ORIGINAL: jwalsh1
Can you guess a ballpark figure percentage-wise on weight gain over the traditional film method? Obviously this will change depending on size, but is there a general rule of thumb, say 2% heavier? 15% heavier?
It's probably hard to pin down even that far, given how many variables there are in different finishes and between builders. Here are a link or two with interesting info on paint finishes:
http://www.egpworld.com/ultrahobby/t...INGARTICLE.htm
There is also a wonderful article in the Feb 2005 MA from Phil Granderson about his finish method on his Diva CL stunter. He covers the entire plane with carbon fiber mat, even the cap strips.. Then he covers the open areas with silkspan and finishes the whole thing with dope, top coated with clear auto paint.
If you fill and paint balsa without tissue, silkspan, .5 oz glass cloth, or CF, you will likely get the grain showing up soooner or later.
Any paint finish can get heavy if you put too much filler and paint on. The keys to a good paint finish include getting the wood absolutely ready to paint before you ever start, and then using sandpaper-lots of it. The materials matter less than the prep work and sanding.