Looking for feedback on a potential solid hardwood build.

[anthony0303]

I tried soliciting advice from a few places and generally got nonsense replies and got pointed here as the best place to get some decent feedback. I am currently in the process of designing a new tank, the sump and filters ect have already been built and fiberglassed.

What im looking at building is a 96L * 36T * 30W floor standing tank/pool with two sides of glass with one corner having both glass edges meet with no brace, the front side glass will be 1/2 the length of the tank.

Here’s where it gets interesting , I was thinking of using 6/4 or thicker hardwood to do the build preferably with white oak or hard maple quarter sawn. I would be laminating my own boards ect. The plan was to build the boards with the bottom of the tank with the two 3/4 marine or oak plywood sheets joined with either a overlapping rabbet or domino/biscuit joining the plywood to achieve 96 inches and then laminating via vacuum and glue two sheets together to achieve 1.5 ish inches for the bottom. The sides would be laminating my own maple/oak boards ala dining table/butcher board style with 6/4 thickness hardwood. I expect to get 1.25-1.4 thickness and 5.5 width of each board and then using a rabbet and splines for the corners for the concerns of the tank. The concern here is the overall dimensional stability of using hardwood vs ply for this application. I was intending on fiberglassing the inside with multilayers of 1700 16 oz fiberglass, I have experience working on boats and wood work as a hobby. The thought in my mind that comes up is old sailboats and older wood boats in general the concern is delaminating of the fiberglass to the wood due to expansion and contraction , this happens due to overtime moisture getting trapped in the wood , this causes the instability and later failure in delaminating glass.

Aesthetically I would like to build this with no visible screws including caps and more like a piece of furniture where it’s more of an Art piece than just a functional tank. My general overall concern is dimensional stability overtime and causing delaminating from the glass. The other thing i’m not sure about is how well epoxy bonds to a hardwood like hard Maple/white oak since woodworkers have some issues with H. maple joints due to the glue not absorbing.

Thank you for the long read and any relevant advise would be useful.
Does anyone here have experience doing something similar?

fallback would be building a plywood tank inside but i would like to avoid the extra/work, weight ect. Not to mention it has its own set of lamination issues and failure problems.

 

[M1A1]

I'm not surprised you haven't gotten any sensible responses anywhere as you are talking about something very few people have ever attempted, if any. Definitely no one I have ever spoken to, heard of, or read about. The effort and investment required to get all of the hardwood laminated together and then assembled without any fasteners does really put it into the category of art.

If laminated hardwood panels were available everywhere and as cheap as a sheet of plywood then I'm sure more people would be using them. There's sometimes questions on the type of plywood like interior sheeting, exterior rated, pressure treated, or marine grade but mostly it comes down to cost and availability. Again, if we could get marine-grade Okoume or Meranti plywood for the same (or close) price as the generic stuff then more people would use it. But no one is doing this for the artisanal look, we do it cause it's cheaper than anything else. Every dollar saved on the tank is another dollar spent on a bigger window or more fish or whatever.

So, all that being said, I don't see any problems with your plans if you know your stuff as well as it sounds you do.

• Plywood tank with a corner where two pieces of glass meet without a brace - yep, been done, basically like a normal glass aquarium at that joint.
• Front glass will be 1/2 the length of the tank - sounds fine, a little weird it's not the full length but whatever. Side glass is ~28" long and front glass is ~48" long or something like that?
• 6/4 or 1.5" thickness everywhere - maybe overkill for 36T tank but you probably need the extra thickness for your splines, rabbets, domino/biscuit joining so yeah, good.
• Dimensional stability - thermal expansion & contraction should be minimal to the point of ignored so it's all moisture absorption. Would have to look up the real numbers but I can't imagine plywood is that much different than hardwood, maybe up to 5% different but not much more at normal humidity levels.
• Delamination - yep, probably in the top 5 of plywood tank killers but it's usually not expansion and contraction that causes it nor is it the choice of plywood (unless it's cheap underlayment sheeting, don't use that stuff folks!), it's improper installation of the fiberglass & epoxy. Didn't prep the raw surface right with cleaning or sanding, didn't prep between layers correctly, didn't work out air bubbles or mechanically remove them later once hardened, that sort of thing.
• Epoxy bond to hardwoods - sounds like a research or test project but I would suspect the boat builders have covered this one extensively. My instinct is any of the real fine or closed grain woods are going to be problems since epoxy won't penetrate without serious vacuum. I don't think white oak falls into this group but I am not a woodworker.

 

[anthony0303]

I'm not surprised you haven't gotten any sensible responses anywhere as you are talking about something very few people have ever attempted, if any. Definitely no one I have ever spoken to, heard of, or read about. The effort and investment required to get all of the hardwood laminated together and then assembled without any fasteners does really put it into the category of art.

