mrhoyo
Member
I wanted the shelf to have an overhang. I could remove the MDF and the plywood would sit on the external frame, with the MDF also in place thr weight touches the cross braces too (they sit below the external frame).
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Racking recommendations?
- Thread starter UrbanDryad
- Start date
UrbanDryad
Member
Gotcha. So if I didn't want an overhang, I should just cut the plywood to replicate the exact dimensions of the MDF, and that'd be fine?
mrhoyo
Member
Correct
Plywood is only moderately better than mdf when it comes to getting wet, but its not A LOT better. If you want to be ultra safe you should use marine ply. Its a higher grade ply where the glues used are not water soluble. Regardless it too needs a waterproof coating.
A boat repair shop in Leeds maybe?, to see if they can source it and cut it to dimension for you, given that you need probably buy one sheet and its going to be 5 min worth breaking it down with a tracksaw or table saw, and them buying at discount, it might just cost the same as ordering from a specialty store. Ask them to throw a coat of poly or lacquer on it?
Otherwise you're going to want to coat raw normal plywood in an oil based polyurethane and hope that you've done it well. 2 -3 coats would be needed, sanding in between. you'll need mineral spirits to clean your brush. Lacquer is just as good but you'll either need to buy it in a rattle can if available or you need a spraying setup.
all in all it may save you money to have a shop do it. if its a one time thing.
I don't know if you can source oil based poly or lacquer with the strict VOC laws in UK, if you can they're likely very pricey and you need to do it outdoors, if you don't have access to a shop. I can buy it no prob in every home improvement store in the US, but I'm not sure you'll have the same access.
You definitely do not want to do it in your living space and just open the windows. Its not safe, like really not safe, becuase it off gasses for like 24-48 hours and lacquer evaporates fast but the off gas is a propellent... but since its not fine furniture, you can just do it outside and live with the imperfections associated with dust.
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UrbanDryad
Member
Thank you for the extra information!
What thickness of marine ply would you recommend? There are a lot of different options and quite a steep upward curve on the prices. This 12mm sheet seems to be the cheapest at B&Q, and it works out at £25 per shelf, so with 5 shelves that's a heck of a lot.
Is there a particular boat shop in Leeds that you know to be a good supplier of marine ply for aquarium racking? I expect there are probably boat places in Brighton too, as we're on the sea...
Re: the rest of your advice, can any UK folks chime in on whether this is possible with the resources available in here? Or indeed whether you've found yourselves needing to source marine plywood, and where you'd recommend doing so?
What thickness of marine ply would you recommend? There are a lot of different options and quite a steep upward curve on the prices. This 12mm sheet seems to be the cheapest at B&Q, and it works out at £25 per shelf, so with 5 shelves that's a heck of a lot.
Is there a particular boat shop in Leeds that you know to be a good supplier of marine ply for aquarium racking? I expect there are probably boat places in Brighton too, as we're on the sea...
Re: the rest of your advice, can any UK folks chime in on whether this is possible with the resources available in here? Or indeed whether you've found yourselves needing to source marine plywood, and where you'd recommend doing so?
zozo
Member
Marine ply is ok and as said it still needs a waterproof coating... On the other hand, there is also concrete ply (Shutterboard) with a factory-waterproof epoxy coating off the shelf which only needs a layer of coating on the saw cuts if used for aesthetic applications. Not sure what colour you are after but it seems it can be ordered coated in specific colours. But the standard black/brown coloured coating can be painted as well with regular paint...
www.spp.co.uk
In "2017" I built a small aquarium with 18mm concrete plywood for outdoor use...
6 years later it's still going strong at the very same spot.
I guess if it holds this long as part of the aquarium outdoors, what can happen if used indoors as cabinet(Rack) panels/shelves?
Regarding the thickness of the panels all comes down to the supporting frame below it. I would rackomend a good supporting frame construction and then 18mm thickness should be more than enough.
Plywood for Concrete Formwork Panels & Shuttering
Smooth phenol faced plywood for concrete formwork panels. Cut to size and edges sealed. Peri, Doka,
www.spp.co.uk
In "2017" I built a small aquarium with 18mm concrete plywood for outdoor use...
6 years later it's still going strong at the very same spot.
