A lot of us have experienced the excitement of running down a rocky stream only to feel the boat lift slightly, accompanied by a scraping noise. If you are lucky this only results in another crease or groove in the bottom of the boat to add to the rest of the battle scars. What do you do if the rock is sharp enough to make a hole, catches on a rivet or rips the bottom of the transom? Bilge pumps are great but I've had some excitement that even overwhelmed the pump.
For our field repairs we have tried duct tape, epoxy, silicone, bondo, plumbers sealer, and a variety of marine sealers. Each of these work to some extent but have two shortcomings in common. They are: The area to repair has to be clean and dry, Plus they all have some cure time that cuts into your hunting or fishing, unless you are in a good spot when the water starts coming in.
The temporary repair I'm going to pass on was given to me by Stacy Krueger and works so well it ought to be patented.
Pound the split edges of the metal together as close as possible and cover the leak with wax from a toilet bowl wax ring.
Yes, you read correctly, a toilet bowl beeswax ring.
The wax is so sticky the repair can actually be done under water and later when you get ready to weld the crack it is much easier to clean off than the other stuff we've tried. We've sealed transom cracks as wide as 1/8 inch but I would hesitate trying to bridge anything much wider with out mixing in some moose hair. Oh yeah, buy the ring without the plastic collar. You won't need it and it costs a couple of bucks more.
3440 Nevin Ave
North Pole, AK 99705
Phone: (907) 388-0789