Official Luthiers Forum!

What kind of guitar is it?

Om size acoustic haans

If you saw the back off it will be easier to plane or sand to thickness. Resanding the rim might get the ledge to where it needs to be.

William, that's a beautiful "outline" treatment in terms of binding your guitar. Cable: Don't despair. More ideas will come along and one of them will work for you!
Patrick

Don't think "mistake", think "feature". Side purfling is a ton of extra work, and in general I've stopped doing it unless specifically requested. But if I really wanted to dress up a guitar, 1/4 of binding accented by 1/8" of side purfling would be something I would try to do. I don't know your aesthetic, I personally like clean contrasting lines. But I've seen ZipFlex side purfling, rope purfling, and even powder metal (between two thin black fiber lines. Actually pretty subtle). Easily 9mm worth of treatment on the sides.

Other than the work it represents, you have no problem at all on your hands.


Sent from my iPhone using Tapatalk

As a repair person, I would say do whatever seems easiest to you with the tools you are used to. I would bend a patch piece of the same wood, if possible a little thicker than the side. Hide glue is the best for minimizing the visibility of the glue lines. The bottle stuff works, you don't have to play with the hot stuff. The hardest thing is to clamp the patch in, so bend the piece until it fits without force. After the glue is dry I would fill any dips with a thick mixture of fine sawdust sanded from the same wood and hide glue. If you are worried, practice by glueing two scraps together with your glue, scrape them level with each other, and seal it with your preferred sealing method and evaluate the results. I find hide glue and shellac to be safest for blending, but opinions on this vary.
Sometimes you can do magic by studying the grain of the wood and scratching some fake grain depressions across the joint. If necessary color the scratches a shade similar to the natural grain.
If it will be your own guitar, relax and enjoy it. No one else will notice it like you do.

Thanks great advice.. am much more relaxed about it all now.. was being way to hard on myself for my first scratch build.. realising its never going to be perfect takes the pressure off cheers

Trevor

Just a bit of advice please for next time..

I have thinned the back now and tapered it thinner towards the edge..
I did struggle a bit with the router as its not sqaure because of the taper so doesn't cut 100% smooth channel
How do you get around it
Cheers

There are special tools and fixtures that help get around this geometric problem/situation some hand held some bench mounted, some way expensive some not so much. But in the end a standard router base with or without a tilt feature, is a rebate/channel quality crap shoot.

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/

The standard back dome I use has a 3m radius, so a fair bit more curvature than most others use. Whichever binding channel cutting system you use, there is inevitably some theoretical geometric error somewhere, but for the better systems (there are a few) this is of no practical significance. I use a shop made tower system, with the guitar held in a carriage which is moved under the router head. A domed collar on the router carriage base rides on the top edge of the guitar.

The tower system constrains movement of the router to the vertical axis. My jig uses linear bearings, others have used drawer slides. In the book I detail a parallelogram system which is much, much less expensive than using linear bearings and works fine. Mostly, the cut rebate straight off the jig is accurate enough and I can get away without having to do any adjustments to it. However, there is some geometrical error due to the body taper and high dome on cutaway guitars if the guitar is set up in its carriage with the sides vertical all round. Hard to explain the geometry, but I wrote about it a while back in this thread. If the guitar is tilted in the carriage so that top edge at the neck end and tail end are at more or less the same height off the bench I find I can get rebates that are accurate enough and don't need any adjustment.

For more pics, the LMI site has a few. Their new machine is in principle much the same as mine.

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

http://www.goreguitars.com.au

I had a similar experience. The clamp holding the Bosch colt was not tight and the depth of cut increased. After the tears dried up, I decided to finish the entire cut at deepest, and bound it that way. Yup, top was shallow, bottom was deep. And it looked great. Custom. Customer loved it.

Thanks Trevor

Thanks Mike..thats what im going to do..routed it to its deepest point all round yesterday. .have got ripple sycamore binding at 6mm just got about 1.5mm to fill with something else..still looking for ideas (probably end up b/w/b purfling) cheers

Cable: A bit of fore warning. If your back has normal curves (cross and longitudinal) a high binding may leave you with lots of gaps when you try to bind. A binding height of 7.5mm(.295") would be hard to get a passable job if the binding and purfling are glued together before binding. Installing the two unglued would help.The method you use to hold during gluing has an influence. Using tape, the method most use now makes it harder to get every thing tight. Roping makes it easier but not guaranteed, depending on height of binding, to get the job done. Hope it works out for you.
Tom

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

Tom's warning is justified, but a lot depends on the wood you use for binding. For example, deep bindings and high curvatures can be a nightmare if binding with say ebony or bloodwood. Figured sycamore (as in Acer sp. sycamore) is pretty stretchy in comparison, so provided you get it to bend without it falling apart (go easy on the wet stuff), you should be fine.



Glass filament packaging tape lets you pull some real tension so you can get things snugged down.

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

http://www.goreguitars.com.au

I was just going to say that side purflings are the obvious solution, but it might look funny if top and back purflings aren't used as well. However, that picture of a cotton candy wood guitar proves that I am mistaken. It looks great with side lines only.

Sanding the back a thinner looks like it will give you enough room to rout out the mistake if you use purflings. Too thick anyway.

Tall bindings look silly except on a gold Les Paul.

I will add that I would not use a different purfling than what was used on top. Find a taller binding.

I think many suggestions about adding side purfling implied that you would rout off the binding you installed on the top half of the guitar and make matching tall bindings/side purfling. I don't think you are going to be able to save yourself that step and have something you can feel proud of with mismatched top/bottom bindings. Fortunately, routing off bindings is not that hard to do.

Thanks..will definitely be matching bindings but with purfling under the wider routed channel..all matching..