Varnish will stick okay to most painted surfaces as long as the pant has been lightly roughed up by light sanding first.  However, varnish normally changes the color of paint and not for the better.  White will become an ugly yellow.  You can guess what happens to green, blue and red.  Try it on a sample piece and see what you get before doing it to your boat.  Good luck.  Jer

It's pretty easy to mask off the parts of the hull you don't want to paint or varnish, using blue painter's masking tape which you can buy in any hardware store.  I masked off the portion of my hull and deck I wanted to paint, and then varnished.  After applying 6 coats of varnish, I removed the tape, and then masked off the portions of the deck I had varnished, applied primer to the parts to be painted, and applied two coats of paint.  I then removed the tape, and thought it all looked great!

The tape is sufficiently flexible that you can form broard curves.  For more intricate shapes, put some tape on a piece of glass and use a sharp hobby knife to cut the design you want, and then place the tape on the boat.

If you take care to be sure the tape's edge is firmly attached to the boat, you'll have little or no spill over.  Oh, besides masking the edge, I also used cheap masking tape to attache sheets of newspaper to protect beyond the masking line.

The attached photo (I hope it's attached; this is the first time I've tried this) shows a Chesapeake 14 I finished this way.

Hmmm, try again with that photo ....

Okay, it looks to me like this application for loading photos wants you to work with Internet Explorer, and I'm using Firefox on a Mac.  Either that, or I'm even more inept than I thought.  Anyway, no luck uploading the photo.  But you can see the photo showing the varnished deck and painted hull of my Chesapeake 14 at <http://www.flickr.com/photos/hawks_and_yaks/3859859694/>

I appreciate the feedback.  One question, won't the varnished areas look "glossier" than the painted areas then?  I was looking at the Chesse 17 LT on your site with the black hull and the stripe down the side which I like a lot. 

I used a high gloss marine topside paint (Pettit Easypoxy simple component polyurethane, to be specific, but there are other good brands out there), which gives a nice glossy finish which I think nicely complements the gloss finish varnish.

Another possibility is to use System 3 topcoats. It comes in a bunch of different colors, including clear. The clear is meant to be used over bright finished wood instead of varnish or over the colored topcoats to give a final glossy finish. So you could paint the designs onto the hull, then put clear topcoat over the entire boat. No varnish needed.

The stuff is a water reduced linear polyurethane, very tough on its own. It also comes with a tiny bottle of cross-linker which, when added at a rate of 8 drops per ounce, causes the paint to polymerize, making it ridiculously hard and tough (difficult to sand in only 6 hours). It would take much less than a quart of topcoat to cover most models of the boats CLC sells.

I'd love to see CLC carry this stuff, as well as the S3 Yacht Primer (a 2-part epoxy-based high-build primer which is the best primer I have ever used). Until they do, google is your friend.

Laszlo