Sanding and glue staining

[A_Novis]

First time builder, so I haven’t epoxied yet.

I’m conscious of Nick Shade’s warning about oversanding. I’ve completed the scraping/fairing (at least on the deck) and taken my first ROS pass with 60 grit. I have some joints that are smooth to the touch, but have what looks like a glue line/staining. The first picture is a close up of one example. I’m aware that things will look very different under a layer of glass and epoxy, so the second picture is it wetted down with alcohol. These are 3/4 inch wide C&B strips (white cedar with western red to the very right) for a size reference, and quite close up. I’m not looking for a flawless finish (that ship sailed, hit a reef, and sank LONG ago), but don’t want to give in to mediocrity prematurely)

As noted, I can’t feel the seam and the surface is pretty smooth at 60 grit

My question - do I need to keep aggressively sanding to remove that line, or will the combination of the finish sanding, glass, epoxy, and varnish make that discoloration just look like grain variation?

Thanks-

Here it’s dry:

And wetted with isopropyl alcohol:

[Howard_Spira]

Those are surface glue stains and they will not go away with the epoxy application…it may make them even more visible.

You guessed the answer above. The way to address this is you will need to take the strip down with sanding until you are through these stains…and back to the underlying wood.

Careful but aggressive sanding with 60 or 80 grit will get you there…you probably have a .5 millimeter to go.

By the looks of it, you have done a great job so far. What you have pointed out is the typical extra work to finalize the sanding job

But with 1/4 inch strips, you have have plenty of room.

H