Saturday, 11 March 2017

The scene of the crime!

Who would think that such a teeny weeny hole could cause so much expensive trouble?
In the lower part of the photo is the cause of our woes, When they built the boat they used pea shale as ballast, this contains salt and is a perfect medium for holding moisture. This caused the bottom to rust from the inside and caused the skin cooling tanks and their balance pipe to rust through so that they too leaked into the pea shale.
We just completed welding on the new base and plug welding the centres of the panels to prevent sag, Next we need to overplate the leaking parts of the skintanks.
Tomorrow I'll clean the hull so that we can give her a few more coats of blacking before she's refloated on friday.

Wednesday, 8 March 2017

A problem solved?

One problem with re-bottoming is that the base needs to be welded to the the old baseplate in the middle of the boat to stop it sagging.
So we'll grind through the new baseplate and jack it up so that we can add supporting welds at intervals.
Another is that, once overplated, there can be a small air gap between the new base and the bottom of the skintanks, this interferes with the ability of the skintanks to dissipate the heat from the engine.
The last pieces of the jigsaw, the sheets were too narrow to fill the area under the swim, I decided not to turn the sheet lengthwise, this meant I'd need a small triangle each side and these would mean two welds would cross the bottom of the skintanks, helping with the cooling.

One of the triangles prior to grinding out and welding to the old baseplate.

Tuesday, 7 March 2017

A new bottom for Freyja.

So, after I found the leak, we decided that, rather than patching the bad section, we would re-bottom her completely.
But, how to go about it? We only have a choice between going on the long trailer or on the rail-mounted dollies on the slipway, but then how would we do all those welds upside down?
Clive, the marina owner, came up with a solution :- 
Thirteen sheets of steel, laid out on the trailer.

The first two sheets champfered and clamped ready for welding, this means most of the welds will be done from above instead of from below.

We also had to weld extensions onto the trailer to support the pen-ultimate sheet.

When the weather turned we got around it by building a temporary tent over the next sheet of steel.

One very large plate, almost ready to receive Freyja.
The new baseplate is reversed down the slipway ready for us to float Freyja on top.
Perfectly placed first time.
After welding the base to the boat Bruce needed to cut the excess steel away.

Using an oxy-propane cutter.

Trimmed tidy! And we started to finger mould the welds with sealantto seal any pinholes (as we couldn't pressuretest the whole hull)