Jointing dilemma

[mdfhater]

Hi all,
First time post on this or any other forum.
Does anyone have any experience of using epoxied steel dowels as an alternative to traditional mortice and tenon joints in external joinery, in particular sliding sash windows. Any advice or tips would be appreciated.

 

[Steve Maskery]

I believe that David Savage has used that technique in complex furniture, but I am not aware of it as a technique in window-making.
What is wrong with trad M&Ts?
S

 

[Peter Sefton]

We do use steel threaded stud bar with the West system if we are joining small sections that require a lot of strength or if you would be jointing sections that would involve short grain tenons that would ultimately fail. The dowel hole needs to be bigger than the dowel so that the epoxy works as a glue and filler, also the meeting faces need to be carved back to allow the glue to form a mass.
My student John Rook used this method when with us last year on his original K desk

http://www.johnrook.co.uk/portfolio/portfolio-desks

 

[mdfhater]

Thanks guys for prompt replies, i am aware of its uses in internal furniture and the technique involved, however not sure of long term properties of epoxy joints used externally regarding waterproofing and expansion/contraction.
With regard to trad m&t joints Steve, nothing wrong with them at all especially since glues have improved considerably, just wanted a viable alternative for a 1-off project in an as yet machinery starved home shop, I know many would say the pleasure of making something often involves a process that that you don't relish, but the end result justifies it, the idea of hand cutting all those joints for 4 windows doesn't appeal much, tho' if that's the route recommended so be it, a router and some jigs could sort that out saving time in the process.


Regards L.

 

[AndyT]

I have an article in an old Woodworker magazine from 1986 describing an experimental technique for timber building in which 25mm threaded steel rod was epoxied into deep holes drilled into the ends of round greenwood poles. It was developed by the architects (Buro Happold) for joints in tension and in compression.

The buildings are still there:

and you can read more about them here: http://www.aaschool.ac.uk/AALIFE/HOOKEPARK/hookebuildings.php

Given that cartridges of epoxy resin for injection into holes has become a standard sort of fixing from Screwfix etc, I think this must now count as a successful technique!

 

[mdfhater]

Thanks Andy, this sounds promising as the building is still there after 26 years, at least i'm sure my windows will outlast me!!!
I'll check out the link, tho' 25mm dowels maybe overkill!

Regards L.

 

[AndyT]

On another tack, looking at your post again, there is another approach for the 'machinery-starved shop' - follow the old techniques and make them by hand.
The upfront costs of making sliding sash windows used to be - and still can be - the cost of:

- one or two saws
- one or two chisels
- a brace and some bits
- a jack plane
- a plough plane
- a sash moulding plane
- a fillister plane (could be plain rebate plane)
- rule, try-square, knife, mallet
- bench.

Anything else would be extras to speed things up or only necessary if you wanted to subdivide the sashes into little panes.

The clearest easily accessible guide to the making is (as far as I know) in Cassell's Carpentry and Joinery which you can read online or download for free. The relevant chapter starts here:

http://www.archive.org/stream/cassellscarpentr00hasl#page/404/mode/2up

You don't need to set up a joinery business for a one-off job!

 

[mdfhater]

As i said in my reply to Steve concerning the traditional methods used in window joinery I am prepared to go down that route.
The list of tools you mention for the most part, are on my bench although i think with the exception of the jack plane, have been superseded by the router or spindler for running the mouldings and rebates. The statement "machinery starved shop" wasn't completely accurate, i do have a pillar drill, chop saw and homebrew router table which would certainly all play their parts in the processes.
Don't get me wrong when i said hand cutting joints did not appeal, there is obviously a great deal of pleasure and satisfaction to be derived from doing just that and after all, practice makes perfect, i just wondered if a relatively new jointing technique could be applied to traditional joinery.
I do already have the cassells link bookmarked and it has been very informative, another site others reading this thread may be interested in is Mumford and Wood, their online brochure shows section drawings and dimensions for both single and double glazed sash windows as well as weather-proofing sytems.

Regards L.

 

[dickm]

I have an article in an old Woodworker magazine from 1986 describing an experimental technique for timber building in which 25mm threaded steel rod was epoxied into deep holes drilled into the ends of round greenwood poles. It was developed by the architects (Buro Happold) for joints in tension and in compression.

The buildings are still there:

and you can read more about them here: http://www.aaschool.ac.uk/AALIFE/HOOKEPARK/hookebuildings.php

Given that cartridges of epoxy resin for injection into holes has become a standard sort of fixing from Screwfix etc, I think this must now count as a successful technique!

That's iinteresting, Andy. I saw the same article when it came out, and wondered at the time how reliable the epoxied joints would be. It seemed implausible that something as unyielding as epoxy would work (especially in tension) when set into wood that is likely to move as the seasons/humidity etc change. But it looks as if the proof of the pudding etc etc..