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I just need to finish carving the top of #2 so I can assemble this guitar. I chose a nice piece of duglas fur and glued it together for the top. Perfect quarter sawn slats. I am having a hell of a time keeping it from cracking. Top side carved with minimal troubles. Once I carved the inside were the top is now .200-.250 in thickness, it splits easy with mininal presure. It seem to crack between the dark lines of the grain. I have been able to repair/glue the cracks to keep them from getting worse, but I am wondering how the heck others can use quartersawn wood for the carved tops. Even trying to cut the f-holes have been tricky. The saw wants to follow between the grain lines and not accross them. I even split the top near the f hole too. I am starting to have doubts about this top. BTW: This absolutely the opposite thing I found true years ago with a violin top made of Douglas fur. That top was so darn hard to carve, it never was completed. This one seemed very soft. I had troubles with tear-out and it carve pretty easy. Now I am having issues with splits.

Thoughts?

JD

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Joe

Sounds like a bad piece of wood. Where did you get it from? Can you post a photo of it?

Douglas fir does not act that way at all. You probably have a piece with ring checking...a growth defect in which growth rings separate in the living tree. Not common in Doug fir, but very common in other species like Pacific yew. This type defect us usually visible on end grain in the log, but can go hidden until it's processed. Just a thought.

JD,
An old US Forest Service pamphlet I once had described douglas fir as "splits easily, holds nails well." I always thought that was funny, but not in your case. I'm sure a spruce top would have more resistance to splitting.

Ken

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Ken Franklin
clumsy yet persistent
https://www.kenfranklinukulele.com

What the USFS means by "splits easily" is by ax or froe...not cracks in use. I think the current term is "clean" splitting to avoid confusion as to interpretation. Couple centuries of use as construction, flooring, panels says a lot. On the other hand, difficult splitting woods are like elm, etc. Doug fir has good history as DB tops alternate wood and often used as steel string soundboards....great tonewood.

Still,

D.Fir does have a propensity to split. I have used it a lot in furniture, I love how it ages a golden colour over time. But I do agree with Barry, some pieces of wood will work better than others in this regard. When carving an archtop you expose shorter fibres and the fibre in D.Fir is not as long or as tenacious as Spruce fiber so you just need to be sure that you keep your work well supported at times while carving and applying pressure to it. It probably works better in flat tops because it is flat...

Shane

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Canada