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Is anybody using a flush cut bit in their binding cutter jig to level the binding after glue-up?
It seems plausible if one follows the same climb cut pattern as when routing the channels. Normally I just spin some tunes and go at it with scraper/flat block, but it seems like a good way to shave a little time off each build...
Thoughts?

Too much risk of tearout for me. Also, if more than a light scraping or sanding is needed, it would pay to work on your technique.

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http://www.chassonguitars.com

+1

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Ken Franklin
clumsy yet persistent
https://www.kenfranklinukulele.com

I'd heard from one builder who uses a router to trim his bindings flush with the top and back.

Pat

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formerly known around here as burbank
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http://www.patfosterguitars.com

I wouldn't want to try it with figured bindings, but tear out in plain woods might be less?

Maybe a robo-sander in the drill press? (in cradle, on big table) I aim for only a couple thou of binding or side to scrape so it's pretty fast.

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Pat

I'm sure I could get them sharper, but even when reasonably sharp scrapers can give me pretty sore hands. They're just kind of awkward to hold.
The robo sander left divots on the sides from the roller when I tried. Kind of self defeating...
Not a big deal using a scraper, but it takes me 40-45 minutes...

45 minutes to perfect a box that you've been working on for a week, two weeks, a month... Sounds like a good time to me. What's your hurry?

Sharp is evidently not the correct term these days. I've been informed by my apprentice that his tools are sharp....mine are REALLY sharp. Evidently there is a difference us old guys don't know about

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

A box only takes a few days at best. Since I sell them for money, any way that I can build them faster without losing quality is a good idea....

I did a few trimming with the flush cut bit. When it works, it's great. When it grabs, or when there's a small stretch that isn't as tightly glued as you thought, you get to learn how to splice in a piece of binding without having to start over (scarf joints work). I mostly use a scraper with sanding in some places.

Which is why I was asking instead of trying...
The common theme seems to be no....

And all I know about algaebras is that mermaids wear them to math tests...

I usually do plastic bindings, and use a flush trim bit to trim them flush to the top and back. I have to remove the base for this and use the bit free hand. I don't think I could do a good job trying to flush trim the sides with a router, would probably wind up with thick and thin bindings.

If it's taking your 45 minutes with a scraper, I'll second my recommendation to get your binding on more accurately to start with. I use 120 grit on a random orbit sander and it's 10 minutes or less to sand the whole body, including cleaning up the bindings. Be aware though that a ROS has a learning curve like any other tool.

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you should have the binding so you sand the sides to the binding. On the top and back just enough to sand and scrape. Anyone that says that they use a router, got very lucky. I did this on the first guitar I made and got lucky ,, the 2nd guitar EXPLODED the binding. Of the builders that I know that do excellent binding the technique is as I described , this makes the bind very even on the thickness when viewed from the top and back.
Most beginners will have the binding get that squeezed out appearance on the back across the upper bouts. The more you build the more you fret over the details
#152 guitar out the door.

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

Nice!

I route .70 channels and leave the binding at .75, and it all scrapes and sands out to my satisfaction, but it is a bit of grunt work that takes a bit of toll. Not sure what else I could do to improve technique. The cutting jig is square, the guitars sides are square etc...

I'm not sure offhand how thick it is. I bought a set of four from Lee Valley and I use the heaviest one. I actually find the thinnest one cuts faster, but it doesn't cut flat and tends to curve the edge a bit, cutting a bit more from the top of the binding than the bottom. I'm sure I could probably get my scrapers sharper, but I'm able to get the little shaving curls that are the de facto beauty shot on all our websites...

A minor scraping technique I've found is I prefer to pull the scraper towards me rather than pushing it away. I find I get a bit more control this way. I scrape and sand my binding flush.

I have heard of guys using stroke sanders to level binding on tops and backs... seems a little risky to me.

Josh

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Josh House

Canadian Luthier Supply
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House Guitars - Custom Built Acoustic Instruments.
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I've been trying to get mine as close to the surface as possible leaving little left to trim. One thing I am realising is I need a few more bearings for my binding cutting bit to fill in the missing sizes. It still always frustrates me with the variation in how much gets left proud of the sides depending on the radius. Why is that? Seems the tighter the radius the more proud the binding sits......... but not always.

Rounding over the corner of the binding that sits in the corner of the ledge helps things sit more evenly.

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Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

Seen stroke sanders in factories a lot where the top thickness is less of an issue. Sure is fast.

Get one of the Carruth scrapers from StewMac. It makes binding scraping a lot easier.

Absolutely correct! This is expert testimony.

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Ken

Most of the binding scrapers will end up pinching the binding. The key is that you find a technique that works for you. Many newbies do have a hard time getting the binding right , especially on the back. There the radius of the back and the taper can cause some problems in the routing process

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it