Almost by chance, I discovered that you can get what is known as a flaw detector kit.
The idea is that the kit can be used to detect cracks in welds, or cracks in materials that need welding.
In my case it's perfect for finding out exactly where the
holes in the deck are that have caused all that corrosion down in the forward hold.
The problem has been that I have rusty patches in the deck head, but no idea of exactly where the water is leaking in from the deck above.
Enter the flaw detector kit, and a squirt or two of that red dye onto the rusty patches.

What happens is that the red dye seeps into the cracks, or holes, and through capillary action works it's way to the other side.
In fact that red dye gets everywhere very quickly.
Judging by the state of my hands and the place, any visitors would be excused for thinking I had just committed some kind of horrendous crime in the forward hold!
To really make the dye show up, you spray a fine white powder around the suspect area. This, as you can see, contrasts really well with the red, showing exactly where the source of the leak is on the deck above.
Interestingly for me, the red dye even worked it's way through what I thought to be three layers of good primer.
Now I know where the holes are, it should just be a matter of welding them closed.
Labels: cracks, deck, dye, forepeak, Forward Hold, red, welding