I started by making a tracing of the shape of the hull under the stern. I clamped a sheet of 1/4" plywood against the keel. I had to make a cutout around the wider part where the propeller shaft comes through so that it would lay flat.
I made sure that the top edge of the plywood was level to provide an accurate reference.
I made a scribing tool out of a mahogany scrap. It's pointed at one end, and has a hole and vertical notch at the other end. The idea is to put the point at a reference point, then put a pencil in the hole and scribe a horizontal arc onto the plywood. Then, making sure the tool is perfectly vertical, draw an intersecting line through the vertical notch.
The result is a series of marks that define the curve.
Next I shored up the stern with 4x4 timbers that are beveled on the bottom. The 1/2" plywood will help keep the timbers from sinking into the pavement.
Next weekend we get out the heavy tools and start removing big pieces. Should be fun!
We didn't get around to painting the deck, there was too much else to do and painting can be done pretty much any time.
Instead we removed the bolts that hold the lower rudder gudgeon to the keel, and gently tapped it down so that the rudder could be removed.
There was just enough vertical room to drop the rudder down onto the ground and allow the top of the rudder post to clear the counter. The rudder wasn't as heavy as I expected, maybe 120 pounds.
Now there's good access to the rotten timber. It's going to take some doing, but it could have been a lot worse.
Next we removed the propeller shaft so it won't get bent, and we won't be trampling on the expensive ProShaft Seal while we're working.
Next we'll shore up the entire stern area to keep its shape while we remove the structural floors and frames.
Removing the port garboard last week was so much fun, this week we removed the starboard one. Now that both garboards are out, I've invited the shipwright to come take a look at the horn timber, which shows some significant rot. Hopefully he'll have some time for us, so plan on coming to the next Meetup!
Here are some more details on removing the fasteners, this time focusing on those ancient bronze screws ...
Typically any fastener starts outside and is driven inside, then the head is covered up with a wooden plug, also called a bung.
The trick is to find them -- sometimes sanding off the finish is necessary to make them more obvious.
Using an ice-pick, poke it into the plug about half-way between the edge and the center. Be careful not to dig into the surrounding material as you pry it out.
Keep digging until the screw head is exposed, then use the tip of the ice-pick to clean out the slot (this is why I prefer slotted wood screws, but that's a story for another time ...).
India was built with a fastener schedule that I haven't seen before. Amidships, the planks have two copper rivets through the frame at each station and a screw into the corresponding floor timber (left photo). As we progressed aft, each station was fastened with screws where the rivets would have been (right photo).
That screw has been in there for longer than you've been around, so it probably has a good bond with the surrounding material, especially if it's bronze and the frames/floors are oak. Before trying to turn it out, give it a few hearty whacks. Then before trying to un-screw it, try screwing it in maybe an eighth of a turn, that will also help break the bond. Be sure that your screwdriver is absolutely in line with the shaft of the screw, otherwise the screwdriver will slip and ruin the slot, making the screw even harder to turn. If that happens, grab that sledge hammer and give it a few more whacks to try to deepen the slot, then try again.
Only after you've turned the screw out a fair amount should you use any kind of mechanical advantage. Once you're sure that the screw is cooperating, a brace and bit can speed up the rest of the extraction. Fortunately I was able to get all of the screws out using this technique, otherwise I would have photos of drilling out stubborn screws.
Bronze is an amazing material. Even after all those decades, this one still has all of its teeth.
After removing all of the screws, we went inside and took care of all the rivets as was described last week. Then a sharp knife helps loosen up the caulking between the seams.
Now for the moment of truth! Gently begin prying the plank at its end. If you find any resistance, stop and try to figure out what it is. Did you miss a fastener? Maybe the caulking is still tight at the point where the plank stops cooperating? Figure it out and be gentle or you could crack the plank or worse. Keep a sharp eye out for bungs that you might have missed, which are still hiding a screw or rivet.
If all goes well, this should be the easiest part. Just keep gently prying and the plank will just pop right out.
While drilling out the rivets from the inside, rivets were missing in a couple places that should have had them. It wasn't until after the plank was out that the mystery was solved -- the rivet wasn't long enough to get a rove on from the inside, so the builder just skipped it!
That's all for this week. Be sure to check back soon, and if you're in the area, stop by!
It was quite a process, finding and removing all of the copper rivets and hidden screws. Next weekend we'll do the starboard one, so feel free to come on by the Meetup! Here's how I did it ...
Start by punching a little divot into the end of the rivet ...
Then drill a small pilot hole ...
That helps make sure that the big bit won't wander as you drill through the shaft of the rivet to release it from the rove ...
Drill just far enough so that the rove comes free, then stop ...
Now you can use a narrow drift and a sledge hammer. It takes a good whack to convince the rivets to move, they're been in place for almost 90 years ...
A classic example of a butt block, with its pattern of 6 fasteners ...
Meanwhile on the outside of the hull, the rivets stick out enough to grab with a vise-grip or pry-bar ...
With a little prying and some choice words, the plank is persuaded to pop out of its berth ...
And the day's work is done!!!