Not sure if anyone can tell me, but here it is: What would the average weight be for a 620 squre inch plane in silkspan and filler coat awaiting paint. I'm trying to decide if this plane I'm working on is average or light. Trying to acertain the average weight of the silkspan, dope and filler. Since starting, I've picked up about 2.13oz overall in silkspan, dope and filler. The plane is about ready for paint. Is that good, bad or average?

Thanks Phil.  I'm used to working on bigger planes and after putting on filler, sanding the heck out of it without, for once, sanding through then shooting on a wet coat of clear, I weighed it and as noted, picked up 2.13oz. Seemed pretty good, but wanted to check. After having the last plane pick up so much weight in the finish, I'm a bit paranoid.

From graphs I have seen, 62 oz would be the max, depending on the engines ability.  Anything over 10 oz per square foot is a high wing loading.  Tom Morris puts out a graph showing weight/wing area = wing loading chart.  Very helpful. 

   Is that what Tom's graph says?  10 oz/square foot is *exceptionally low* wing loading for a full-sized stunt plane. My new airplane is ~13.3 oz/square foot (4.58 square feet, 61 oz), and there is *no* possibility of getting it down to 10 (46 oz) without leaving out half the structure - literally. There have been real stunt planes that were build that lightly but they are very few and far between.


   Even back in the good old days before infinite power, 12 oz/square foot was considered pretty good. Now, with a good engine, I wouldn't even think about it unless it got into the range of 14.5-15 oz/square foot.

Approximate wing loadings of recent NATs winners:
1990-94 - 13.2 oz./square foot
95 - >15  (sworn to secrecy)
96 - 14.4
97 - 14.1
98 - 13.2
99 - 14.1
00 - 13.2
01 - 14.1
02 - ~14.5
03 - 12.72
04 - 12.72
05 - 13.2
06 - 13.3

Even Billy's WC winner was in the 11 range.

Trying to shoot for 10 oz square foot is unecessary, and certainly for most of us, will be quite detrimental since you have very little structure left once you put in all the required hardware.

    Brett

p.s.OK, I got it, I think you actually MEANT to say 10 square inches/ounce which is 14.4 oz/ square foot. bb