Redwood Oil Finish?

[Dan Lautner]

I am finishing some 1X6 clear heart Redwood siding. I am sanding with a RO sander up to 180 then a final pass by hand with 220. I remove all dust then apply two coats of Penofin Marine Oil. Some of the boards are coming out with a striping pattern as shown on the picture. Any ideas what is causing this or how to minimize this? Thanks for any help.

Dan