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Hypothetical XXL tank build - options ideas and comments.

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XXL tanks are not always built "all glass" and I have been checking out plywood construction but the examples so far have been expensive and heavy. Another option could include a frame to increase strength and reduce weight and cost or to make it prettier.

We could write a book on it but this is a forum so we have to be concise. What it comes down to is making a box that can be filled with water without distortion or leaks, it should have an opening in the top and a fixed window in a side.

The advantages of a tank with a frame are:

a) There can be a cavity for insulation and pipework and wiring.

B) A wide choice of attractive external cladding becomes optional

c) Attractive claddings can be pre-finished so no painting or painting preparation is required

c) Stands and hoods and filters can be easily attached or built as part of the whole unit.

There are two frame types that look likely.

1 The way they build caravans

2 Steel house partition frame (light cheap strong and rigid) and a stitch and glue light weight composite (ply and fibreglass) aquarium insert.

So it is not too confusing I will deal with 1 and 2 above separately in different posts. (if you are not interested do not bother to read, but someone might be interested in saving time and money).

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The way they build caravans is

1) They cut the shape of the side of the van out of ply, lay it down flat (with the inside face down).

2) Glue light weight framing onto the ply

3) Make their box (Caravan shell) by putting all the sides together and bending roof ply into place

4) Now they have the inside lining "box" with a frame to attach the external cladding

5) they then clad it with aluminium and it appears to be an aluminium caravan

So your average aluminium caravan shell is wood but it appears to be aluminium. Internal furniture and fittings help hold it together.

An aquarium tanks are much smaller and the materials can be beefed up but the build technique is proven, at least in caravans.

I would suggest 6mm or 8mm ply with surfboard fibreglass cloth epoxied on to strengthen and waterproof the plywood. the fibreglass side will be the inside of the tank with no water touching any wood). The frame can be any size you choose and to glue the frame on I would use a high strength construction adhesive (Liquid Nails).

Screw and glue the sides together to make your box but make sure the frame is securely joined in the corners.

The next job is to fibreglass tape and epoxy all the internal corners to prevent leaks.

You should now have a free standing tank with fibreglass cloth inside then 6mm or 8mm plywood then a bonded on frame to make your tank absolutely rigid. You can strap the frame on the outside corners if you choose.

You can put insulation between the frame and any wiring or pipes at this stage.

Then the last thing you do is clad the outside. The cladding will make it even stronger, you can clad it with weather proof material or padded cladding for a softer look, or plank it with timber strips you can do anything you like.

PS

Any window cut-outs holes etc are done before the frame is glued on and then the frame around the openings is glued on at the same time as the rest of the frame. A trim can be fitted when the outside is clad.

Anyway that is roughly how they build caravans and my spin on using the method for a tank build.

Edited by Bottomfeeder

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This next method is a light weight composite fibreglass and ply aquarium fitted inside a galvanised frame. (house partitioning wall frame)

For the aquarium tank liner see stitch and glue boat building using zip ties as temporary stitches here

Rondo http://www.rondo.com.au/products/walls/steel-stud (a BORAL company) is one supplier of the steel frame but there are more suppliers - the frame is rigid and straight when assembled and mistakes can be pulled apart and the material re-used.

Essentially it is 2 sized channels and one fits neatly inside the other and it is pushed together and secured with self drilling screws. It is a fast build but you can take your time.

You will need a caulking gun to fill any gaps between your box and the frame.

You can fit insulation,pipes and wires inside the frame then clad the outside with anything you choose.

That is my two suggestions for discussion "the caravan method" and the "steel house frame with a stitch and glue liner". They are all proven systems of construction and it is easy to make it very strong and rigid.

Please have your say, I am here to learn too.

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Pine frame, mdf box and pond liner was the cheapest way i could find to do it (whilst still considering strength and longevity).

However mine is only 1400L. I would happily build one with a much larger footprint this way, but i would definitley make a few changes if it were 1m in height+

post-6895-14711635094165_thumb.jpg

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Thanks @lgw it has to be a cheap option probably one of the cheapest.

Have you clad it yet?

