any advice for mortice joints?

[jeffinfrance]

hi all,

i'm working on a large oak entrance door 2mx1mx60mm wieght 150kg.

there are a total of 6 mortices (4 corners and one central rail). i managed (just) to glue and clamp them all together last night, but i'm wanting to re-enforce the joints. what is the best solution, screwing through the stiles into the end of the tenon, or pegging with oak dowels through the face of the door into the cheeks of the tenon?

one other bit of advice needed if anyone can help.

i've just taken delivery of my shiney new bit of kit (felder 741 pro combi....thanks mum) and i'm a complete novice with a spindle moulder. any tips on what tooling to go for? by the way, i cant afford £6,000 for a window set. are the universal blocks any good? how often do the blades need sharpening? and can i really sharpen any profile using a tormek (with the appropriate jig)?

hope you can help,
all the best,
jeff

 

[Steve Maskery]

Hi Jeff
Well screwing in through the stiles will add nothing to the strength but will look horrible. Don't do it!

Pegging the joint is your best option, although, TBH, you are thinking about this rather too late, I'm afraid. What you would have been best doing (for future projects) is making a proper pegged M&T, where the holes on the tenon do not quite line up with the holes through the stile. The offset causes the joint to be pulled together, but as you have already glued up, you can't do this. Still, if the joints are nice and tight now, drilling through and pegging is your best option, I'd say.

I'm sure others will be along, too, with more ideas.

Cheers
Steve

 

[woodbloke]

...i'm a complete novice with a spindle moulder. any tips on what tooling to go for?
hope you can help,
all the best,
jeff

The best advice is to get some serious training if you fancy using the SM... do not use it if you don't know what you're doing...the red colour is deliberate btw :wink: - Rob

 

[jeffinfrance]

cheers steve,

coming from an engineering backround, i can't see how screing through the stiles would add nothing in strength. a 8mm or even 6mm screw will hold a great deal of tension. surely if i create a tension joint with the screw at the top of the rail on the hinge stile and the bottom of the rail on the latch stile, i will increase the strength of the door by 6 times the tension capability of one screw. admittedly screwing into endgrain reduces the strength somewhat, buit please let me me know if i'm m,issing something else.

cheers rob,

i'm getting a dvd with the machine, i'm hoping that helps enough. the only option is to teach myself and be VERY careful.

any thoughts on tooling?



jeff

 

[Steve Maskery]

Well you have it right about the end-grain. A screw will add nothing here. Now if you were to insert a plug and screw into that, then yes, I agree. But if you are going to do that, you may as well peg them properly in the first place.

Also, if this is an oak door you would have to use screws that are brass or stainless.

All I can say is that people have been making doors for hundreds of years and if what you are considering had proved to be efficacious, I'm sure it would have become standard practice by now. It hasn't!

And sorry, I'm no expert on spindle moulders. I have one, but you need help from someone who uses it more often than I do.

Cheers
Steve

 

[jeffinfrance]

thanks again steve, but i'm confused...

just done a test. fixed a bit if oak vertically to a joist, screwed in a bit of 2"x4" with one 5mmx80 screw into the end grain and swung off it (no broken legs). i'm 10 and a half stone.....hardly "nothing". i'm obviously inexperienced, this is my first door project, but in order to learn i need to know why. am i missing something else.

hundreds of years ago, stainless screws would have cost a small fortune (maybe a factor) also, i havn't seen a modern door or window in a showroom pegged, granted they're not as big or heavy as mine which is why i wanted to re-enforce the glue joints. i thought pegging was originally for gluless joints.

any thoughts anyone?

cheers,

jeff

 

[Racers]

Hi, Jeff

I have only made a few doors all for a Victorian house, and they where all done with wedged through mortice and tennon joints the only glue was on the wedges, two are over 40 inches wide and are holding up fine.

You need to step back from your engineering background and look at wood as a living, moving material. A tight screw may become lose after the wood expands and contracts a few times.


Pete

 

[jeffinfrance]

thanks pete,

but.........would the shrinkage princilpe not affect the peg also and loosen the joint?

i'm beginning to think i would have been better off making wedged stopped tenons, just thought that was a bit too adventurous for my first door.

all the best,

jeff

 

[Chris_belgium]

thanks pete,

but.........would the shrinkage princilpe not affect the peg also and loosen the joint?

i'm beginning to think i would have been better off making wedged stopped tenons, just thought that was a bit too adventurous for my first door.

all the best,

jeff

Normally when pegging a m&t joint, the holes in the mortice are offset slightly to the holes in the tenon, when the peg is hammered in it pulls the joint very tight.

Pictures say a thousand words, see page 2 of this topic:

https://www.ukworkshop.co.uk/forums/wip-driveway-gate-update-25-oct-t34019.html

 

[mailee]

I would also have recommended wedged through tennons on this job. As has been mentioned the wood will move and with that sort of weight it does need a strong joint. Pegging the joints would also work as Steve had described but there is also the chance that they could become loose over time if not bonded in well. Still it wouldn't harm to peg them after the fact glueing them in well. As has also been stated do NOT use any steel screws in the door as it will stain the Oak. HTH. :wink:

 

[markymark12]

Long time since i posted but i saw this and thought at last something to comment on.

