spider web cracks - now with photos!

[marekpavel]

Hi,

I realize there are many threads dedicated to this subject however none seem to relate to me, so I would really appreciate if someone out there could help me.

My father have recently purchased a 27 ft power boat. We knew that it needed work but being new to boat building we underestimated the amount of work required. To keep the story short we are now trying to fix up all cracks in the gel coat and beyond. If there were as many fish in the sea as cracks on our boat there would be no hunger. The cracks I am referring to are those spider web cracks. I grinded many of them with a standard grinder down to fiberglass and we plan to fill it in with bog, sand it smooth and paint (picture below).



and


However there are many spots we can't get to with a standard grinder, e.g. 90` angle spost (stairs etc) - pictures below. Are there any special tools that can be used for this purpose?



Also there are many small cracks all over the front part (pictures below). What can be done to fix these? (do I have to grind or sand down the gel coat here as well and then fill it in)



You are more then welcome to see more photos at: http://picasaweb.google.com/kleinsociety/Boat

and if you have any suggestions please do let me know.

Thank you for your help.

Marek

[marekpavel]

For some reason photos didn't come across so you're welcome to use link above to see them on my web.

[alan white]

Try a dremel tool with a carbide veining bit, or better, a hand-held router such as is used for drywall cut-out (look for a 1/8" collet size tool, in other words). It's a lot of time-consuming work, and requires eye protection.
Use epoxy filler. Not Bondo or polyester resin-based fillers.
The tendancy is to just use a big grinder and go nuts. Maybe where crazing is really bad.
However, try to leave as much original material alone as possible and it will provide an accurate surface to guide your patching. You don't want to be adding fiberglass too (I've had to do this when the boat owner "helped" one day when I wasn't around. Grind sparingly!

Alan

[oliverdcq]

I agree with Alan White, Be careful when grinding and use epoxy fillers 1st. After all patch work is done I would highly recommend 2 to 3 coats of good name brand primer for marine use, then sand accordingly complete any minor filling. If you plan on using a polyester based topcoat then I would use a polysester filler on top of the primer.
Oliverdcq