Nice work so far. I've rehabbed a sunfish of this general age and so I wanted to share some of my observations and lessons learned as you start working on yours.... Your boat is of the age where, once the trim is off, it is easy to split the deck from the hull cleanly, using a sharp new painter's metal scraper tool, and a few love taps with a mallet. That's also a nice way to pry the metal trim off the perimeter after removing the rivets, without distorting it, keeping it's original shape, and that trim is EXPENSIVE to replace, because the shipping for long pieces is high. Ask me how I know:-P Anyway, splitting the joint for a few feet at the stern will let you get inside to access the foam and change the rudder gudgeon plate and the backing plates for the traveller wire attachments, without making a bunch of inspection port holes. Same at the bow: the deck will flex up quite a bit to let you get in there and work on the daggerboard trunk and foam, and the backing plates or blocks on the underside, all without needing to cut inspection ports. Do NOT split the *entire* deck away from the hull: leave the middle attached to keep alignment, while you work on the bow and stern, or your job gets much harder. As to the split by the small drain plug; some well-saturated fiberglass tape jammed into the split, and more epoxy will fix that right up, clamp it together well to set. That split happened from years of dropping or standing the boat on-edge to drain it. Sunfish were built using Polyester resin, so automotive parts store Bondo resin and hardener is quite compatible and cheap. Epoxy resin can work on either polyester or epoxy hulls, so that's best to use when you're not sure what the original was made of. Epoxy resin also doesn't smell as bad as polyester, but all resin work should be well-ventilated. I added a stern drain plug to my 1974 Sunfish, like you want to. IMO you want to get it as low on the transom as practical, so less water remains trapped when you drain it. Be sure to use the right 3M marine adhesive sealant there, so it stays tight over time. When unscrewing deck hardware on old sunfish, there's a chance the backing plates or blocks have debonded, and if you undo both screws at once, the backing plate or block can just fall off into the hull and get lost. So the careful thing to do is only fully undo one screw at a time, keep one screw partly engaged to hold the plate in place until you know the plates are not going to fall off and make you have to open up the deck to retrieve or reinstall. That hole in the foot well is concerning. I would first clean the heck out of it with TSP or Barkeepers' friend powder and water, followed by acetone (do that outside), then sand and clean a few times until you have a spot that will take the new fiberglass patch well and hold onto it. If it was my boat, I'd fix the hole in two steps: inserting a patch backed with cardboard into the hole, well-covered with epoxy, with a string tied thru the patch and knotted on the back of the cardboard, to the center of the patch. Pull up hard on the string to squeeze the first patch up against the back side of the hole. When it hardens, cut off the string, and lay the outside patching layers of cloth in on top, and fair it out. This way the patch is much stronger and longer lasting because it is sandwiched on both sides of the hole, spreading out the loads. A piece of ziplock baggie plastic laid over the wet patch with a sandbag on it, peels off easy when the resin is dry, and it will make the final patch surface really smooth, and greatly reduce the sanding and filling otherwise needed to finish. Rustoleum makes a cheap yet decent marine paint that you could then repaint the footwell with, if you want to hide the patch... but that might be going too far, budget-wise. There are gelcoat matching kits that let you color a patch or hide cracks in gelcoat, matching the original color. Your boat looks pretty good for the age it is, and the original color is lovely. I like your idea of just clear gelcoating over the top, after you'd polished out some of the cracking and crazing. These boats have to be labors of love at that age, because you're never going to make back the money you put into the repairs and restoration work. Ask yourself are you just needing it to be functional and look good from ten feet away... or are you trying to make it a concours-level finish? You're doing it to see how well you can do it, and to make it something you're proud to show... But who said boats were practical things anyway:-)
There's a good chance that all of the water incursion is coming through the big crack in the side that you found. But I hope that you also looked underneath and checked the bottom of the daggerboard tunnel and the bottom side of the bailer. I have a 1970 sunfish that is mostly original. I updated the rudder this spring using mostly scrap and spare parts. Sailing it where I do, we have lots of waves and tightening the wing nut on the old rudder was a nightmare and I'm lucky I never got my thumb crushed. It's a relatively simple upgrade. I added a 4" inspection port on the back. The hardest part for me was because the wood frame below the fiberglass deck was about 1" thick and I was trying to use a scrap backplate inside for the rudder bracket, but because the wood deck was so thick I had to trim up the backplate to fit it inside and I had a hard time getting the bolt holes to line up with the new rudder bracket. Also I rehabbed the old rudder to convert it to the flip up rudder hardware, but the shape of the old one is so different that I had to trim it really good and some of the holes I drilled for the cheek springs and tiller were far back into the taper on the back of the rudder. I don't recommend doing it that way. Instead try to find a used rudder from 1972 or newer.
