This could be git related or not. So, what's on your workbench at the moment?
I have 4 scarf joint necks in different stages of work.
A 25" scale pine 5 string neck for a Banjo-Res, A 25" scale Red Oak neck for my 6 string Strat-Res build, A 24 & 1/2" scale Red Oak neck for my 6 string Double Cut Tele build and a 27" scale 6 string Baritone Conversion neck for a Modern Strat body I have.
Right Taff. The mating surfaces have to be perfect, hard to do by hand. If you really want to blow your mind, read a boatbuilders book on scarf joints. There must be a dozen different ways, interlocking, etc., for carvel planks on the side of wooden boats. Amazing and for me seem impossible. But for a headstock, a chop saw or very angled workpiece on a table saw is the only way to get a "seamless" scarf joint. Except for the wood you lose in the kerf. Another topic.
Dowels are very good for alignment, but in general will not add strength to the joint unless you're using some material that is substantially stronger than the parent material and even then it's not really able to add a lot (depends on the direction of the load). I do have problems keeping a scarf joint from sliding around when I glue & clamp though unless I pin it in some fashion. I often use a fine wire brad or two for that purpose but have done it with some contrasting wood dowels too.
Hey MadGomer, Here's a true and tested way to get perfect joints every time. The jig is just sitting on the bandsaw for the photos.
As you can see, very simple and adjustable for different length pegheads.
A baseboard with a fence bolted to it, this holds the neck shaft firm and upright.
A stop fence at the other end that is the adjustable part.
Place the peghead part of the scarf joint in place on the neck shaft, clamp temporally while you move the stop up to the end of the peghead and clamp it. This will now stop the two pieces moving away from each other as the clamps are tightened.
Remove p/h apply glue, put it in place and clamp it up....it ain't going nowhere.
No need for any thing else just good mating surfaces and good glue.
And if you are interested here's my cutting set up for the drop saw. Taff
I use the Oak dowels when I can get them.
The hole reason for using the dowels for me is I attach the 2 pieces of the scarf joint with screws when gluing it together. Why? because trying to clamp 2 glue covered pieces together on an inclined plane and expecting it to stay in place is very hard to accomplish. After the glue has dried, I remove the screws and drill the holes for the dowels, glue the dowels in and trim off excess after it's dried. The more pieces involved with glue coverage will make a stronger joint.
I will be doing mine like Taff does his soon when I get my shop in order. I was using a chop saw, but I think my blade was dull because the last couple cuts had to be straightened out with a block sander. ;)
Taffy - thanks for sharing the jig ideas! I'll definitely make one up for gluing future scarf joints and may also make one up for my miter saw. Up to now I've been using one I made for my table saw but it might actually be better on the miter saw bed.
Just curious - is that a 6 string neck you're showing in the glue jig photos or do you glue them up using wide boards and then rip them down the middle to make 2 or more three string necks?
Hi Madgomer, yes its a 6 string neck blank in this case, but I use the same jig for CBG necks.
The jig for the saw has reference holes in its base that match up to threaded holes on the saw table, for quick and repeatable setups. You may also notice an adjustable rod sticking out from the back saw fence, this adjusts the for different peghead lengths.
I will definitely be making a jig for my miter saw. I have 2, so one will be dedicated for scarf joints. Thanks for sharing Taff.
Hi all, thanks, I'm glad to pass it on and glad you feel its worth while trying. Here's a photo that might help you further.
You see the "stop" pin better, but it may not be needed in all cases. I build lots of different instruments that all have different peghead lengths, so I use it at times.
The fence is adjustable to change the angle as not all instrument need the 15deg that is used on an acoustic solid peghead.
Just for fun I have included a mock up to show a table saw version. The saw fence may get in the way of the neck shaft so it is not used.
Paul....(reply to a few messages up)........
that's why to glue the scarf joint i use electrical tape. i can stretch it around the joint but still move it. when the glue gets less sloppy i apply clamps first to the sides for alignment, take them off to check the joint, then add a clamp with a caul (triangle sanded to fit, or a wide v shaped object), then add the clamps to the side. titebond III give you a longer set up time, and you can simply make two lines outside of the electrical tape, marks on the neck and headstock, to check the fore and aft part of the joint. plus going slower doesn't glue starve the joint. and to keep rambling, a bunch of the squeeze out comes off when the tape is removed. remarkable how stretching electrical tape can clamp a joint. i'll use it for gluing down a fretboard, just keep streching in a random pattern until every bit is covered. i like your method also, it works. just my personal opinion that the joint is stronger without any holes. jeez, didn't intend to carry on.......
Daniel makes a good point about squeezing out too much glue. No matter how exactly we make our scarf joints, gluing a fretboard to the neck or making a box, we need to be careful about how tight we get the pieces together so we don't squeeze out all the glue. ;)
Taffy - that's the way I've been doing mine as well. So far they've worked fine on 3 string guitars and 4 string ukes without any failures. The lines do show up in the finished product since I normally just do clear finishes, but they're not too bad and it adds to the character of the instrument overall.