Official Luthiers Forum!

I purchased this Carpathian spruce top from John at Old world tonewoods (cannot recommend him enough) and although it looked nice at first, after joining and planing, a good amount of runout surfaced. After enquiring if the grade of top should have runout, John immediately sent a replacement top. With this replacement top, I'll be able to build the commissioned guitar the top was intended for, but this leaves me with an otherwise stunning top save for the runout.

I'd love to do something with this top, but I'm not sure what: at first I thought maybe a sunburst, but I have no experience with bursts. Any suggestions?

Runout is a tricky thing. The only way to really tell for certain is to sand the two halves to about 150 grit and then wipe with mineral spirits -- even then, your eyes can sometimes be deceived.

It is extremely important to note that you can reverse the edge used for the center joint. On a good quality top, this is often a very valid option assuming the grain lines are fairly even. What we normally put on the outside comes from the center of the tree and it is usually less susceptible to runout compared to the new growth. I have done this exact thing a number of times and was able to salvage some absolutely killer tops that would otherwise have had bad runout.

As far as what to do with your top - you can do a completely black finish as some have done. I think even with a burst finish, you will still see the runout.

--
Simon

Or realize that you can make great sounding guitars that have top runout. You really can!

Thanks for the suggestions, Simon and Filippo




Oh I know you can, it's just that most guitar buyers view runout poorly (aesthetically) and tend to avoid guitars with runout.

Make an accurate Gibson Hummingbird copy and just tell people you used a top with extra runout for authenticity.

_________________
Old growth, shmold growth!

Build a mahogany back and sided guitar with simple appointments and find a buyer who listens to the way the guitar sounds rather than the way it looks.

Give me a break .... most guitar buyers dont have a clue what that is when they see it .... if its a great sounding and playing guitar, no one will care.

I have a poster in the shop of Dave Matthews playing his Taylor 900 series .. the top looks exactly like that. He doesnt care .. he bought becasue he thought it sounded good to him.

_________________
Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

thanks for the insight everyone,

Tony, I guess I've been spending too much time on the AGF: it seems like there is a general disdain for runoff in tops. I think I'll follow Clay's advise on building a simply appointed guitar. Perhaps I'll try my hand at bursting this top: because so many vintage sunburst gibsons have runoff, it seems most people don't seem to care that much about runoff if the top has a sunburst.

There are like 10-12 guys at the agf who talk about runout incessantly. Other than that, if its a quality top otherwise, use it.

_________________
http://www.CostaGuitars.com
PMoMC

Back in the mid 60's my Dad bought me a Gibson Blueridge (the one with the screws in the saddle). I didn't know anything about runout and i always wondered why the top was two perfectly different shades like the one in this thread. I found it very odd and annoying, especially when all my friends pointed that out to me.
I didn't like it then and i still don't like it now, even if it makes a great sounding guitar.
I've seen similar tops hanging on the wall at Guitar Center and i would never buy one nor would i ever make one. To me they look like mis-matched wood, like they ran out of the good stuff. Just my opinion.


Sent from my iPhone using Tapatalk 2

I hate to ask a stupid question but can you tell me what you are seeing as runout? I have been repairing guitars for some time now but completely new to building. I know what runout is and always split my brace material to avoid it but this is the first I have heard about it being a problem with a top.

I can understand why you would not want it on a top for structural reasons so I would like to know what exactly to look for.

Thanks

Bob

One of the halves is lighter than the other until seen from the opposite direction where the lighter one is then darker.

Thanks for that explanation. I have run into that in refinishing a couple of guitars in the past. My solution for it is to seal the wood and then tint the clear with a bit of color the same as the wood. It does hide the grain a bit but it will usually blend the seam so it isn't as prominent.

So am I wrong in thinking it could be a structural issue? And does it have any effect on the tone of the wood?

It can be a structural issue, but it's not severe enough in this top to be considered an issue structurally. In this case it's entirely aesthetic and effects nothing except for the visual aspects of the guitar.

As far as suggestions on what to do with it, A sunburst would not actually hide it since the burst is at the edges of the guitar unless you did a clown burst (as it is called) which is black fading into red which fades into yellow. The grain is pretty much hidden by color. You could take my suggestion and tone the finish after sealing it. A lot of the big manufactures do that to make their guitars all look very similar. You can do a respectable job of not making it quite so visible that way.

Or you could get crazy and have a laser etching done on it. I have seen some really nice designs done on wood.

Here is one I just found on Ebay

Yeah, I have read plenty of those folks who obsess about Runout on their tops....

and yet those SAME exact people will Ooohhh and AAAaaahhhh ALL DAY LONG over a 1930's or 1940's Gibson or Martin.... with COMPLETELY UNMATCHED TOP HALVES.... Or... Runout so strong that one side looks like Mahogany and the other looks like notebook paper....

If your "Holy grail" of guitars has either a completely unmatched top, or crazy Runout... and it's still your Holy Grail... but then a New Guitar can't possibly be allowed to have the SAME EXACT feature because it's defective... then I must not understand "Perfection" particularly well....

