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Scarf Joint Surfaces


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Ok, anyone have any tips? I've cut the scarf jiont, then taken the surfaces to be joined and saned them.... didn't match up. Hand planed them.... didn't match up. I for the LIFE of me can't get them to sit 100% flush together!? They're always off by just a little gap? Especially at the sides. It's driving me insane!!!

Chris

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Lay the pieces on top of each other so the angled faces form one continuous surface. Now sand that entire surface uniform and flat with a RIGID block. Your sanding method must be very strict to attain a uniform flat surface. A little bit of rocking or the wrong angle is the problem. If you use ANY type of block that has a sanding surface that yields (foam bottom etc.) even a little bit then you will have problems. The block's sanding surface must be RIGID and HARD. You have to constantly check your progress with a carpenter's square, to ensure the sanded faces will be at right angles to the sides, and a straight edge to ensure the angled faces come out flat in all directions.

If you have access to a band saw or large belt sander then use those for the easiest and best results. :D

Edited by Southpa
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Do what everyone said above! A rigid FLAT sanding area is essential.

Try this to make sure your gluing surfaces are flat: Scribble on the surface with a soft pencil then sand again. The marks should disappear evenly else any high or low spots are easily visible. Re-apply some more pencil marks (the more the better) and keep sanding until they all disappear siimultaneously.

Keith

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Here is what I just did last week. I clamped my two pieces together (using strong spring clamps to leave clearance room) so that the angle pieces lined up nicely. I then ran the angled surfaces over my joiner a few times- perfect results. But be extremely carefull, this is definately not the safest way to use a joiner.

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Here is what I just did last week. I clamped my two pieces together (using strong spring clamps to leave clearance room) so that the angle pieces lined up nicely. I then ran the angled surfaces over my joiner a few times- perfect results. But be extremely carefull, this is definately not the safest way to use a joiner.

That's extremely dangerous, when I was first starting off, I was using a jointer to do that same thing and it flung my neck across the room and broke pieces off of the wood. I was later talking to a person whose a great woodworker and asked him how he got a scarf joint level for gluing. I told him I had tried a jointer, and he held up right hand and said, "I wouldn't do that If I was you". The tip of his middle finger was gone, and it was because of trying to do that exact thing with a jointer. Needless to say, I never will use a jointer again for leveling a scarf joint. Since I value having all my fingers, and it was a visual that woke me up to the reality of how danger it is to use tools improperly.

I since found a way to do it with a router and it smooths it out perfectly level for gluing. Here's where you can read up on it.

Scarf Joint Smoothing Jig

Good luck and be safe above everything else.

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I certainly didn't mean to give anyone dangerous advice... but of course I didn't, and never would, feed it over the joiner blades with my hands, push blocks are the only way to do it even remotely safe.

A jig with a router is the way to go unless you have a CNC. I made one awhile back out of frustration because the was no way I could get it straight like the guy on the video I have. The only thing I have to worry about know is the glue time not the glue line. And I thought that I came up with that jig first! Oh well.

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Here's a small video that I found a long time ago, that shows how to use a router to do a scarf joint. It's the method I prefer to use since it works so great. Of course, on this video, they are using it for joining two pieces of wood to make it longer, but the same thing applies for guitar scarf joints, except the piece is flipped over for the headstock angle.

Scarf Jointing with Router and angled jig base

Hope this makes it clearer and easier for you guys. Maybe we will never have another question about scarf joints again.. haha.. wishful thinking..

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Has anyone here used a table saw for this? My old saw was too small to do this but with my new saw it actually goes very quickly and is accurate. It does need a bit of sanding but 95% of the work is done in seconds. You need a jig to do it this way but it doesn't take very long to make one.

Also - I am another one of those fools that tried using a jointer for something it shouldn't be used for back when I was just getting started. I was literally within 1/16 of an inch of losing a finger tip (on my fretting hand). It buzzed the very tip of my skin but no deep tissue/bone loss. Very frightening.

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Has anyone here used a table saw for this? My old saw was too small to do this but with my new saw it actually goes very quickly and is accurate. It does need a bit of sanding but 95% of the work is done in seconds. You need a jig to do it this way but it doesn't take very long to make one.

Also - I am another one of those fools that tried using a jointer for something it shouldn't be used for back when I was just getting started. I was literally within 1/16 of an inch of losing a finger tip (on my fretting hand). It buzzed the very tip of my skin but no deep tissue/bone loss. Very frightening.

