Closing the Box - Luthier Tips du Jour Mailbag
In this episode, Robbie O’Brien gives a tip about how to keep the back and top aligned with the centerline of the guitar as you close the box.
Video Transcription
[on-screen text reads: Luthier Tips du Jour Mailbag]
Mailbag question: Is there a way to prevent the back from sliding off the center line when closing the box?
Robert O'Brien: Today's Tips du Jour Mailbag question comes to us from South Carolina. "Robert, recently I was closing the box on my guitar following your method outlined in your online course videos. Somehow the back slid off the center line. It isn't much, but it is noticeable. Is there a way to prevent this in the future? Thanks for your videos. Glenn in South Carolina."
Glenn, there's actually a very easy way to prevent this. It's so simple that you're going to think, "Why didn't I think of that?" The back or the top sliding off the center line during glue-up can look really bad, especially if there's a nice decorative center strip or purfling lines on the in wedge of the guitar. So let me show you a very simple way to keep this from happening.
How to keep the back from sliding off the center line
So here's a guitar I'm working on. It's got a very nice little inlay here in wedge that's got a purfling line on it that matches the inlay on the back. And I would really like to keep those aligned as I glue it up, because that would look really bad if it was just a skosh off-center to the left or to the right. So here's a very simple trick. Just take a small little block of scrap wood, this is actually a piece of an old back brace, and glue it right to the side, and then put a nail in it to hold it. And let me show you how I do that.
So Glenn, I'm just going to glue my block of wood to the side here with some CA glue. And I like to use this UFO version, it's called User-Friendly Odorless, and I get it from LMI or Satellite City. And the really cool thing about it is that it has no odor. It doesn't irritate the nose or the eyes as you work with it. So just a small little dab on there, put it off to one side, make sure that it's up against the back so there's no gap between the back and the block. If you want to hit it with a little shot of accelerator, you can, or you can just become a human clamp for a couple of minutes.
The next thing I'm going to do is place my back on the guitar in the correct position that I want it and make sure that all of the lines are lined up. I then come in with my drill and drill a hole through the back and into the little block that I've glued to the side. I then place a nail, and it's not going anywhere at that point because it's been pinned. Here in the video I used a 1/16th inch drill bit with an 18 gauge finishing nail. LMI also sells a nice little pack of locating pins that comes with a very small drill bit. Next time you order something from LMI, throw that in, take advantage of your shipping costs, and that also works very well.
So it's a back in the correct position and pinned, so it's not going to skate off. I'm now ready to close the box. Once you're done with your glue up, just pull the pin out, come in and just chisel the piece off. Sometimes it pops off in one piece, other times you just have to kind of chisel it down right to the side, but it comes off very easily. Now you're ready to flush, trim, and you've got a back or a top that is perfectly aligned with the center line of your guitar.
So Glenn, I told you it was very simple, and if you use this method in the future, you should have no problem keeping that top or the back from skating off the center line when you're closing the box.
[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.]
