TalkBass Forums

TalkBass Forums (http://www.talkbass.com/forum/)
-   Luthier's Corner (http://www.talkbass.com/forum/f57/)
-   -   Scarf joint vs. not scarf joint (http://www.talkbass.com/forum/f57/scarf-joint-vs-not-scarf-joint-964712/)

YuvalR 03-07-2013 02:43 AM

Scarf joint vs. not scarf joint
 
Hey everyone!
I've just started planning a new bass (4 string single cut jazz bass), and got to thinking about doing a scarf joint. After reading all the threads I could find on the subject I got to wonder-
How hard to do is it? Is it posiblle to scarf joint a neck using a jigsaw? What are the adventeges and dis adventeges of a scarf joint?
I must add I never tried scarfing a joint, and a bit scared to screw a project up over it.
I'd be really appreciative of any advise and tips any of you luthiers can give.
By the way. How can I upload photos? I'd love to get some comments on my design.

roberthabraken 03-07-2013 02:57 AM

A scarf joint is not hard, but with a jigsaw it's impossible. You would never get a straight cut that's good enough to glue. Next to that, most jigsaw blades aren't long enough for this type of cut.

I do not have the tools either (bandsaw or table saw), so I have a cheap solution where I use my handsaw.

First I make a jig: http://www.robhabraken.nl/index.php/...arf-joint-jig/

Then I place it in (guides my saw in the correct angle) and cut it. After cutting with the saw I clean up with a sloped guide and a router: http://www.robhabraken.nl/index.php/...e-scarf-joint/

Then glue with enough clamps (also fix the ends with stop blocks to prevent sliding): http://www.robhabraken.nl/index.php/...e-scarf-joint/

That should do, if you have any questions, ask!

miziomix 03-07-2013 07:27 PM

Why making a scarf joint then? You could just make a straight headstock a la Fender.

To upload pictures you should have an account with say, Photobucket. Then paste the image link in your post reply. It's a bit of a pain because it's double work. But we'd like to see your pictures just the same ;)

YuvalR 03-08-2013 12:26 AM

Thank you guys
 
Thanks for the tips and links.
One thing I didn't understand yet- what is the adventeges of scarf joint over a flat headstock? And if I build a flat headstock wouldn't it be problematic with the string tension and angle? Must I use a string retainer then?

roberthabraken 03-08-2013 01:21 AM

Quote:

Originally Posted by YuvalR (Post 13996201)
Thanks for the tips and links.
One thing I didn't understand yet- what is the adventeges of scarf joint over a flat headstock? And if I build a flat headstock wouldn't it be problematic with the string tension and angle? Must I use a string retainer then?

Yes, a flat headstock requires a string retainer (most of the times, as Dingwall has special tuners with shorter posts further away from the nut, also recessing them, but that's quite exotic).

The advantage of a scarf joint is string tension over the nut without having to use a string retainer.

iamlowsound 03-08-2013 05:07 AM

Quote:

Originally Posted by roberthabraken (Post 13996284)
Yes, a flat headstock requires a string retainer (most of the times, as Dingwall has special tuners with shorter posts further away from the nut, also recessing them, but that's quite exotic).

The advantage of a scarf joint is string tension over the nut without having to use a string retainer.

Dingwall also uses a flat headstock so they don't have to worry about the compound scarf joint angle that comes with doing fanned frets.

lowsound

roberthabraken 03-08-2013 05:12 AM

Quote:

Originally Posted by iamlowsound (Post 13996571)
Dingwall also uses a flat headstock so they don't have to worry about the compound scarf joint angle that comes with doing fanned frets.

lowsound

True, a compoound angle scarf joint is very difficult to produce. And I love their way of recessing and using gradually shorter tuner posts!

jmorbita 03-08-2013 05:24 AM

I believe another advantage of the scarfjoint is to save wood, since you can also have a thicker slab of wood for the neck and just cut the headstock at an angle with no need to do a scarf joint (I did this with my build, tilted headstock with no scarfjoint, and no need for string retainers.)
I heard some people say that the scarf joint will make the headstock stronger than if cut tilted, I don't really know if this is true.

So I'd say the main reason for the scarfjoint is to save wood, but some more experienced luthier might correct me if I'm wrong.

roberthabraken 03-08-2013 06:53 AM

Quote:

Originally Posted by jmorbita (Post 13996602)
(...)

So I'd say the main reason for the scarfjoint is to save wood, but some more experienced luthier might correct me if I'm wrong.

Opposed to having an angled headstock out of a single piece of wood, yes. Not opposed to a straight headstock.

But you're right, we should make a differentation in this:
  • An angled headstock increases tension over the nut without having to use a string retainer.
  • A scarf joint saves would when doing an angled headstock.

Ps. I believe a scarf joint is stronger because you keep the grain in the direction of the wood, where cutting it from one piece creates thin short grain parts in the headstock, but that's debateable.

Hopkins 03-08-2013 08:25 AM

Quote:

Originally Posted by jmorbita (Post 13996602)
I believe another advantage of the scarfjoint is to save wood, since you can also have a thicker slab of wood for the neck and just cut the headstock at an angle with no need to do a scarf joint (I did this with my build, tilted headstock with no scarfjoint, and no need for string retainers.)
I heard some people say that the scarf joint will make the headstock stronger than if cut tilted, I don't really know if this is true.

So I'd say the main reason for the scarfjoint is to save wood, but some more experienced luthier might correct me if I'm wrong.


