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Hello,

Last night I followed the tutorial here for making an end wedge and mitering the binding / purfling. viewtopic.php?f=10117&t=40548



First, this process was exhausting. I started at 6:00 after work and collapsed into the bed at 3:00AM. I guess I'll need a red bull later today.

The results are "acceptable" at best, I'm sure I'll improve with some more practice. I have a question about the process. The tutorial suggests to mark and cut by hand and then sand to fit. I suspect that Larry's skills allow for this. I quickly went off the rails when trying to do this by hand. What I did instead was mark a 45 on the binding using a square and cut it right on the line. I then slid the lower edge of the binding to the edge of the channel for the end wedge and tacked in place with CA. I did this for all four binding pieces. Like the tutorial mentioned, I followed the usual process for attaching the rest of binding / purfling. Then I used the two pieces of binding for the end wedge and marked and bumped them on the disk sander until they fit snug. I CA'd them into place and started the scrape / sanding process.

Questions:

1) Do you guys like to use the disc sander approach or is there another tool that would give more precise results?
2) The upper left miter is just a bit off. Any ideas on how I can clean that up post mortem?
3) Any tips for improving the output?

Thanks!
Brad

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Chop the purling miters with a sharp chisel by standing the purling on edge. Set the chisel on top at a 45 degree angle and chop down. You can sneak up on the line by taking about 1/32" cuts.

I use the chisel as well. Just go slow and take small bites.

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Steve Smith
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Brad - I hand sand instead of power sand. When I sand, I makes sure I'm using a dead flat surface. It goes slower but that allows me to be very precise. I dry fit everything and make sure everything is very snug. For the miter angles I use a razor saw and mini miter box design for it.


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Let me make sure I understand. The binding I was using had a W/B purfling glued to the bottom. What you are suggesting is set the binding on its edge and flipped over so the purfling is up and cut down on a 45 with the chisel? I would have to maybe cut a board on a 45 or something to follow. I doubt I can do it by eyeballing it.

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This little tool is nice to have for miters.
http://www.micromark.com/miter-master,6943.html

If your chisel is polished on the back side you should get a reflection showing a 90 deg angle, or whatever the finished angle will be.
I have more problems with the cut skewing as I go down with the chisel. Thankfully the butt wedge is short and its easy to grab another piece of purfling to cut. If it was taking more than an hour, I would walk away and come back to it with a better game plan.

There is another way to do this. If you have the Cumpiano book, its in there. The binding itself is not mitered just the purfling. That is my preferred method.
Tom

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Brad - Just for clarity in this discussion, did you follow that tutorial because your goal was to use that specific type of end wedge scheme to get that look, as opposed to the more common approach that doesn't require mitering the binding?

"What you are suggesting is set the binding on its edge and flipped over so the purfling is up and cut down on a 45 with the chisel? I would have to maybe cut a board on a 45 or something to follow."

As far as using a chisel goes for this application, I don't see how you could miter the combined binding/purfling by standing it on edge to get that type of miter. You have to lay it on its side to cut the miter. The mirror trick using the flat side of the chisel to get the 45 angle works great. As Steve pointed out, go slow and take very small bites to sneak up on the final cut. You get a much cleaner final cut that way. I've made miters by sanding and by using a sharp chisel and settled on the chisel as my preferred method. In my hands, I can get nicer joints with the chisel.

Also, can you post a close up photo to get a better idea of how it came out? The photo above is too dark to see the details.

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Thanks, Jay. I followed the tutorial because I assumed that was a common way to do it. If there is a more common approach, I'd love to hear it. What I'm working with is binding with the purfling already attached. I don't know if that would factor into a different approach.

If you have an overview or link to info on a better way to accomplish this look it would be appreciated. I do have the Cumpiano book and can look there as well this evening for the method Tom recommended.

Thanks for the help! I'll post some better pics this evening.

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I was wondering if that might be the case. The approach you used looks distinctive, but I'm guessing it's a bit more challenging to pull off than the usual method. In the typical method, the binding runs straight across the end of the end graft. It is often done with binding that has the side purfling attached like yours does. It means that you miter the end of the purfling, but not the end of the binding it's attached to. The end of the binding coming from both sides is butted or scarfed together where they meet in the center above the end graft. The trick is to not rout the binding channel to the full depth of the binding plus the side purfling through the end of the end graft insert. The end of the insert must be left proud by the thickness of the side purfling so it will butt against the edge of the binding.