Did you cut the liner or fold it for the corners.

I havent clad it yet. I left it open, so it was easier to spot where any leaks/bowing/movement were. After 4 or so months of trouble free operation, i will probably finish it off soon.

The liner is folded in the corners, however cutting and joining wouldnt be a big job. It just increases the likelyhood of a leak if done incorrectly.

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Great post, I have been planning a 2.4m x 1.2 x 1.2 doing a similar thing. Fiberglassed ply on the inside, frame (wood or metal unsure yet) and clear acrylic sheet for the window. I'll look into the 2 framing products you have described.

Thanks

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There is a detailed build of a ply/fibreglass tank buried in the forum somewhere, it has all the measurements and bracing.

I think it may be in the diy section and posted by greenterra but I could be wrong.

Cheers mick

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Great ideas here, but. Caravan designs are for caravans - the moment something unexpected happens to them they disintegrate far too easily. Cannot afford that low level of safety factor when talking thousands of liters. And 6mm or 8mm plywood, I dont know the structural maths - am neither an engineer nor a builder, but most large builds have used 20 to 30 mm ply, 'with' bracing.

I hate to put a negative spin on this, and am following the post eager to pickup some new ideas :D

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Informative post - could even be a massive 'Shed' type of post ..... as *Mens' Shed100 has posted elsewhere, the use of a video camera could suffice.

Just dig as big a badass whole in the ground, line it and plonk a lot of video cameras around wired to an array of flat screen monitors in your patio / living room. No worries with glass breakage!

* Ok, so it does turn out to be Shed100 just re-named. Only saw your earlier post on Page 2....

Edited by aqc247

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Thanks @IsaRich

I will be heading out to play bowls shortly so I have some time to fill in so I hope this helps

I am talking about the construction method used in caravans, I am not necessarily talking about using the same thickness ply and the same size frame.

The caravan construction method, as you have noted, produces a super light weight box that is safe enough to drag along the highway at 100 kph or more, but impact can destroy them, they are not bullet proof.

The weak point for our box with window will probably still be the window - the issue tho is rigidity of the box that supports the window.

Plywood strength and flexibility changes dramatically when I have "coated" ply with surfboard firbreglass cloth and resin the cloth is as fine as tee shirt material and it takes very little resin to fill the weave. So I would be adding another "ply" by "coating" one side with fibreglass. So 7 mm ply done this way would be extremely strong but might still lack some rigidity in a big panel, (fibreglass coated XXL eskys are very rigid and they are totally fibreglass encapsulated.) (surfboards are very rigid too)

Frame can be cheap, for example:

You can rip up pine studs to 35 x 35mm and you will get framing for about 50c per 300mm length.

Alternatively Bunnings thickest ply is 17mm one video I watched he uses double thickness 20mm ply of the highest quality.

Bunnings has CD structural plywood (pretty crappy but strong) 17 mm is their thickest in 8 x 4 sheets for $65 so adding frame for rigidity would be I expect a lot cheaper than double thickness ply around the edges.

The grade plywood grades are A - B - C - D and is the verneer quality and is basically a knot count so C D is for construction not furniture. The thickness may be less than nominated because sometimes they quote it before sanding one side.

7mm CD ply at Bunnings is only $31.

So to make the back of a tank you could use 1/2 of a 7 mm CD 1200 x 2400 sheet ($16) plus frame it all a round the outside with 35 x 35 pine ($10) put another frame horizontally up the middle ($5) and use up any shorts to divide it up even smaller ($5). $20 for more than enough Selleys top of the line construction adhesive.

So I make that $56 (say $60) to make the back panel for a tank by the caravan method. (8 x2 (2400 x 500) tank and it has no nails or screws).

For the back panel

Cost = $60 + fibreglass surf board cloth and epoxy resin.

Size = 2400 x 1200

Thickness at frame = 44mm

Thickness between frame = 9mm

Max size between frame = 250mm x 440mm

Alternatively one sheet of 17mm ply cost $65 and you need the same amount of glue + screws or some other fixings say $20 total = $85

So the comparison is $60 for caravan method Vs $85 for the all ply method with 17 mm crappy ply. (quality veneer ply in 20 mm could be twice that price.)

