In reply to gethin_allen:
Best way Ive found with Silnet to get a good thin seam coating is to use a small stiff artists brush (or cut off at least half the the bristles on the small brush supplied to get it down to a better and stubbier shape) Something like this Maybe a bit shorter so that the bristles are fairly rigid
https://usercontent2.hubstatic.com/6585909_f260.jpg
Dab a small amount of Silnet onto the seam and then use the brush to carefully paint it down the seam. You can get a fairly thin coating this way. Its an idea to try this on some paper or similar first until youre confident enough to go for it. 1 tube of Silnett should easily do a flysheets seams
Post edited at 16:30