How do you fix hairline cracks in gelcoat

[bigshrimpin]

Those cracks are superficial. No need for the glass. I like the way skoolz used his grinder to prep the crack . . . but it's a little risky unless you have a very steady hand. dremel tools are a little safer. Also you can get matching gelcoat through minicraft . . . they sell in a liquid or a paste (which is just thickened gelcoat using cabosil)

Get the paste.
Grind out the crack.
Clean with acetone
Tape off the area
fill with the thicken gelcoat.
spray on PVA
let it dry.
sand flush with existing surface
start with 120 (on a sanding block) all the way to 600 (wetsand)
buff and wax.

On vertical areas like that I like to use 3M 2" blue tape to prevent any sagging . . . just put tape over the repair.