If laminated hardwood panels were available everywhere and as cheap as a sheet of plywood then I'm sure more people would be using them. There's sometimes questions on the type of plywood like interior sheeting, exterior rated, pressure treated, or marine grade but mostly it comes down to cost and availability. Again, if we could get marine-grade Okoume or Meranti plywood for the same (or close) price as the generic stuff then more people would use it. But no one is doing this for the artisanal look, we do it cause it's cheaper than anything else. Every dollar saved on the tank is another dollar spent on a bigger window or more fish or whatever.

So, all that being said, I don't see any problems with your plans if you know your stuff as well as it sounds you do.

• Plywood tank with a corner where two pieces of glass meet without a brace - yep, been done, basically like a normal glass aquarium at that joint.
• Front glass will be 1/2 the length of the tank - sounds fine, a little weird it's not the full length but whatever. Side glass is ~28" long and front glass is ~48" long or something like that?
• 6/4 or 1.5" thickness everywhere - maybe overkill for 36T tank but you probably need the extra thickness for your splines, rabbets, domino/biscuit joining so yeah, good.
• Dimensional stability - thermal expansion & contraction should be minimal to the point of ignored so it's all moisture absorption. Would have to look up the real numbers but I can't imagine plywood is that much different than hardwood, maybe up to 5% different but not much more at normal humidity levels.
• Delamination - yep, probably in the top 5 of plywood tank killers but it's usually not expansion and contraction that causes it nor is it the choice of plywood (unless it's cheap underlayment sheeting, don't use that stuff folks!), it's improper installation of the fiberglass & epoxy. Didn't prep the raw surface right with cleaning or sanding, didn't prep between layers correctly, didn't work out air bubbles or mechanically remove them later once hardened, that sort of thing.
• Epoxy bond to hardwoods - sounds like a research or test project but I would suspect the boat builders have covered this one extensively. My instinct is any of the real fine or closed grain woods are going to be problems since epoxy won't penetrate without serious vacuum. I don't think white oak falls into this group but I am not a woodworker.

Thank you for the thoughtful reply, from the responses i have received it seems to be the case. Although it makes it interesting doing something no one or not many people have under taken. I think this is going to take some time to say the least.
1. I plan on testing the hardwood with the different epoxies. My initial thought is im going to need to thin down the initial coats of epoxy to get into the wood. Going to give the guys at polymer composites inc a call and also my friend who owns a large boat yard and repair shop about oak and maple. I do know both hardwoods are not generally used for boat construction below the waterline.

2. The dimensional expansion properties vs ply is actually fairly significant. Plywood is actually very dimensionally stable. What gives me a bit of confidence is the guys who built tanks from 2x6’s and 2x4 which seem to have held up fine … even without jointed/planned studs to get actual flat surfaces for both the wood on wood contact and the fiberglass on wood side..It also seems like people are picking up random lumber as well? (i mean why not kiln dried yellow pine? Strongest, straightest, normal lumber you can get at lowe’s/HD) My assumption is when they are fiberglassing stacked lumber thats rounded corners is it causes a lot of air pockets. I haven’t seen people with issues even with this… People who have framed and put plywood i think potentially have a better constructed tank if they are fiberglassing. I saw on one youtube channel i can’t recall the individual‘s channel but he had a hugh fish room with massive tanks salt and fresh all themed, (thousands of gallons) in his basement which actually was doing a lot of No no’s when it came to how boat builders/Repair do fiberglass and he seemed to swear he had no issues??? ( So my thought is my margin of safety seems a lot higher than everyone else? )

3. Other question i had which might be another thread but i’ll try here. Why are people using 1708 Fiberglass vs 1700 when using epoxy? Fiberglass guys generally 1700 with epoxy, since there’s very few CSM+biaxials which were meant for epoxy. 1708 was intended for poly resin not epoxy resin. I could see using 1708 if you were planning on gelcoating or otherwise to use the Matt side up to get smooth flat surfaces but I don’t quite understand in this application. It’s more prone to air pockets and uses significantly more resin per layer, the CSM doesn’t provide much addition strength compared to the biaxial layer. Also you can apply 2x the layers for the same thickness as 1708 while getting several factors improvement in strength.

4. Your approx right on the dimensions , reason for the weirdness was i was doing a bit of an offset on the wood planks for a specific look. I was also going to integrate some home made laser etched edge banding and also some pieces from wine crates .

Thanks again everyone for the read.

 

[anthony0303]

Other curious thought i had was why not use LVL instead of normal studs for building these very tall tanks ? LVL has many great properties (much stronger, dimensionally stable, straight and square) other than not being great at deal with water but in theory they should never get wet?

