Electrolysis damage in my Starcraft. Salvageable?

I recently purchased a 1987 Starcraft Bass Boss BV170 with the knowledge that it was used in salt water and had some bottom damage, possibly from electrolysis. I could feel a 2" x .25" gash in the bottom edge below the transom. The boat was in pretty good condition otherwise and the price was less than $500 for boat & trailer.

Last weekend I gave the hull the water test and noted a very slow drip out of the gash that I previously noted. However, I noticed that the bottom of the hull had been sprayed with a grey sealer and yesterday I went back under the boat with scraper and wire brush on my drill. Here is what I found:


There is a 2' x 3' section that has gashes, pin holes and screw/washer repairs starting at the stern seam near the center. Pounding on this area it seems as stout as the rest of the hull. Does anyone have some experience with this problem? I'm thinking have an experienced aluminum welder either spot weld or possibly weld a plate over the damaged area. Most of the damaged area is also accessible from above as the inside stern area is open for the bilge pump and drain plug.

The Starcraft brochure states that the bottom hull is .080 aluminum.

My plan for the boat is very low power for use on either electric only or 10 hp max lakes. Occasionally I might put a 35 hp on the back but I don't plan to take this up to the 120 hp capacity max.

If repaired, do I need to be concerned for additional electrolysis if only used in fresh water?

Any advise, experience or suggestions are greatly appreciated.

Don

Re: Electrolysis damage in my Starcraft. Salvageable?

I think you have to pull up some flooring in the rear, at a minimum. You're only seeing what has worked through the hull and there could be more corrosion further forward under the floor. Might be too soon to say if it's repairable.

Re: Electrolysis damage in my Starcraft. Salvageable?

It may electrolysis, or it may be galvanic corrosion eating from the inside out.

As GB stated I'd pull some decking and have a look see on the inside.

Check your floatation foam to see if it is saturated, if it's saturated with saltwater it's just going to keep eating your boat. If your foam is saturated, remove it and check for more damage.

I'd prep the damaged area inside and out to make a quicker job for the welder and cheaper for you.

Re: Electrolysis damage in my Starcraft. Salvageable?

I'm a novice and don't understand "eating from the inside out" concept. The limited area that I can see on the inside floor of the boat directly above the pitted/damaged exterior looks fine. All the attached photos are the exterior bottom of my boat. If it's getting "eaten from the inside" should I expect to see some damage on the inside of the hull?