to put up pictures, so hard to describe how the sides will be laid out. I guess the best way would be that there will be picture frames around the glass on all 4 sides, then another picture frame over the previous with all edges overlapping the previous.

 

[doughmonkey]

To be more concise...I am a paranoid plywood builder.

I always worry about this exact possibility, so while I build the actual box wherever it's convenient, I don't actually seal the interior or install the glass until the thing is situated where it will be living, just so that I don't need to worry about this. Having said that, I have moved several tanks over the years, sometimes across the basement, other times across the province, and didn't have any difficulties. An 8x3x2 foot tank that we moved from my place to a buddy's house, 300+km away, had held water for 8 or 9 years before the move, and continued to do so for at least another 5 years afterwards, maybe much longer.

I read a lot about "micro-fractures" forming in the the epoxy liner of a plywood tank, resulting in leaks, but have never had a leak that could be attributed to that mysterious cause. Some sources state that these microfractures occur along the seams, so I always put a healthy bead of silicone on all the interior seams after the tank is built and after the epoxy has been applied. After the application of the silicone, those corners can microfracture to their hearts' content and it won't matter.

I also worry a bit about microfractures occurring right in the center of panels, possibility as a result of slight "drumming" of the panels as pressure is released and then re-applied during water changes. I have no idea if this a realistic concern; I have probably done something like 5000 major water changes in plywood tanks over the past few decades...I change a lot of water...and again, no mysterious leaks have occurred which could not be traced to some obvious cause, never "micro-fractures".

You are obviously doing this build right, taking everything into consideration and planning carefully. Two completely separate treatments of two different epoxies, either of which alone should be adequate? Overkill for sure; I like overkill!

Epoxy is tough stuff; I have kept lots of big turtles in the past and never had them damage an epoxy sealing coat. I think you will be fine, but would suggest that you contact the manufacturer of Pond Shield to determine how well it will adhere to the MAX ACR, paying particular attention to the application time window within which the best adhesion will be obtained.

If you must move the fully-completed tank, why not temporarily attach a top, or at least several wide solid braces spanning the top opening, which will add immeasurably to the strength and rigidity of the whole thing? Once it is in place, remove them and seal the screw holes with silicone. You might be able to use the cut-out pieces from creating the window openings for this purpose. Keep us posted!

I'd say good luck...but with proper planning and careful execution, luck becomes much less important...

Thank you so much for your response,
I have read a lot about these micro fractures as well, and made some test pieces with the fiberglass and epoxy to see how much they could bend without cracking or breaking. it is WAAAYYY more than a tank is ever going to flex. That, plus the additional layer of the pond sheild, the hull should be bulletproof. I suppose there could develop small micro cracks in the pond shield, but then it will just run into the fiberglass layer

I know it's overkill, and I too am a fan of overkill and redundancies, and a believer in Murphy's Law. Pretty sure no one ever stood over a pile of rubble an said "well, there's the problem, they built it too strong"

Where most of my concerns lie is in the silicone seal between the glass and fiberglass, from reading through as many builds as I can find, this seems to be the biggest culprit of leaks. That and bad seals around bulkheads.
How long do you leave your tanks after glass is in to let the silicone cure and gas out before filling and moving?

I like the idea of putting a temporary top on it to move it, would certainly increase the rigidity. I wont have window cut outs, the frames around all the glass will be with 3" wide strips of plywood. They will be lap jointed. then there will be a second frame with he rails and stiles in a different orientation so all joint will be overlapping on the face and the edges. A wider top plate will be going around the top perimeter, and that should eliminate any bowing.

I think I will be fully assembling in the garage so I can leak test everything including the overflow and sump. I have had a 10 gallon leak in my house once, and that sucked to clean, really don't want to find out what 140 looks like on my floor.

Thank you again for your advice and experience
hoping to start the build when it starts to cool down a bit, the summer heat makes the epoxy kick much faster than I would like

 

[jjohnwm]

Yeah, I am starting to believe that the dreaded micro-fractures are a creation that exists in the minds of professional worriers, or perhaps those who can't figure out where the leak is and so need an explanation that does not draw attention to their questionable design and construction choices.

I have zero experience with fibreglass so can't comment on that. Am I understanding this correctly, i.e. that you are fibreglassing the interior surface and that MAX ACR will be the resin component of the glass layer? If so, the main question is still, IMHO, the degree of adhesion of the Pond Shield to the MAX. The silicone will adhere to the Pond Shield so well that you are not going to tear or damage that bond by simply moving the tank around; I have built several tanks using free salvaged glass that was not cut entirely square, and was held in place entirely by silicone with no support "shelf", i.e. the somewhat-irregular shaped glass was just glued with silicone to the vertical face of the wood, centered on the cut-out window opening, but with no other support at all for the weight of the glass. Your build will be supported within that lap-jointed window frame construction, so the silicone won't be supporting the weight at all, merely creating a seal. I've had equally excellent silicone adhesion to Pond Shield, Intraseal, and (back in the day) Pratt&Lambert Palguard epoxies.

I assume you will install each pane with the tank laying down on that face, so that you can just lower each pane of glass onto a bead of fresh silicone and then weight it down while it cures? I always wait at least a week before removing the weights and setting the tank upright. With my single-viewing window construction, this is no big deal; in your case, with four panels...it'll take a month! Patience is golden; nothing will provide an even, controlled amount of pressure to those panels as well as gravity, weight and time.

