I would like to enlist the aid, if I could, from the experienced wood workers on this board. The short version is that I had never done any woodwork before I started building kayaks and any skills I have now were learned during boat building. Needless to say there are lots of things I don’t know.

I just finished glassing the hull of my current strip project and I find several dark stripes left over from my use of the fairing board. I knew there was a potential issue because you could see the scrapes from the course sandpaper after the fairing. I followed up with an orbital sander to remove these scratches. I was certain I had gotten down past the scrapes but low and behold there are still some blems that are quite visible under the glass. Up till that moment I thought I was building a showpiece. Now I’m disappointed in the final result of the deck because of these sanding marks.

My question here is how do you know when you have completely eliminated a sanding mark. I looked close after using the orbital and couldn’t see any marks but apparently they were hiding. Is there a secret method that makes these blemishes show up before they get immortalized under glass?

I would appreciate any help on this for use on any future projects.

Thanks,
Kyle T