k well i need some opinions...i have been sanding my wood chris craft. i fiberglasseed it and i started with 100 Grit and now im at 220 and boy is it smmoooooooooottttttthhhhhh! and when i run my fingers down her you cant feel one bump. i mean its super slick....BUT i notice when i trun it at different angles the glare on the boat revieals that their are some imprents still in the layers of resin..you know little divits BUT YOU CAN FEEL EM AT ALL!!!!! soo now i dont know....i mean i REALLY hope i dont have to run another coat of resin over the sides and then sand it down again..prob is i cant go too much further cuz i may hit the cloth..i was thinkings maybe the next sanding level would just take those blemishes out........buttt then agian thats why i am here asking you people...soo i just need some pro help as too what i do next cuz i KNOW SOMEONE has had this problem and has been at this stage.....and i need to know whats the right thing to do.....is it put finishing resin over it or g to the next level of sanding...reasion i ask is cuz i dont wanna take alllll the time to sand the sides down then find out i have to re coat them again....so please help!!

jserb;
If you see imperfections here is one thing you can try. If you plan on painting the fiberglass, you can add a guide coat (light mist of contrasting paint over the area) this will guide you as you block sand showing you the low spots. (were the paint remains after block sanding) Add bondo (automotive filer) to low spots and sand smooth.
If the fiberglass is over the wood you intend to keep. First take a pencil and holding it at a sharp angle to the hull, lightly rub lines down the hull in opposite direction to your sanding. These become your guide coat. Block sand as before and reveal your low spots. You will fill the low area with resin. Be sure to sand out your pencil lines before adding the resin to raise the low spots so that they will show up under your finish. Sand smooth after cure and finish.
Hope this helps.

Hello jserb:

I have used fiberglass extensively in my real J-24 sailboat and my Midwest Coast Guard model. There are two critical things.
1. Fine grade of fiberglass cloth.
2. West Marine Epoxy resin. You can get it from Home Depot. Do not use Bondo or Polyester resin, because they will absorb water and will ruin your wood bottom.

If you suspect voids inside the coated fiberglass after sanding, it is better to rough it up and recoat with another layer of epoxy. Use wet sand to start with 320 grit and all the way to 600 grit. This way you will not oversand the remove too much resin.

Over smoothing the bottom will actually slow down your boat speed due to excessive surface tension. A 600 grit finish will give you a surface like the shark skin that reduces friction.

Your epoxy fiberglass is the most important protection against water penetration (or Osmosis). Do it right and will save you tons of repair work later.

Enjoy

IDM