1855 has not been a sealed tank for a long time. It has had a few corrosion issues. It has four holes in it.
Over Christmas, I set to preparing to repair one of the holes. Its taken nearly 3 months to get this far due to lack of proper tools (a suitable welder) and suitable weather!
That changed this weekend when, finally, the first hole got welded up.

I had prepared the hole early Jan, and spent a few minutes cleaning any surface rust

Here is the new plate held in place ready for tacking. The big magnet is to enable me to fish it out incase it falls inside the tank, it didn’t luckily!

The plate is tacked into place

The eagle eyes might spot no welding at the top – that is because the tank above has eroded into just 1mm at the very edge so it all needs cutting out, which is the next job!

You can see the welded-in plate at the bottom and the gap left. Everything inside the yellow box will be cut out, and a plate will be welded in.
I estimate another 1 weekend of work (possibly 2).
I am back to it this weekend.