I am getting ready to glass the exterior on the Chesapeake LT17. I have been preparing the surface with Random Orbital and my trusty cabinet scraper, but I am not sure how far to go.

For example, along the seams, I filled the wire holes and plywood edges with epoxy thickened with wood flour. I was not particularly neat during this process. There remain areas where I have scraped fair and level, but the epoxy from the thickened mixture soared into the plywood, leaving the area darker than the surrounding wood.

My concern is that the epoxy in that area has picked up some permanent color change due to the wood flour.

Here is the cause of my concern: This is my first boat, and I was not very neat while filleting inside. After I taped and glassed the inside, I noticed the effect of the wood flour on the color of the seams. As the seams fair out, the thickener leaves areas darker. Obviously, I want to avoid these effects on the outside of the hull.

My gut feeling is that if epoxy plus wood flour cures on a surface, the epoxy soaks IN and the thickener stays ABOVE the surface. So, if I scrape off the wood flour, the remaining darkening is just due to epoxy resin, and will disappear as soon as more epoxy is applied during glassing.

But if my gut feeling is wrong, I will end up with a blotchy hull. So what will it be, gang? Scrape and sand till April? Or "don't worry, just glass it?"

Thanks in advance,

Dave