Tell me about motor issues! I have a 1975 Sea King 15hp on mine. It runs, have the idle adjusted all the way and still it's ify. Oil in the water tank during running that I think is coming from the lower unit, but really not sure. No chance on getting parts for this piece of excrement, but have to run it till I can get something else. Really want to get a Honda 9.9 hp with electric start around 3k; but may have to settle for a Tohatsu 9.9 for 2.2k; Yamaha, doesn't make an electric start 9.9 with a 12 amp alternator that I can tell.
As far as cleaning out the boat, I had to deal with old sealant, and over 4 coats of different paint. here is what I found:
1. Wire brush works best around rivets.
2. Aircraft Stripper was ok in removing paint, but you need at least lightly sand the area to give it some texture to help adhere paint.
3. Orbital sander worked OK and left a good finish, but it was slow...again, I had multiple layers on a 30 y/o boat.
4. 41/2 " grinder with a disk pad and 50grit paper and a light touch worked best for me with the multiple layers.
What ever you end up using be sure to clean it well and before priming wipe with acetone. Prime with RustOleum Etching Primer to give a good substrate for your paint to adhere to. You may want to wait on inside paint until you at least have your framing in if your going to make any new holes or welds.....or maybe not.