 

[phreeflow]

wednesday13

 

[SilverArowanaBoi]

I tried soliciting advice from a few places and generally got nonsense replies and got pointed here as the best place to get some decent feedback. I am currently in the process of designing a new tank, the sump and filters ect have already been built and fiberglassed.

What im looking at building is a 96L * 36T * 30W floor standing tank/pool with two sides of glass with one corner having both glass edges meet with no brace, the front side glass will be 1/2 the length of the tank.

Here’s where it gets interesting , I was thinking of using 6/4 or thicker hardwood to do the build preferably with white oak or hard maple quarter sawn. I would be laminating my own boards ect. The plan was to build the boards with the bottom of the tank with the two 3/4 marine or oak plywood sheets joined with either a overlapping rabbet or domino/biscuit joining the plywood to achieve 96 inches and then laminating via vacuum and glue two sheets together to achieve 1.5 ish inches for the bottom. The sides would be laminating my own maple/oak boards ala dining table/butcher board style with 6/4 thickness hardwood. I expect to get 1.25-1.4 thickness and 5.5 width of each board and then using a rabbet and splines for the corners for the concerns of the tank. The concern here is the overall dimensional stability of using hardwood vs ply for this application. I was intending on fiberglassing the inside with multilayers of 1700 16 oz fiberglass, I have experience working on boats and wood work as a hobby. The thought in my mind that comes up is old sailboats and older wood boats in general the concern is delaminating of the fiberglass to the wood due to expansion and contraction , this happens due to overtime moisture getting trapped in the wood , this causes the instability and later failure in delaminating glass.

Aesthetically I would like to build this with no visible screws including caps and more like a piece of furniture where it’s more of an Art piece than just a functional tank. My general overall concern is dimensional stability overtime and causing delaminating from the glass. The other thing i’m not sure about is how well epoxy bonds to a hardwood like hard Maple/white oak since woodworkers have some issues with H. maple joints due to the glue not absorbing.

Thank you for the long read and any relevant advise would be useful.
Does anyone here have experience doing something similar?

fallback would be building a plywood tank inside but i would like to avoid the extra/work, weight ect. Not to mention it has its own set of lamination issues and failure problems.

I know this thread is about your build, but I'm really curious: what fish are you doing?

 

[anthony0303]

I know this thread is about your build, but I'm really curious: what fish are you doing?

I already have a reef tank , this is for my watonai, wakin goldfish and for some of my smaller koi to keep indoors. Tbh , i’m more interested in having a show piece for where this is going than the fish although some of these fish are amazing and a pita to find and get.

 

[M1A1]

Thank you for the thoughtful reply, from the responses i have received it seems to be the case. Although it makes it interesting doing something no one or not many people have under taken. I think this is going to take some time to say the least.
1. I plan on testing the hardwood with the different epoxies. My initial thought is im going to need to thin down the initial coats of epoxy to get into the wood. Going to give the guys at polymer composites inc a call and also my friend who owns a large boat yard and repair shop about oak and maple. I do know both hardwoods are not generally used for boat construction below the waterline.

2. The dimensional expansion properties vs ply is actually fairly significant. Plywood is actually very dimensionally stable. What gives me a bit of confidence is the guys who built tanks from 2x6’s and 2x4 which seem to have held up fine … even without jointed/planned studs to get actual flat surfaces for both the wood on wood contact and the fiberglass on wood side..It also seems like people are picking up random lumber as well? (i mean why not kiln dried yellow pine? Strongest, straightest, normal lumber you can get at lowe’s/HD) My assumption is when they are fiberglassing stacked lumber thats rounded corners is it causes a lot of air pockets. I haven’t seen people with issues even with this… People who have framed and put plywood i think potentially have a better constructed tank if they are fiberglassing. I saw on one youtube channel i can’t recall the individual‘s channel but he had a hugh fish room with massive tanks salt and fresh all themed, (thousands of gallons) in his basement which actually was doing a lot of No no’s when it came to how boat builders/Repair do fiberglass and he seemed to swear he had no issues??? ( So my thought is my margin of safety seems a lot higher than everyone else? )

3. Other question i had which might be another thread but i’ll try here. Why are people using 1708 Fiberglass vs 1700 when using epoxy? Fiberglass guys generally 1700 with epoxy, since there’s very few CSM+biaxials which were meant for epoxy. 1708 was intended for poly resin not epoxy resin. I could see using 1708 if you were planning on gelcoating or otherwise to use the Matt side up to get smooth flat surfaces but I don’t quite understand in this application. It’s more prone to air pockets and uses significantly more resin per layer, the CSM doesn’t provide much addition strength compared to the biaxial layer. Also you can apply 2x the layers for the same thickness as 1708 while getting several factors improvement in strength.

