Making my own wall hung cabinet

[J19T75]

Hi, relatively inexperienced woodworker but have a project in mind but have some questions that could your experience can probably help me with.
I want to build a wall hung cabinet, mounted onto a brick wall.
It would be 2.4m , long, 50cm tall, 30cm deep.
I thought I'd use MDF to reduce cost.
Would 18mm be appropriate?
Could I use kitchen cabinet wall hangers to mount it or is there a better way?
Would need biscuit joints be the best way to secure it all together?
I have a pocket hole drill jig if needed.
I was going to put a back board in and biscuit that in. It's that the right approach?
Should I use three same thinkness of MDF for that?
I was going to build a section that had a drop leaf table on it , 1.2m long x 50cm. The 18mm MDF was an idea to stop it warping. Would that do it?
Many thanks
Jonah

 

[Sachakins]

Is that one 2.4m long cabinet?

 

[J19T75]

Yep, it's going to be storage, with a flip down desk leaf.

 

[J19T75]

Yep, it's going to be storage, with a flip down desk leaf.

I could make it as three sections.
Two 60x50x30cm
One 120x50x30cm
Had assumed one section might be better as less material and lighter?
Appreciate its harder to put up a long single unit.

 

[Sachakins]

That's one big lump to handle, very heavy and some big clamps needed for glue up!
I would go with 4 x 600mm units or at a stretch 2 x1200mm but they're awkward to.
Also if your wall is not perfectly flat, one 2.4m cabinet will likely twist and bow as you try and screw it to wall.

 

[J19T75]

That's one big lump to handle, very heavy and some big clamps needed for glue up!
I would go with 4 x 600mm units or at a stretch 2 x1200mm but they're awkward to.
Also if your wall is not perfectly flat, one 2.4m cabinet will likely twist and bow as you try and screw it to wall.

So my 3 section idea might work?
60, 120, 60.

 

[Sachakins]

Yes

 

[recipio]

Break it into boxes. The dimensions are purely aesthetic and up to you. With MDF anything over 600 mm in length will tend to sag on the bottom shelf under load so some support would be needed. I would think biscuits would be plenty strong. I prefer ply biscuits over compressed beech for that reason. For the back something like 6 mm ply let into a rebate would add stiffness. A fold down flap will add complexity and certainly needs careful design and support with a chain or folding metal stay. For mounting them on a brick wall it's hard to beat French cleats - the triangular brackets for kitchen units look a bit ugly imo. Best of luck !

 

[J19T75]

Break it into boxes. The dimensions are purely aesthetic and up to you. With MDF anything over 600 mm in length will tend to sag on the bottom shelf under load so some support would be needed. I would think biscuits would be plenty strong. I prefer ply biscuits over compressed beech for that reason. For the back something like 6 mm ply let into a rebate would add stiffness. A fold down flap will add complexity and certainly needs careful design and support with a chain or folding metal stay. For mounting them on a brick wall it's hard to beat French cleats - the triangular brackets for kitchen units look a bit ugly imo. Best of luck !

Thank you, will look at French cleats.

 

[J19T75]

The French cleats look a great solution. Would I be best to build the cleat in the cabinets as part of a kind of toprail joined into the top and sides to take the load?

 

[recipio]

The French cleats look a great solution. Would I be best to build the cleat in the cabinets as part of a kind of toprail joined into the top and sides to take the load?

French cleats can be wood or metal. If you want a back for the cabinets then they need to be mounted behind the back but inserted into the cabinet. The wooden cleats are a bit bulky but can be screwed to the top using pocket hole screws . Of course this will create a gap at the back as the back is set forward in the cabinet.
It's a bit complicated to do - French cleats are easier if there's no back. Another option is use a thicker back, say 12 mm screwed to the cabinets in a rebate and then screw directly through the back to the brick wall. From experience using concrete screws into a 6 mm hole rather than rawlplugs is ideal for this but it can be tricky getting the holes absolutely level and the screws should be recessed and plugged.

