Making 8ft doors for a wardrobe using MDF

[harvey1]

Hello chaps,
Plenty of customers are asking me for full height doors on their built-in wardrobes. My cheeky way to make them is one 12mm section cut to door-size and glue/pin some 75mm strips around the edges to create rails and stiles. Pop a bit of beading in and bobs yer uncle.
Once glued and pinned i lie them on an uber-flat surface for a day or two....
Trouble is, the buggers are still prone to minor warping, not sure why....
Does anyone have a more reliable way of making 8ft doors quickly and cheaply?
Keep well folks,
Harvey.

 

[Jasonb]

The warping is likely due to the different thicknesses of MDF drying out at slightly different rates as it adjusts to the houses heated enviroment.

I can make MDF doors quite quickly and cheaply with grooved styles & rails, MDF panel and loose tongue joints. On the bigger doors I prefer 22mm board with 9mm panels all MR MDF.

these doors are in a 2.65m room so about 8ft tall most of my stuff is inset doors so you cant hide warps as easily as you can with layon doors

Jason

 

[freddiemercurystwin]

The warping is likely due to the different thicknesses of MDF drying out at slightly different rates as it adjusts to the houses heated enviroment.

I can make MDF doors quite quickly and cheaply with grooved styles & rails, MDF panel and loose tongue joints. On the bigger doors I prefer 22mm board with 9mm panels all MR MDF.

Forgive my ignorance, I'm no joiner or anywhere close so may be missing the obvious but if the warping is due to different thicknesses of MDF then why do you use 22mm and 9mm?

 

[ColJack]

22mm is going to be a lot more stable than 12mm..

 

[freddiemercurystwin]

Oh ok, so the 22mm is unlikely to warp even with the 9mm stuck to it?

 

[ColJack]

I dunno.. try bending a piece of 12mm by hand, then try it with 22mm...

 

[foxhole]

I find 18mm mdf is stable enough for tall doors, important to fix with at least 4 hinges,[18mm allows the use of concealed kitchen style hinges] prefer 5 as this also help stabilise the doors.As stated 12mm just too thin.

 

[Jasonb]

Its not the thickness its the OP's construction method. By gluing the two different thicknesses on top of each other you can create an imbalance in the door (same problem as just veneering one side of a board)

I put a groove centrally in the styles and rails and then put the thinner panel into this that way the construction is balanced. This picture and this show the construction method. I put the groove in with a wobble saw in a spindle moulder but a grooving cutter in a router will also do it quite quickly.

When making shaker type doors I find a 6mm panel too light on wardrobe doors, usually OK with an 18/6mm combination for kitchen size doors.

I have used the OP's method of sticking strips to a board to produce low cost "hardwood" doors just take a sheet of 13mm veneered MDF, machine up some 100x7mm hardwood and stick it on then edge with iron on veneer. Both the maple wardrobes and the pine wall paneling in this album use that method

Jason

 

[freddiemercurystwin]

Very impressive!

I'm drawing up a loft conversion at the mo, out of interest is it possible you could give a (very crude) ballpark cost to produce something like this in a loft, 600 deep wardrobes with a few shelves in each wardrobe and a mid-range veneer. overall length of the room is 8m. I'm in Plymouth so don't get excited!

Untitled

• freddiemercurystwin
• 19 Mar 2010
• 1

Untitled

• freddiemercurystwin
• 19 Mar 2010
• 1

 

[harvey1]

Hi Jason,
Thanks for your advice...
Trouble is, I am using the same width MDF. 12mm back panel with 12mm x75mm rails and stiles. Usually 500 or max 600 wide x 2400 high. 25mm thick should be enough?
I'm using this method because I've given up maching MDF in my home workshop. life's too short.. (or will be if i continue filling my lungs with that stuff)
Do you think 18mm panel with 12 on top would be more or less stable?
Cheers!!
Christian.

 

[mjm1977]

Hi, I am about to build some doors using 18 MDF Rails and Styles with 9mm panels. When gluing should I leave the panels loose in the grooves, or fix everything to create one solid structure. I'm concerned that if I do the latter , and the panels or frame expand/contract then the whole door will come apart or warp.

Thanks.

 

[Jasonb]

Glue the panels in. With manmade boards you do not have the same expansion issues that you get across the width of natural timber. You don't have to spread the glue that well for teh panel, I just run a bead from the bottle along each edge of the groove, for the style/rail joints I will spread it with a brush to make sure all surfaces are coated.

Jason

 

[mjm1977]

Thanks Jason!

I found this post too late, having made some doors using 12mm MDF board with 9mm pinned and glued to it to create a shaker door. They have warped so badly that i'm having to remake them. I'm going to use the method you suggest...fingers crossed! Do you do anything to prep prior to painting? I use water based MDF primer, then Acrylic eggshell (both sprayed with a compressor). This has always worked on flat/plain MDF doors ok, but i'm now paranoid that having made the doors using your method, that they warp again at the painting stage.

Matt

 

[Jasonb]

Just don't leave it too long between coating one side then the other, ideally spray the door vertically so you can hit both side in one go.

Spraying always adds more water as you use it to thin teh paint.

Try using MR MDF its so much better to work and won't suck the water in like cheap MDF

J

 

[JohnD]

OOI, wouldn't ply be stronger and more rigid than MDF?