Aquarium Stand

[CaptainBudget]

Hi,

I've started my next project today, and I'm going to try and use this as a log to update my progress.

I have a 120L aquarium currently sitting on a repurposed (and reinforced!) MDF TV cabinet circa 42" tall. The reinforcements to the TV cabinet have allowed this to be used as a Games cabinet, with a large portion cut off for the External Filter. The goal is to replace this unit with a custom-made one. I also have ambitions on a 6ft x 2ft x 2ft tank further down the line, so this I intend to use as a "working prototype" to identify any potential issues prior to starting that one (I will design it and build it the same way, but the timber members don't have to be anywhere near as big)

The issues with this current setup (and which this replacement must resolve) are:

1. Movement. The existing stand is starting to show some signs of compression and localised bending; I don't think it will fail due to the way I have reinforced it but this is not ideal

2. Cabinet space. The tank has a footprint of 810 x 360mm, and just fits on the top. The cabinet underneath only has ~520mm of width due to the vertical divider that acts as an additional compression member and segregates the contents from the External Filter. This compromises its efficiency and due to the way I modified it, getting the filter out to clean it is a complete b***rd.

Below is my preliminary design. What I have done is increase the cabinet depth to 600mm, allowing me to fit the filter behind the tank where it is easier to access (I intend to fit a door of some sort to the side so it can just slide out) and hide all the plugs and hardware that goes with. I'm hoping I can also put this space to good use by developing an auto-water change/top-up system to make the maintenance easier (the 6ft tank will need a functional version to be viable, so I'm hoping to experiment here).

This means with the filter gone and the increased depth there is far more storage space, and the depth means we can store the bigger games "end on" which should make organisation easier.

The timber I will use will be more reclaimed pallet members from work (these are typically 75 x 45 rough sawn sections, and provided you are careful with selection these tend to be better than you Wickes/B&Q stuff, and they're free!).

Having done some initial calculations (base on a 5x load safety factor, so 600kg) as long as the member cross sections are at least 38 x 50mm they should be more than strong enough, though I've increased the top side members to 38 x 95 as there was a touch more deflection calculated than I would like with a 50mm one; with a glass box it needs to be as close to zero as practical to prevent stress points and cracks.

The sides will be Solid wood Frame and Panels; I haven't decided whether to make the door panels out of solid wood or ply yet.

The interior will have one bottom shelf, and a Middle shelf fixed to the central side members. This will act as a Strut and help resist the sides bowing out. The back will have plywood panels fitted to the frame, probably with a rebate and screws so it can add additional resistance to racking.

Finish colour is currently TBC, possibly a pale Walnut. Finish itself will be my go-to Mann's water based wood stain covered with Hard Wax Oil. The interior of the lid may require some form of Epoxy paint to restrict water vapour damage.

 

[CaptainBudget]

The progress I have made can be seen below.

I have cut all the members for the Core Frame (shown below). These have been cut over-long and planed square and flat. This was about 6-7hrs work.

As this wood tends to Stress-Relieve after an initial rough dimensioning I have not quite planed these down to finished sizes yet; I will let the wood re-acclimatise and Stress-Relieve so next week I can hopefully take out any twisting or bending and plane down to finished size (and maybe at least mark the joinery if there's time...).

These have all been planed by Hand. I started with an old Marples Number 5 (that was an Ebay burn), I've put an 8" camber on the blade and it chews through the sawn layer quickly, and is very good at chewing away twist and bending. I then used my Stanley No.5 to clean away the "scrub" marks and mostly true it. A few passes with my finely set Axminster no.7 finish off the trueing and leave a lovely finished surface.

The initial dimensions were ~75 x 45, these are now ~68 x 41mm. The top two side members (95 x 40) were made from a piece of 2 x 4 C16 studding timber I found in my offcuts bin, this was actually the most twisted piece I worked with today and required a lot of work to make flat.

This image shows one side laid flat on the work-bench. The vertical frame shown in front of my Wall of Tools is where I intent to fit the front cabinet doors

Where the parts overlap is where I intend to fit the joints. I'm thinking Wedged Mortice and Tenon joints where practical and Blind Mortices where not.

