Padauk phenomena

[Robert Edington]

I have cut, glued up, turned and finished a 10.5" diameter segmented bowl. It has 48 segments per ring. Each ring is composed of Padauk, Purpleheart, and Cherry. The different woods produce a geometric pattern on the bowl. I have finished it with thinned Fast Dry Poly. About six or seven coats. Light sanding between coats. The segments were cut on a wedgie sled, using Jerry Bennett's technique (making a straight line on one face and a squiggly line on another face). That means, every other segment's outer edge is from the opposite side of the board once a ring is made up.
On some of the Padauk segments, something is wrong. I've never seen this before. The segment appears like it has not taken a finish. On some, the adjacent Padauck segment appears that it has taken a finish and the other hasn't. I can feel the change. The problem is isolated to only one segment (it does not cross the joint line). No other wood has this problem. The affected segment feels and looks dry (no sheen) and not slick like the others. This occurs on all rings at several, various/random places on the ring.
Does anybody know what is happening?
Did i describe the problem properly?
Can it be fixed?

Thanks.
RP

[Steve Schlumpf]

Robert - a photo would help in analyzing the problem. Without seeing the segments in question - my first guess is that the wood is end-grain and as such is soaking in the finish more than the other pieces.

[daryl moses]

I'll agree with Steve, it certainly sounds like end grain.

[Robert Edington]

It's not edge grain. You don't have exposed end grain on segmented bowls, unless you want it that way.

Thanks
RP

[robert baccus]

Padauk is a very oily and waxey wood. Originally highly valued for its red dyes and fortunes were made exporting the stuff to Europe. Later valued as furniture, dock and warf timbers and railroad ties. Exremely rot resistant ect. All these oils, waxes and chemicals made it tough to finish at times. Forget oils like many tropicals. I have had good luck with lacquer and carnuba.

[Tom Giacomo]

When you flip a board in doing segmented turning there will be a grain change the wider the board often the greater the grain change will be. All of the segments from one side of the board should be kept together or in the same ring. It may not be end grain to you but the grain may be coming out one side of the board quite different from the other side. This happens quite a bit in woods with a lot figure.