Checking the diesel fuel tank for corrosion
- As many of you know, a problem area for the J/42 (and, I guess the nearly identical J/40) is a failing starboard fuel tank. Water gets under the tank, causing corrosion until the tank fails.
As part of my ongoing project to figure out why my diesel is failing, I found myself with the tank empty and all the fuel hoses off and realizing that it would be quite easy to take it out completely and look for corrosion. So, I took the occasion to do that. It was about an extra half hour job. Fortunately, it was in good shape with no signs of corrosion.
If you did this from a dead start I would estimate it to be about a four hour project start to finish, including removing and replacing the fuel. These kinds of "petroleum products" projects are not fun, but then neither is finding 30 gallons of diesel in your bilge. Tip: take all the hoses and electrical connections completely off before attempting to remove the tank.
Here's a picture of the corner of the tank. There was no sign of corrosion (the lumps are the weld).
And here's a picture of the cavity that's left behind. As I understand it, the large 1 inch hole seen on the right hand side (the forward side of the cavity) is atypical. Most installations have only the small limber hole seen just behind it. Perhaps this explains why my tank was in such good shape?