Maple binding gap
 

Binding is cut
Channels have been routed
The fit ... unsatisfactory.

I'm getting a huge gap I can't close up no matter how much pressure I apply.
The binding just doesn't want to match the angle and contour of the back upper bout

If I run the binding in high it fits well , as soon as I push it down towards the sides it bends out (can't post pictures unfortunately)

I ran my router with an angled bed from the neck to mid upper bout and blended the difference not sure if this is the problem. Feels like the binding is straight and won't fit the radius.

If anyone has any idea what im talking about without the need of a photo , I'd love to hear your ideas.
Thanks

Sent from my SM-G770F using Acoustic Guitar Forum mobile app

I think I understand what you're talking about, maybe not though.
The binding wants to splay out when you get to a point near the waist where it has to follow a sharp compound curve?

You did bend the wood binding on an iron or fox type bender before install?

Can you splice the wood binding with a scarf joint in the troublesome area? Practice with scrap wood cut to binding dimensions.

Will plastic binding follow the curve?

Compound curve ... Well put

I bent it in my fox bender

It's bent to the right shape, it fits around the soundboard.
Because the back has a angle and a 15ft radius (on an l-00) it makes the area from the waist to the neck steeper than the lower section.

Is there a way to bend this sort of angle?

Thanks

Sent from my SM-G770F using Acoustic Guitar Forum mobile app

I am no expert, I built a 0-18 recently and had the similar issue, the guitar had a fairly prominent neck to tail curve near the waist and the binding wanted to splay out there. I was using celluloid tortoise binding though and was able to coax it in place by putting a rubber jawed bar clamp across the waist. I am sure plastic are easier to bend because of no grain.

I had no problem on a previous L-00 build, I used the Grellier plans which include a side profile. On the 0-18, I had to estimate the side profile and will be softening the curve for future builds. A L-00 Nick Lucas would be easier.

Is your maple binding quarter sawn? I could see flat sawn binding sawn being tougher to bend in 2 directions.

I would try wetting the binding and taping it in place on the guitar and letting it dry.
How thick is the binding? Thicker binding is more problematic. I generally use 1/16" by 3/16" wide.

I used the grellier plans as a guide, originally had plans off gen one which I didn't rate

Binding is 7mm x 2mm probably too deep

I think its going to be a case of just trying to bend it any way I can, possibly even steam it and clamp or tape it into place

Thanks for your input

I'll let you know how it goes

Sent from my SM-G770F using Acoustic Guitar Forum mobile app

I pre-bend maple binding in the same press with heat blankets as I do the sides. I just shut off the heat, and leave it alone overnite. Letting the bindings cool in the press really helps them hold their new shape.

Then, I start glueing the bindings in the waist, with lots of good taping. Let that dry a good day or two, then glue the rest. Hope that helps, if thats what the problem is. Had same issue, but that fixed it.

It's not uncommon to have to dress the binding channel with a chisel or some such tool to make it perfectly square. Sounds to me like your rout is not square. If it is then the binding might have a twist in it.

What are you using to 'clamp' the bindings in place? If you use the roping method then you can pull pretty much any gap closed. But if you do use rope then make sure you fit all your bindings in place then glue one of them down. That way you don't put little dents in the soft spruce at the edges.

Sounds to me like your rout is not square. If it is then the binding might have a twist in it.

This is quoted from redir, makes sense to me.

Two things: A lot of folks seem to use tape to clamp on their binding. This works with plastic, but is inadequate with wood. Not only is it incapable controlling the fit in the channel, but it is also incapable of applying adequate pressure to get the bond that glue is capable of, which negatively affects the guitar’s performance. I use rope, and all of my strength for the task.

The other is a trick of the trade. On a light color binding like maple, always use a black line as purfling as it disguises an imperfect reveal at the binding edges.

I use rope on wood bindings too for the reasons Bruce stated. Well actually I use both. I use tape first to hold it in place then I rope the hell out of it and yes you will break out into a sweat doing it. I have used tape with string filaments in it but found that is still no where near as strong as the clamping strength as rope. I have always been one to believe that clamping pressure is important when making any joint on a guitar.

In any case though if you have wood bindings that don't fit perfectly they will when you rope them up.

IMO, if your wood binding doesn't fit perfectly, you are doing something wrong. If you have to force it to fit, you are doing something wrong. Improper prep of the binding channel. Improper prep of the binding. Or both.

It has less to do with perfect fit and more to do with proper clamping time and pressure. As an added bonus if your bindings are off a bit roping pulls them in tight.

If you are building perfect guitars then congrats. But the OP is asking a question that most of us mere mortals have addressed in many ways that has made less then perfect perfect by other means.

I respectfully disagree. If good prep work on the channels and binding is made a priority, then there's no need for things like high pressure clamping to compensate for poor prep work. Thing is, good prep work is not rocket surgery. It can be easily done even by mere mortals like me.

As for the OP's binding problem, maybe clamping the crap out of it or some other trick would make the less than perfect perfect for this guitar, but wouldn't it be helpful to figure out why there's a problem in the first place so as to avoid it happening again in the future?

JboneCapo - You said "Binding is 7mm x 2mm probably too deep". The bindings I use are typically very close to those dimensions and have worked fine for a number of different types of wood on guitars with tight waist bends and 15' radius backs so I doubt that is causing the difficulty.

What is your setup for routing the binding channels? A tower? Something else? I wonder if something was off when routing the channels.

What do you do to prep the channels before installing the binding?

a thought - - - reaction and opinion
 

A lot going on. Depends on the shape of the body and the plane of the soundboard, I think. Even if the binding channels are square to the body, I think it will get 'interesting' for a binding to conform to a downslope of the soundboard north of the waist. The binding will be asked to conform to a compound curve wrapping around the upper bout when the upper bout isn't parallel to the lower bout. Betcha' that helps explain plastic bindings on factory guitars.

Maybe the problem would respond to the binding being reduced in height and some purfling taking up space at the bottom of the binding channel. Test pieces? It's tough to bend a piece of wood a quarter of an inch high and a sixteenth of an inch thick. Three sixteenths high, maybe it could be forced into submission.

Or plastic bindings.