*Sigh*

Runout is not a structural problem (in terms of top failure) unless it is very bad indeed, but it does reduce the longitudinal (along the grain) stiffness of the top. One of the reasons that spruces, cedar, etc. are used for tops and bracewood is their very high stiffness to weight ratios, and a top with runout has that ratio reduced.

Having a little heavier or less stiff top can work to your advantage sometimes depending on the tone you're looking for, so runout is not necessarily a bad thing, but IMO it is very important for the builder to recognize and understand it.

Unmatched tops and backs are not uncommon in Gibsons, but I have never seen it in a Martin.
Note that 'unmatched' and 'bookmatched with runout' are not the same thing. Any top that has runout at the joining edge will show it when bookmatched, because one of the halves is flipped over, reversing the direction of the runout. In other words, if a top has 2 degrees of runout on the joining edge, the difference in grain direction when bookmatched is four degrees.
With proper technique, you don't need to sand or finish the wood to detect runout. It can be seen in the rough wood if the light source is distinct.....a long fluorescent tube oriented across the grain is one of the best. Hold the two halves in the same plane and with the edges to be joined together. You will see a crosswise band reflected from the light. If the band on each half is aligned at the joint, the finished top will have little or no visible runout.
If the band is not straight across, that means that the tree grew with some spiral, and there will only be one point on the width of each top half that will have no runout. This is the point illustrated with a blue line on the first two photos. In the first photo, the top would show less visible runout if the other edges were joined. This is typical with spiral growth trees that are conventionally sawn as long logs. There will be little or no runout in the heart, and progressively more runout toward the bark edge.
This also appears to be the case with the subject Carpathian top, evidenced by the lighter band of sapwood in the center. Sapwood is just under the bark of the tree. It is too late now, but I suspect that top would have shown less visible runout if the other edge were joined.
In the second photo, the zero runout line is near the center of each half. This produces the minimum amount of runout from a spiral log, with opposite runout on each edge. This can only be accomplished by cutting the wood into short blocks, splitting it, and sawing parallel to the split surface midway between the bark edge and the heart. In the third photo, the reflected band is basically straight across, meaning that the tree grew with little or no spiral. In this case, there is no advantage to splitting the wood first, unless the sawyer is not competent.



What is not shown in these photos is that it is possible to cut a spiral log and still have no visible runout at the joint, even if the preferred bark edge is joined. In that case, the diagonal reflection will be continuous on the two halves, with no offset in the center. This is done by splitting the billets, and sawing parallel to the split at the bark edge. Unless the tree has excessive spiral, this is the method I have used to saw red spruce tops for the last 23 years.
I used to be of the opinion that there was nothing short of an opaque finish that would hide runout, since it is a function of reflection. I do think that this reflection is a major part of the beauty of naturally-finished woods, especially chatoyant woods like spruce, mahogany, and maple.
But I did have a surprise when regluing the bridge of a Blueridge BR-180 guitar, which revealed runout on the bare wood underneath. The top did not appear to have runout, and it also appeared dull and lifeless. Whatever had been applied in the finish had reduced that reflection, but still showed the grain of the wood. I have yet to find out what the material or process is, but it obviously was done to hide the runout.
Although the typical amount of runout in a guitar top is not a structural issue in normal conditions, it does become a concern when the bridge lifts. Since a fixed bridge lifts from the back side, that means that it will 'dig in' to the spruce grain on one side of a top with runout. This can damage the top, requiring more repairs before the bridge can be reglued. On numerous occasions, I have seen this split travel all the way through the top of the guitar, exiting above the bridgeplate.
Since most of the stress on a guitar top is concentrated at the bridge, it make sense that anything you do to minimize runout in that area will be advisable. The fact that it improves the cosmetics is just a bonus, IMHO.

_________________
John

Great post, John. Thanks for taking the time to put that together.

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

http://www.goreguitars.com.au

Here's a Terz I built a few years ago. The first Terz I've made, own design. It was experimental, otherwise that Top wasn't going on one of my Guitars:



I still have the Guitar and I use it for finish experiments. I play it fairly regular. It's already showing signs of large distortion to the soundboard, especially the hump that you get behind the bridge. In fact that hump is much higher on one half of the soundboard than on the other, something you do not normally see on Tops without runout.
As already been stated, joining the wide grain as the centre sometimes lessens the runout. I've used that method on a couple of occasions.

John, I'll echo Trevor's post. As a newbie, I'm especially appreciative of the trouble you went to, to provide such a clear, detailed and well illustrated explanation.
Thanks, Marty.

is this level of runout acceptable for grade A spruce sitka

recently bought it, my first build

is starts about half way up, the bottom half is more straight

http://s21.postimg.org/vwrrqdw4n/DSCN3057.jpg

it's about 7 degrees so i am guessing it's ok

+1 I learned a lot reading that. Very informative.

You taught me a few things with your last post John, thanks.

_________________
Formerly known as Adaboy.......