Cutting a door out of an MDF sheet

[Deluks]

I need to cut a door out of a sheet of MDF, then use the door within the hole I've just made.

The sheet will be a full height cupboard front, and will require nearly all of the sheet.

I'm thinking partial plunge cut with a circular saw (not a proper plunge saw alas)

Then use a hand saw where the corners meet, and then maybe use a router to lightly clean up the edges.

I need to make sure the door isn't too small for the hole, I could always lip it I suppose, but will probably use paintable edging tape which could add up to 1/2 mm to each cut edge.

Not really a question, more of a method statement!
But does any know of a better way, or have any useful tips?

.

 

[freddiemercurystwin]

B&Q? - depending on the operator skill! I confess I have left a load of cut MDF on the shop floor after I checked it and found it was a bit crap. Usually they're pretty good though.

 

[Deluks]

Too much of a gamble!
Plus I've already purchased the MDF.

 

[foxhole]

I need to cut a door out of a sheet of MDF, then use the door within the hole I've just made.

The sheet will be a full height cupboard front, and will require nearly all of the sheet.

I'm thinking partial plunge cut with a circular saw (not a proper plunge saw alas)

Then use a hand saw where the corners meet, and then maybe use a router to lightly clean up the edges.

I need to make sure the door isn't too small for the hole, I could always lip it I suppose, but will probably use paintable edging tape which could add up to 1/2 mm to each cut edge.

Not really a question, more of a method statement!
But does any know of a better way, or have any useful tips?

.

No advantage to finishing cut with hand saw , just rip with circular saw, straight edge clamped to sheet aids straight cuts.
What hinges are you using , will affect dimensions you need to allow a close fit.?

 

[Deluks]

I'll have to finish with hand saw, otherwise the curvature of the blade will mean I cut into the 'frame'

The entire sheet is the workpiece, no waste or offcuts.

Haven't decided on hinges yet, probably kitchen carcass style. The inset cups hold the door better than just screws. Now that you've mentioned it, that isn't something I'd taken into account. The gap needed when using this type of hinge. 4mm? 5mm?
That actually might provide me with a little wiggle room.

 

[foxhole]

I'll have to finish with hand saw, otherwise the curvature of the blade will mean I cut into the 'frame'

The entire sheet is the workpiece, no waste or offcuts.

Haven't decided on hinges yet, probably kitchen carcass style. The inset cups hold the door better than just screws. Now that you've mentioned it, that isn't something I'd taken into account. The gap needed when using this type of hinge. 4mm? 5mm?
That actually might provide me with a little wiggle room.

Don’t understand you are cutting a door not frame?
Standard kitchen hinges overlay the frame,you need inset hinges for a more flush finish.

 

[Deluks]

What I mean is that the sheet of MDF will be the face frame of the cupboard, I already have a skeleton frame built in softwood, this will overlay it, with the door cut out of the centre. Hence the desire to make the cut as accurate as possible, as to not make unnecessary marks or cuts on any other part of the MDF.

By kitchen hinges I meant concealed hinges. In which case I'll add a strip internally to fix the hinge to.

 

[Notch7]

buy 2 sheets ya mean bugger

 

[freddiemercurystwin]

What about a slot drill in a router, if you could get one thin/long enough?

 

[Deluks]

I did think to buy more, it's just the time taken to go get it, the money, and the wastage I'll be left with. Just trying to be efficient!

The router idea crossed my mind, but I could see a 4mm-ish bit snapping under such load.

 

[foxhole]

What I mean is that the sheet of MDF will be the face frame of the cupboard, I already have a skeleton frame built in softwood, this will overlay it, with the door cut out of the centre. Hence the desire to make the cut as accurate as possible, as to not make unnecessary marks or cuts on any other part of the MDF.

By kitchen hinges I meant concealed hinges. In which case I'll add a strip internally to fix the hinge to.

Basic kitchen hinges require an overlay which you won’t have if you cut frame and door from one sheet .

 

[freddiemercurystwin]

I did think to buy more, it's just the time taken to go get it, the money, and the wastage I'll be left with. Just trying to be efficient!

The router idea crossed my mind, but I could see a 4mm-ish bit snapping under such load.

I'm guessing you'd have to do several passes.

 

[big-all]

if you mean a single 8x4 sheet covers the space fully and you want to cut out the door so zero extra lines[joints] then it can be done but you need to keep the sheet fully supported with a blade no bigger 2.5mm to avoid excessive gaps you cannot drill a hole so must use a plunge saw or plunge a circular saw +finish to the corners with buzzy toy or jigsaw and clean the gap to full width then dependant on head size temporary baton between legs until vertical where you can lean remove baton and clamps where careful moving wont snap the head whilst you screw it in position

but having said that you will have screwheads on the face to fill anyway

 

[opps]

I have a plunge saw, and in such cases, I use a jigsaw to cut the internal corners.

The jigsaw cuts the outer parameter of the opening. The blade is thinner than my saw blade, so the door part will need the excess to be removed.

If you cut the MDF from the underside, you could theoretically negate the need to use the jigsaw. The excess cut will be invisible (from the outside).

Given that you don't have a guide rail saw, you can screw your timber guide to the reverse side without need to worry about visible screw holes.

Ideally, you will be able to see the cut line from both sides to ensure that you don't cut too far.

Another advantage is that the better (less chipped) cut will be on the visible side.

 

[Tigercubrider]

How thick is the MDF?
It may well flex like a wobble board in use.

I would hire a router if I didn’t have one.
Ideally one with a track or carefully mark and fit a straight edge, held with clamps (even screwed down)
A router doesn’t cut all the depth at once, you do several runs each getting deeper.
You will need sacrificial material under it.

Cut almost every line up to the corner then stop
If you are ok about screwing into the sheet (even from the back) you could add temporary braces behind the sheet to avoid it dropping out/breaking the corners before you are finished.
You could use v strong carpet tape to add braces

An easier way to have done this would have been to cut the door out of the sheet first, then use the two offcuts to construct the frame. Most wall saws have to cut a whole length/width so
the height of door line first, then cut the long strip in two
Cut the bottom of the door, half the offcut.
Shove ply plates on the rear of the “frame” and use filler.

My B&Q normally have offcuts for 50p -£1