I have also built the table saw jig, but find it easier and more accurate to just cut it with a bandsaw and finish it off with the Router Smoothing Jig. Either will work, and I'm not saying that one way is better than the other. It's just the fastest way I've found to do it, with less sanding. A lot of people didn't really understand the jig, and that's why I uploaded this video so everyone could get a better idea of how it's used. If all you have is a table saw, then I don't see why you can't use the Table Saw Scarf Cutting Jig with ease like DaveQ said.

As far as using the jointer for leveling the scarf surfaces, yes, we did a very dangerous thing DaveQ, but we was lucky, and hopefully no one will ever try it again as long as we are around to point out how dangerous it really is. I definitely value having all my fingers so I can play the guitar after I'm finished. :D

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  • 6 months later...

The topics a bit old, but I thought it relevant to my situation..

Just a note from my experiences trying a scarf joint.

Did a search and out came this topic.

I made the jig that is used with the router. Did not work well.

Joint not flat...reason?...guides not perfectly flat. Lots of wobble.

How to get guides flat?...use table saw to cut them...

Hava a table saw?...Then no need for a jig.

All day trying to tweak the jig, then the plywood made nowadays is full of gaps, so that piece of wood was trash. And the worst part, they show up AFTER you've cut the wood.

I made scarf joints at a guitar factory years ago with a chop-saw.

Set a piece of wood against the edge with a 13 or 14 degree, or what ever it was, angle, and cut away.

No need to sand, no nothing.

BUT, them puppies run several hundred dollars.

Was it really worth wasting a whole day for something like this?

For me it wasn't.

The pictures and videos are from people who have the complete shop with everything available to them.

For the regular guy, buy the tool if they have it.

The time wasted making a tool could have gone towards buying the tool and a little extra time for the family.

And less aggrivation.

Do I sound like a defeated man? I'm broken and want to curl up into a little ball in the corner and cry......

Who's got a chop-saw for sale?

Thanks,

Mike

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Tip: if you're going to make jigs, either use MDF, or high-grade, void-free baltic birch ply. Also, how to get sides flat: use a flat reference something as a guide for your router, and use the router to make it flat. Then template route the second piece for a perfect match. For the record; the machined edge on a piece of MDF is very, very, very close to dead-on flat.

Also, don't get too discouraged; there's a learning curve! Honestly, I think the best way to do a scarf is cut it by hand (handsaw, practice following angled lines a bit first), line it up, and use a handplane (I like my block plane for this, or my #4), and if that's too challenging (tuning a plane takes a bit of practice), a sanding board. Long, unidirectional strokes. My first one took about an hour and a half to cut, plane, and tune. Now I'm down to maybe 15-20 minutes, half hour if it's being annoying, including thinning the headstock piece. And it's kinda fun.

Then again, maybe I'm just a weirdo.

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Thanks Mattia.

It is for a piece or rock maple.

The only problem with hand "scarfing" is the occurance of rounding the joinf surfaces.

My very first guitar, in 1981, was done completely by hand. A crosscut saw, a scraper and a file.

It was perfect. I checked it all the time with my straightedge.

It took days of patience.

At 42, my patience is thin.

It should be the other way around. Now that I am older, I have less patience. Maybe I'll buy the MDF (fancy name for particle board)

Thanks for the help.

All the way from Holland too!

Mike

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You know Mickguard, I never really thought about using the handtools again, like I once did

You're right.

I'll give it a go with those same tools again.

Sometimes, I forget the passion that this hobby was built on.

It's the will, not the skill....

Thanks again,

Mike

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When using a handplane for a scarf joint be sure that it is sharp. That's usually the problem I ahve when I get gaps. I start by taking a few passes to get it mostly flat. Then I set the plane so that it takes the finest cut I can get. When you push the plane only hold the nose of it when getting it started. Once a shaving starts to curl hold it down in the middle. Expect it not to take anything at the edges if you have any gaps to start with. Do that a fwe times and you should start getting a full shaving all the way across. Use a straight edge to check it as you go.

The trick is really to keep the blade like a razor and set to a fine cut. Works like a charm for me. I do all of my scarf joints by hand still. It is very enjoyable work!

~David

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I did my 2 neck blacks like Daviv mentioned above... altho I did not find it enjoyable :D , since it was my first time using hand planes. it took me a while to get it straight the 1st time, but on the second blank everything was a lot easier.

Also I like to point out that I think that the whole 13 degrees is a bit too much. There are necks out there from 9 to 13-15. So I just go for a medium, I don't like 9 because I think that a bit more pull on the strings is always better. But anything between 11-13 is acceptable. I got the 1st at 12 and the 2nd at 11.

I think that I will make a jig once I get home in late July to use a router like the one David uses for his neck joint. This will be a multi use jig, neck-scarf joint, thicknesser, and to give angle to carved tops.

