Curved kitchen cupboard doors

[aebersold]

Hi,
I need to make a couple of radiused doors to finish my kitchen off. I want to laminate them from thin layers of mdf over a former. If anyone has experience of this and can offer Info. regarding glue type, spring back, thickness of laminates etc. I’d be most grateful, save me making 10 ! They measure H710 x W300 x 25mm R = 260 through 90 degrees.
I would have attached a photo but that seems too complicated !
Thanks
Alex

 

[Sgian Dubh]

Hi,
I need to make a couple of radiused doors to finish my kitchen off. I want to laminate them from thin layers of mdf over a former. If anyone has experience of this and can offer Info. regarding glue type, spring back, thickness of laminates etc. I’d be most grateful, save me making 10 ! They measure H710 x W300 x 25mm R = 260 through 90 degrees.
I would have attached a photo but that seems too complicated ! Alex

5 X 4 mm thick pieces of MDF will give 20 mm, or 6 X 3 mm MDF will give 18 mm: adjust laminate numbers to suit, but either thickness should be able to bend to a 260 mm radius, although you should check to ensure the material is supple enough. You should get little or no appreciable springback if you use either of those thicknesses and that number of layers.
Glue type: I'd use a non-creeper such urea formaldehyde or epoxy resin rather than PVA or aliphatic resin, but I generally avoid polyurethane adhesive for veneering and laminating.
Former: ideally something that won't give, so you could use lumps of MDF glued together after cutting a radius on each piece, make something with a framework and skin it with thin ply or offcuts of your MDF, or get a former cut. Or you can use a lump of styrofoam with the arc formed on the top surface and the flat face opposite.
Bending: An excellent option is either a vac-press or vac-bag, although you could make a male/female former and clamp your laminates between these, but this wouldn't be my preferred option; there are too many variables and the potential for things not working out.

Top tip of the lot, probably: make the doors first and then make the cabinets to suit the arc of the doors ... not the other way about. That way, if you miss the radius of the arc by a few millimetres, you can adjust the cabinetry without having to try and get a door to match an existing opening.

Apart from the above, I don't know if you already have a plan to treat door edges, apply a finish, attach hinges, pulls, and include a catch, so I've ignored those elements of the job. Slainte.

 

[Setch]

Dr.Bob had posted some excellent stuff on how he makes curved doors, and this thread is one example - good info from custard too.

curved-kitchen-doors-t111626-15.html

This isn't the thread I was looking door, maybe some more searching will bring that up

 

[aebersold]

Thanks for taking the time guys, that’s really helpful. I’ll take a look at those links Setch.
Unfortunately Slainte, I can’t exercise your top tip, which in hinde sight would have been the way to go, as the cabinets are completed and installed.
Before veneering the doors they will be lipped in with 5mm oak, and will make the oak handles to match the others. I’ve cut the radiused mdf formers, but wondering whether to tighten the radius a little to allow for spring back ?
I have access to a vacuum bag, but I’m guessing that’s a bit of a learning curve also.
Thanks for the heads up on glues too, most helpful. Alex

 

[Droogs]

Just to let you know the poster was Sgian Dubh. Slainte is Scots gaelic for your welcome

 

[owen]

Just to let you know the poster was Sgian Dubh. Slainte is Scots gaelic for your welcome

I have always wondered what it meant :lol:

 

[Sgian Dubh]

I’ve cut the radiused mdf formers, but wondering whether to tighten the radius a little to allow for spring back?

You won't know how much springback to allow for until you execute a lamination. There are formulae out there meant to help in calculating the relevant allowance, such as the information at this link, but I can't say any of the formulae are truly reliable - I've tried them. I suspect with five or six laminates of either 3 or 4 mm MDF you'll get very little springback but, as I said at the beginning, you won't know for sure until you try.

And, you never know, you might even experience the very rare, and somewhat annoying, spring-in. Yes, it does happen, ha, ha. Slainte.

 

[peter-harrison]

I've had mixed results using MDF. I would definitely avoid the kerfed MDF.
I now use flexiply exclusively as it's much more reliable. I use a radius a little smaller than the actual, and fix the pressed panels with cramps or bits of scrap for at least a day to allow the glue to fully cross-link .
It's always fun!
Good luck!

 

[Inspector]

Have you ruled out bending plywood?

https://www.amazon.co.uk/Flexible-Bendi ... B077GR3F9M

https://www.atlantictimber.co.uk/flexible-plywood.html

https://www.ebay.co.uk/itm/Flexible-Ply ... 2543296033

Pete

 

[Yojevol]

This is a method I might try in this instance. 2 sheets of 5mm bendy ply separated with 10mm square spacers. It would need a couple of formers which could be shaped to your exact carcasse design. The spacers would be glued to the inner panel whilst still flat. If some surplus ply is left at the ends of the curve, the panel could be pinned to the formers for gluing. If the spacers are left say 10mm short, the top and bottom edges can be filled with 10mm strips on bendy ply. The outer panel would then be pinned and glued on. This method will not suffer any spring back problems and it can be made with the minimum of tools and equipment. A cheaper option might be to use MDF. Worth an experiment if you have some thin sheet.
I haven't used this method for doors but I have made the skirting for this cupboard unit:-

Just a suggestion
Brian

 

[aebersold]

Hi everyone, thanks for some great ideas and apologies for my ignorance regarding your name Sgian ! (Thanks droog). Those links are useful Pete, with knowledgeable contributions and obviously the topic has been covered before.
From what’s been mentioned, I think I’ll make my former with a slightly smaller radius and hope it doesn’t go the other way Sgian, then use some bendy 5mm mdf or ply, cascamite or similar and place in a vacuum bag and keep my fingers crossed.
I do believe that if you glue up with loads of stress in joins, it’ll come back to bite you, so I’ll do my best to avoid, and I’m only gonna get one shot at the matching veneer lay ons !
Thanks again
Alex