Builders' Forum Archives
Re: Paint, Sand, Varnish
Posted by John Beck on May 14, 2007
Shawn, I've done it both ways; paint first and varnish last and vice-versa. Since I just completed by SW17 hybrid and, I now prefer the "hybrid" method; I do a few coats of varnish first, then paint followed with final varnish coats. The barrier coat of varnish makes for each cleanup of paint drips, and tape sticks better to it.
I think the number of coats of finish that can be applied with tape is theoretically limited to the depth of paint relatvie to the height of the tape. If the thickness of 2 coats of paint is less than or equal to thickness of the tape then the finish stops at the tape's edge and removing the tape creates a sharp line. On the other hand, the edge of the tape is no longer a transition when 10 coats of varnish builds up over the edge of the tape. At this point the tape is part of the boat, and removal is a nightmare as it either breaks in pieces, or worse yet, peels up the edge of the last few coats of varnish.
I know there as many valid practices as there are builders, but I have found that 3M fineline tape holds up to cautious sanding, particularly with 3M gray scotch bright for between coat finishes. I usually apply all the paint before removing the tape, because 2 or 3 coats is usually enough. I remove the tape immediately after the last coat to help soften the paint line. I'll build up varnish as long as there is a transition at the tape edge.
Cool blog, Shawn. Is the picture at 56 hours primer? If so, I see you've got lots and lots of sanding to essentially remove it all. I used Interlux Pre-Kote on my blue/white kayak to cover the "pecker tracks" (swirls from ROS) that I didn't want to treat with another skim coat of epoxy. The Pre-Kote has super fine ballons to fill such voids, and only those voids. All the rest needs to be sanded off with 220 to yield a translucent appearance. I'd recommend hand sanding towards the bitter end.
Good luck, John
In Response to: Paint, Sand, Varnish by Shawn on May 14, 2007