Keel bolt #1 - Extraction
I almost lost hope to find this nut, suspecting that it might have corroded into powder and melt with lead when I treat it with acetylene torch. But then - something started to glow red under the flame - iron! Finally!
I managed to melt all the lead up to the nut and little behind it - good! I don’t have to remove the same amount of lead on the other side of the ballast keel.
So now it was time to unscrew this 60-year old screw. Tools of the trade:
It would not move without heat so my trusty MAPP torch came to play. After applying heat for 30s I could unscrew the nut without any problems.
It came out in surprisingly good shape.
So now it was time to apply some force!
Estimated strength of this thread is 3 tons (when new). I got 5/8 connecting nut and screw to use as keel bolt extension and anchor for my pulling rigg. Two 10 tons hydraulic jacks should give me some surplus force - and they will be handy next seasons when I will work on the backbone rebuilt.
So up to the cabin floor!
I’ve placed the whole jigg on some 30x70mm wooden beams to protect the floors and distribute forces. On top of jacks I have rectangular steel pipe which I found in garbage. Anchor chain and strong shackle are wrapped on 5/8 screw which is connected to keel bolt with “skarvmutter“.
On top of the beam I have small water level - to control that I lift both sides at the same pace. Adjusting the chain was needed to make sure that the keel bolt is being pulled vertically straight - otherwise it might brake or by bending - increase the size of hole in wood, forcing me to use bigger replacement rod later.
I pumped the jacks to stretch the chain and apply pulling force to the keel bolt. It did not move. Leaving it on pressure I went down and torched the bottom of the bolt for 30s with high-power flame. Coming back to the cabin I started pumping the jacks some more.
If anyone will attempt to do this - beware that there are huge forces involved. Should anything brake - the chain will snap with great force and velocity, cutting anything on it’s way. Face protection is a must - I wear full face mask when doing it. Better than nothing. I also try not to be in harms way when pumping the jacks - this chain is a loaded gun!
After some more pumping - and keeping my eye on the water level - I went down to see if the bolt in keel pocket has moved. Yes! It disappeared!
So now I continue pumping and after a while I can see the bolt emerging from it’s floor. Jacks went to their max height so adding some wooden spacers was necessary. Installing the setup again - and we pump more.
It was a good idea to oversize the jacks. The price difference between 4 ton and 10 ton jack was minimal and it is always more comfortable working with some power reserve.
After 2 sessions with adding spacers and re-setting the jigg the bolt is out. As it emerged I was surprised to see it in such a good shape. But then the last bit came out - and it looked as I expected.
Well, it was high time to take care of things: half of the total thickness (3/4 inch) is gone. I estimate that most damage occurred close to ballast - wooden keel junction or at the connection of floor to wooden keel.
By the look of it I would say it was a wrought iron. Not bad for 60 years! I plan to replace the bolt with the same type of iron - there is only one shop in the world (not kidding) which still sells wrought iron. And it is in England.
As this bolt is one of the 5 bolts to which I have relatively easy access - I’ve decided to go on and extract one more. It will probably be in similar condition so there is no time to wait with replacement. If I manage I would like to replace all 5 this season but that depends on how long will it take to melt lead in pockets - and how much will all these oxygen tanks cost!
Without further due - I started melting my way to the second bolt.