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-   -   Repair Tech/Luthier to Route Binding/Purfling channel (https://www.acousticguitarforum.com/forums/showthread.php?t=551799)

funkymonk#9 07-11-2019 10:30 PM

Repair Tech/Luthier to Route Binding/Purfling channel
 
This is the last instrument that I had started a couple years ago when I had all the building tools available to me.
I still am looking forward to doing all the hand work but some of the jobs may take tool/jig investment which I wouldn't likely need in the future. And I don't have a good space now to utilize them.

Basically the binding channel and mortis and tenon joint are 2 upcoming parts that I am looking to have done so that I can move on with the instrument.

I've seen the available routers and jigs. I used the binding jig with the floating router stand on all instruments and it is super stable but I am not investing hundreds of dollars for one more use.
To be honest I'll use a bandsaw, planer, sander and whatever else but I hate using routers near instruments.

Any ideas of repair/luthiers who would prepare the channel and mortis and tenon?
I know someone who will do the binding but he wants to do the whole thing and I just want the channel cut so I can do the rest.
Highly appreciate any thoughts.
I am in Asheville but will drive or send wherever if necessary.
https://i1302.photobucket.com/albums...ps1hqgxsbl.jpg
https://i1302.photobucket.com/albums...psmij6byfk.jpg

redir 07-12-2019 06:54 AM

It looks like the binding channel is already cut.

funkymonk#9 07-12-2019 11:39 AM

Quote:

Originally Posted by redir (Post 6109351)
It looks like the binding channel is already cut.

Yes it has, I managed to cut a basic channel with a router jig ala lmi. But afterwards realized I wanted a purfling channel.
I assumed the binding channel could be filled temporarily to make the purfling cut more stable or use something like an ibex purfling cutter. Thanks

charles Tauber 07-12-2019 01:14 PM

Quote:

Originally Posted by funkymonk#9 (Post 6109626)
Yes it has, I managed to cut a basic channel with a router jig ala lmi. But afterwards realized I wanted a purfling channel.
I assumed the binding channel could be filled temporarily to make the purfling cut more stable or use something like an ibex purfling cutter. Thanks

A router, just like was used to cut the binding ledge.

redir 07-12-2019 01:32 PM

Ibex purfling cutters are very difficult to use.

Have you asked any friends if they have a router? IF they do then you could make or purchase an end guide that will work like a charm. You might also consider buying a Dremel since they have many uses other then guitar making.

Or do you still have a router but think it's not the right tool for the job?

Anyway you would not need to fill the binding channel. Are you using any books for this job? If not search around online and you will find plenty of tutorials for cutting purfling channels.

If you have the router then you are 90% the way there.

The mortise can be cut by hand but again if you have a router then it makes light work.

Alan Carruth 07-12-2019 02:55 PM

This job can be done with a jury rigged marking gauge, a sharp chisel, and a file or two.It takes time and some skill, but it's the way it was always done before people had plug-in tools. Normally in that case you'd mark the purfling line on the top first, take that down, and then mark the binding line, so at this point you're bass ackwards. A shallow gauge that runs on the binding rabbet would work. I'd make one by sticking a guide pin into a stick sideways, to guide on the rabbet, with a sharp two sided cutter to mark the top at the right distance, if I had to do that. ;)

funkymonk#9 07-12-2019 08:00 PM

Quote:

Originally Posted by redir (Post 6109720)
Ibex purfling cutters are very difficult to use.

Have you asked any friends if they have a router? IF they do then you could make or purchase an end guide that will work like a charm. You might also consider buying a Dremel since they have many uses other then guitar making.

Or do you still have a router but think it's not the right tool for the job?

Anyway you would not need to fill the binding channel. Are you using any books for this job? If not search around online and you will find plenty of tutorials for cutting purfling channels.

If you have the router then you are 90% the way there.

The mortise can be cut by hand but again if you have a router then it makes light work.

Ok so I think I have a dremel and I have looked at the end guide online. As Alan stated usually you do the purfling first so unsure if the guide would follow the channel or the side of the instrument.

I would also need the right bit/bearing? I think I would be more comfortable with the dremel just because it is a little lighter and less intimidating.

On the other hand all I need is a repair tech to do the top purfling, how much could it cost? Compared to buying the tools. But it does seem more doable than before.

Quote:

Originally Posted by Alan Carruth (Post 6109786)
This job can be done with a jury rigged marking gauge, a sharp chisel, and a file or two.It takes time and some skill, but it's the way it was always done before people had plug-in tools. Normally in that case you'd mark the purfling line on the top first, take that down, and then mark the binding line, so at this point you're bass ackwards. A shallow gauge that runs on the binding rabbet would work. I'd make one by sticking a guide pin into a stick sideways, to guide on the rabbet, with a sharp two sided cutter to mark the top at the right distance, if I had to do that. ;)

Yup Bass ackwards, I thought simple in the beginning and got more ambitious. So yeah the guage that runs on the binding channel instead would work. I have used the purfling cutter once before and had pretty good results.
I like a mosaic style inlay banding for purfling but its always wide and hard to bend. I used a 7/32 wide before and that was about as difficult as I can imagine. Is there a width for a top purfling that is inlayed that is reasonable to bend or it depends on the construction type and wood?

redir 07-12-2019 08:37 PM

I'd dare say that Alan must have the hands of a surgeon if he can accomplish this job with hand tools like that. My first few were done with an Ibex cutter I made myself (which may be the reason why I think they are the Devils spawn), some chisels and sanding sticks. But it's and exercise in humility to say the least. Binding is one thing but to get accurate purfs is entirely another. And I am not talking about violin purs, I mean guitar purfs that are ledges above the binding to a depth just barely less then the top thickness around the whole perimeter.


