Official Luthiers Forum!

It doesn't matter if you level the bindings to the sides, or the opposite, if the result is identical. In my experience, it is easier to get even thickness on the bindings if you install them a hair below the surface of the sides, and scrape the sides down (as John says). The reason I level the sides prior to routing is to have a good surface for registering the binding cutter bearing, not to make that the final result. They need to be smooth, but not necessarily all pretty etc, so I level them accordingly.

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Rian Gitar og Mandolin

I level the sides before routing too.
I've never tried setting the bindings deeper than the sides....

I install my bindings proud of the sides. Been routing with a flush bit for about all 73 guitars I've made, minus maybe 3 or 4. Always did climb cuts, both on figured and none figured wood bindings and never ever had a single issue.

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

Binding to me is the scariest part of the whole building process. Makes me nervous! A screwup here is not easy to recover from. I do cut the channels with a router then spend a lot of time dry fitting, using a razor and chisel getting everything just right. Once it is a good flush fit all around with no gaps, etc. I glue them in.

After doing all of that, the thought of turning a router loose on it causes me to break out in a cold sweat. Even if it is your guitar.

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Joe Beaver
Maker of Sawdust

Alain,
Do you climb cut all the way around, or do you climb cut 4 sections like the stewmac guide shows?

The climb and rout cutting has to be done with care. Climb cutting at the bout areas is usually a safe cut. Climb cutting across the lower area a climb cut can cause a compression fracture. It is all about reading the grain and the angle of attack of the cutter. You want that angle to be with the grain and cutting along the grain at the bouts the angle of attack on a rout cut will be across the grain and increase the tear out angle.
Binding is indeed one of the parts of fit and finish on the guitar. There are many techniques and early builders often don't know the skills needed . Keeping the appearance of the binding . especially on the back is all about the technique. Scraping is not a bad way to do thing or is sanding but it is easy to squeeze the binding and make it look thin.
Learn to read your chips , cutting is all about matching cut to feed rate. Too slow you will smell smoke too fast your chips will be more like chunks.

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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

Great question! I would vote for the scraper, but if I were an adventurous builder, maybe one of these would be a good choice (Whiteside, spiral down cut, bottom bearing)

I always like reading Johns tips. I normally have to read them 3-4 times before it sinks in, he includes so much info in a few sentences. Then, almost like the clouds parting and the sun shining through, I get it!

Thanks John!

Mike

To avoid the situation Todd describes , your routing set up needs an addition. If you are using a non modified router, you will in fact need the 2nd pass for the binding. The key is to locate with as few points of contact as possible aside from holding the cutter vertical. It is all about process at this point. The backs are often the point of interest as the radius and plate angle will lift the router from upper bout , neck and upper bout.
Also bearing cutters are far superior to pilot guides where you have to maintain a tangent to the cutter and guide.

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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

To avoid the situation Todd describes , your routing set up needs an addition. If you are using a non modified router, you will in fact need the 2nd pass for the binding. The key is to locate with as few points of contact as possible aside from holding the cutter vertical. It is all about process at this point. The backs are often the point of interest as the radius and plate angle will lift the router from upper bout , neck and upper bout.
Also bearing cutters are far superior to pilot guides where you have to maintain a tangent to the cutter and guide. These are things you need to be aware of as you do binding. Also as a point of technique I will do the wider ( purfling ) cuts first then the binding.
I will do Top and back purfling cuts then I do the binding this allows the same set up for the top and back. It is a small detail I can see that the binding of the top and back often differs. Learning to do a good binding is difficult and often the hardest part next to setting a neck. It is all in the details . There is a reason , If you are not cutting through the top or back plate you run less tear out risk , also if you do the binding first , your pilot may be locating in a area that was worked and you loose control of the pilot track.
Another point of interest , The inside corner of any cut is seldom perfect , so break the inside corner of the binding so you locate on the side and bottom. If the inside corner of the rout cut holds off your binding , it may cause a void or gap.
I think Todd and I gave you enough to think about . It is all about process and repeatability . If you have a process with variability you may not be able to get the same result twice.

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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

Sorry, I've read this several times and it doesn't compute...... this jig would fit your description ...... only the outer edge rides the body and it references the top for depth, vertical referenced from the sides..... outer edge not correct binding want be.....other wise?

Blessings,

Kevin

When I bind I flatten and clean up the sides of the guitar first. No humps and bumps. Ready for finish sanding. These are used as a depth reference. The binding is installed slightly proud of the sides and scraped level with the sides. To me cleaning up the sides to the binding is extra work not needed. One does what works for one.
Tom

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A person who has never made a mistake has never made anything!!!

All the way around.

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

Cool. I know I'll just have to try it despite all the very good reasons not too....

Boo!

A proper shoe will do the job of positive location. The key to this is to locate off the front leading edge of the cutting area , the closer you can locate the more accurate you will be . If you are not accommodating for the radius and angle of the back , yes you can have a poor cut. I can tell you that the proper angle on the location "donut" shoe will give a good result. There are a number of binding set ups out there that miss this last point.
I do prefer to cut the purfling channel first as some binding cutters , if the binding channel is cut to deep may not allow the bearing to track true. The top is much less problematic than the back.

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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

My "shoe" is a piece of high density polyethylene that is about 1/8" by 1/4" and it sits within an 1/8" of the router bit. This keeps my binding rabbets fairly even. I was originally worried that a shoe this small would leave an impression in the spruce top, but that hasn't proven to be a problem.

Actually as long as you can locate to the leading edge of the cut , you will get a very accurate rout . The farther into the body you locate the more error.

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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

Am I mistaking or this thread started with discussing trimimg binding flush, and somehow shifted to routing binding chanels?

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

yes
you cannot trim binding with a flush trim bit

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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

Next non-commission guitar I'm gonna try it anyway. Worst case Ontario is a rebind...

Oh, and anger, shame, humiliation, self loathing etc...

This is what happens.
The binding will pull up with the router bit and from a safety aspect I suggest you don't do it.

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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

On the last few archtops I made it struck me it might look nice to round the edge over like an electric guitar so I used a bearing guided roundover bit to trim the binding. It took a couple of passes but went very well. After a little time with a sharp chisel removing larger proud areas, I did one pass to get things started, sanded the sides clean of crud and did one more pass. Done.

I'll certainly try it again.





nigel
http://www.nkforsterguitars.com/#/book/4568936095

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nigel

http://www.theluthierblog.com

Yes, you can. As I mentioned, I did it more than 70 times without any binding pulling off, nore any other issue.

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

wood maybe
Plastic I wouldn't recommend it.

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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