 

[MF1000]

The best way to mount a wall cupboard to allow adjustments for out of plumb walls etc

https://furnica.co.uk/products/adju...MI9LrfnrT1_gIVhoBQBh28-g6gEAQYBiABEgKLufD_BwE
I’ve used them lots of times

 

[Doug71]

And if you do use adjustable brackets as linked to above get yourself a long length (or 2) of hanger rail. You might need to cut a bit out of the back edge of the carcases but if it's a run of cabinets it's easier than using the individual little brackets.

https://www.sdslondon.co.uk/cabinet...W1ILB5AAyndcXsdao1Aj_XszIRF3DNWBoCY_8QAvD_BwE

 

[J19T75]

Thanks for all the advice.
Was my suggestion of 18mm MDF the appropriate thinkness?

 

[Sachakins]

You could use 15mm, now you're planning smaller units, but I prefer 18mm personally.

 

[MF1000]

Most wall mount kitchen cabinets are 18mm carcasses

 

[Sean33]

The French cleats look a great solution. Would I be best to build the cleat in the cabinets as part of a kind of toprail joined into the top and sides to take the load?

I normally plant a piece of 15mm to the back and bottom of the cabinet and use a 18mm ply French cleat, that way you only get a small gap of 3mm ish at the back

 

[recipio]

MDF has a few downsides. It is the heaviest of the sheet materials. It also doesn't take screws very well. If you were using a lid stay for instance you would need to glue in dowels first to take the screws. The front edges need finishing. Another way to mount the cabinet is to use keyhole metal plates on the back edges. Haven't tried it myself on MDF but it would also need long screws let into glued dowels. You need to insert pan head screws into the brick to fit in the plates and that needs care. Overall if you can leave out the back a wooden French cleat is probably the optimum solution.

 

[J19T75]

MDF has a few downsides. It is the heaviest of the sheet materials. It also doesn't take screws very well. If you were using a lid stay for instance you would need to glue in dowels first to take the screws. The front edges need finishing. Another way to mount the cabinet is to use keyhole metal plates on the back edges. Haven't tried it myself on MDF but it would also need long screws let into glued dowels. You need to insert pan head screws into the brick to fit in the plates and that needs care. Overall if you can leave out the back a wooden French cleat is probably the optimum solution.

I had originally thought I'd be doing it with ply, but in conversation with a cabinet maker he indicated that ply as a desk would warp more if it was 1.2m x 0.5m which is why I went in the MDF direction. Is that something you would agree with?
Ply would look nicer from my point of view. What thinkness of ply would you use for cabinets and desktops, 12mm?

 

[recipio]

1.2 m would be pushing the limit for 18 mm Baltic ply without any risk of sagging under load. If the loads were light you might get away with it but if you want to store hardback books for instance I would expect a little sagging in the middle unless you reinforce the front edge with a batten. Most people seem to use particle boards for DIY shelving and they are 16mm but I have seen a lot of banana shaped shelves.
If you want a fold down flap which will take the weight of writing or using a laptop you will probably have to design in some supports or lopers. I can't see a lid stay taking that kind of weight,
If I were making it I would probably reduce the spans into four 600 mm units and use 18 mm Baltic ply but that is purely down to aesthetics.
As a last suggestion you might consider two options : Use blockboard which I have found is the stiffest of all the panel boards. You would probably stretch the spans to 1.2 m at a pinch. Unfortunately it has a horrible meranti veneer surface and would probably need painting and the front edges would also need covering,
Consider using a cheap flush door. I have posted here before about this so excuse the repetition. If you cut into a cheap flush door you expose the 'eggbox ' interior. You can then glue in a snug fitting batten between the outer leaves to restore the strength. Being a torsion box it is extremely stiff and will comfortably span 1.2 m. They are typically 800 mm wide so you would get two 400mm wide lengths out of each door. They are 40mm thick so allow for that in the design. I've done it and it works a treat. The outer finish is of course in the eye of the beholder but you can get a pleasant birch ply look.