I, unfortunately have a little experience with Fglas , my brother owned a body shop , so I got to "play " there as much as I could ... Built quite a few Kustom Vans from scratch ... Fun stuff , some time ago ...
What I was looking for was edge resolution .... Seems like all my projects eventually get a little weary around the EDGES and the decay sets in from there.... Ha!!! Sounds like old age .....hahahahahahaha
Anyway , I'm using a 6 0z/sq. yd. Fglas tape .. 4" wide...also a "system epoxy " made for this kind of stuff . I've cleaned and sanded the surface and rounded the edge of the seam .... Wiped it down with a rag and vacuumed it off. I mix the epoxy in SMALL batches thoroughly, apply to the wood seam a little larger than the tape on both sides of the edge with a disposable brush (foamie)... lay the cloth tape on some heavy plastic sheeting (Visquene) and use the same brush to "wet" the cloth with resin .Apply the wetted cloth and smooth out with a stiff brush (it'll get stiffer) or my favorite a simple automotive squeegee (plastic) till it's smooth . let cure thoroughly , sand the rough spots (no matter how ya' try ) prime and paint ...
NOTICE: I try to do this in a VERY WELL VENTILATED AREA+FAN ...viz. OUTSIDE, wearing gloves and a light chem mask ... Epoxy fumes are dangerous, and are cumulative in the body .... NOT GOOD ... TAKE ALL PRECAUTIONS... if you take care , no troubles...
...On the other hand it is pretty quick , seals as well as strengthens the edges, and you don't have to punch holes in the edge (more potential for eventual leakage /rot ...) But It doesn't have "that look ...???
I know , I know !!! Why did I use that nasty old expensive epoxy and not the much cheaper Polyester resin ....
1. the poly seems to not stick as well to wood...
2. the epoxy is FLEXIBLE , much more so than the somewhat brittle Poly .... subject to vibrations/whatever the td will be better served by the flexibility of the epoxy ...
3. It's much more expensive , you can brag to your friends...
4. especially if it's summer , get the Slow hardener, gives you a little working time
Hope that helps a bit .... !!!!