connecting two short boards

[tpuzio]

If i want to make a four foot long board but only have two two foot long boards can you reliably join boards end to end?

How? Dowels? Biscuits?

What's better?

Is this common or do you just buy the length of piece you need?

As i gain experience i've noticed most placed just sell random width and lengths. Some places sell only up to a certain length which can be rather short some times.

What do you do for this?

[cclaunch]

Hi

What you don't want to do is try to glue end grain to end grain -- won't work well and no mechanical reinforcement.

As to dowels or biscuits, that depends on the use. If the long board is simply decoration without any serious bending, twisting, pulling etc then they can work okay.

A lap joint or a scarf joint lets you get some long grain to long grain bonding, which is much stronger. Again, it will depend upon the kind of pressures that might be put on the board. Mechanical reinforcement to a lap joint could include a peg, but that is more visible even than the line where you join the two together.

There are many joints you can use -- however in general it is better to just use a board of the desired length. the joint itself is a relatively weak point that you are introducing when you join two boards together.

Carl

[coroger]

For end-to-end connections you should use a finger joint. It's fairly easy to do if you take small cuts until you get the correct depth. Here's one from Freud

http://www.amazon.com/exec/obidos/tg...arden&n=507846


Cheers,
Roger

"Form and function are one." - Frank Lloyd Wright

[KnightJCK]

You can join boards end-to-end but I wouldn't want to rely on it structurally except possibly in a vertical application. Even then it would be a case by case call. Use biscuits or dowels to join them.

Now it's a whole different story if you're boards are a little longer than 1/2 of the final length. From your example, say 2'-6". Then you take the last 6" of each board and make a half-lap joint that will be much stronger than end-to-end as you describe. Or you could opt for a tongue & groove joint. The structural integrity depends on the amount of overlap, and precision of the joinery.

You might browse through your local bookstore. There should be several books on Joinery that will describe this and many other techniques.

Jon
"Don't need a tool twice!"

[mogebier]

I was just going to suggest a lap joint for this.
If it was me, I would just go and buy a longer board.

[tpuzio]

all very good suggestions. I never even thought about the half-lap joint (i must need more vegetables or something).

So basically if i need an 8' length of wood i should just look around until i find it.

[bucheron]

Like Carl said, a scarf joint works well to do what you want.

I repair vintage aircraft. Wing and other components are built from clear spruce, tacks, recorcinol glue and doped fabric. The FAA specifies a scarf joint for repairing spar (long, usually horizontal frame members) damage. The joint must be 12 times as long as the spar is thick. So a 1/2" spar repair joint is 6 inches long. They also require gussets over the joint ends, but you don't need to do that.

These repairs are amazingly strong.

[Sonny Edmonds]

I'd dip the ends in B vitamins, plant them, and let them grow longer.
Then you could have 2 - 4 footers. :P

:D

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[jwstine]

UHHH Sonny I don't think that will work!!!!..........





Everyone knows you need Vitamin E with folic acid for that to work :+


JStine

[mapleman]

thats what she said...
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