I am attempting my first board bow.  I am using 4est's build along.  Last night as I was scraping the belly, "ridges" began forming at one limb tip for about four inches.  I am using a red oak board that I was certain had straight grain both on the side and top.  I'll try to post pictures later.

Jeremy, where mid mo.?

Centralia, just North of Columbia about 20 miles

are the ridges perpendicular to the stave? or are they parallel? (tip to tip) When I get scraper chatter or perpendicular ridges I file them down with a fine file. that lets me scrape again without the chatter.
enjoy the process. and remember. its just wood. It literally grows on trees.

without seeing pics....
It does sound like chatter as said above.
Just sand that spot smooth and you'll most likely be able to scrape it again.

Might want to practice sharpening your scraper and your technique for running it.

Not sure if this will work
 

If you only scrap with the scraper perpendicular to the surface it will cause these ridges. Use your scraper perpendicular but also angle it to the left and the right in alternate scrapes. By doing this the angled scrapes will remove the high spots of the ridges and help to keep the surface smooth.

My attempt at posting pictures failed.  I'll try later tonight. From your discriptions it appears to be scraper chatter. Pat, I will try that technique. Thanks!

The main problem with scrapers is them not being sharp.
It should produce no dust only shavings.
Also regardless of how sharp it is scrapers , if used to the exclusion of other tools, will start to leave your wood 'chattery'!
Alternate being rasp/files and your scraper.

Good info.
Jeremy, i'm 2 hours from you if you ever want to drive down.
I could assist in you making a bamboo backed bow.
Cost would just,be materials.
Have a bedroom in shop for overnight visit.
Ron

Ron,
I would be interested in that. My schedule is pretty full for a while with work and kids. Can I pm you sometime to discuss further?  Thanks

Yes you can. If I don't have friends or sombody else scheduled for you date.