joining 2 boards end to end, best method, dowels?

[masraum]

If you had to join 2 boards (3/4" pine) end to end and wanted them to line up, how would you do it? biscuits, dowels, tongue and groove?

Then, what are the tricks? There's gotta be tricks, there always are. Woodworking is as much an art as a science.

[BRPORSCHE]

I have used biscuits with gorilla glue on oak to make wood flooring. It was extremely strong.

[gassy]

For what application?

[TimT]

Biscuits..

Last year I did the deck on my house in Vermont with blind fasteners and biscuits..still looks amazing after its first severe winter.

Why do you need to join wood on end grain?

[masraum]

I needed a 10' piece of 1x12 premium pine (really only needed just barely over 8') and my local hardware stores didn't have it, so I'm going to make it. The joint won't be structural.

[dad911]

If you don't have dowel jig or biscuit joiner, you can cut both ends on 45, giving a larger area to glue and clamp. then short nails or screws from backside.

If it is just over 8', how about an 8' board, then 1x4 etc at both ends, running the grain at 90 degrees to the original 1x12, to add a decorative end?

[89911]

You can do this numerous ways with varying degrees of perfection and strength. First, you have to make sure the boards are flat and don't have a noticeable cup to them. They also have to have a straight edge, which they usually don't unless they have been run on an edger. If they fit together reasonable well (again, this could vary from building a shelf to making a fine cabinet) you could simply apply would glue, line up the edges and clamp them with pipe clamps. If you want reinforcement, dowels or biscuits can be used. Dowels are simplier because all you need is a placement tool to align your drilling, a drill and bit, and the dowels. The biscuit jointer is better, but then again, you have to borrow or buy one. If I need a board wider then 12", I usually use veneered plywood, cut and rip the the size I need, and add a cover trim piece on the edges. The plywood usually takes out the issues with warping, cupping, and uneven seems where they have been joined.

[ednj]

http://www.kregjoint.com/index.php?p=faq

Kreg website

Kreg Jr.

[Porsche_monkey]

Look at hardwood floors....sort a V and a notch.

[HardDrive]

[Zeke]

Kreig is good, but he may not have the tool. The beveled overlap is called a scarf and gives more glue area. Non structural, I'd just glue a scarf and tack it. clamp up until dry.

[Porsche-O-Phile]

+1 for a good biscuit joiner.

[masraum]

Thanks all, lots of good responses.

[masraum]

Originally Posted by dad911

If you don't have dowel jig or biscuit joiner, you can cut both ends on 45, giving a larger area to glue and clamp. then short nails or screws from backside.

If it is just over 8', how about an 8' board, then 1x4 etc at both ends, running the grain at 90 degrees to the original 1x12, to add a decorative end?

I tried to make my own dowel jig, and got it close, but not quite. I was at HD earlier and noticed that they had a dowel jig there for purchase, but don't know that I'd use much so decided against it.

I like the idea about the 1x4s at the end, but while not structural, the ends may have a little stress. I decided to get a biscuit joiner instead. I've needed one in the past, and suspect I'll need one again some time, so I figured for $100 it was a good deal.

I read up on "scarfing" a bit. I read one webpage that said that the recommended ratio is 12:1 for length of glue area vs thickness. Wow, how in the hell could you get a 12:1 ratio on anything other than 2/2 or 1/2 or maybe 1/4? That's a pretty shallow angle. I'm sure under most circumstances, 45* would be fine.

Thanks again all.

[dad911]

Well, you said it wasn't structural, so it is common when installing long trim moldings(base, crown, etc) to bevel rather than butt seams. That way if/when it shrinks a little, it doesn't leave a gap.

More specifics may have yielded a better solution.

Now that you have a biscuit joiner, depending on your application, you can also use 1x6 and stagger the joints, and join the edges. Or use longer 1x6. Joint lengthwise may be less visible than a butt joint.

[masraum]

Originally Posted by dad911

Well, you said it wasn't structural, so it is common when installing long trim moldings(base, crown, etc) to bevel rather than butt seams. That way if/when it shrinks a little, it doesn't leave a gap.

More specifics may have yielded a better solution.

Now that you have a biscuit joiner, depending on your application, you can also use 1x6 and stagger the joints, and join the edges. Or use longer 1x6. Joint lengthwise may be less visible than a butt joint.

That's an excellent idea. I wish I'd have thought of it before. Oh well. That's what I get for asking at the onset instead of a few days prior to starting work.

I'll mental note that one for next time. I'm still very much in the baby/learning to crawl stages of working with wood. I really enjoy it but don't do it often enough. What I really need is someone like Dad911, Milt, or any of the other experienced carpenter type guys for a neighbor to consult with over a beer when I start these little projects.

[mike55]

If you have access to a local mill, ask them to finger joint the ends - it'll never come apart. Otherwise, I'd use couple of biscuits or cut the ends at a 45. Good glue helps too.

[Tim Hancock]

Aircraft wood spars are often scarfed and the resulting joint is just as strong (if not stronger than the wood itself). I typically go about 15:1 by running a router mounted to a wide base plate over two sloped rails straddling the board at the end being scarfed. Works pretty slick.

I have also scarfed 1/8 aircraft plywood... that was a real beotch using a belt sander to create the feathered edge. Thankfully I only needed to scarf about 16" on the four parts needing to be joined.

This main wing spar here is made of laminations of perfect tight grained quarter sawn douglas fir boards. It has several scarf joints buried in the layers. It is good for over 10 g's positive/negative. I glued it up using West Sytem epoxy.

(I have a 35mm pic somewhere of my scarfing operation, but I don't know where)

[Zeke]

Biscuits are for edge joining, whether it is be flat or angled. End joining is done with dowels for tensile strength. Kreigs are a form of dowel. You said it was non structural, so the long scarf is not needed.

[javadog]

I would have bought the wood at a lumber yard, gotten the length I needed in the first place, and been done by now.

Seriously, this is too much work to make something that isn't hard to find.

Good luck,
JR