: I can see some discoloration I can only attribute to glue. I have
: some showing on my finished boat and as I plan on making
: another, I was wondering, ??How do I know that I have removed
: all glue from the surface of my boat by cleaning and sanding the
: wood surface prior to glassing??

: I wiped with a damp cloth during stripping, washed lightly with a
: little bleachy water and sanded the hell out of it. Dusted,
: wiped, and tack clothed the hull and still had a little glue I
: could not see until the epoxy brought out the colors.

It does sound to me like you have some glue spots that are preventing even absorption of the epoxy where the glue is. I don't want to start a precoat or don't precoat thread again, but this is one reason I like to precoat with epoxy before glassing. You can see all those little spots that didn't show up before, and you have an opportunity to fix them before you glass.

The problem is that when you wet the boat with water, alcohol, or other liquid it also wets the glue, so you don't see the glue. When you wet with epoxy, however, after the epoxy cures the glue hardens and you will see the glue. It's going to look lighter colored than the other areas because the glue prevents the absorption of epoxy in those areas.

I don't know of a workaround other than precoating with epoxy, and then sanding down any spots that show up until you sand out the glue.