Gentlemen,
 I want to share my experience using SLC under Silk. First, and foremost, I absolutely love SLC! I covered a Gotcha with it and love the way it worked for me. Super light and unbelievably strong. This is not a thread to slam a product and I am not an expert finisher as some are here. I just want to inform everyone of a few mistakes I made along the way. First, I did not find the Silk to fill any faster using the SLC under it. That was my goal for using it in the first place. The frame work for my plane was a little heavier then I wanted, and I wanted to go with a traditional covering method and figured I would save some weight with multiple coats of clear.
  So here's what happend on my Killer shown below. The killer wing has only a 1/4" square leading edge with no sheeting. When I covered the wing with the SLC I had concerns of adhesion of the silk to the leading edge, being that the silk would only be attached to a piece of 1/4" stock covered with polyester. So now I'm thinking I'll just abrade a 1" perimeter along the leading edge, Fuselage since there is no sheeting there, and also the wing tips. Just to make sure the silk stayed put!
 Here's what I think happenend.  I applied the silk as you would normally, doping down the perimeter and getting it as tight as possible at application. No problems it look very normal the next day. Before applying Dope to the open bays I wanted to give a nice coat to the 1" perimeter to make sure nothing started moving on me. This is where it went bad! Apparently, there was a small gap between the two coverings and I had major pooling of dope under the silk. The SLC deflects/sags more then the silk does. Now I had a mess! The silk stuck to the SLC in a couple of places and had the pooling in most others. It looked like S*%t!!!
 Anyway with a little massaging, I got most of the stuck areas out but still had to deal with the ugly 1 inch perimeter around 3 sides of the wing. The trim scheme is the result! Again this was my mistake but I wanted you all to be aware of this issue I had. I think a lot has to do with wing construction, rib spacing , etc. I will say this, you will not puncture this wing! This technique will be very beneificial under silkspan but I don't know if there was a benefit to having it under silk. IF you look above the AMA number on the outboard wing . You can see a small are of pooling..