My first time!!
I may not be typical here - I had and still do have a lot to learn about fiberglass ops! I found the 'process' enjoyable and challenging at the same time. Followed Van's instructions as exactly as I could with one deviation as described below.
I estimate about 5 hours of actual pattern measuring and cutting, epoxy application and trimming after curing. Sanding and filling about 3 hours more. But there is a 'the rest of the story'.
My first attempt at the 'skirt' area (the bottom of both sides in the front) (RV-12 which hang over a void) were were disappointing because they were wavy after curing. Correcting this problem cost me another 3 or so hours of work, etc. I don't know which RV you are building so you may not have to face this problem.
I cut out the wavy sections on both sides and replaced them with a new fiberglass layup under which - the second time- I placed a foundation of aluminum overlayed with 6mil plastic. Then I made sure that the second setup was straight and wrinkle free. My education in using fiberglass was taking some time and work! I got some tutoring on 'how to' from Dan H here on the VAF as to how to make the cuts and the splices. Thank you Dan H.
Then, because I did not want to use tape on top of my firewall aluminum as described by the Van's instructions, I used 6mil plastic under the layups. This worked very well - no problems of the layup sticking to the top of the fuselage. This also caused me problems because I did not have enough clearance between aluminum skin on the top of the fuselage and the bottom of the lay up because a few layers of tape is thicker than 6mil plastic. So, I had to add additional layers of fiberglass to the top of my layups - let it cure - and then remove a few layers of fiberglass from the bottom of my first layup.
Next time, I will use use 5 or 6 layers of 6 mil plastic and I will have the proper clearance between the aluminum top of my fuselage and the bottom of the fiberglass.
The lateral layups across the top of the fuselage went well. As per Van's directions, I had all of my fiberglass cut and numbered as to which ones went first and where, etc. I read and followed Van's instructions on how to wet up the fiberglass cloth and how to apply it, and how to get it to lay flat with no void spaces.
At first, I did not wet my fiberglass as thoroughly as I should have. Learned to wet thoroughly, apply, and then remove the excess epoxy from the layup. Learning here again. Be sure to try to remove all voids in the layup.
So, with all of the beginner mistakes that I made, I estimate that my actual working time to be about 20 hours to ready to paint properly fitting product. Next time, I think that I can do it in about one half that time - we'll see!
This will take some time to get it right so, don't expect to rush thru it. Good skills to you
Hope that this helps to give you some prospective of a beginners first time with fiberglass.