Sooo, the smudge of wood flour epoxy will show up as wood flour on your wood grain, if you finish the boat bright. If you paint - no bid deal. Also is it in the center of the bottom? In which case you wiil be the only one who knows. Of course if you paint - even you will forget.

The technical problem is that with the glass fibers already coated in epoxy and wood flour - the glass cloth might not sit flat on the wood. This could mean air bubbles/pockets under the cloth and those make the glass weak. If so, you will need to cut, or sand out the glass in that area and do the patch you are envisioning. 

You can try it and see if it meets your standards. Or you can patch it from the begining. Your choice.

Have fun and keep building,

Joel

I would cut it out before applying the glass and plan on patching it. It's not going to wet out, it's forming a hard spot on the soft fabric so it'll be a stress concentrator and it'll look bad. It won't get any better on its own and it's always easier to fix a problem as early as possible, so I'd say cut it out now before it's a part of your boat.

Good luck,

Laszlo

 I trimmed the cloth last night, and the blotch is right on the edge of the joint.  I think I will cut it out, and put a small patch over the area before wetting it out.  I am going to paint the outer hull anyway, so maybe it won't matter.  Thanks Joel and Laszlo for the input!  

If you do it carefully and sand and fill, it'll be invisible even finished bright

Laszlo