bearmech:

I think if he really uses an 049 on a Guillow's kit conversion he's going to have so much excess power he wont notice the weight of a few extra coats of dope.

But you are most definitely correct. A little extra sanding will remove weight, but there's a fine line between removing weight and airframe strength when using an 049 on a plane an 020 would fly nicely.

Bill.