External doors using biscuits

[davin]

Morning all.

have been asked to make a pair of porch doors. (copying an existing pair-too rotten to repair)
Victorian, Glass panel at top, panel with moulding at bottom.
They had a quote from a joinery firm of close to a £1000 (not glazed or primed or hung, just the doors)

I haven't got access to any workshop machinery at the moment.
So mortice and tenons are out.

Can I use biscuits (double row) on the rails and stiles of an exterior door?
Quite a high door 2.3 mtr`s.
Another idea I had (you purists will cringe) was to buy a pair of fire doors, cut out the glass panel, fit with beading, then add applied moulding on the lower half, then paint. Customer would be happy with this, but I can`ta seem to find fire doors this high.

Thanks in advance for your ideas.

Davin

 

[woodchip]

I've just made 6 patio doors, I laminated them from 3 layers of par 19mm tulipwood, so forming mortice and tennons with just the chop saw ( by overlappin the inner layer by the two outer layers if you see what i mean).

I don't think biscuits will be strong enough. What about a dowelling system? Or loose tenon like the Beadlock.

http://www.beadlock.com/

 

[Derek Willis.]

Davin, do you have a router or could borrow/hire one? If so you can cut your mortices and your tenons with that, I do all mine this way.
Derek.

 

[davin]

Thanks for the rapid responses.

Yes I could rout out the mortices and either use a chop saw or router for the tenons. The tenons would need to be pretty deep though, could I use a kitchen worktop cutter?
(the original door has a double row of through tenons).

And the tulip wood lamination is pretty clever as well.
I should have mentioned that the doors are not that wide 560mm.
Would this still rule out biscuits.
Now the other problem I have is obtaining straight timber, in my experience most small workshops don't want to machine timber for people like me (or charge a lot).
Due to the height of the doors, the timber needs to be very straight (so that rules out 90% of timber yards.
Most annoying thing about it is that I have a garage full of machinery I can`t use (until I take the plunge and rent a workshop- one day!)
So I am at the mercy of suppliers...
Anyway, food for though, thanks

As a side note, do you think that the softwood you buy in say timber yards and builders merchants Is joinery grade, ie good enough quality for windows and doors, or is it more for construction purposes.

thanks

 

[Derek Willis.]

Davin,
I reckon a kitchen w/top cutter would be ideal, in small increments, of course. The timber you buy will not be joinery grade unless specified, but my local yard have extremely good and very straight timber that I use for the likes of this. so just go and sort it!! and the best of luck,
Oh! by the way, if you are in doubt about the strength of your m/t joints, use star dowels through the face to strengthen them, quite a regular thing in standard joinery.
Derek.

 

[jeffinfrance]

hi davin,

re the softwood, i recently used nordic pine for a sofa and it machined and finished fine. most decent yards have a good selection of pre sawn sizes so you wont have the problem i'm having with my oak. the problem with buiscuits is the surface area of glue. thats the reason for the mortice/tenon joint. end grain is just not a good surface fo a glued joint.

re the router, how deep is your plunge? i've recently discovered the limitations of my hitachi m12v....a pathetic 50mm. even with a extra long mortace cutter, i've still only got a 60mm mortace depth when using a mortice jig and thats after changing cutters from a shorter straight cutter, cos the mortaicer is too long for the plunge.

jeff

 

[Max Power]

DO NOT use biscuits or you will be back before your cheques cleared to replace the doors. On thicker sections of timber as used to construct external doors ,the joints will pull apart under adverse weather conditions.
I would also advise you to get some suitable timber (not tulip wood ) if you want your friend to remain friendly.

 

[davin]

Right,

That pretty well leaves out biscuits then...
So I need to source some good quality timber, maybe bite the bullet and get a workshop to machine up for me.
(the joinery shop which quoted for the doors also had a 4/5 week wait!).
Then its use the router for tenons.
Or for a less authentic look - fire doors as mentioned earlier, any thoughts !
Need to keep this customer happy. She has been very good to me.

Thanks
Davin

 

[ProShop]

Right,

That pretty well leaves out biscuits then...
So I need to source some good quality timber, maybe bite the bullet and get a workshop to machine up for me.
(the joinery shop which quoted for the doors also had a 4/5 week wait!).
Then its use the router for tenons.
Or for a less authentic look - fire doors as mentioned earlier, any thoughts !
Need to keep this customer happy. She has been very good to me.

Thanks
Davin

Most of the big joinery manufacturers have been making internal & External doors for many years, using nothing but 16mm dowels. before that they were using loose tennons and before that, mortise & tennon.

 

[FatFreddysCat]

Most of the big joinery manufacturers have been making internal & External doors for many years, using nothing but 16mm dowels. before that they were using loose tennons and before that, mortise & tennon.

Yes, but can the big outfits really be said to be producing "quality" doors? My experience of dealing with modern manufactured pframe and panel doors is that many don't have a life in excess of 25 years before either panels split or joints start to fail.

