Lining old casing with MDF.

[paulalde]

I'm currently renovating my house and the internal door casings look like they have seen way better days. Replacing them isn't an option and I the amount of scuffed edges and dents would mean it would take some serious TLC to get them in shape.

I was wondering if there would be any major concerns in cutting some 6mm MDF on the table saw and re lining them securing with nails and Evo Sticks Like Sh*t?

I'd lose 6mm either side which aint a big deal but after priming and a couple of coats of satin they should look spot on without the need to strip fill, sand, fill what i missed, sand again, etc. As most of the architrave is still to be fitted I can just fit the arch so it sits nicely on the lip of the MDF. Oh, I don't intend to line past the jambs so no impact on the door opening.

Interested to read peoples's thoughts on this idea.

Cheers

 

[foxhole]

Easy enough to take off architrave and door stops then plane and sand , finish top and bottom with sharp chisel where plane won’t reach . Mdf May look poor.

 

[paulalde]

Thanks for your response,

I'm curious in what way could it look poor though? The arch and skirting is all MDF so if it was prepped and painted right would it not have the same finish as that?

Cheer again for your response.

 

[Deleted member 174758]

Next time you go into a shop which has recently been returned take a look at the casings and architraves. It is quite a common "trick" to remove the architraves and stop laths, face the casing with hard wood, hang a resized, reveneered and relipped door in the opening, then fit need top laths and architraves. I've done this in ash, oak and more recently in walnut (for Next) and Wenge (with "veneer wrapped" MDF) and I don't see why it wouldn't work if done carefully in MR-MDF (not ordinary MDF) with new softwood stop laths. The main thing is to ensure that your new material is thick enough - so if using 12mm MR-MDF you'd plant the architraves on with no more than a 10mm set-back. Only downsides are that it leaves you with a non-standard door opening and you need to chop the hinges in and rehang the door. The architraves will also need to be wider than the old ones (to cover the inevitable gap at the skirting) unless you want to replace the skirtings or terminate the architraves with plinth blocks

On some doors like cupboard doors it's a lot simpler - remove the architraves, remove the stop lath (if any), add a 12mm MDF capping to the existing casing/lining then recut and replace the architraves on one side. The door just stays as is

BTW - reason for MR-MDF over the ordinary stuff is that it sands up better and paints out far better

 

[Gerrydelasel]

I'm curious in what way could it look poor though?

It won't, it will look fine. After sanding and filling the doorways in my (Victorian) house I now wish I'd done exactly the same thing as you suggest -line them with 6mm MDF and fit architrave with a 4mm reveal. Would have been simpler and better. Go for it.

 

[Deleted member 174758]

The only problem with that, Gerry, might be the size of the knuckle on the hinges. If that is greater than 4mm then the OP will need to use thicker material to get a sufficiently large set-back (reveal) of the architraves unless they chop into the architraves, which looks a bit naff. Fire door hinges (i.e. standard 4in/100mm stainless steel) often have 5 to 6mm knuckles

 

[Gerrydelasel]

The only problem with that, Gerry, might be the size of the knuckle on the hinges.

He isn't planning to line past the jambs, so the door aperture (and hinges) aren't affected. Unless I misunderstood something.

 

[Deleted member 174758]

The issue is that if you just line the casing without moving the architraves, then you end up with a very obvious joint which will never really look good no matter how you try to fill and sand it plus the architrave reveals may look a bit oversize especially if starting from a 3/8in or 10mm reveal. That's why you need to move and resize the architraves, so that you can hide all that, which is why I bothered to give the explanation of how we do the job on shop fits where top quality appearance is an absolute must.

 

[Gerrydelasel]

That's why you need to move and resize the architraves

Yes but he said the architrave hasn't been fitted yet so he probably doesn't have that issue, unless the skirting is original and in place and would lead to a gap, as you pointed out earlier. (Easy solution is to add a layer of 'architrave' made from 4mm MDF, then place the ordinary architrave on top of that, set back by the original amount, so you end up with slightly enhanced architrave overall and no gaps)

 

[Deleted member 174758]

Still introduces a joint where the 4mm meets the lining. Easy enough to eal with in a workshop, n=but potentially problem-making in situ