I have used the 5 Min epoxy method, works great. Another one is simple and faster but more expensive. Bob Hunt did this years ago. .5 Glass cloth applied with Foam friendly CA, sand off , apply more if needed sand off , filled and ready for Nitrate dope , then primer and paint . Dries in seconds and very easy to sand . It is as light as resin and possibly easier to sand. I use it on all solid surfaces. I did an entire plane with it before. The downside is the cost.
The upside it is done NOW! And to me easier to sand than epoxy. I then use spray can auto primer , sand off it is now ready to paint!!!!! Use just like the epoxy sand until it is flat no shiney spots , fill the weave then sand. And I
can vouch for the weight not being excessive .