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As mentioned, Mr. Cumpiano's explanation is simple and clear - it is the reason why I felt compelled to buy the book, despite using it for little else in terms of techniques. Using a machine to handle the job seems a lot like hand tool avoidance...which I can identify with, after a very nice couple hours spent shortening purfling scraps to unusable bits before I got my first miter trimmed to the boss's satisfaction. It did eventually click for me - if the chisel was vertical with regard to the purfling, the reflection was at 90 degrees, and the chisel was sharp enough to shave everywhere necessary, the cut would be consistently good.

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I, too, follow the Cumpiano/Natelson approach of only mitering the purfling, while butting the binding. A chisel and the reflection trick usually get me where I want to go. Sometimes I might need to do light sanding to get the fit just so.

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George :-)

I lay mine on its edge upside down (purf up) and cut the mitre with a chisel by approximating the angle .. its not that tough ... start out a little long so you can see if the angle is correct ... then sand the extended binding until its centred on the top of the wedge .... repeat for the other binding piece, but sand the binding over hang until it touches the other binding end to end, AND the mitre on the purf fits tight ....

the wedge and its side purf are already in, and have the correct amount sitting proud in order to receive the binding mitres ...

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Tony Karol
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It sounds like you're describing mitering the side purfling for the standard method most people use to join the binding ends at the end graft rather than the method that Brad used in which the binding ends are also mitered into the end graft.

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Here is a better pic after wiping some naptha on it. Good lord, the canyons in the Padauk are ridiculous. I'll be z-poxying for days.

None of the miters came out perfect, but the one on the top left is bad. I might cut this all out and start over unless there are ideas for how to clean that top left up?

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My experience is that to cut out and fix the white is a PITA, unless you replace the whole thing. It has never looked right to me The black is fairly easy as ebony dust fills and hides pretty well under finish.

It doesn't look terribly bad. Far from perfect, but liveable unless it is a custom build for someone. Another option is to think inlay.

Dont feel bad about the canyons in the padauk. I recently lost a block plane in one of them

Steve

I also use the micro master for all my mitering and can't recall any failures. It is about as fool proof as you can get.

Brad, how many guitars have you made? I'll have to say, 3 out of 4 ain't bad. I've tried fixes that really didn't improve things much. I also use the Cumpiano and Natelson approach, but I can see where this mitering technique might look more interesting depending on the binding wood used. I like the little mitering tool that been mentioned, but I just use a sharp chisel. As for a the pores in padauk they are large, but I still didn't pore fill the one I made; pores just don't bother me that much.

This will be my second completed instrument. I've prioritized it over some other projects that are in progress because this guitar will be for my son for his birthday this summer. If I get it done that is.

I might just move on with it given the time constraints.

Thanks for the feedback. I did order one of the miter tools. If it is idiot proof I will put it to the test.


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I have the mitermaster and like it, but I don't see how it could be used for this particular miter. It is hard for me to describe, but it would cut the 45 across the flat part of the purfling, I don't see how you could stand the this part up and cut the 45 across the thin section. If someone successfully uses it for this, hopefully they will weigh in and tell us how to do that; it would be useful,
Mike

At this link Charlie Hoffman shows the trim miter technique used by many:

http://www.hoffmanguitars.com/bindingBODY%202.htm

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Ken Cierp

http://www.kennethmichaelguitars.com/

Yes, that is the only way I know to cut this miter. It is one of the few woodworking processes that for me is easier than it looks!
Mike

Thanks, Ken.

For this to work I have to put the bottom purfling and binding on in two steps, correct? Otherwise I will be trying to miter just the purfling while attached to the binding and then cutting off the purfling that would be covering the channel for the wedge. Is that correct? Here is a ridiculous drawing I did to show what I mean:



I already have binding with purfling attached. If I have to do it in two steps that's fine, I'm just curious of this approach is used or if I'm inviting more trouble?

BTW: After much hand wringing last night, I'm going to cut the binding and end wedge back out and try again. I'm such an anal dude.

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