Firstly think, shrinkage, long tenons should only ever be wedged and glued at the shoulder end and for around 1.5" into the mortice in the case of a 5" stiles,, apply the glue to the tenon only, this was how i was taught to avoid it being carried to the back of the mortise.. The wedges are made to tighten up towards the shoulder end first, this then allows the ex 5" of stile to shrink back without being restricted which can result in it splitting, which i have seen happen with a lot of doors made by inexperienced joiners who slap glue everywhere instead of only on the the tenon end closest to the shoulder.

Yes you could have draw dowelled/pegged it as well, but it is now too later as already pointed out the boring is offset to create a pull when assembled. As for screws, complete waste of time which will ruin the look of the job, and try to resist the natural shrinkage of the stile, thick of a tapered pin bang it in and fasten one end into the end grain which cannot move and then what happens when the timber stile shrinks back to the held tight shoulder line, the taper is no longer a tight fit, worst still modern screws with no shanks will have bitten in and formed a hold across the full depth of the stile itself. Same really applies with cross doweling and fixing into this, unless you are going to counterbore a hell of a hole through the stile to get within a resonable distance of the shoulder to prevent problems with the stile shrinking back. Some argue that modern glues will allow some creep etc, but to my mind, people having been making doors for quite some time, to a very good standard in the main in times gone by, so why dismiss all this knowledge and say the glue will allow for this.

All good joinery needs to made in a manner to allow for small potenial movements and not in a manner to work against the natural movement of the timber itself.

It would pay you to get some old joinery manuals, not sure what they teach from these days, but if you have been having training i would question what they are showing you to do.

Hope that helps

 

[scholar]

I am self-taught on my spindle moulder - I approached it with a good deal of respect.

I found this book http://www.amazon.co.uk/Spindle-Moulder ... 0854420312 and this dvd http://www.thegmcgroup.com/item--Basic- ... DLE-0.html pretty helpful (although in the case of the dvd presenter, I did note that he had only about 81/2 fingers....!)

I have only done reasonably basic work on it so far, but it is really efficient.

I have bought a power feed for the machine and would see that as really essential to really getting the best out of it safely.

cheers

 

[jimi43]

As others have said...steel and oak don't mix!!

Spindle moulders are potentially lethal. They are like routers with attitude! Make sure you read up on all the aspects of using one so that you can operate it safely.

There are many here who have that experience...take their advice...

Jim

 

[jeffinfrance]

thanks guys,

well, it would appear the common consensus is pegging. and yes i should have read a decent old book first, i will definitely be stocking up the library.....any favourites anyone?

thanks markymark for explaining why not to use screws, makes more sense now, although i still cant see how shrinkage over a morticed stile thickness of 20 mm (after countersinking and plugging) would make such a huge difference. yes the tenon could expand slightly, but not enough to loose a 1.5mm thread. the problem i forsaw with the screw fix method was the potential for the rail to pull the screw through the stile.

but anyway, i'll be plugging the joints. i'll take a pic when its finished so we can all see the results.

you've all got me a bit worried about this steel business......what do i do about the hinges, lock, 5 point latch, gaches and door handles.......all steel. surely all this steel is coated, are modern screws not zinc/bichromate coated? does anyone have experience with these products staining oak?

thanks also for the warnings about the spindle moulder. i was going to start by using my router tooling on it first to gain a bit of experience. it is however a very expensive router table, so i'd appreciate a bit of advice on proper tooling to get the best out of the machine. would it be best to start with a universal cutter block or take the plunge and invest in profile blocks?

and yes, i promise i'll get a book on that too (thanks scholar)

 

[markymark12]

Hi

Through wedged mortise and tenon construction is my preferred method for the job you have in hand.

Stainless steel or brass fittings are common place items now. Or in fact if you want something a bit more special i have used bronze also. These are a little harder to find but they are around on the internet.

There are numerous books on traditional joinery around, an excellent text for reference, is the classic, Modern practical Joinery by George Ellis, there are lots of others also worth reading. Not really sure on any modern day publications, perhaps someone else can point a few out.

The shrinkage issue is not through the thickness of the stile/tenon but across width of the stile/length of tenon, hence why if you run your hands over a traditional made door, the ends of the tenons appear to be either raised or recessed according to where it is and the time of the year/ heating etc. The tenon face/long fibres being at right angles to the grain of the stile. The glue is only applied to a short area at the shoulder end to the face of the tenon, so that the other 3" or so of length is free to move in the mortise, so not restricting it which can invite a something to split, again the same reason the wedges are made to bite at the root of the tenon, to ensure shrinkage is to the outside width of the stile member. Really more of a issue inside a centrally heated house, but one every good joiner will apply to any door.

 

[jeffinfrance]

thanks for the advice markymark, it really is greatly appreciated. i'll be ordering those books immediately.

as i cant unglue and make the mortices through and wedged, i'm going to have to do something to re-enforce what i have (stopped straight mortices). i came up with a solution last night, not one for the purists i admit, but a steel (stainless) angle brace hidden in the panel section between the stile and the centre rail will do the job. i'll be pegging the mortices to stop them separating (i allowed a millimetre gap at the end of the stop) and making sure its well oiled to keep out the weather.

for my next project i'll be using the through wedged mortices, although i'll be doing more research because i've got to make four folding doors with the centre leaves hung off the end doors. i think taller top and bottom rails will be the answer there.

once again, thanks for all the help everyone and i'll keep you posted.

all the best,

jeff

 

[markymark12]

Only to glad to help.

Look forward to seeing how you get on.