Try the sanding both. They may behave differently. I have not tried that yet, so I cannot comment.
Nick's sander method worked pretty well for me. I scarfed a few ribs for my Putz's Walrus and found that I could control the tapper by the amount of pressure I applied on the strip.

: I was in Menards yesterday picking up last minute things before stripping my
: kayak. I noticed Elmer's Exterior Carpenter's Wood Glue (light tan) that I
: hadn't seen the week before. I bought a bottle of it, (clamp time 1 hour)
: and a bottle of Elmer's Interior Wood Glue (yellow, clamp time 30
: minutes). Is the Exterior OK to use. I can't remember reading any comments
: about it. I was thinking of using it on my scarf joints where there would
: be a stress bend where I will be using water steam and a heat gun to help
: in the bend. The exterior glue would be less likely to fail in the water
: wet scarf. I could use polyurethane glue which I have only found in one
: store in another town. I have make two 6 to 1 scarf jigs, one for the
: table saw and one for the router and I'm not real happy with either one.
: Both are slightly tappered at the feathered end. Do you get this or do I
: need to try and correct it some? Thanks.

: John