Wood joints

[flash]

I have a large pile of wood outside that is hopefully going to become an allotment shed, following the demise of my previous much loved item :

being an allotment shed I want to build it for absolutely no money at all and the wood I have is all scavenged FOC.

This policy has left me lacking some big fence post type bits of wood to make up the four corners of the shed. I do have some thick timbers but they are all three foot long, so what I want to do is join them together somewho to make six foot posts.

Anyone know the best way to do this? All the joints I have seen are for joining stuff at right angles.

Or maybe there is another way of doing it?

Cheers

[BigWallop]

Half and half joints would do this for you. Measure half the thickness of the timber and mark it from end to about four inches in. Do the same with another post. Cut down to half the thickness, then cut off from the end to the cut down.

You should have two posts that will marry up to give a full thickness post with a hidden joint. You can glue and screw through to make the join good and strong.

[David Lang]

Hi Flash>

You could use either a scarf joint or a butt joint. Best pictures I could find

joint is neater & stronger, but harder to cut. Butt joint is simple, albeit unsightly. Use plenty of PVA glue on either, water resistant one is best.

Dave

[soup]

Must admit when I first read your post I thought "ah scarf(ph) joints are what he wants" but having read the poster that said butt joints will work can see where s/he/it is coming from, would still go the scarf(ph) route though.

[Chris Bacon]

What the hell's one of those? Do you smoke it? Do you mean a halving? Perhaps you mean a lapped joint?

He'd probably be better off using simple joining plates. Put some boards up against the butted-together posts, and lam in some nails, or even screws, as it's an allotment shed. No joint cutting at all.

[andrewpreece]

A slight improvement on the half-and-half joints mentioned ( IMHO ) is to cut the two square faces ( actually they will be rectangular ) you will have on each joint as 45 degree chamfers, sloped in such a way that if you hold the two pieces of wood together and then try and bend them at the joint, the chamfers themselves resist the joint bending. Then glue and screw, using cramps. It is difficult to describe, and ASCII ART NEVER WORKS WITH FIXED WIDTH FONTS, BUT.....

--------------------------------\ \------------------------------------ \ \ \----------------\ \--------------\ \ \

-------------------\

\ ----------------------------------------------

Andy

[Andy Dingley]

Personally I'd find some new timber, long enough. The joints are too much trouble.

Obviously you're hard-pressed to get six foot from two three footers, unless you use a butt. That's not a bad way to do it, if you use steel plates bolted on from either side.

A scarf is inappropriate for a vertical post. it will also lose the most length. If you must, it needs to be a more symmetrical birdsmouth (either halved or cornered) scarf, rather than a simple scarfed lap. You could also use some form of stubbed scarf. None of these are easy to cut.

Perhaps the best joint is another Japanese joint - jyuji mechigai tsugi

- the cross-shaped mortice and tenon. This is good from locating verticals and it's also easy to cut. One face has a cross cut into it by removing the four corners to leave a cross with arms about 1" wide and 1" deep. The other is cut to leave four castellated areas with two grooves between them.

[David Lang]

"Andy Dingley" wrote;

Are we talking about different scarf joints? The ones I know don't lose any length at all?

Dave

[Rob Morley]

ASCII art _only_ works with fixed width fonts.

[David Lang]

Sorry, I'm cracking up! I read your post as 'butt' joints lose length!!!

I'll get my coat...............

Dave

[Chris Bacon]

Yes it does. You've got fixed and "the other one" the wrong way around.

[Richard Conway]

I have images of poor flash making a right pigs ear of his shed trying to follow that!

[PC Paul]

Damn.

I saw a picture a while back on rec.woodworking of a Japanese temple pillar done with a totally impossible dovetail butt joint cut in 16"+ timbers...

can't find it now :-(

I suspect it wouldn't be the sort of thing the OP was looking to do anyway though ;-)

[flash]

Cheers. Have made a couple up and they seem nice and strong. Joints are not extactly hidden due to lack of cutting skill but it'll all add to the character of the shed.

[flash]

Indeed. The first dash I tried to nail almost had me in a comma.

[Richard Conway]

I slipped with the saw and got a slash through my colon

[BigWallop]

I never get them exact either. :-) LOL

[Andy Dingley]

Probably a shiho kama tsugi - the four-faced gooseneck joint. This has a gooseneck tenon, but it appears to have one on each of the four sides. Like most of these "impossible" joints to assemble, it's a diagonal slide to assemble it.

It's not a particularly good joint, because it offers no location along the 45° plane (that's how you assemble it). It's impressive though, so it's largely a decorative feature.

[Rob Morley]

A large peg through the top would take care of that, surely?

[PC Paul]

I've made simple trick dovetails like that.

That shiho kama tsugi looks impressively difficult to do (by hand anyway), but I don't think it was the one. The one I saw (shakes memory vault to stir the dust) had bits sticking out all over the place including wedges at strange angles.

I'm sure it was pointed to by a post from rec.ww but it would have been 7-8 years ago now!