VARNISH MEETS PAINT at the LWL

[Bob at Compass Boat]

Let me preface this by saying that about 95% of my woodworking projects are oil finished. I did some searching on the forum, but didn't find an answer to this particular question.

My question is when putting varnish on the outside of a hull (stripbuilt-epoxy -glass cloth Cosine Wherry) and also painting the bottom to the LWL, HOW DO YOU MATE THE TWO FINISHES???. For general info, boat will be trailered and in fresh water only. It is MAS epoxy w/Slow hadener, on the hull about 12-15 days,( sort of a filler coat), varnish is PETITT Flagship 2015, bottom will be painted with VALSPAR 3487 White fiberglass primer and KIRBY'S
hull and deck Malachy Green. Kirbys provided and recommended the primer.

I see two possible scenarios, which would be best or is there a much better answer.

SCENARIO ONE.. Varnish hull from sheer to a couple of inches below the LWL and feather out the varnish edge. Tape LWL and apply primer and paint to bottom.

SCENARIO TWO.. Tape LWL and varnish to the tape, applying 6-8 coats and allow to dry thoroughly. After varnish is dried, apply tape on varnish edge, prime and paint bottom mating paint to varnish at the taped LWL varnish edge. No overlap, just butt paint against varnish.

Sorry to make a major story of this, but wanted to cover all the bases to the best of my ability. Your thoughts and suggestions on the best approach please, OR IS THERE A BETTER IDEA STILL?

Thanks in advance

Bob at Compass Boat

[Steve Miller]

I vote for number one. I have not had good results doing the transition as outlined in #2.

[Scott P]

I would also recomend #2 , I painted the bottom of my cedar strip canoe after it had been varnished for several years so i just sanded out the scratches, primed and painted and it came out well. Also on varnishing fiberglass I only put 3 coats of varnish and it seems to hold up quite well.

[Crusoe]

SCENARIO ONE..........every time :D

[Bob Cleek]

Obviously, option one. Let the pigmented stuff cover the varnish. If you butted them on the tape line, you'd pay hell to get the tape just right. HOWEVER, consider which side will be up when finishing. It's easier to paint her upside down, but be careful not to drip or run over the tape line and mess up the varnish. Also, if you aren't planning to do so already, use 3M fine line tape. Unfortunately, I don't think it has a lacquer proof adhesive, so be careful when hitting it with your epoxy based paint. Sometimes, epoxy solvents will lift the tape in a hot minute. Test it first. If so, you will have to use the lime green 3M lacquer proof masking tape, which works pretty well, but is much harder to get a perfect line. In that case, I leave the tape on until the paint dries completely dry to the touch, but just that far, and then remove the tape and CAREFULLY clean the paint that ran under the tape. That paint that was covered by the tape will not be as dry as the stuff that was exposed to the air and will come off with a bit of solvent if you time it right and work quickly.

[Don Kurylko]

Hey guys, that’s what the boot stripe was invented for – to cover the transition zone between the bottom coat and the topsides paint or varnish.

Butt the bottom and topsides at the waterline, or wherever, then apply a beautiful contrasting boot stripe slightly overlapping the butt line along the bottom edge.

Hmmm, butt line….. I think I’ve just coined a new boat building term. :D

Cheers,
Don