Nice work so far. I've rehabbed a sunfish of this general age and so I wanted to share some of my observations and lessons learned as you start working on yours....
Your boat is of the age where, once the trim is off, it is easy to split the deck from the hull cleanly, using a sharp new painter's metal scraper tool, and a few love taps with a mallet. That's also a nice way to pry the metal trim off the perimeter after removing the rivets, without distorting it, keeping it's original shape, and that trim is EXPENSIVE to replace, because the shipping for long pieces is high. Ask me how I know:-P
Anyway, splitting the joint for a few feet at the stern will let you get inside to access the foam and change the rudder gudgeon plate and the backing plates for the traveller wire attachments, without making a bunch of inspection port holes. Same at the bow: the deck will flex up quite a bit to let you get in there and work on the daggerboard trunk and foam, and the backing plates or blocks on the underside, all without needing to cut inspection ports. Do NOT split the *entire* deck away from the hull: leave the middle attached to keep alignment, while you work on the bow and stern, or your job gets much harder.
As to the split by the small drain plug; some well-saturated fiberglass tape jammed into the split, and more epoxy will fix that right up, clamp it together well to set. That split happened from years of dropping or standing the boat on-edge to drain it. Sunfish were built using Polyester resin, so automotive parts store Bondo resin and hardener is quite compatible and cheap. Epoxy resin can work on either polyester or epoxy hulls, so that's best to use when you're not sure what the original was made of. Epoxy resin also doesn't smell as bad as polyester, but all resin work should be well-ventilated.
I added a stern drain plug to my 1974 Sunfish, like you want to. IMO you want to get it as low on the transom as practical, so less water remains trapped when you drain it. Be sure to use the right 3M marine adhesive sealant there, so it stays tight over time.
When unscrewing deck hardware on old sunfish, there's a chance the backing plates or blocks have debonded, and if you undo both screws at once, the backing plate or block can just fall off into the hull and get lost. So the careful thing to do is only fully undo one screw at a time, keep one screw partly engaged to hold the plate in place until you know the plates are not going to fall off and make you have to open up the deck to retrieve or reinstall.
That hole in the foot well is concerning. I would first clean the heck out of it with TSP or Barkeepers' friend powder and water, followed by acetone (do that outside), then sand and clean a few times until you have a spot that will take the new fiberglass patch well and hold onto it. If it was my boat, I'd fix the hole in two steps: inserting a patch backed with cardboard into the hole, well-covered with epoxy, with a string tied thru the patch and knotted on the back of the cardboard, to the center of the patch. Pull up hard on the string to squeeze the first patch up against the back side of the hole. When it hardens, cut off the string, and lay the outside patching layers of cloth in on top, and fair it out. This way the patch is much stronger and longer lasting because it is sandwiched on both sides of the hole, spreading out the loads. A piece of ziplock baggie plastic laid over the wet patch with a sandbag on it, peels off easy when the resin is dry, and it will make the final patch surface really smooth, and greatly reduce the sanding and filling otherwise needed to finish.
Rustoleum makes a cheap yet decent marine paint that you could then repaint the footwell with, if you want to hide the patch... but that might be going too far, budget-wise. There are gelcoat matching kits that let you color a patch or hide cracks in gelcoat, matching the original color.
Your boat looks pretty good for the age it is, and the original color is lovely. I like your idea of just clear gelcoating over the top, after you'd polished out some of the cracking and crazing. These boats have to be labors of love at that age, because you're never going to make back the money you put into the repairs and restoration work. Ask yourself are you just needing it to be functional and look good from ten feet away... or are you trying to make it a concours-level finish? You're doing it to see how well you can do it, and to make it something you're proud to show... But who said boats were practical things anyway:-)
There's a good chance that all of the water incursion is coming through the big crack in the side that you found. But I hope that you also looked underneath and checked the bottom of the daggerboard tunnel and the bottom side of the bailer. I have a 1970 sunfish that is mostly original. I updated the rudder this spring using mostly scrap and spare parts. Sailing it where I do, we have lots of waves and tightening the wing nut on the old rudder was a nightmare and I'm lucky I never got my thumb crushed. It's a relatively simple upgrade. I added a 4" inspection port on the back. The hardest part for me was because the wood frame below the fiberglass deck was about 1" thick and I was trying to use a scrap backplate inside for the rudder bracket, but because the wood deck was so thick I had to trim up the backplate to fit it inside and I had a hard time getting the bolt holes to line up with the new rudder bracket. Also I rehabbed the old rudder to convert it to the flip up rudder hardware, but the shape of the old one is so different that I had to trim it really good and some of the holes I drilled for the cheek springs and tiller were far back into the taper on the back of the rudder. I don't recommend doing it that way. Instead try to find a used rudder from 1972 or newer.