Corrosion advice
Posted: Sun Jun 24, 2018 7:03 am
I have a 2005 Pacific 2025 hardtop, 1350 hrs, used and kept in salt water for 1-2 weeks at a time, and stored outside on a roller trailer when not in use. When stored, the bow had been jacked up high enough to allow water to drain from the deck, but in retrospect MAY not have been high enough over the years to fully drain the inside of the bow section. The factory installed hull anode and motor zincs (pictured) are in good condition, although my understanding is that the hull anode is zinc, not aluminum as has been recommended on this forum
I have had no issues with the boat, bilge has been bone dry until this spring. I put the boat in the water, and after a day there was several inches of water in the bilge. Took the boat out and found the pictured hole in the hull, indicating corrosion arising from inside the hull. We drained the bilge, tapped the hole and put a stainless bolt in, and fished for several days without incident.
Coincidentally, and not sure if related, I have had electrical issues, with sluggish starting of the motor and brief battery/electrical alarming after starting since last summer. Last fall I changed the batteries (which were 8 years old) and that problem initially resolved, but has now come back. The alternator and batteries have been tested recently and are OK; this problem is in the process of being evaluated and corrected but no diagnosis yet. All other aspects of electrical systems seem to be functioning normally
I brought the boat to an aluminum boat builder in northern Mass for inspection and repair. We jacked the bow up high, and a gallon or so of salt water drained from the bilge, from the bow section, as the stern was dry.
The hole is located a foot or so forward of the console a few inches from the center line (just forward of the front rollers on the side picture). We probed the hole and it appears to be just lateral to a longitudinal stiffener on the inside, without foam in the area of the hole
The hole was drilled out and the surrounding metal was sound full thickness. The hull was inspected externally and was felt to be in excellent shape outside of the hole pictured. There was 3 areas of pitting inside the stern which was felt not to be an immediate problem. There were no other areas of any concern.
There are two relatively small Armstrong deck hatches, one at the stern, and one inside the console storage box. Therefore we could not fully inspect the interior of the hull except the area at the stern and over the gas tank mid hull, which looked fine
The hull was patched with 3/16" aluminum, as pictured.
We concluded that the corrosion may have occurred due to standing water in the bow. I rinsed interior of the hull with salt away as best I could, dried and sprayed Corrosion X on the interior of the stern section. I keep deck hatches open for ventilation when weather allows and the interior appears nice and dry. Plan moving forward is to store the boat with the bow jacked high enough to drain bow section and keep an eye on things.
I have several questions:
1. Do you agree that the cause may have been water in the bow section? Anything else I need to consider
2. Should I replace the anode with an aluminum one? If so can you recommend a specific manufacturer and exact type of anode I would look for
3. Should I install an inspection hatch in the bow deck? if so, does anyone with knowledge about Pacific construction have recommendations as to where to put the hatch?
4. I plan to install a bilge pump. Any advice or pitfalls to be avoided here?
5. Should I be concerned about internal foam being wet?
Any other thoughts or advice would be appreciated, thanks
I have had no issues with the boat, bilge has been bone dry until this spring. I put the boat in the water, and after a day there was several inches of water in the bilge. Took the boat out and found the pictured hole in the hull, indicating corrosion arising from inside the hull. We drained the bilge, tapped the hole and put a stainless bolt in, and fished for several days without incident.
Coincidentally, and not sure if related, I have had electrical issues, with sluggish starting of the motor and brief battery/electrical alarming after starting since last summer. Last fall I changed the batteries (which were 8 years old) and that problem initially resolved, but has now come back. The alternator and batteries have been tested recently and are OK; this problem is in the process of being evaluated and corrected but no diagnosis yet. All other aspects of electrical systems seem to be functioning normally
I brought the boat to an aluminum boat builder in northern Mass for inspection and repair. We jacked the bow up high, and a gallon or so of salt water drained from the bilge, from the bow section, as the stern was dry.
The hole is located a foot or so forward of the console a few inches from the center line (just forward of the front rollers on the side picture). We probed the hole and it appears to be just lateral to a longitudinal stiffener on the inside, without foam in the area of the hole
The hole was drilled out and the surrounding metal was sound full thickness. The hull was inspected externally and was felt to be in excellent shape outside of the hole pictured. There was 3 areas of pitting inside the stern which was felt not to be an immediate problem. There were no other areas of any concern.
There are two relatively small Armstrong deck hatches, one at the stern, and one inside the console storage box. Therefore we could not fully inspect the interior of the hull except the area at the stern and over the gas tank mid hull, which looked fine
The hull was patched with 3/16" aluminum, as pictured.
We concluded that the corrosion may have occurred due to standing water in the bow. I rinsed interior of the hull with salt away as best I could, dried and sprayed Corrosion X on the interior of the stern section. I keep deck hatches open for ventilation when weather allows and the interior appears nice and dry. Plan moving forward is to store the boat with the bow jacked high enough to drain bow section and keep an eye on things.
I have several questions:
1. Do you agree that the cause may have been water in the bow section? Anything else I need to consider
2. Should I replace the anode with an aluminum one? If so can you recommend a specific manufacturer and exact type of anode I would look for
3. Should I install an inspection hatch in the bow deck? if so, does anyone with knowledge about Pacific construction have recommendations as to where to put the hatch?
4. I plan to install a bilge pump. Any advice or pitfalls to be avoided here?
5. Should I be concerned about internal foam being wet?
Any other thoughts or advice would be appreciated, thanks