Plywood warping - inexpensive timber for some cabinet doors

[Rorton]

Looking to make some 1620mm x 500mm shaker doors for some cabinets I’m making at the end of my garage. I need to make 6 doors in total.

I bought a sheet of 18mm hardwood ply, and had it cut to 70mm strips so I could then cut this down for the parts

It’s warped to high heaven after being cut, so pretty useless.

What timber am I best using to make the rails and styles? It’s a budget build, hence the ply, which I thought would stay straighter than something like Joinary redwood? I have 6mm to go in for the panels and that’s stayed flat (so far)

 

[AJB Temple]

Do I understand this correctly - you have cut the ply to make the door frames?

Ply is unsuitable for this. I do not find that the ply I buy warps, but there are lots of grades and the cheap building grade stuff (hardwood or not) is generally rather affected by voids. 1620mm is fairly tall and if you are hoping to do this with a single panel for each door I would say you are building too light.

My thoughts: go to a timber yard and carefully select straight lengths of Redwood. If you have no dimensioning skills or facilities, try to get planed all round close to the dimensions you need and adapt your door design to that. Do not order on line - select the wood and reject anything bent or twisted before you part with your money. Sight down the length of it at a minimum.

Or use tulipwood (poplar). It's stable and easy to work.

Do not go to the likes of Wickes, B&Q etc unless you want to waste your money again.

The term Shaker is usually misused. It sounds like you are just trying to make plain framed doors.

I would not personally use 6mm ply for the door face infills, but I know people do. I always think they can look rippled after a while, but I probably overbuild compared to most people.

 

[Rorton]

Hi, yes. The ply has been cut into 70mm strips which I was then going to cut to length to make the rails and styles. It was from a Timber yard

I was doing 2 panels for each door, so a top middle and bottom rail with 2 6mm panels.

So redwood is the one to go for then? I priced the poplar up, and that worked out around £170 for what I needed which I didn’t really want to spend.

I did think about doing mock panel, and using 12mm of something, with 6mm planted on to form the rails and styles hoping this would be more stable.

I have a table saw, it’s not a big one, so can’t rip sheets down, but can rip redwood down

I’m really just trying to make the garage more organised

 

[powertools]

Take a look at Peter Millard's videos on YouTube.

 

[Doug71]

18mm or 22mm Moisture Resistant MDF is a good budget choice for cupboard door stiles, really easy to work with, just make sure you store it flat.

 

[Rorton]

Thanks, yes I’ve been looking at peters videos. Using 18mm MR Mdf will I be ok with 70mm rails/styles based on 1620mm high doors with a rail in the middle?

 

[petermillard]

Thanks, yes I’ve been looking at peters videos. Using 18mm MR Mdf will I be ok with 70mm rails/styles based on 1620mm high doors with a rail in the middle?

I wouldn’t, no. 22mm MRMDF and 80mm wide strips for rails and stiles is my starting point for these plain panel doors. 120mm for the base rail on a door of that size, with a mid-rail.

6mm or 9mm panel; 9mm has a bit more heft, obviously. HTH. P

 

[Rorton]

Thanks Peter, so, 22mm it is then, 120mm base rail and 80mm mid and top rail.

I’m sure I remember you saying on a video that the std 110 degree Blum hinges 71b3550 work ok with 22mm with some adjustment to the spacing of them

4 hinges per door or 3 be ok?

 

[Rorton]

Cor, who would have thought 22mm mr Mdf is difficult to find in these parts

I’m in Stoke on Trent, all I can seem to find is 18mm and 25mm at local timber yards

 

[owen]

How wide are your doors? 18mm MRMDF with 6mm MRMDF panels would be fine IF the doors aren't too wide.

 

[petermillard]

Cor, who would have thought 22mm mr Mdf is difficult to find in these parts

I’m in Stoke on Trent, all I can seem to find is 18mm and 25mm at local timber yards

I’d go for 25mm. It’s a bit overkill, but the reason why I stopped using 18mm on doors of this size was bowing. Using 22mm sorted that out, 25mm will be fine, and within spec for the Blum hjnges.

My guess would be that 3 hinges will be fine, but you’ll need to do the maths; 18mm MRMDF is ~ 15Kg/sq metre, so a reasonable guess for 25mm would be 20Kg/sq m, and 5kg/sq m for 6mm MR.

Blum hinges are good for ~4 Kg/hinge comfortably. Add more hinges as the weight increases.

HTH. Best, P

 

[Rorton]

Ok thanks - 25mm it is, 6mm also seems scarce in MR form - will 6mm regular MDF be OK for the centre panels?

Will do the math for the hinges, thanks - will the regular blum be OK with that thickness door?

Just thinking about the cabinets - they will be 1664 high x 1000 wide x 540 deep, I was planning plywood on these for strength - should I use 18mm ply, or go 18mm MR MDF?

The shelves will be full width - 964mm, and was concerned about bowing, some may have 80ish kg on them - plan was to put a batten on the sides and rear panel to support the shelf 18mm square from the cabinet material, glue and screw that to the cabinet, then pin and glue oak to the front of the ply as I have some lengths of that kicking around - its 15mm thick, and 40mm wide.

I was doing the plinths/kick panel separate, get that installed and level, and then drop the cabinets in top and secure them.

Bit like this

 

[petermillard]

Regular Blum hinges should be fine with 25mm - from memory max thickness is 27mm but it might be worth checking the specs to be sure.

As long as the garage is dry regular MDF should be OK for the panel, but MR is a better quality board and worth seeking out IMHO.

For the carcasses, plywood will almost certainly be stronger, but unless you’re planning to move them around a lot once constructed MDF will be fine; I’ve never had an MDF carcass fail, and I’ve made a fair few.

And yes, at that span I’d lip the front edge of the shelves with solid timber, and yes to levelling up the plinth first, then adding in the carcasses.

HTH P

 

[Rorton]

Thanks Peter. I’ll revisit my designs to take into account the revised rail and stile thickness and give it another go.

Thanks again

Rich