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David,

Guitar #30 with the P-90's is simply too beautiful.

You have a jig for the scarf joint? Which one?

Maiden 69,

My first thought was 10 degree angle but I'm not sure how the string might sit in the slots.

12 was the amount I chose.

Thanks guys.

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Also I like to point out that I think that the whole 13 degrees is a bit too much. There are necks out there from 9 to 13-15.

I'm waiting for someone to build a better headstock :D

You'd think there'd be some way to develop a headstock that's relatively easy to build, looks good, is strong and stable, and provides the necessary string tension over the nut without resorting to glue or string trees.

I recognize that tradition plays a role in a lot of this, but really, this one shouldn't be so difficult.

Not that I'm against the look of an angled headstock...but they are pretty weak. I don't like scarf joints though--I prefer that the neck that's one solid piece of wood. For the look, more than anything. Although it doesn't make a lot of sense to have a layer glue on a crucial part of the guitar, even if the effect of the glue is probably minimal. I don't mind string trees --I think you can be pretty creative, but they're a weakness in the whole staying-in-tune equation.

Seems to me there are plenty of ideas to try still. For example:

Recessing the tuners --there's a couple of millimeters of play there. That is, the string holes on the tuners don't need to stand so tall off the headstock, do they?

A deeper drop-down. Just because Fender uses thin blanks doesn't mean you have to --maybe if the drop is deep enough, the string trees become unneccessary?

A better tuner arrangement --I saw one luthier site where he came up with a reversed tuner arrangement--said it provided better down tension on the lighter strings. Made a lot of sense.

String-through headstock --- any reason why the strings can't pass through the headstock somehow? There's always Rickenbacker's open headstock. But I'm thinking more along the lines of a string through as one would have at the bridge (Godin-style). Of course, you'd have to mount the tuners upside down, and they weren't designed for that, might not be the look you're going for....

Okay, sorry, it's the coffee talking...but still... :D

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Dude, if you don't believe strongly in the effect of wood on a guitar's tone, arguing that glue at a location like that is critical is pretty laughable. A good glue joint is a) pretty easy to make and :D more than strong enough. Angle heads are fragile mostly because of the way they get smacked when they get smacked; a good scarf has less short-grain (= good), slap on headstock veneers on both sides and you reinforce it s'more. The reason Fender's aren't as fragile is that they're in line with the shaft of the neck. Lower it further and you lose some of that strength; string trees will be unnecessary, but you add a nice bit stress riser, as I see it.

Honestly, the slickest solution is probably a V-jointed head glued with hide (if it gets smacked, it should just pop off, clean, and you can glue it back without problems). If you just want rigid, a laminated 1-piece, or laminated combo of 1-piece (center section) and scarfed (other sections) probably provides plenty of overkill.

And it's not 'Rickenbacker's open headstock'; methinks they just stole that from classical guitars and open-headstock Martins. It's also not any 'safer' than a thinner, solid headstock with an angle.

I don't like 1-piece angled heads mostly because of the massive amount of waste involved; for laminated necks, this is less of an issue.

Of course, while I do admire Leo's industrial design chops, and he created an aesthetic all his own, I'm not in this game to simplify the woodworking tasks. And honestly, calling scarf joints 'difficult' strikes me as...weird. They're complicated in a production environment (any additional joinery is), but not inherently complex joints to do. Taylor's finger jointed headstocks are complex, but strong, and save wood.

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Dude, if you don't believe strongly in the effect of wood on a guitar's tone, arguing that glue at a location like that is critical is pretty laughable.

Nope, I'm not arguing...I meant that I DON'T believe there's any huge effect on tone.

What I'm saying is I just don't like the way the scarf joint LOOKS. It's an entirely subjective thing. I haven't tried to make one, yet-- I'm tempted to try a scarfed headstock though.

Anyway, here's one of my favorite headstocks --gives you an idea of where I'm coming from :D

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I ran across a fancy mitre box set up at the hardware store the other day and was thinking of picking it up, I figure I'd still have to clean up things with the planer, but it seems like it'd get me a more accurate surface to start with.

unfortunetly, I can't tell from the package if it locks at any angle or just the handful of angles that it says it's notched for. In fact, this seems to be the only mitre box I've seen that specifically says it can lock at any angle. The price tag is quite a bit however. (although I'm sure it's worth it, I like Lee Valley's stuff.) But that's pretty much what the one I saw looks like. I'm going to have to see if I can't get them to let me open the box and take a look, I figure it shouldn't be too hard to jig up something to hold the wood at a slight angle or modify the plate to have stops at new angles.

I don't know, seems like it might be an option for those of us stuck using mostly hand tools to make things a little easier.

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