These shavings are all new today...

(Obligatory Shaving shot)

More progress to follow next week hopefully, presuming I can find time to do it...

 

[Sachakins]

Have a look The King of DIY on YouTube. It is an aquarium chanel and joey builds loads of aquariums stands filters etc.
Here is one such vid, but trawl his channel as tons of build ideas.

 

[CaptainBudget]

Thanks.

I have seen a good chunk of his videos, and that is where the initial design came from. I have refined it by removing a lot of the material and using traditional joinery instead of a shipping container's worth of screws.

I'm not bashing his design, it very much fills it's intended purpose by being easy to build for those who haven't done much woodwork before and by his own admission it is grossly over-built.

He gets around the lack of racking resistance in a screw joint by using 3no 2x4s for each upright. Only the middle one is a Strut in compression, the other two act as "shoulders" to resist any racking movement.

Mine gets around this by using Mortice and Tenon joints instead. When fitted tightly and glued these will have better shear and moment strength than a screw joint, so I only need one member in compression. Incorporating the side and rear panels into the frame increases this further, increasing the stiffness.

The trade off is this design requires a much higher level of skill to build than Joey's but a lot less material. It will also take a lot longer to build...

 

[CaptainBudget]

UPDATE:

Today I've taken all the core frame members and planed them to Finished dimensions. Some of these had warped a bit but most didn't require too much work.

These stated out as Rough sawn 45x70mm and have now finished at 63x39mm. This was all done by hand. Converting an eBay burn of a no.5 to a scrub plane has really paid dividends here, the rate it could scalp waste off when planning to thickness was quite impressive (the shorter members were closer to 45mm than the columns, and needed thicknessing to the same dimension so a lot of material had to go...)

Next stage is to mark and cut the joinery...

I have also decided the case sides will be Frame and (solid wood) Panel. I've found a video from Paul Sellers where he raises panels by hand, so I'm very keen to give this a go! The grooves in the frame to accommodate the panels will have to be routed as I don't have a plough plane.

I have collected the timber for the panels, looting Pallet Surrounds. These are sitting in my workshop drying out at present and if time permits next week I will dismantle them and cut slightly over-length to speed up the process.

 

[CaptainBudget]

UPDATE:

I didn't have as much time over the weekend to work on it but I have made some progress. One side has all the mortises and tenons cut and has been pushed together in a trial fit. There is some minor fettling still to do to make all the display faces flush and close up some hairline gaps in the shoulders. This weekend I intend to get the other side done, and possibly the cross-members so the core joinery will be done (see how that goes...)

You can see the joinery is not quite as tight as I would like, I think most of this can be fettled out though.

On my Chest-of-Drawers thread someone asked me how I keep track of project parts, you can see this below. Every joint is marked with a unique Letter during the marking up stage, and when the tenons/mortices are cut it is re-marked to make sure it is not lost. To aid with trial fits and glue-ups (and because it is naturally convenient) a stile will have two consecutive letters (A for one Tenon B at the other). It means if the letters don't match I've got the wrong piece, or it's the wrong way round! I use biro in an inconspicuous place so when it is glued up I don't have to get rid of it (joint shoulders are an easy one).

In the case of this example, this is one of the joints for the middle rails on one side, the joint on the opposite side will generally be "P" or "R" (in this case R), so I know straight away that I've got the wrong stile during glue-up if they aren't consecutive.

One issue I am having (and I'm fairly confident it is technique rather than tool but I'm happy to be enlightened) is the mortises seem to be "tapered" through the depth (i.e. 1/2" at the bottom, but an extra 1/32" to 1/16" at the top, meaning there is a small amount of twist movement in the joint when trial fitting. Mortices are about 25-35mm deep depending on which side they've been cut. I don't think this will affect the integrity of the stand as most of the forces are not acting along this line but it is irritating (even just on a dry fit, the racking resistance on this frame is ridiculous, and I can barely get the assembled frame to twist at all). Also the mortise walls themselves are quite ragged (See below; not sure if this is material or tool or technique)

Tool is a 1/2" Robert Sorby Mortise chisel with a ~35 degree cutting bevel and a 30 degree primary bevel. Back is flat and blade edge is (almost) square to the chisel sides. I have no issues getting a razor edge on this. What I have noticed is the chisel does sometimes want to "twist" in my hand and I find myself fighting this as much as I can (but frequently don't win), and it does "rock" when hammering (I try not to smack it too hard and let the weight of the mallet do the work as far as practical). It does appear to struggle to cut a bit as well, I'm assuming it's the steep angle that means it needs more "encouragement" to chop?

