Making cupboard door (ply face, timber frame)

[ClockPie]

I'm making an under-stairs multi cupboard setup and want 3 flush/plain doors that will be painted wall colour so they won't look like doors (maybe!)

The 3 doors will each be 500mm wide, 45' (ish) angle at the top, and one door will be 2.2 max, one 1.6 and one 1.2. Hope you get the idea

From another thread, someone suggested buying a premade door and cutting it down. And I've seen 34mm thick doors which are ply front/back and timber frame. Obviously will need narrowing, and shortening/angling at the top, and then cleaned up and edging reinserted/glued. I'm happy I can do that if needed.

But - how much harder is it to just make your own? 3.6mm ply front (and maybe back ) and a frame made from PSE (25 (depth) x50 pre-planning, so 21 x 44 ish plus 2x 3.6 ply) I'm happy I can make it and join it (M+T +glue). And not significantly more work than modifying a bought door.

My main concern would be it warping either straight away or over time - and this is where my skillset/experience is lacking. Also bought doors have card cores which I guess stops them warping. I was thinking of "cheating" and cutting kingspan insulation and contact adhesive for the same effect. But that is 25mm and I can't source PSE @ 25mm finished - so bit stuffed.

So what are your thoughts?

 

[Deleted member 174758]

So long as your timber is of decent quality (e.g. FAS joinery redwood - not B&Poo white wood) properly seasoned and acclimatised, and you have a proper dead flat surface to assemble a frame on, it should be possible to make-up a nice straight frame. Not really so sure that you need to go to the trouble of making full mortise and tenon joints as bridled (open tenon), halved or even but jointed and glued to the skins will perform almost as well providing you choose a strong enough adhesive and cramp-up properly (or pin through the surface) whilst the glue goes off. Ideally something like Cascamite UF glue will give the best bond, but a D4 PVA such as Everbuild D4 PVA will do a reasonable job (although do a dry run as it starts to go off very quickly - 10 minutes - and if you aren't sure that you can work fast enough stick to a D3 PVA). Avoid D2 PVA (e.g. a certain "green" bottle) which are not moisture-proof and polyurethane glues such as Gorilla which tend to swell

My main concern would be it warping either straight away or over time - and this is where my skillset/experience is lacking.

That's why you need to go to a proper timber merchant and get properly kiln seasoned joinery grade redwood with as few knots as possible (FAS or Firsts and Seconds). It's also why you need to sticker the timber and allow it to acclimatise inside the house for a week or two before use.

Also bought doors have card cores which I guess stops them warping. I was thinking of "cheating" and cutting kingspan insulation and contact adhesive for the same effect. But that is 25mm and I can't source PSE @ 25mm finished - so bit stuffed.

Don't use contact adhesive on just one side of the skins - that most certainly will cause warping - just lay the Kingspan/Cellotex in the gap (cut to be a snug fit) and leave it at that. Sourcing planed to size timber? Ring a few timber yards or joinery firms in your area - they are bound to be able to help

 

[Doggit]

As job says, you don't need any fancy joints in this job, just stable wood that you butt joint at each corner, and if you talk nicely to the wood yard, they may even plane the wood to the exact thickness you want. Take one leaf, and cut the brace pieces and glue them in place, and put a couple of cross struts for stability. Cellotex won't give you a lot of stability unless it's the right thickness for the centre, and unless you glue it in there with some adhesive foam, otherwise it'll just rattle. Once the first leaf is glued and set, and the cellotex is in place, then you can glue and clap the second leaf on.

 

[ClockPie]

Good advice here, thanks
I have used a hard-wood merchant to get oak before they planed for me.
But softwood I've only seen/bought from the likes of Travis Perkins or Buildbase....
So looks like I need to find a proper merchant!

Interesting you guys say a "proper" joint isn't needed - good to know.

Thanks for advice.

 

[big-all]

when you have sheet material it takes all the racking and diagonal forces normally held by mortise and tenons or lap joints a structure faced with sheet material off perhaps 6mm/1/4" on both faces is far far stronger than mxt joints if properly fixed in about 10% off the surface and with far far more strength as the percentage increases