Edge joining scaffold boards

[TomP]

Hi,

i have some new scaffold boards that I'm going to use to make a top for a desk. To join the edges i am thinking of using my biscuit jointer, is this the best way to do it?

im not really sure, or would dowels be better?

Tom

 

[MattRoberts]

The glue will do most of the work, so anything else is just going to help with alignment and a little bit of support. So whichever method you prefer.

Just make sure the edges are flat and straight

 

[novocaine]

dowels are a pain in the arris.
just a warning, but scaf boards (especially new ones) will move a lot as they dry out inside, so be ready for that, either bring them in and let them dry for a few weeks or be ready to flatten again once it's all settled.

 

[RobinBHM]

biscuit jointer easy......

dowels difficult.....

at least for edge jointing.

As Matt says, biscuit joints are mostly for alignment not strength for this purpose

 

[Random Orbital Bob]

...and what they mean by alignment is that by using biscuits you should get each adjacent surface flush with one another with relatively minimal effort as long as you reference off the same surface with each biscuit plunge of course. The glue will do by far the majority of the holding as already said.

But the issue of moisture content is critical. If the boards are seriously wet when bought you'll be creating a rod for your back as they wont just move a bit but a whole lot, almost certainly causing splits once the table is in a centrally heated space.

You need to ascertain the moisture content (from the supplier) before you decide how to manage the boards.

 

[NazNomad]

Personally, I'd spline-joint the whole length of the board (I don't have a biscuit jointer)

Possibly make it interesting by dropping a few contrasting butterflies in it.

 

[owsnap]

a top for desk I would not faff around with biscuits, specially since I don't have a biscuit machine..dowels.. I don't have the patience either.
but.. would take kregg jig , drill holes on the other side, align them, squeeze some glue, take clamps, squeeze it all together and align as needed + screw it together. job done.

 

[MattRoberts]

Just bear in mind that pocket holes are often off centre, which applies pressure when edge joining that's closer to one edge - this will 'cup' the table top slightly.

Not a real issue if the top is supported by the rails all round, but something to bear in mind

 

[54Strat]

I've built quite a bit with scaffold boards, and after a few months drying inside (stored under my bed) I have to disregard about 1 in 3 as they either twist or cup way too much to save. Not too bad as I get them cheap enough. I did want to preserve the worn look, so planing wasn't really an option and besides, there's all sorts of nasty things embedded in them.

For the couple of wide boards I made from them I used dowels and wasn't too fussed about getting everything neat, after all these are scaffold planks and they will move.

 

[Benchwayze]

Scaffold boards used to be top quality pine (Pitch-pine) and a good full 2" thick. They have to be best quality even now, given that lives depend on them.
So its good timber hopefully. I jointed 6ft scaffold boards for a friend, who wanted a heavy , pine table for his kitchen-diner. I used plywood splines a full 1 and 1/2 inches wide, stopped at the ends. Said friend was happy as Larry with the job.

 

[Jacob]

Strongest is plain butted without any dowels, biscuits etc. They just help with alignment but actually may weaken the join.
Main thing is to get a good fit and flood both surfaces with glue - don't leave any bare patches under the assumption it will spread under compression - it probably wont.

 

[Phil Pascoe]

Main thing is to get a good fit and flood both surfaces with glue - don't leave any bare patches under the assumption it will spread under compression - it probably wont.
? I agree totally - but why do glue manufactures specify to apply glue to one side only?

 

[No skills]

The scaff boards I've seen have been soft spruce type timber, not nice pine.

Just prepare the edges well and plenty of glue and clamps, biscuits and dowels might cause problems at glue up time if the boards are typical scaff boards that are a bit cupped twisted.

Badly warped boards can sometimes be improved with some well placed kerf cuts on the underside of the board, you won't magically fix all the problem but you can make the board a bit bendy or relaxed ( ) and then force it flatish - obviously this is taking a lot of strength out of the board and you will need to reinforce as needed.