In short, the joints (appear) to be solid, but don't look anywhere near as neat as they do in the books I'm using for reference and I'm not entirely sure why, nor are they quite as snug fitting as I wanted.

Will keep at it this weekend and hopefully have an update...

 

[CaptainBudget]

Next Update:

On the weekend gone I managed to complete the joinery for the main components of the core frame. There is still some minor fettling work to do but everything fits together and is square, it's just some (very minor) adjustments to get the hairline gaps to close. Some of these do not close as tightly as I would like, but I do not have any concerns about the structural integrity of the piece once glued up. The back will also have two 6mm ply panels rebated into the back to provide additional shear resistance, the sides are more than strong enough as they are so the solid wood panels in the sides don't NEED to provide additional strength (but it won't hurt if they do). The horns on the end of the columns will be sawn off after glue-up.

Speaking of the side panels, I have also processed the pallet surrounds reclaimed from work. Unfortunately some of the sections were not as thick as I intended and some are unusable. This is what I started with (3rd one not shown):

Some defects and damage are clearly visible, but as I have determined my panel sizes are 493mm wide by 463mm high (443mm for upper panel) I can work around these and any significant knots, salvaging useful offcuts and scrapping the rest. The first stage however was to remove the metal hinges; a coarse handsaw would have been better but as I didn't have one I had to use my rough TCT Irwin DIY Abuse saw; yes it is nowhere near as nice as my proper Sheffield re-sharpenable saws but it is a lot faster, and I don't mind using it on stuff like this because it was cheap (hence the term "Abuse Saw").

After this it was a case of breaking down the useful boards from this set into rough lengths for edge jointing. I then planed one edge flat and ripped these on the bandsaw, the width dependent on where the defects were and the nature of the end grain pattern (those closer to quarter sawn I ripped wider, I cut out and pith or overly-tight "crown cut" segments to minimise cupping/warping during manufacture. In the end I got the below, and these now need to normalise and dry out a bit further before I joint them. I would like to have scrubbed them all to expediate this process but I ran out of time. I should have enough to easily do both the bottom panels here, with some left over. I do anticipate discarding a couple of these if they warp badly over the next week or so.

The actual timber (once scalped) should be very nice, below is the one board I had time to do to show the typical grain from these. I will of course match the tones as best I can when edge jointing to make it as seamless as I can. The black mottling I believe is oil staining, I have found in the past these patterns tend to disappear once the wood is stained and you won't notice it. I had tried to make this a feature on one of the drawer fronts of my chest-of-drawers and all the interesting oil patterns in the grain vanished when stained, I was quite disappointed. The contrast between the white/biscuit tones however will still come through when stained, so I should be able to produce some aesthetically pleasing panels.

This weekend's task is to scrub all these to remove the outer layer and set them aside to stabilise further, and process more timber for the upper panels. I will also try and work on the front face of the stand and start prepping timber for the doors.

 

[Jameshow]

Well done!

Using reclaimed wood can a pain in the backside!!

Your design looks good.

you should put a sheet of 3/4" plywood under the tank if you aren't.

Cheers James

 

[Sachakins]

Well done!

Using reclaimed wood can a pain in the backside!!

Your design looks good.

you should put a sheet of 3/4" plywood under the tank if you aren't.

Cheers James

Before adding ply base need to check tank bottom, some are designed to fit on edge beam support, others need a full smooth base like ply.
If putting onto ply, add a insulation, like polystyrene sheet, this will absorb any undulations in the ply, and help prevent condensate between glass and ply.

