New to the forum but have been reading lots for my first build. I’m using Cajunes plans for a kingfisher recurve and have just put the 3rd flow coat on the glassed sides. The first coat and glass went really smoothly, waited until tacky and flow coated the second. Let it cure about 16 hours (Raka resin with their slow hardener) and then did the 3rd coat. Starting sanding it with 80 grit and 120 and see some orange peel effect now. 1st coat was squeegeed, second and third rolled with a foam roller.
Question is, will sanding alone get it smooth enough for painting (plan to go to 220) and the paint level or should I put a 4th thin coat of epoxy on to fill the “dips”? It’s the outside now and will be sanding after the 3 coats on inside ( to be varnished). Thanks for any tips folks can provide a newbie!
As a newbie, I tried to coat and coat and coat to fill the low spots...but the epoxy will "telegraph" the weave of the fiberglass below even after the original valleys in the weave are filled and I made my first boat unnecessarily heavy.
Generally it only takes 2 coats if the 2nd coat is thick enough. A 3rd coat will only add thickness.
16 hours should be short enough between coats to get a bond between the 2nd and 3rd...get to sanding.
I absolutely don't think you need a 4th coat.
If when sanding you start seeing white spots (the weave of the glass cloth) before you sand down to the bottom of the pits/valleys, you need another fill coat. If no white spots, just sand the panel flat and prep for varnish. Pretty sure you just need more sanding.
Got any pics?
Thanks Shawn- appreciate the tips and insight. I’m heading back to the shop tomorrow and will get some close ups. I’m hoping that I’ll be able to get a flatter panel tomorrow without having to get too aggressive with the sanding.
Spent about 5 hrs today sanding (80-120-150 and then decided to put another flow coat on. Left this one thicker with a squeegee and then tipped it with a foam brush. Looks much better so we'll see what it looks like after curing. Here’s the pics before additional coat on the glassed side. Nonglassed looked similar just more of the dimples.
Thanks Shawn- I did scrub with scotchbrite and soapy water/spray bottle and then applied one more coat. Came out much better and after sanding was nicely flat (at least enough that I'm sure primer, paint and a build up of varnish on the bright work will fill).
A couple more hours sanding and I think I'm ready to stitch on Saturday!