What's the lightest way to finish a HLG?

From : Joe Hahn

One of the most weight saving products for finishing to come along is water based polyurethane varnish.

I apply it by dampening a folded paper towel with the varnish(gloves are nice during this part!) and lightly wiping it over the wood surface. A note of caution here; in any areas that are thin, such as Monarch wing/tail trailing edges, or Chrysalis tail surfaces, moisten the wood on either side of the surface at the same time. This will help to minimize or eliminate any warping tendencies as the varnish dries.

The varnish will dry fairly quickly, the first coat taking the longest(about 45 minutes in my experience does the trick). Lightly sand the surface(s) and repeat. During the 2nd and 3rd applications you will notice that the paper towel begins to slide over the wood surface easier, and less sanding is required to smooth the surface. I usually stop at 3 coats on my handlaunch ships. More coats gives a prettier surface, but adds weight(although not much!).

A neat trick if you want to add color without a weight penalty is to get some "water washable" acrylic model paint, found where plastic models are sold, add a bit to the varnish to act as a tint, and you end up with a very nice translucent to opaque colored surface. Yellow tint will be translucent, red will be nearly opaque. Other colors? Haven't tried any others, but I'll bet some pretty schemes are possible.

Another method of applying the varnish is by spraying. This will give the lightest finish, but the waterproof characteristics are not as good. My contest ships I do this way, or else I put nothing on them at all!!

Several companies make the Varnish I'm referring to(Carver-Tripp, Diamond Finish Varathane,etc.), but the key is "water soluble/water based" types. A nice side benefit is that the stuff has very little odor!!! My wife appreciates that immensely!

If you have any questions about the process, just let us know!

Joe
DJ Aerotech