In part 1 of Precision Guitar Purfling Techniques, we looked at how a few simple tricks can help your decorative guitar purfling can be installed a bit easier and with cleaner and tighter miter joints. Here in Part 2 we will look at how these some of the same techniques can be applied to fitting those tricky side purfling areas of the guitar body to help them stay clean and tight as well. I will not be getting into how to glue the body bindings in place as that is an entirely new subject and will need its own series to cover the important details thoroughly enough, and because the technique is a bit different in some critically important ways. I will, however, be showing you some really handy tricks that help me keep the level of quality consistent and looking clean and crisp with the side purflings and miter joints as they interact with the end-graft and other binding elements.
Planning For Purfling Before Cutting Binding Channels
Routing decorative elements for your side purfling is not hard if you plan it out a little bit beforehand. I always put a small piece of masking tape over the guitars end-graft to help me remember not to cut into it at the full binding depth while I am routing the first pass around the guitar. I get so focused on making those cuts that I can almost forget about the engraft or neck framing details and cut right through them. The tape makes sure I remember and also make a very easy to see where I need to stop the cut too.
Once I am done with the initial full depth cut, I use a little trick that I think I originally learned from Charles Fox Guitars but I can’t remember for sure. This little trick really makes it easy to have a tight seam between the main side elements like the engraft or neck framing and the side bindings themselves. Al you need to do is take a scrap or extra piece of the purfling material that you used to when you made your bindings (or any material that exactly matches its thickness) and lay it on the guitar so that he router can ride on it while making the final cuts through the decorative side elements.
By raising the router up that same amount as the purfling thickness, it allows the side elements to be left just tall enough so that you can complete your miter joints in the purfling and the side bindings will perfectly and tightly fit against them.
Perfecting The Binding Channels
Once the cuts are made we can then prepare the areas closest to the miter joints and get them ready for the binding process so that they will be a perfect fit.
I use my 1″ chisel for this and the trick here is to use a slow and controlled rocking motion and begin removing just a tiny bit of wood at a time and slowly work your way down to the full depth of the rabbit.
the right side of the blade is resting on the bottom of the binding channel and then I am pivoting it around to hold the plane of the cut even and straight as I cut into the corner leaving the purfling tall at this point.
then I can clean the vertical surface up and make sure its depth is correct and all the planes of the binding channels are smooth and evenly aligned with the surrounding areas. Here again I am not touching the purfling yet just getting the surrounding areas perfect first.
Last couple touches to get it all just right, and now the end-graft and binding elements are the perfect height and ready to be mitered and fit to the bindings and side purflings before gluing.
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My Special Trick For Perfect Binding & Side Purfling Miter Joints
The trick is to cut off an extra little piece of binding about 1″ or so long. I then trim it down with my 1/4″ chisel so that it has a 45-degree angle on one side and a 90-degree angle on the other. I use the reflection of the purfling lines in my chisel blade to help make sure my angles are correct.
Here is what it looks like when I am done. It’s a simple little thing but it really helps to make sure everything is dialed in before we get glue involved and start putting the bindings on the guitar.
The first step with our new little tool here is to make the micro adjustments with the same rocking motion on the 1″ chisel and adjust the bottom of the binding channel so that the test piece can fit perfectly into the slot using the 90 degree side. It needs to have the purfling on the bottom seated tightly against the binding channel and the bare wood (without the purfling) must be a perfect fit to the side element, wheater it be some type of neck framing design or the end-graft of the guitar. Take special care to be sure that it does fit tightly because on light woods that joint can really look bad it isn’t perfectly tight.
Final Miter Joint Preparations
Once I like the way bottom of the binding channel is set and I’m happy with how the test piece fits using the 90-degree angle side, it’s time to start fitting the miter. I trim it down a tiny bit at a time. Remember guitar making is a subtractive art so you remove material slowly until its just right. Don’t go for the hole-in-one on this part, just take it a step at a time. You can’t put the wood back on once you take it off 😉
A series of testing the joint and then making adjustments follows until its just right. I do this for all areas that will have this type of design where the side purfling is interacting with these other decorative elements.
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My Special Trick For Perfect Binding & Side Purfling Miter Joints
Learn techniques and secrets to creating perfect perfling and miter joints around the fingerboard, guitar body, and other parts of the guitar in this 38 page eBook containing Part 1, Part 2, of this series, PLUS the Luthier’s EDGE Exclusive Step By Step Photo Tutorial.
Click below to find out more details about this eBook and how to download it now:
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[fancy_box]
My Special Trick For Perfect Binding & Side Purfling Miter Joints
Learn techniques and secrets to creating perfect perfling and miter joints around the fingerboard, guitar body, and other parts of the guitar in this 38 page eBook containing Part 1, Part 2, of this series, PLUS the Luthier’s EDGE Exclusive Step By Step Photo Tutorial.
Click below to find out more details about this eBook and how to download it now:
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Pre-Fitting The Bindings
Now your side purflings on the body are ready to receive the bindings. I do the same thing to the bindings themselves and I usually start by fitting the and graft areas and getting the purfling miters right before I start putting the glue on to taping the binding in place. If you have both a mitered engraft and a mitered neck framing then you have to start at one side and work your way up as you install the binding, then when you get close enough you can do that last final fitting of the miters in the side purfling. You can’t pre-fit both of the miters because in the process of installing the binding the position could shift even the tiniest bit and mess up the joint.
Don’t worry, though, just take it slow and work your way little by little until its perfect.
One last Super Important Tip – Don’t Skip This Part!
[note_box]If you are going to use CA glue to install bindings on the body of the guitar you must seal the binding channels and preferably the whole guitar first, especial light colored woods first with a sealer. I seal the top back and sides with shellac and then seal the binding channels with vinyl sealer (yes the one last stinky toxic thing in my shop, well other than the CA I guess) This is critical because the superglue can wick into those woods and make visible glue lines or even pull color out into the top or back if you don’t seal it first. This is very important! [/note_box]
Remember in Part 1 of this series, when I told you my secret of using the tight bond glue to make the miter joint invisible on the light colored wood stripes? Well, that same little trick, even if you are using superglue to install your bindings is critical to making the wood to wood butt joint look good. Look at the image below, do you see how nice and tight the maple binding seem is where it meets the neck framing element? That’s partly because it was fit perfectly using the techniques I just shared with you above, but also because I used the aliphatic resin glue (tightbond) to glue that area. It prevents the superglue or epoxy or whatever your choice of glue, from getting into the end grain of those light colored woods. If the fit was good, then the sealing properties and the slight swelling caused by he water content of the tight bond will make an almost invisible joint, even in light woods.
Now you can see how simple it is to get good clean tight purfling and miter joints around the fingerboard and body of your guitar. But those aren’t the only places these techniques can help you, be sure to apply this to the headstock and other areas as well.
Thanks for the great information Tom!
Steve, so glad you found it useful! – Tom