I don't believe wood savings was the reason the scarf joint was invented. A scarf joint is much stronger than a tilt back headstock carved from a single piece of wood, because with a scarf joint you have a lateral grain orientation through the joint. When cutting from a single piece of wood the grain gets shorter at the joint causing a weak spot, which is why you see so many Gibson's with broken head stocks.

jmorbita 03-08-2013 08:44 AM

Quote:

Originally Posted by Hopkins (Post 13997427)
I don't believe wood savings was the reason the scarf joint was invented. A scarf joint is much stronger than a tilt back headstock carved from a single piece of wood, because with a scarf joint you have a lateral grain orientation through the joint. When cutting from a single piece of wood the grain gets shorter at the joint causing a weak spot, which is why you see so many Gibson's with broken head stocks.

well, you can have truss rod access at the body to counter act for that weak spot, and you can also have a bigger volute underneath that weak spot to make it not so weak. And with laminated necks, granted, a scarf joint might be stronger, but I don't believe the particular added strength you get from the scarf joint is really necesary.
I do believe the main reason you'd really want a scarf joint is to save wood.
Bare in mind Gibson is not the only builder using that method, yet they seem to be the only ones with broken headstock problem.
I might be wrong of course...

HaMMerHeD 03-08-2013 08:53 AM

In a very unscientific test a few months ago, I made a fender-style neck/headstock joint and compared it with a disused scarf joint headstock I made a few months earlier (the neck wasn't used because the laminations didn't line up correctly during gluing).

I had a friend of mine whom is about half the weight of my tubby self stand on it. The head on the fender-style neck blank snapped off almost immediately. The scarf joint neck blank bent to a disturbing degree, but did not splinter, crack, or break.

Scarf joints are stronger.

Now...you can debate the necessity of the added strength all day long, but scarfs are quite a bit stronger. Surely there are loads of new and old Fenders out there with no problems.

I do scarf joints because it's easy and I think it looks better, and I really hate the look of string trees. They're a hack there to accommodate a poor design.

Hopkins 03-08-2013 09:49 AM

Quote:

Originally Posted by jmorbita (Post 13997550)
well, you can have truss rod access at the body to counter act for that weak spot, and you can also have a bigger volute underneath that weak spot to make it not so weak. And with laminated necks, granted, a scarf joint might be stronger, but I don't believe the particular added strength you get from the scarf joint is really necesary.
I do believe the main reason you'd really want a scarf joint is to save wood.
Bare in mind Gibson is not the only builder using that method, yet they seem to be the only ones with broken headstock problem.
I might be wrong of course...

Well Gibson's problem is kind of compounded with their use of mahogany. If they used a scarf joint it would be fine.

A lot of players, myself included, don't like the feel of a big volute, when playing. Also aesthetically I prefer the look of a one piece neck vs laminated. Its also more user friendly and easier to put the truss rod adjustment at the headstock on a tilt back neck.

So with all of those things combined I prefer a scarf joint. I prefer the scarf joint glue line to be around the 2nd or 3rd fret, not right under the nut. To accomplish this you need a pretty thick neck blank anyway. So at least the way I do it, wood savings has nothing to do with it at all.

SGD Lutherie 03-08-2013 10:33 AM

I have a Pedulla bass here with a cracked head stock, so even with maple a band sawn head is not as strong as a scarf. This is the third time I'm fixing it too. It keeps falling and breaking in a new spot.

I do my scarf buried in the headstock, and not under the 3rd fret. This requires veneer on the front and back (optional) of the head, but I like that look. I use a 1" thick neck blank for the whole thing. I have my truss rods adjustable at the nut, and use a volute in the back. The first of these basses were made back in about 1994, and have lasted many gigs since then with no fractures. I have also dropped my personal basses a few times, as much as I hate to admit it. But they fell off stands onto the floor. :crying: Nothing broken except for the tips of the headstock.

I was once at a big name boutique bass builder's shop, and he had a table of multi lam cutoffs from the band sawn through neck blanks. It was an amazing waste of wood!

Here you can see that the scarf joint is invisible.









Another with purpleheart "ears". I tapered the headstock blank before gluing them on this one.



This one had a fall and this is all that happened:


funnyfingers 03-08-2013 11:09 AM

Is the only option here scarf joint for the angle or no scarf joint for straight? Can't you do no scarf joint with an angle?

HaMMerHeD 03-08-2013 11:22 AM

You can, but it wastes a lot of wood.

Consider this:



Everything in grey would be wasted. Of course it could be repurposed, but it still increases the cost of materials. 12/4 isn't all that readily available for most peeps.

funnyfingers 03-08-2013 11:31 AM

I THINK my Epiphone Classic is no scarf and angled, and the body (neck through) is angled as well.

You able to draw something like that? Just curious.

funnyfingers 03-08-2013 11:32 AM

But you wouldn't need that 2.8" thickness would you? You can draw a less wasteful rectangle around it. Well that is quite the angled neck though...

HaMMerHeD 03-08-2013 11:37 AM

Using a shallower angle would reduce the thickness required, and CNC manufacturers can more easily extract multiple necks out of a single beam.

But...for my purposes...It's easy to do, it's stronger and it's more practical, so I don't really see what the problem is.

funnyfingers 03-08-2013 11:39 AM

Oh I was just curious. I doubt I would ever be able to do a body let alone a bolt-on neck.

But yeah 2 necks out of one would be a neat way as well.


All times are GMT -6. The time now is 07:37 PM.

Powered by vBulletin® Version 3.6.12
Copyright ©2000 - 2013, Jelsoft Enterprises Ltd.