i have a john boat that has i small water leak and a small crack on a side i don't have an aluminum welder so what other ideas are out there that work great and long lasting
I have had great luck with JB Weld. Just make sure the surface is super clean and rough it up a bit.
All of the above are pretty good solutions, but... The biggest problem with the JB Weld technique is that JB Weld (as with other 2 part epoxies), is that they tend to be brittle and are sensitive to UV breakdown due to sun exposure. The hull of a Jon boat tends to flex a lot and may crack or break the epoxy. You should also evaluate what caused the crack. If it is indeed a crack and not a tear is is likely from fatigue induced by flexing that cold worked the aluminum where it failed. Welding can be a bit tricky and I would totally avoid that unless you have a professional do it, otherwise you'll have a much bigger mess than when you started. Here is the solution I propose: Cut a coupon of aluminum of the same gage (11ga-14ga) large enough to cover the crack plus some extra. Sand the surface of the cracked area of your hull very well (bright metal) to remove any paint and oxidation and to provide good adhesion. Apply a semi heavy layer of 3M brand 5200 polyurethane sealant to the boat and to the coupon and clamp. Allow this to cure for at least a couple of days. 5200 is a very flexible sealant for use above and below the waterline and I assure you, you will not be able to remove that patch without tearing a hole in your hull. So, make sure it's right the first time. This sealant is excellent for leaks with seams, rivets, cracks, pinholes etc. It is available in black or white and is a heavy, thick paste.