 

[CaptainBudget]

HI James,

Thank you for the suggestion. My understanding is given this is a glass tank (with a plastic trim base) it needs to be fully supported along the entire perimeter, but the centre is not important. If it was Acrylic then yes I'd definitely put a ply sheet on and add an additional front-back member along the centre to support the centre of the base, as the material will flex under load whereas glass won't. The thing is glass doesn't deflect by any appreciable amount, it just fails once the load reaches its ultimate tensile strength. Acrylic however deflects, then permanently deforms, then fails (hence why it needs full support along the base).

In fact the plastic base trim this tank comes with (it's a Fluval Roma) raises the base off the surface of the stand by circa 6mm, so any further support beyond the perimeter of the tank is completely pointless anyway. This tank is currently "live" so I won't be able to get the trim off, before installation it'll be a case of extracting the larger residents, draining as much water as I dare and then getting/bribing the Mrs to help me lift it from one stand to the other. I will however put a ~3mm polystyrene strip on the top surface of the stand to help negate any high spots I miss during glue-up/installation. I will be using a carefully sized moulding to hide the plastic base.

I have realised looking at this frame again that I need to add an additional horizontal member as the back edge of the tank is not supported, so I'll try and sort that this weekend. Oops!

 

[Timthetangent]

Well done!

Using reclaimed wood can a pain in the backside!!

you should put a sheet of 3/4" plywood under the tank if you aren't.

Cheers James

Yes but that pain is an integral part of the joy that something has a new functional and beautiful life. I will always pick reclaimed wood with a story, but that's because it's integral to what I try and do if time and supplies permit. I come in peace by the way. Not always easy to see when on forums or social media. Your feedback was helpful. Thank you.

 

[CaptainBudget]

This week's update:

I've added the missing member that supports the rear of the tank. Note that if I were to use a Mortise and Tenon Joint, the mortise would be cross-grain (and according to Google a pig to cut). The traditional method I am led to believe is to use twin/triple mortise and tenons to make them square, however I felt this would compromise the strength of the member as you're effectively halving the area of the shear plane when loaded. The solution I used was to cut a sliding dovetail at each end, which will have the added benefit of resisting racking across the whole top frame.

My joint is not the neatest (there's a couple of small gaps), but this will be hidden by the tank and a moulding. The joint itself is rock solid and is a tight enough fit it requires "assistance" with a mallet to fit home.

The other thing I have done is to cut the components for the door panels. I'm leaving the boards for the side panels as long as I can to normalise before I start cutting them, and the logic is whilst I'm cutting and fitting the side panels the door panels can be re-acclimatising.

I started with these big pallet bearers (circa 100x80mm). Some of these have huge (2-3" DIA) knots in them, so I had to cut around these. The beauty of these is the grain direction and the radius of the growth rings. By cutting these perpendicular to the nail holes you can see below, more or less all of the material becomes quarter-sawn (so more stable!) and there is very little crown cut material to deal with.

These were cut into roughly 460mm lengths, and a reference face and edge planed onto each like the below:

These were then fed through the bandsaw into 20mm thick pieces, re-establishing the reference face between cuts and labelling the faces where they can be Book-matched later. The thing about these members is you genuinely can't predict what the material will look like until they are cut open; sometimes you get a very clear cream-coloured straight grain, other times you get (what I think is) oil staining soaking into the wood and producing lovely patterns like the below (these are two blocks from the same member book-matched down the middle).

A lot of this dramatic colour change will disappear when stain is applied, though there will still be some tonal differences. The grain patterns will be preserved of course. I have cut up about 4 separate members and tried to produce a layout for the doors.

Each door will consist of 2no panels circa 450 x 310mm, and there are two doors side by side. I think the easiest solution will be to edge joint pieces into two oversized boards and rip them in half to produce four panels, this has the added advantage that the grain pattern continues from one door to the next. Below are two options I have determined, showing roughly where the split would be, but I'm not sure which looks best.

What do you all think? Option A or Option B?

OPTION A:

OPTION B:

I've added a Poll so you can let me know, I'd be interested to see what you think.