Binding Jig Advice - Luthier Tips du Jour Mailbag
In this episode, Robbie O’Brien answers a question about lowering the pucker factor when cutting binding channels.
Video Transcription
[on-screen text reads: Luthier Tips du Jour Mailbag]
Mailbag question: How can I lower the pucker factor when cutting binding channels?
Robert O'Brien: Today's Tips du Jour Mailbag question comes to us all the way from Australia.
"Dear Robert, I'm following your online course and I'm about to cut my binding channels. Can you offer any advice to help me lower the pucker factor? Thanks for all your videos, Andrew in Australia."
Andrew, I've used just about every device and tool out there to cut binding channels, including doing it by hand. My favorite method these days is using the LMI Binding Cutting Jig. There are several features that this jig offers that really helps me lower the pucker factor. Let me show you a couple of them.
LMI Binding Cutting Jig
So here's the LMI Binding Cutting Jig. The first thing I like about it is that I can clamp it to my bench with a couple of bolts that are included with it. I just put a couple of inserts into the bench and then bolt it on so it's rock solid when it comes time to use it. Another feature I like is this counterweight here. Now that helps support the router so the full weight of the router is not resting on your top, or your back. Now if you're using redwood or cedar or softer soundboard material, that can be a definite plus, because you're not leaving a mark in it from the router or the weight of the router.
Here's another really neat feature to this jig. In the past, most of your routers and your jigs out there, if you want to lower the depth of the bearing, you have to fiddle fart with the router mechanism to raise and lower the router. Now, that is a technical term. However, with the new LMI Jig, it's got a little donut on there that screws on and you can raise and lower that and that will expose the bit more or less, and there's your depth or height adjustment. That's really cool. I think Ed at LMI stayed up overnight to think that one up.
Bosch Colt Router
Now, here's something that will really help the pucker factor be lowered a little bit. I like to use the Bosch Colt Router with the LMI Jig. You can dial down the RPMs with the little dial here on top of the router. I run it at about five, which is about half of its maximum RPM. In other words, you can relax a little bit. It's not as much noise and not as much vibration as you're using the tool. So that's also another plus.
Take two or three passes to complete the cut
Here's another little tip that will help you save the router bit. It also helps the pucker factor go down. When it comes time to cut the channel, you control the depth in or out, how deep you go in or out on your soundboard or on your back, by the size of the bearing in there. You also control up and down with the little donut under here that I've already talked about.
Now, take two or three passes to complete the cut. In other words, put a bearing on that makes a shallow cut in and then adjust the donut so you're making a shallow cut down. That just gets you started. Then change your bearing and change the depth with the donut here to finish up the cut. And I think you'll find that the pucker factor will go down quite a bit just by doing that, and it saves the bit. The enemy of the bit is heat or friction, and so if you can do something to reduce that, then you're golden.
LMI Binding Cutting Base
With the LMI Binding Cutting System, the router stays stationary and the guitar rotates around the stationary router. So it's important that you have a base that will maintain the guitar firmly attached to it as you're doing your work. And the LMI Binding Cutting Base is the best on the market, and that certainly helps lower your pucker factor.
[Robert runs the guitar sitting on the binding cutting base through the router]
Make shallower cuts
One other thing, Andrew, as you saw me cutting that first cut there, is you notice I came in at the widest point and traveled this way and this way. Same thing up here, widest point, traveled this way and this way. The reason for that is when your router is coming around here, it's actually cutting into the grain and it could chip or chatter or do something there. So I like to travel downhill. Now that presents a problem in some of the areas of the top. Now you're doing what's known as a climb cut. In other words, you're going in favor of the bit. You're going in the same direction of the bit, and it's going to want to pull into it slightly. So if you make shallower cuts, that helps remedy that.
Store your bearings in a closed container
Here's another little tip. Store your bearings inside a little plastic container like this with little compartments in it. This is like a fishing tackle box and you can put your fishing lures in there. I like to store the different size bearings in there and then actually mark them. For example, this is the steel string back. This is the classical back, so I know which one I need when it comes time to use it.
One of the problems I've had over the years is keeping the dirt and the debris from the tool out of the box. Now I'm going to show you a little tip that I learned. It took me many years to figure this one out. I'm even going to do it in slow motion. Watch this. Just that little tip right there will keep the dirt and debris out of the bearings.
So Andrew in Australia, thank you very much for your question. I hope the tips and the information I've offered you here in this video will help you lower the pucker factor when it comes time to cut your binding channels. So cheers, mate.
[on-screen text reads: More Luthier Tips and online courses available at www.obrienguitars.com. Private and small group guitar building and finishing instruction available.]
