leaky jon boat

hey guys im new to boating in general and bought my first boat the other day an old 11' aluminum jon boat. took it out in a canal behind my house and it didnt really have any leaks, so the next day i go into saltwater to see its seaworthy-ness and water ended up leaking into the boat. came home and filled it up with water and found alot of little holes. after further inspection using paint stripper on the boat to see any other potential leaks under the multiple layers of paint. the transom is really thin aluminum and has alot of holes looks like it rusted but aluminum doesnt rust ( correct me if im wrong ) also where the drain plug is, is a little crack on the underside of the boat. i am wondering how can i go about fixing these issues ? i really want my first little boat seaworthy so i can fish the flats in my area for fun. all help is very much appreciated


^this pic shows a crack in the rib where the drain plug goes


^this pic shows the "rust" damage



the last two pics show the transom and the holes in it. i want to repair all the smaller holes and redrill when it comes time to mount a small outboard or trolling motor

 

imho, that boat is shot, you'll probably spend more fixing it than buying a new one. that said you could try to slap a layer of fiberglass cloth on it w/epoxy or resin and paint it and probably be fine for a while (are you sure it's aluminum? if it's steel patching it would be much easier just weld a few patches on)

 

i got the boat for $25 so i dont have a problem putting at most $250-350 into it to make it sea worthy

 

heck if its just a 25 dollar boat and you have no longterm plans i'd consider getting a sheep of plywood and a tube of PL premuin. glue the ply onto the inside of the transom, making sure to cover the holes with PL first to plug em up. bring along a bucket just in case.

 

You can do your patching with fiberglass and epoxy, putting a layer on each side of the transom metal. The hole in the bottom by the drain will need to have thickened epoxy put onto it, then glassed. It has just plain been worn through the metal by dragging.
The holes are caused by pit corrosion (which still happens in aluminum) I suspect a chunk of wood was bolted to the transom in each spot...the one with all the little holes got wet and stayed that way. This wet wood held against the metal for a long time and it did corrode in a way. Make sure you clean (buff lightly with sand paper) the surface just prior to laying the cloth and wipe it with a solvent to make sure you get the best bond.

 

i finally stripped all the paint off the boat and sanded it down with 60 grit sand paper. i am going to go sand it one more time in one direction so that everything is even. what i was planning on doing was covering the holes in the transom and the crack where the drain plug goes with fiberglass, then after cover the entire bottom of the boat with steelflex. how does that idea sound to you all ?

 

can you send me a link to this "thickened epoxy" that you are talking about ? and yes you are correct about the wood behind bolted to the transom and was rotted. i believe under the seats also have wood and if that is the case i am wondering if the wood under the seats are rotten also. how would i be able to go about checking the wood under the seats, they are riveted ? can you also send me some links on the fiberglass products to use and techniques ? thanks

 

Thickened epoxy is regular epoxy that is used in boat building and a thickener added such as wood flour or milled glass fibers or even talc (baby powder) or I have even heard of regular wheat flour being used. I use epoxy from progressive epoxy products but WEST has it and there are many others...a quick google will find you many different brands. This isn't really structural so you won't need the absolute best epoxy...Clark Craft sells a decent 1:1 ratio epoxy in smaller batches.

The wood under the seats probably has not seen much water and has never sat damp for extended periods of time so I doubt it is rotted. If it is you can simply drill out the rivets and replace with screws but I don't think it is necessary.

The only real instructions you need for epoxy is to use it outdoors if possible, wear long sleeves and rubber gloves and perhaps a respirator mask. Most people don't need it but some who have reaction issues or asthma could use it. There are others here who will chime in with other opinions but this is mine. Mix your epoxy very well (1 minute +) before adding your thickener and add enough to get to a peanut butter consistency... so it won't sag. It will warm up and thin out a little as it reacts and starts to cure. Butter the area with a little unthickened epoxy first and let it cure to a tacky texture then smear on the thickened stuff.
To do cloth it is best if you can get the surface to be level but being as this is a transom, that might be a little difficult. At least get it at an angle so the weight of the glass will help hold it on the surface. Put a light coat of unthickened epoxy on the clean surface and then place the glass on it. Gently wet out the glass until it almost disappears (no white spots). Use clean gloves when handling the cloth to keep your skin oils from contaminating it. Let it cure until tacky and then recoat with a thickened coat of epoxy to fill the weave. This thickness should be kind of runny so it flows but with some filler in it to fill the little pocks of weave. Let this get tacky and then one more light coat of unthickened epoxy to finish. Sand and finish to taste. When sanding epoxy DO use a decent mask/respirator