Re: cracks on old sport lido 1959
There are a lot of threads in the "restoration" portion of this forum, search on "cracks", "cracked gel-coat", etc. I also found a good set of videos on a commercial site over on the Sea-Ray site I also visit. Site is Spookeay Marine,
http://spookeaymarine.info/videos.htm
Look at the videos on the "Sea Ray SRV 190" restoration. Shows fixing the cracks. Basically you open them up into a "V", then fill with a boat filler (I don't recommend bondo- use polyester gel-coat or something like MarineTex).
You'll have two choices as you fix the cracks. If you want to use gel-coat you'll spend a bit of time to match the original gel-coat in color. The other way is to fill with a filler that's close to your hull color, then prep and paint the entire surface. Your choice, if you have a lot of cracks it's probably easier to paint. Just a few, easier to match/fill/buff.
I'm not attached to Spookeay marine in any way, I just thought these were a good set of videos.