Fibreglass can be added on the inside for both methods (conventional double thickness ply and caravan build with frame)

It should be light strong and rigid and before assembly I would lay it down flat and coat the inside face with surfboard cloth and epoxy. I have not got the price of the surfboard cloth but it is the cheapest cloth and uses by far the least resin. You apply the cloth like wall paper first a tack coat of resin then lay the cloth and work out any bubbles then brush on another coat. Epoxy resin has a good working time but you can set it faster with a hair drier if you need to.

So the timber work for all ply for the back panel could be $85 or $140 depending on the size of the ply and the quality you choose and you can put the face side out and fibreglass the inside. Now you can paint it or varnish outside.

Alternatively the caravan method costs $60 and it needs to be clad with something for appearance.

The advantage of the latter is you have a cavity for insulation and wires (maybe you can make the cavity big enough for pipes) and of course it will be a lot lighter,

Just a guess but if you multiply the cost of the back x 5 it will be close to the tank build cost as above without the window and without the fibreglass and any painting or cladding.

So as above Caravan method = $300

All ply method between = $425 and $850 Depending on the thickness and quality of ply that you buy.

One is plus cladding and the other is plus painting

Strength is not an issue both methods will produce a box strong and rigid enough to not break the window.

Edited by Bottomfeeder

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do the shed have access to free airplane fuselage? that may work and it already have the viewing panes as well as insulated. not just the normal hobby planes but those passenger units as big as a house.

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Thanks [MENTION=6679]aqc247[/MENTION]

Yes it is still me but I represent myself NOT Shed100. So that gives us more freedom to discuss issues without destroying Shed100s great reputation for community service.

I chose "Bottomfeeder" as a name because I am always looking for scraps of information for ME.

Yes a pond has got to be the cheapest and video is cheap as chips. If I was doing a pond I would include a window as a dam wall for the pond and then add cameras too would be good. I have been thinking about making windmill to lift water for a run back waterfall but only lift the water 100 mm or 200 mm so it could be a crappy pump alternative (some cheap method of lifting the water inches not feet.)

At the mo at the mo I am making a 1 metre long Whirlygig (Those novelty things that face into the wind with a propeller that works in reverse and spins when the wind blows, the spinning propeller drives some figures doing stuff like chopping wood or rowing a boat). It might not be a big step from there to making a windmill to pump up a bit of water 200 mm. But first I have to get the whirlygig going.

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Thanks [MENTION=916]litigator666[/MENTION]

Shed 100 gets donations but we have not been given a plane yet. I was at Darra Bowls club and we watched a small plane from Archerfield go down into a back yard in the same street as Shed 100s new shed, but I do not know if they let them keep the plane. The pilot walked away.

Gotta have lunch and go to bowls now, see ya.

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XXL tanks are not always built "all glass" and I have been checking out plywood construction but the examples so far have been expensive and heavy. Another option could include a frame to increase strength and reduce weight and cost or to make it prettier.

We could write a book on it but this is a forum so we have to be concise. What it comes down to is making a box that can be filled with water without distortion or leaks, it should have an opening in the top and a fixed window in a side.

The advantages of a tank with a frame are:

a) There can be a cavity for insulation and pipework and wiring.

B) A wide choice of attractive external cladding becomes optional

c) Attractive claddings can be pre-finished so no painting or painting preparation is required

c) Stands and hoods and filters can be easily attached or built as part of the whole unit.

There are two frame types that look likely.

1 The way they build caravans

2 Steel house partition frame (light cheap strong and rigid) and a stitch and glue light weight composite (ply and fibreglass) aquarium insert.

So it is not too confusing I will deal with 1 and 2 above separately in different posts. (if you are not interested do not bother to read, but someone might be interested in saving time and money).

There are several other methods not mentioned but choice of materials and type of construction is heavily influenced on the persons skill set and familiarity/experience. For example, you could weld a steel frame (not to be confused with light weight steel house frames) and use colorbond or tin sheet metal riveted/screwed walls. The strength coming from applied tension, not thickness or rigidity of material.