===

I don't think it's common to do the purfling first and then the binding but I suppose there are some that would do it that way.

If you really are desperate (and I can find a few hours of time) and you want to travel 3-4 hours north to Virginia then I can help you out with the bindings. I would not want to mess with the mortise though as I am not tooled up to do that.

I still think though that you have come this far, and by the looks of those pics have done very well, so you really should be able to come up with something yourself. Or surly there is someone in the Ashville area?

Alan Carruth 07-13-2019 06:17 PM

redir:
Thanks. I don't know about 'the hands of a surgeon', but I have been building for over forty years, much of it with hand tools, so I hope I've acquired some skills. OTOH, I've taught beginning students to do some things that were no less difficult, and they've come out fine Often enough). The keys are sharp tools, patience, frequent measurements, and did I mention sharp tools?

Normally when doing binding and purfling by hand you'd mark the purfling ledge first, cut that down, and then cut the binding ledge. However, it also makes some sense to do it the other way, since the purfling ledge has to be uniform in width as measured from the inside of the binding.

I agree that the usual gramil is the devil's work: you can't see the cutter. I made up a marking gauge where the cutter is set at a right angle to the post out at the end, and there's a round guide pin that can be moved and locked to set the width of the rabbet. It's not a cutter, but a marker; you usually cut the ledge with a knife or chisel, depending on how tall it is, although it could work as a cutter for a shallow purfling ledge.

For mosaic purflings I find it easier to build them in place. You make a ledge of the appropriate width, and glue in whatever veneer strips you want on either side, with 'no stick strip' where the mosaic will go, just as if you were doing a shell inlay. For herringbone (say), you make up a block of stacked veneers and cut off slices so that they show a side grain diagonal along one edge. I'd make the slices 1/16" (1.5 mm) thick, and use two 1/16" no-sticks with a strip of .5 mm veneer in between, for a total width of 3.5 mm. It's wise to allow a bit extra for glue: water in the glue makes the wood swell, and if the purfling is tight when it's dry you won't be able to get it in with glue. DAMHIKT I use a strip cutter to cut pieces off the half herringbone slices. These can then be dipped into hot hide glue and put into the groove once the no-stick strips are removed. Just go around putting in one side and the other beside the center veneer. You don't have to put any glue on that; there will be plenty around to hold it in.

Fancier mosaics are, or course, variations on the theme.

funkymonk#9 07-17-2019 08:31 PM

Quote:

Originally Posted by Alan Carruth (Post 6110877)
redir:
For mosaic purflings I find it easier to build them in place. You make a ledge of the appropriate width, and glue in whatever veneer strips you want on either side, with 'no stick strip' where the mosaic will go, just as if you were doing a shell inlay. For herringbone (say), you make up a block of stacked veneers and cut off slices so that they show a side grain diagonal along one edge. I'd make the slices 1/16" (1.5 mm) thick, and use two 1/16" no-sticks with a strip of .5 mm veneer in between, for a total width of 3.5 mm. It's wise to allow a bit extra for glue: water in the glue makes the wood swell, and if the purfling is tight when it's dry you won't be able to get it in with glue. DAMHIKT I use a strip cutter to cut pieces off the half herringbone slices. These can then be dipped into hot hide glue and put into the groove once the no-stick strips are removed. Just go around putting in one side and the other beside the center veneer. You don't have to put any glue on that; there will be plenty around to hold it in.

Fancier mosaics are, or course, variations on the theme.

Not completely sure I am getting a clear understanding how you install the herringbone but I think I get 80%.
What I was thinking which may correspond is to purchase a 1/8th-3/16 wide inlay banding and try to cut down the long way into .40-.60 wide strips.
Is that doable? you mentioned a strip cutter. I have seen one that cut .8- 1mm.
And then you can lay them in side to side lining them up horizontally correct of course.
Is there a tool that can acurately cut these this veneers into consistent widths? widths?

MC5C 07-18-2019 07:18 AM

On my first guitar I wanted to have the "complete experience", so I cut the binding channel for the top with shop-made tools called a gramil.

https://www.hovingtoninstruments.com...-make-a-gramil

I made several non-adjustable ones from scraps of maple and exacto knife blades, one for the depth of cut that cut along the side of the guitar guiding off the top, and others for the width of cut that cut along the top of the guitar and were guided by the side. These defined the cuts, and then I completed with a sharp chisel and small files. Not hard - tricky, fussy, but not hard. So it can be done with no investment.

Similarly I cut the mortise and tenon for the neck joint by hand, with traditional hand saws and chisels. Then, still seeking the "complete experience", I went to routers, built jigs, etc. So now I've done all the jobs all the ways, except automated.

For you, anyone with a trim router and a router bit kit a'la Stewmac could cut the purfling channel for you in about 20 minutes. For me, the hardest and longest part of that job is setting up. It might be a problem if the existing channel is too deep for the guide bearing to have something to ride on.


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