To the OP: Whilst the idea of using beech biscuits is attractive and some modern glues are excellent the PVA glues normally used with biscuits (and for that matter dowels) are never completely weather proof, at least not in exposed positions. The timber used is generally beech which is not durable if moisture penetrates to it.

I think I'd have to agree with the old timers that the mortise and tenon joint developed over hundreds of years is still the best joint for structures such as doors and that if you can't manage a full mortise and tenon then loose tenons are a reasonable second choice, albeit not as durable.

 

[Paul Chapman]

Another alternative would be to use loose tenons but draw bore them as well http://www.youtube.com/user/LieNielsen# ... AkWMHDKB-E

Cheers :wink:

Paul

 

[ProShop]

We've been making doors with loose tennons for years now and also with dowels, and never had a failure yet. But we've seen mortice & tennon doors fail. These things happen from time to time.

Looking back in our records the last time we made a mortice & tennon door was 9yrs ago, it was a special with Fox Stopped Tennons.

 

[PAC1]

I would only use M&T joints for external doors. biscuits are fine for internal work. also tulipwood is described in BS EN 942i/996 as not being durable. I have seen tulipwood rot in 3 years when used for French doors

 

[woodchip]

re the tulipwood, good job my doors are between the lounge and conservatory and not exterior!

Hemlock laminations then?

 

[Inspector]

For what it's worth Davin, I made a screen door for my house over 17 years ago out of 3/4" or 7/8" dressed white oak and used biscuits. It is sheltered from all but the storm driven rain by a porch roof, but has the same humidity swings you get. The spring hinges are set to slam the door hard and loud since that's the way I think they should. It has held up well with no loosening of the joints. The thickness of door you are looking at would accommodate 3 layers of biscuits, mine had 2.

The biscuit might not be the best joint in the world but it is not as evil as portrayed here. :twisted: With your project I would probably go with the 3 layer laminate even if the inner one was thinner. Consider a more durable wood for the door.

 

[jasonB]

Getting an 8x4 door blank should not be a problem, you will get the two doors out of one Not sure where in the South East you are but Richard Russels do them and cover the area.

Don't froget they may need weather stripping and double glazing to meet part L so you may have to go upto 54mm

Jason

 

[FatFreddysCat]

We've been making doors with loose tennons for years now and also with dowels, and never had a failure yet. But we've seen mortice & tennon doors fail. These things happen from time to time.

Then we should agree to differ because I've replaced quite a few Far Eastern dowelled hardwood doors over the last 15 or more years where the joints have definitely started to fail, including no less than five on the street where I live. The beauty of a wedged M&T door is that even if the glue fails the joint rarely seems to because the wedges often hold which is why you still see some Victorian doors around. Admittedly not many, but some.

I have to say that when we make doors at work we normally just start with an appropriately-sized door blank, cut it to size then lip it all round - but that's standard commercial practice; practical and cheapish rather than beautiful.

 

[ProShop]

We've been making doors with loose tennons for years now and also with dowels, and never had a failure yet. But we've seen mortice & tennon doors fail. These things happen from time to time.

Then we should agree to differ because I've replaced quite a few Far Eastern dowelled hardwood doors over the last 15 or more years where the joints have definitely started to fail, including no less than five on the street where I live.

I

We never make or made far eastern doors :lol: I remember those softwood supposedly hardwood doors well .

Before we changed strategy we used to make over 250 doors a week :shock: :lol: .

 

[davin]

Thanks for the responses.

I have found a local timber yard that I didn`t even know existed (East Sussex), Their timber is actually pretty good, clean and straight redwood.
The dimensions are close enough to the original door for the customer to be happy with.
So there is no reason not to have a go with router and chop saw.
For the lower panel could I use 18mm exterior ply, rather than glueing up narrower sections?
I was expecting howls of protest about my idea of using fire blank doors, but seems you don`t think it too daft. Has anyone done it?
The only problem I could foresee is if I cut the panel for the glass, and find the centre core is chipboard not softwood.
Would a fire rated door blank have to be solid softwood?

Also what is it about joinery work that scares cabinet makers?
I asked a few cabinet maker friends if they would be interested in making the doors, "ooh no, I don`t know anything about joinery".
Even the workshop where I used to work turned it down, and they make high end bespoke furniture.

Thanks again

Davin

 

[Night Train]

There is a lot of difference between a cabinet maker and a joiner, usually it is one of time.

I turned down a job to make a set of windows and doors because I know I couldn't compete with a joiner or a specialist door and window company.

The other aspect is based on what my first thought was on opening the thread. If you have no workshop machinery then M&T joints is the best way to go as all you need to cut the mortises is a mallet and chisel and maybe a brace and bit to remove a lot of waste first. You can get a really nice M&T joint that fits perfectly and is properly wedged in about the same time as a joiner will take to make the whole door and hang it!

It is how I started when I decided to go back on tools 5 years ago. I was making four panel doors with hand tools and cutting door liners using an electric handheld planer to cut rebates on the timber balanced on the edge of the kerb.