I was replacing stanchions. under two stanchions there were two bolts that didn't make it through to the other side because of their location too close to the edge of the hull. They had drilled really wide holes then got the bolt, put the nut on the end and cemented it in with sikkaflex like laying a foundation for a house. I dug it out, filled it with thickened glass and used self tapping screws instead.

When I bought my boat, the PO proudly showed me the nice wooden gunwale rubbing strakes he had replaced. They looked great, but he didn't tell me that he had neglected to fill the old screw holes concealed underneath. It took me several years to rack down the hull-deck joint leak in one particular area. And it took in both salt and rain water - one day salty, next day not ,drove me nuts.
GRRRRRRRRRRRRRR!!!!!!!!!!!

garymalmgren said..
It's gotta be wiring.

Red with white stripe leaving alternator.
30 cm later a bullet connector to red, 10 cm later a twist and tape connection to brown.
50 cm later a bullet connection to red which fed into a plug and came out yellow at the other side which was the Yanmar ignition switch.
Replaced with 60 cm of yellow.

I am sure that there are a lot of stories like this.

Gary

Yep wiring for sure, the other day I noticed that the anchor light had stopped working, it's happened before due to corrosion of unsuitable wires so I knew where to look. Anyway it wasn't the usual problem so it must have been that the LED strip has finally died after being on almost constantly for at least 5 years. Put everything back together and switched on the steaming light which is all round and high so good enough for anchoring. Then suddenly realised that the light on the bilge pump switch was off, I'd tested the pump an hour earlier and it was working fine, so everything back to find the fault. Everything is such a mess that there is no way of working what is what, so for now the bilge pump is directly connected to the battery. Suddenly fixing the wiring has been elevated to the top job on the boat.

Yep, wiring

I'm owner #3 and it seems to me that owner #1 was pretty meticulous about most things on board, including wiring, based on the underlying work here. But then owner #2 has "added" a few things and perhaps not been as particular with routing cables, labelling, using tinned wire etc.

This pic is from 2018 and I'm slowly removing unnecessary wiring (seriously I have a bag of about 12 kg of it so far) and replacing the domestic/household cable with tinned wire and numbering everything.

The rat's nest on the floor of this cabinet has improved but is still not finished.

Like Zzzzz says, if the circuit still works, other stuff gets prioritised above it.

Here's a good one. This was our shore power "inlet" when we purchased our boat

Achernar said..
Worst bodge job - anything involving silicon, followed by using white bog to goo electrical cables to the ceiling.

Yeah, black is so much more prettier.

... and this from the archives of my previous boat ...

Yes, that is a turnbuckle used to anchor the forestay and furler to to bow. Surely, it will never work loose. Its got locking nuts. Don't worry about all the torsion applied to it by the furling and unfurling. It will do its job. Except when you're in the middle of Moreton Bay, underway.

Thankfully, I had a crew with me who could take the tiller while I worked out how to reassemble it. Photo taken after the event.

I wasn't very happy when I discovered that the power cables to the VHF radio were connected by twisting stripped wires with a wrap of insulating tape. For some reason they also used high impedance video cable to the mast antenna. This was apparently suitable for Bass Strait. Amazing it still got any reception, but the improvement after it was replaced was massive.

I had to fix a HDMI cable from a laptop to a monitor on a 40' er that wasn't working.
The install chap didn't want to make a big enough hole for the HDMI connector, so he cut the cable in half and twisted all 19 wires back together.
He did use insulation tape though.
The fix was a mini HDMI cable and the mini connector slid right through the hole .