Replacing a muntin in a front door...

[Harrris303]

Hi everyone, I've been approached by a guy whose front door is letting rain in at the bottom. I had a look at it yesterday and it's glazed at the top, and the bottom is field and raised panels with a single vertical muntin in the middle. There's a fairly large crack in the bottom of the muntin, from the joint upwards, so I'm assuming this is where the water is getting in.
The door is only stained and not painted, so any repairs would ideally be invisible, which basically says to me that the muntin needs removing and replacing as a whole.
One possibility I've thought of is just cutting it out where it meets each rail (leaving the tenons inside the rails). Then inserting a replacement piece with a small tenon at the top, and butting it up to the bottom rail, then just gluing and screwing it from beneath the door.
My only concern with that is I don't know how load-bearing a muntin is. If it does take some weight, then gluing and srewing might not be the best fix...
I'm not sure I've described the door and the problem brilliantly but I hope someone can see what I mean! Any input would be much appreciated. Cheers.

 

[James-1986]

A butt joint isn't really a sound repair, the water can penetrate quite easily if its a straight cut, the muntin could easily twist with no tenon at the bottom. Personally I would fill the split with epoxy or a coloured mastic, if they weren't happy with that then I would walk away.

 

[Harrris303]

Thanks for the quick reply. Yeah I was a bit skeptical about the butt joint but couldn't really think how else to replace one component without pulling the whole door apart.

The guy said he's had someone fill it before and it didn't last, but I'm not sure if they filled the crack or just sealed around the panels (because that's where they thought the problem was).
I didn't mention he really likes the door (mainly the stained glass) and he said he's happy to have a new one if necessary. I've just qualified as a joiner so I'd love to make him a replica, I just wanted to exhaust all repair options before he starts forking out for a new one!

 

[Mar_mite]

Is the inside painted? Maybe you could form some sort of a housing joint/half lap by taking material out from the back of the door. Then screw from the back into the mid and bottom rails. Or do it in such a way that you can put a patch repair over it after, kind of like forming a new mortice.

 

[Jacob]

I'd look at filling the gaps with putty, giving the whole door a good dose of linseed oil making sure it runs into the cracks and gaps especially upwards facing ones, and then a paint job.

 

[RobinBHM]

Ive found that most muntins end up with gaps, They are set between two rails which are often quite deep so the rails naturally shrink over time. I wouldnt think a muntin contributes any strength, its often only got small stub tenons for ease of assembly.

If you want to replace it, one way to it is cut the old one out, and make a new one in 2 halves. The inside half will be the thickness of the moulding and the outer the thickness of the panel rebate. You will probably need to remove the panels to clamp it.

Im not sure the amount of effort is worth it though, especially as it would be tricky to match the profile and scribe. Id be tempted to fill and make good or price for a new door. If you decide to repair, I think I would probably remoce the bottom panels and refit them making sure they are sealed all round with silicone, esp the bottom bead.

Congrats on qualifying as a joiner

 

[Bradshaw Joinery]

Iwould router out along a straight guide, the thickness of the crack, the full length of the muntin, square the ends with a chisel then plane a replacement piece of timber to a tight fit, and glue in. Remove proud material with plane,/scraper and sand/finish. Get some sikkens kodrin, or teknos teknoseal v groove sealer on before re-varnising. It dries clear and is designed to take paint.

 

[deema]

The simplest way to replace the muntin is to remove one panel, then cut out the old muntin. Manufacture a new muntin with provision for loose tenons top and bottom by making the joints a bridle joint. Place loose tenons into the cleaned out Mortices using plenty of glue. Now from the side slip the new muntin back into place. Allow the glue to dry or go off if full curing is not possible and replace the door panel.

If the rails are moulded on one side, mark where the muntin edges are on the two rails. Remove the muntin and then cut away the moulding to within 3/8" of the outside edge. Cut the muntin end square, and now using gauges / chisels replicate the mound for about 1/2"" on each side. Note it's only the very edge of the muntin that's on show, the rest just needs to accommodate roughly the moulding. This allows the wood to swell and shrink without a gap appearing. You use the old muntin for the pattern. It should be very a fairly quick and easy repair, that will last and be water tight.

 

[Phil Pascoe]

If he'll have a new one, fine. If not, walk away. It will fail before long whatever you do, and you'll be the worst in the world.
My opinion, not a commandment.

 

[hanser]

+1 for Ollie's [Bradshaws] solution. Done well enough. It should be a permanent fix.

 

[Harrris303]

Thanks for all the replies everyone, haven't been online since yesterday so it's a nice surprise to see lots of contributions. Certainly a lot of ideas to consider!
I must say Bradshaw's idea sounds quite good and not over-complicated (ie. within my ability!)

I think I'll offer the guy the repair option but warn him it might not last forever just to cover my back. He's a pretty friendly old chap so I'm sure he'll be fine about it.