Another economical wall material is cement fibre board (used under tiles/wet areas).

Or if you want a tank bigger than XXL then use pre cast concrete slabs. Pour 4 flattish slabs on site using water proofed concrete mix and when dry, stand them up and join to form your tank, pour the base and insert window.

In aquaculture, they use flat HDPE (high density polyethylene) sheets and a plastic welder to make their own water tight tanks. Some circular for better structural strength and water flow/self cleaning, some rectangular.

You could also modify existing water tight containers such as rain water tanks, IBC containers, megabins etc. All fairly straight forward to add a viewing panel in.

There is also a wide range of water proofing options. Rubber paints, plastic liners, ceramic tiles, glass, acrylic etc.

Edited by aquaholic99

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Thanks [MENTION=470]aquaholic99[/MENTION] thanks for some great info.

Concrete is an old favorite of mine I built a tilt concrete house more than 40 years ago and I was going to offer the system up in here.

My concrete system is good for an aquarium build and the panels are easy to bolt together. I used Lysaght stud frame (Steel channels as discussed earlier) and bonded on 50mm of reinforced concrete. Bolting concrete to concrete is difficult but with my system you bolt the frame together.

To make the panels you make a stud frame panel, then lay it down flat then fill it with sand to within 25mm of the top face of the frame. Then put builders plastic strips on top of the sand.

Next you tie reo mesh across the top face of the stud frame, then box it up another 25mm higher.

Pour your concrete and trowel finish it like a path.

One week later you can lift the panel and the sand falls out, so you have a stud face for sheeting, then a cavity, then 50 mm of reinforced concrete.

The frames bolt together to form a concrete box.

I used a lifting bar and bolts embedded in the concrete panels.

It works, the house is still where I left it. (sold it)

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Thanks @Harris yes it looks the goods, What surprises me tho is despite the wood build no one seems to want to integrate the stand into a total aquarium.

Actually I have already done this and so far it is awesome :) It's a 120cm w x 50cm H x 60cm d tank but the whole set-up is 6ft tall.

It is fully lockable because it is in a nursing home and the residents like to put a variety of things in with the fish, including green cordial and sandwiches.

Also the cabinet space is huge so it is easy to remove the huge canister filter. post-6226-14711635100998_thumb.jpg

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I also got an engineer to do a full assessment (was about $500) of this design and it is interesting to find out where the stress factors are, what the F rating is for different plywood and much more.

I have been researching and planning alternative aquariums for a while now and there seems to be some great alternatives, unfortunately there are a lot of costs involved with the Research and Development (mostly engineering and testing).

I will take a video of this set-up later today.

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Brilliant @Aquatic Paradise your composite build of tank/stand/ lock-up cupboard is just the ticket.

This thread is going very well for me and I expect lurkers and posters are at least finding out what the options are.

The "hangover" from all glass aquariums on a wood or steel stand is a good thing to avoid if you want something special. The lock-up to make access private is a great bonus.

Re Engineering when I built my concrete house my mate who is a civil engineer advised building the frame to Lysaght specs and telling the council it was to be clad with AC sheets, but in fact bond on 50 mm of concrete. I did it and they gave it the tick without having to pay for engineering.

The next step in "öut of the ordinary" aquarium build is getting rid of the square box look.

A more natural appearance surrounding the viewing window would be good. The place to look for how to make that could be model train topography. I have an idea that they have a thermo plastic sheet of some kind and they lay out objects to represent hills and valleys, they place the plastic sheet on top and heat it until it droops into the valleys.

But I have no experience with model train topography.

An alternative that keeps coming to my mind is a lock in-place screen on coaster wheels. Unlock the screen then wheel it aside for the easiest possible access, do what you want to do then push it back and lock it. No doors or hinges should make for an easier build.

Re engineering:

Yes, if it is for ourselves it is fine to make what we like but if it is for sale or to go in a public place then we place ourselves at risk That is why an engineered product like galvanised stud frame is good, if you can fudge their engineering specs into your design.

Edited by Bottomfeeder

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