Mission Bathtub 2023 - Azolla Mania
Springtime is rocking again! Still a tad cool at this time of the year, but it doesn't seem to bother the plants in the tubs... :) All survived the winter and are growing happily... Even the young Willow tree i planted 2 years back is growing like a champ and needs a trim again... The bog...
ukaps.org
I guess if it holds this long as part of the aquarium outdoors, what can happen if used indoors as cabinet(Rack) panels/shelves?
Regarding the thickness of the panels all comes down to the supporting frame below it. I would rackomend a good supporting frame construction and then 18mm thickness should be more than enough.
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UrbanDryad
Member
I called SPP - they said that five shelves of 120x45 was too small an order, but the person I spoke to was extremely helpful and recommended the following two sites: Cut My and Woodshop Direct.
I initially thought they wouldn't work out due to the shelves being below the minimum size, but then I realised they were displaying mm rather than cm! So I'll have a play around with the options on those. Sharing here in case it's useful for anyone else
I initially thought they wouldn't work out due to the shelves being below the minimum size, but then I realised they were displaying mm rather than cm! So I'll have a play around with the options on those. Sharing here in case it's useful for anyone else
UrbanDryad
Member
... okay, I absolutely cannot countenance spending £80-120 per shelf, so I think custom-cut plywood is a no-go for the moment. The G-rack site does say that their MDF is water-resistant, so I think my best option for the moment is to just treat the MDF that comes with the rack, and see how that goes. Maybe I'll be able to do it at a friend's house on a dry day or something - I think my balcony is too small to do it here.
mrhoyo
Member
Holy Moses, just go to B&Q and get some plywood cut. I think an 8x4 sheet was £40 when I last went.
UrbanDryad
Member
mrhoyo
Member
That's the one. It's not the best but it's better than MDF for moisture and they cut it to size for you. Marine plywood is way more than you need, it's for use on boats and still needs sealing with yacht varnish or similar to be waterproof.
You're using it for a shelf that might get a few drips on every now and then so obviously very different.
Exterior grade plywood is in between the two but still more than you need- that's used for things like roofing.
My plywood shelves will be replaced with solid timber eventually but only due to aesthetics and the fact I work for a joinery company.
UrbanDryad
Member
Rack's arrived, still sourcing replacement plywood for the shelves (I've been ill and distracted), got a few more questions.
1) There are a few places where the paint has come off. Is this something I should be concerned about in terms of water resistance? Examples shown below.
2) The shelves have got 2 of their corners cut off. I'm trying to work out whether these are necessary in order to put the shelves onto the rack, or if it's a stylistic thing, or something else. There's nothing about it on the G-Rack manual or website. I've sent them a message to ask but checking in case anyone here knows, since obviously if it's necessary then I'll need to replicate that on the replacement shelves.
1) There are a few places where the paint has come off. Is this something I should be concerned about in terms of water resistance? Examples shown below.
2) The shelves have got 2 of their corners cut off. I'm trying to work out whether these are necessary in order to put the shelves onto the rack, or if it's a stylistic thing, or something else. There's nothing about it on the G-Rack manual or website. I've sent them a message to ask but checking in case anyone here knows, since obviously if it's necessary then I'll need to replicate that on the replacement shelves.
dino21
Member
Yes, just touch up any such scratches with any black paint, though think Hammerite Black Smooth might be a close match for its slightly dimpled finish.
Hammerite Metal Paint Smooth
If you look at Gracks site you can just make out the two cut corners, think thats so you fit the side of the shelf with the square corners first and then lower the two cut corners down, they need that little bit taken off to avoid catching the frame as they drop in.
Hammerite Metal Paint Smooth
If you look at Gracks site you can just make out the two cut corners, think thats so you fit the side of the shelf with the square corners first and then lower the two cut corners down, they need that little bit taken off to avoid catching the frame as they drop in.
Hi Im doing the same thing with the Rhino racking system. Ive chosen to go for the B&Q 12mm Ply.
The Rack i have is 1200 x 450 mm it has maximum spans without support of 400 x 380mm. So the ply will be thick enough to support the tanks (4 @ 300 Cubes on one shelf and 2 @ 600 x 400)
Im painting the wood with black Satinwood paint and topping with 5mm EVA Foam Sheets.
The Rack i have is 1200 x 450 mm it has maximum spans without support of 400 x 380mm. So the ply will be thick enough to support the tanks (4 @ 300 Cubes on one shelf and 2 @ 600 x 400)
Im painting the wood with black Satinwood paint and topping with 5mm EVA Foam Sheets.
