Quality Issues with Rift Sawn White Oak
Sawing methods affect the presence of visible rays or fleck but how much fleck is acceptable? March 4, 2006
Question
Does anyone have an opinion on the quality of rift sawn oak available today? We are getting Rift Sawn White Oak that has a tremendous amount of fleck in it. Can anyone comment if this is a trend? Or is there a lack of Rift Sawn White Oak?
Forum Responses
(Architectural Woodworking Forum)
From contributor A:
Are you getting more then 25% fleck? Wood Institute (formerly WIC) guidelines state "Rift Grain Oak shall permit twenty-five percent (25%) of the exposed surface area of each board to contain medullary ray fleck."
From contributor B:
Perhaps I've interpreted your question incorrectly but what I consider ray fleck is actually a good thing since it indicates the piece has been quarter sawn.
From contributor A:
Quarter sawn oak can have fleck, and the more fleck the higher the price. Rift should not have much fleck as the cut is designed to limit it, and its less noticeable than in quarter sawn.
From the original questioner:
The situation that prompted this question is that we contracted out Rift Sawn White Oak doors. They came in with varying amounts of fleck and our client has not accepted the doors because of it. We have thought a certain amount was inevitable and acceptable but have lacked a reference or standard to back our product and thoughts. We need to have a high standard to compete in the market we are in. AWI seems to have a standard and I have ordered their book - is that the Wood Institute? In addition, I called Rex Lumber they have a yard in CT. They said some amount of fleck is present in their stock.
From contributor A:
Doors come under a different specification than lumber or veneer. Were they specified AWI? The AWI Specification for rift doors in the manual is not as a percentage but more size and slope. If you bought a door that meets AWI spec then it would be on the door manufacturer. It may be that they wanted or expected the characteristics of comb grain rather than rift grain.
From contributor C:
In my experience, rift grain means different things for veneer and solid. Rift veneer is usually just plain sliced with the cathedrals trimmed out, so you get the familiar straight grain pattern with minimal rays. Solid rift is actually quarter sawn, so rays are unavoidable. On a door, perhaps veneering the flat surfaces would minimize the objectionable rays, even if you are veneering over the oak to do it. This could be the simplest solution, all things considered.
From contributor A:
Rift and quarter sawn are two different cuts. The veneer cut you refer to is sometimes referred to as a European clip, and provides a similar look at a lower cost, depending on what the end user wants.
From contributor C:
I realize that what you describe as European clip and a true rift cut veneer are different, but our veneer people in the midwest told us that is the way they processed their version of rift in the product we were getting. I suspect this is a common practice in many areas because true rift slicing might require more specialized equipment and cost.
From Gene Wengert, technical advisor Sawing and Drying Forum:
Being somewhat technical, oftentimes quarter sawn grain has the annual rings at an angle of 75 to 90 degrees to the face, while rift is 45 to 75 degrees. So, quarter has more ray fleck than rift. When making veneer, it is easiest to start slicing at a perfect quarter sawn, but unless the cant piece is turned, the grain will have a transition to rift. Turning takes time.
The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).
Comment from contributor D:
Quartersawn white oak has the most spectacular fleck, flake or figure from the Medullary Rays than most other species and that is why it is the most popular. It is noted for its straight grain (called radial in other parts of the world) appearance. Rift sawn lumber occurs during the latter process of the quartersawn production. Rift sawn can be produced several other different ways, however, including a simple rip of very wide plain sawn lumber separating the outer two edges from the cathedral grain appearance of the center of the board. In this technique the parallel grain will not be identical in width separation as in the quartersawn process.
At our sawmill our rift comes during the quartersawn process when roughly 2/3 of the quartered log has been sawn. At this point the growth rings are no longer perpendicular to the board but are at about a 30 degree angle. Since the Medullary Rays are also perpendicular to the growth rings, these too are at an angle to the boards face and therefore do not appear as figure. True rift should not have any figure and can be purchased this way. There is a point during our production process that we obtain less and less figure and a point where there may be figure on one half of the face and none on the other as we approach that point of zero figure.
Wide, true rift is more expensive than quartersawn lumber. If you are looking for true rift only (no figure), say 12 wide, you had to start with a tree that was about five feet in diameter to start with. These trees exist, but no longer in abundance, hence the law of supply and demand takes over.
