Runout

[David Nelson]

Having read Frank's explanation of 'grain runout' as well as some others I think I finally understand, in theory, what to look for. As it seems very difficult to spot runout with the naked eye in most tops that are dimensioned ready for use, is it therefore, generally, only realistic to be able to see runout when the spruce is hand split? Basically, I guess I'm asking is this the only time when runout can be spotted during all the processes that are involved in the production of a soundboard? Clear as mud?

[David Nelson]

I'm replying to my own question with another question. A standard procedure for a politician. Answering a question with a question, that is. Anyway, I've since remembered Frank's photos (in the "Runout" article), where he shows that the darker shade on one side of the soundboard-join viewed from the neck-end of the guitar becomes light in color from the butt-end and vice-versa. Look for yourself. He explains it more clearly. Does this mean that this apparent difference in the coloring of the two parts of a spruce top always means that there is runout in that top??? Also, I suppose its possible, in theory, for one half of a top to have runout and the other not?

David.

[Ronnie Nichols]

Your question about identifying runout by the light reflection in the finish is a good one that I can't answer. I can tell you that runout in tops and in braces is (imho) a problem that affects the tone of a guitar. I have replaced tops in some older Martins that had some serious runout in the grain. I believe the grain on braces and tops should be as runout- free as humanly possible. I built some guitars a couple of years ago with some brace wood that a supplier "threw in". It looked all right with the proper-looking grain for a brace. When I later did some minor scalloping on these braces, I found that there was excessive runout so that it was reallly hard to plane in one direction or the other. My last braces were made from a split billet I purchased and I could plane them in both directions without a lot of splitting and tearout. I think you are wise to think about runout on a guitar top. I remember seeing Roy Underhill talking about wooden wagon wheels years ago. They use split hickory for the spokes because the wood is stronger along the grain. Bow makers also are very particular to follow the grain. I believe this principal would carry over to transferring sound in an acoustic instrument, also.
Ronnie Nichols

[David Nelson]

Thanks for your interest Ronnie. I'm just about to build my first guitar. In a month or two anyway. I had always just thought I would buy the ready made pieces approx 1"x2"x20" for bracing, you know the stuff. Some are split, some are sawn but from larger pieces that were split. There seems to be little control over what a buyer will end up with. Over the period of a few weeks I began to consider buying sizes such as 1"x6-8"x36-48" and then using a sharp edge and a mallet and a bit of gentle persuasion, to try to learn how to do the whole thing myself. Maybe I'll mess up somewhere but that's how we learn. Cumpiano & Natelson's book was probably a major influence on me over this issue of making bracing from scratch. I confess though that I think I will buy ready-made kerfing.

As for runout on older/vintage Martins.........are you sure??? Sounds like blasphemy to me!!! Vintage guitars seem to some to hold an aura of complete perfection and no modern instrument, no matter how good, could possibly equal those from the by-gone eras. But seriously, any factory, no matter what product they are building, will use up all the basic parts or components they have purchased unless it is broken/unusable. The Martin builders aren't going to reject tops because of a bit (or even a lot) of runout! Would they even have looked? Would they even have known what to look for?? Some maybe would, others wouldn't.

Yeah, I can certainly believe that the wagon-wheels' construction and the choice of which woods and which cuts to use, would have been critical. During those times when horses & coaches/carts were the predominant method of transport, the spokes must have taken a great amount of energy directly along their length from the roads of the time, which were likely little more than dirt tracks at best.

David.