4. Your approx right on the dimensions , reason for the weirdness was i was doing a bit of an offset on the wood planks for a specific look. I was also going to integrate some home made laser etched edge banding and also some pieces from wine crates .

Thanks again everyone for the read.

1. Thinning the first coats makes sense.

2. Interesting, did not realize it was that big of a difference but I guess it makes sense as plywood has the overlapping and multi-directional plys instead of a single straight grain. Cost cost cost is always the answer for 'why not...' questions. Since there's no structural benefit from a kiln dried S4S fancy board at the levels of overkill most tanks are built at, we don't see the benefit. If you were right on the edge of the safety factor then it would make a difference.

3. A lot of the older builds were from when poly or viny resins were the norm or were more common and cheaper. When it comes to the CSM vs. biaxial vs. woven debate then I think it again comes down to cost and availability. I buy whatever cloth is on sale or cheap drops or partial rolls. I don't need the bleeding edge of performance with the best strength in the thinnest cloth and least amount of epoxy. My plywood tank isn't going to sail through choppy seas or experience weather and temperature extremes. Water's always 72 to 76 F, maybe a 1 or 2 inch wave if I got my hands in there, limited UV exposure except from the reef lights.

4. Have you started designing or planning how you'll do the framing around the glass so that it's evenly supported everywhere? This is probably the number one area for leaks if the glass doesn't face up against a flat and strong surface.

Other curious thought i had was why not use LVL instead of normal studs for building these very tall tanks ? LVL has many great properties (much stronger, dimensionally stable, straight and square) other than not being great at deal with water but in theory they should never get wet?

I'm only familiar with LVL as used in larger timbers for framing or whatever but it does look like there's smaller more relevant stuff available in some places. I think I'd say cost and availability again as to why it's not used for aquariums. I can't just pop down to the local big box store to pick some up and my lumber yards all consider LVL a custom/special order, call-for-price type.

 

[fishdance]

Hardwood is more expensive, more difficult to work with and handles moisture worse than plywood. I build my first fish room racks from hardwood and despite sealing them well, they would warp - twist and bow especially if weight changed.

If your set on making a hardwood tank, the best advice I can provide is to make a much smaller version to test out your materials and techniques on. Your the only person who will know if the extra effort required is worth the end result.

Most of the experienced tankmakers have left this forum unfortunately.

 

[anthony0303]

1. Thinning the first coats makes sense.

2. Interesting, did not realize it was that big of a difference but I guess it makes sense as plywood has the overlapping and multi-directional plys instead of a single straight grain. Cost cost cost is always the answer for 'why not...' questions. Since there's no structural benefit from a kiln dried S4S fancy board at the levels of overkill most tanks are built at, we don't see the benefit. If you were right on the edge of the safety factor then it would make a difference.

3. A lot of the older builds were from when poly or viny resins were the norm or were more common and cheaper. When it comes to the CSM vs. biaxial vs. woven debate then I think it again comes down to cost and availability. I buy whatever cloth is on sale or cheap drops or partial rolls. I don't need the bleeding edge of performance with the best strength in the thinnest cloth and least amount of epoxy. My plywood tank isn't going to sail through choppy seas or experience weather and temperature extremes. Water's always 72 to 76 F, maybe a 1 or 2 inch wave if I got my hands in there, limited UV exposure except from the reef lights.

4. Have you started designing or planning how you'll do the framing around the glass so that it's evenly supported everywhere? This is probably the number one area for leaks if the glass doesn't face up against a flat and strong surface.



I'm only familiar with LVL as used in larger timbers for framing or whatever but it does look like there's smaller more relevant stuff available in some places. I think I'd say cost and availability again as to why it's not used for aquariums. I can't just pop down to the local big box store to pick some up and my lumber yards all consider LVL a custom/special order, call-for-price type.

I can get LVL here at the local lumberyard. I was going to use it for the base and veneer it so everything stays square. The reason i suggested 1700 was because you ultimately waste less resin which is one of the things people seem to complain about the cost of it.

Regarding how i was going to mate the glass, I haven’t finished the design of how i want the boards to inlay and overlap but if maintain a straight board across the bottom front face and side with the glass I can mill 3/4 inch from it, put 1/8-1/4 inch of fiberglass on the face grain side leaving the edge grain for stain and mate the glass to the fiberglassed face. Clearly there’s going to be an order of stain, seal , silcon ect. Most likely I will be using something more elastomeric for the seal and silicon for the edges using RTV 108. The glass i’m going to use will be beveled edge for the nice corner.