'73 leaky hull repair

So I've talked to a couple of people about using air pressure on the inside of the hull to detect leaks but also potentially carry a fluid to seal these leaks much like those auto tire repair cans.

Though this through and I don't think it will work because the air flow to maintain these sealant droplets in suspension is quite high plus you can probably overpressure the hull.

My approach will be to use low P air simply to detect hull leaks with soap water on the outside.

Any additional thoughts?

You are spot on. I have used a shop vac in reverse and you have to still make sure that all the force of the vac is limited. Likely spots are the fittings, hull/deck joint and the bottom/inside of daggerboard trunk.

Hey Chris,
Any suggestion on how to repair a leaky daggerboard trunk? Mine leaks on the inside front edge down low and on the rear edge up high.
Thanks,
Dale

Hi Dale,
I placed my boat upside down on short saw horses and inspect the joint where the hull, deck and daggerboard all meet. Usually there is a break at this joint. once you locate it I suggest grinding it out with a dremmel with the small saw blade or a grinder blade. You want to make it about 1/16 to 1/8 wide so that it can accept the thicken epoxy. Once you have it ground out, you need to blow it out with the air compressor and then clean the area with acetone to remove all residue and dust. I use west systems epoxy with the 404 High Density filler. I mix it to about the consistency of peanut butter. I use a craft popsicle type stick to push it into place. Also, you can push it into the fore and aft trailing edge with a plastic spoon or plumbing flux brush. Tape it to a wood dowel if you want to get up further. Keep in mind that you will have to come back and sand it smooth after you are done. This can be best done by wrapping sandpaper around a small dowel. 
Hope this helps!

Thanks for the advice. We made the repair last week. Hope to do a leak test soon.