I've usually used a single solid piece of plywood for each panel, with a cutout window opening that allowed a 2-inch minimum contact surface all the way around each glass panel for silicone. I've made two tanks with your "window" frame construction method as well; I like the ease of constuction. I didn't use lap joints, simply made two frames with the joints reversed to create a sort of lazy-man's lap joint at the corners. I took no chances, and made those tanks with the same 2-inch contact surface all the way around the glass. How much are you planning to allow for this?

I am really looking forward to following this build! Good lu....oops! Almost forgot, you won't need that.

 

[doughmonkey]

I'm sure that small fractures are a possibility, we have all seen cracking and webbing in finished fiberglass work, especially on marine equipment. How much they are a threat or really a thing for tanks, who knows.
I have a fair amount of experience with fiberglass, but always with polyester resin, this will be my first time using epoxy for fiberglass. till now I have only used epoxy for a coating or filler. The reason is that cured epoxy resin is 100% waterproof and polyester resin is not. the main reason I'm even using the pond shield is because I already have it, and it's the color I like. If I had to do this again, I would simply color the epoxy resin that I was using for the fiberglass. I agree that a simple phone call to verify compatibility wouldn't hurt. I will be curing and sanding between coats, so there will be a mechanical as well and a chemical bond.

I have been going back and forth about just making the back panels solid wood since the tank will be in a corner, after hearing what you said, that is becoming a more and more likely path. I will still have the one front and one side viewing panel. The wood panels would be easier to drill through for the overflow piping also. Patience is not one of my virtues, lol. However, I also hate failure, so that helps with the wait times weather I like it or not.

the glass panels will be touching on the edges, so there will still be a little over 2" of contact around the entire face. I realize that since the ends of the glass will be touching, that I could just silicone them like I was making an all glass tank, but there would still be a bit of a worry about structure for me, and I want to be able to sleep well at night, so I'm making this thing like a tank (the boom boom kind, not the splash splash kind)

when I start the build, I will take pics and try to remember to tag you on the build thread
Thank you sir

 

[Flaring Afro]

As a fellow turtle keeper, I'd skip the massive water changes and just use a continuous flush/water change system. It's less work to add plumbing where the tank is than to fight the waste of turtles the old fashioned way. It also would mean the pressure is more stable, since you are worried about that.

I have a under sink filter dripping in through a bulkhead above the water surface, then a drain at water level. Since I don't have glass, the only maintenance I perform is rinsing the filter sponge a couple times a month and swapping the inline filter every 6 months.

 

[doughmonkey]

As a fellow turtle keeper, I'd skip the massive water changes and just use a continuous flush/water change system. It's less work to add plumbing where the tank is than to fight the waste of turtles the old fashioned way. It also would mean the pressure is more stable, since you are worried about that.

I have a under sink filter dripping in through a bulkhead above the water surface, then a drain at water level. Since I don't have glass, the only maintenance I perform is rinsing the filter sponge a couple times a month and swapping the inline filter every 6 months.

I will have a water supply by the tank, but I would have to run the drain and vent all the way on the other side of the house, which I'm not doing. I'm going to have a sump, and it's only one turtle. She is messy, but, rinsing out the sponges shouldn't be that big of a deal. Right now, I'm just running a canister in her current tank and that only needs to be cleaned out once a month. Water stays nice an clear and no odor.

 

[Gpdriftwood]

Yeah, I am starting to believe that the dreaded micro-fractures are a creation that exists in the minds of professional worriers, or perhaps those who can't figure out where the leak is and so need an explanation that does not draw attention to their questionable design and construction choices.

I have zero experience with fibreglass so can't comment on that. Am I understanding this correctly, i.e. that you are fibreglassing the interior surface and that MAX ACR will be the resin component of the glass layer? If so, the main question is still, IMHO, the degree of adhesion of the Pond Shield to the MAX. The silicone will adhere to the Pond Shield so well that you are not going to tear or damage that bond by simply moving the tank around; I have built several tanks using free salvaged glass that was not cut entirely square, and was held in place entirely by silicone with no support "shelf", i.e. the somewhat-irregular shaped glass was just glued with silicone to the vertical face of the wood, centered on the cut-out window opening, but with no other support at all for the weight of the glass. Your build will be supported within that lap-jointed window frame construction, so the silicone won't be supporting the weight at all, merely creating a seal. I've had equally excellent silicone adhesion to Pond Shield, Intraseal, and (back in the day) Pratt&Lambert Palguard epoxies.

I assume you will install each pane with the tank laying down on that face, so that you can just lower each pane of glass onto a bead of fresh silicone and then weight it down while it cures? I always wait at least a week before removing the weights and setting the tank upright. With my single-viewing window construction, this is no big deal; in your case, with four panels...it'll take a month! Patience is golden; nothing will provide an even, controlled amount of pressure to those panels as well as gravity, weight and time.

I've usually used a single solid piece of plywood for each panel, with a cutout window opening that allowed a 2-inch minimum contact surface all the way around each glass panel for silicone. I've made two tanks with your "window" frame construction method as well; I like the ease of constuction. I didn't use lap joints, simply made two frames with the joints reversed to create a sort of lazy-man's lap joint at the corners. I took no chances, and made those tanks with the same 2-inch contact surface all the way around the glass. How much are you planning to allow for this?

I am really looking forward to following this build! Good lu....oops! Almost forgot, you won't need that.

I had micro fracture in 1 corner of my 1000gal build when I first filled it years ago. As you stated u do, heavy beads of silicone were added to all seams and corners and the problem was solved. Could not see the cracks at all, couldn't figure why it was leaking at first. But they were there apparently. Lol