Jiggs

December 09, 2018 by Lukasz Kumanowski

To have some rest from melting lead and extracting keel bolts (I just reached the second nut! ) I prepare for epoxy work with lamell-glued ribbs. These will be built to repair broken frames on Meritaten - all at the turn of the bilge.

If there were just few frames I would not bother with making the jigg but since there are many - it should be easier with proper tools.
Besides - Glypto also requires reframing.

First tool needed is something to take the shape of existing frame in a boat. Glued sticks, cardboard, spilling - all these will do the job but I like chain template as it is the fastest and looks cool!

I intended to make my own but, as a custom, I checked first on blocket.se.
Well - here there was: Johan is making them on CNC router at reasonable cost, delivering complete with screws and wing nuts. I got mine very quickly and I’m impressed by the quality. Nice time saver!

The second part of the puzzle is lamination jigg. In principle it is a table top to which you attach solid anchor points to be used for holding gluing laminate in place. Anchors are spaced to match the shape taken with, for example, chain template.
Since I will be building 20+ laminates I’ve decided to make it adjustable.

Nothing fancy but it took me few hours to prepare all wood pieces and assemble them into square and true jigg.

At the end of the day I got 1 x 1,4m working space with 15 movable anchor points. Dry fitting to example shape shows that there is a chance that this will work.

Keel bolt #1 - Extraction

December 02, 2018 by Lukasz Kumanowski

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.

Keel bolts - can we get serious now?

November 26, 2018 by Lukasz Kumanowski

After digging deeper into the keel pocket it became more and more difficult to chisel out lamells in lead and melt them with MAPP burner. In desperation I even started drilling this damn lead but it ended up as expected - drills get clogged very quickly with easy-melting, sticky lead. In the end I broke the drill bit and almost seized my machine.

Something better was needed.
Something serious.

I’ve figured that even 2400 degrees C which MAPP gives is not quick enough to melt lead (which melts in ca 300 degrees) due to extremely quick heat dissipation. Two things can remedy this: even higher temperature and/or narrower welding nozzle - to heat the metal in smaller portions, quickly enough to melt it into drops before it solidifies again.

The highest temperature set available to me is acetylene welding set: welding gas + oxygen tank.

I’ve decided to give it a try. After all - I was desperate as my current approach stopped working.

So we got serious now: 3000 degrees C.

And it goes like cutting through butter!

A combination of high temperature and concentrated heat makes a trick.

The nice thing with acetylene welding kit is possibility to fine-tune flame composition to suit particular need. In my case I wanted concentrated but not very strong heat so adjusting oxygen flow gave me a torch which melts lead but does not cut it.
This same thing - adjustability - makes this set a little tricky in the beginning, when one learns how to adjust the flame. As seen on the film below - lightning the burner first time was a little troublesome but with few trials one gets a feeling for initial gases flow needed to succeed.

Unfortunately - oxygen tank lasted only 30 minutes. I need to get more supplies at hand. Anyhow - these 30 minutes made a work equal to 3 hours yesterday (and one MAPP gas tank!). So it was worth it. And no more chiseling in lead!

Meanwhile I ordered also smaller MAPP burner end-piece. I hope that it will work equally well - and I can have use for all this MAPP supply from my storage.

As for lead in the pocket - I intend to close these pockets again with lead but NOT pouring metal into the pocket. Instead I will use US-boatbuilders’ method: making lead pluggs which are hammered into the pocket, thus filling the space and making it watertight. The problem with poured lead is that one needs to accommodate metal shrinking on cooling (roughly 15% of volume) and also - future removal is again time- and money-consuming exercise. Having a plug hammered into pocket gives a possibility to drill and tap a hole in the middle, screwing in eyebolt and pulling the plug with hydraulic jacks.
Good discussion about ways of doing this is on WoodenBoatForum:
http://forum.woodenboat.com/showthread.php?158899-Lead-Ballast-Question/page2

Keel bolts - melting lead

November 18, 2018 by Lukasz Kumanowski

After successfully unscrewing nuts inside the boat - with the biggest spanner I could get in Biltema - it was high time to get to work on reaching nuts on the other side - in ballast keel.

My boat has iron keel. Unlike American-built boats, most Swedish boats with iron keel have bolts NOT going all the way through iron but instead they are ended a couple of cm from the top.

There are also versions where bolts are directly threaded into iron ballast. Luckily my boat is not one of them - removing such bolts is impossible without dropping the ballast.

Solution used by Arvid Laurin is to have bolts going through iron, a few cm, and end up in deep pockets. Here the builder will install washers and nuts on threaded bolt end.

On boats with cast which came out from foundry too light, the pockets are filled with lead. If opposite - too heavy ballast - filling is done with cement or wood.

In my case I have lead-filled pockets.

Filling has 2 functions:

to stop water from entering into bolt
to prevent nut&bolt from spinning when it is being re-tightened or unscrewed (to change washers or for removal)

Lead seems to be the best option indeed - adds weight to the ballast and is not permeable for water.
The disadvantage is that some day (like after 60 years) someone will need to remove it to get into the nut and this will be a hell of a job.

So here I am now, with hell of the job.

I’ve consulted with Janne Gustavsson - who has built my boat - on how I should proceed. Well, the best would be to melt the lead, he said. But you need to have a good gas burner for that - all this iron around will dissipate heat very quickly.

All right, I thought - so I buy a gas burner. And so I did - bought propan-butan torch and cheerfully tried.

Nope! With propan-butan I can maybe make creme-brulle for desert but it is too weak for this huge metal clump around.

Off again, I went to buy something stronger - the strongest in fact, if you don’t count acethylene-oxygen setup: MAPP torch.

Cheap it was not but hopes were high so I’ve tried with my new, heavy duty toy.

Weeelll - nope! Not so easy.
In fact I could see that lead is starting to melt but in the next second is was solidifying again. Too much thermal mass around, dissipating heat very quickly.
After blowing 2400 degrees C for 5 minutes into one point on lead it just got soft. Luckily though - this thermal dissipation protects the wood above the ballast but fire extinguishers were at hand anyway.

I then realised that this will not be like walking in the woods. Elbow grease is needed.

I’ve started with mechanical means, to see how it will develop.

It turned out to be quite possible to chisel into lead and cut away small chunks at at time. As long as I was on the surface it went pretty good but the deeper I went the more difficult it became - due to lack of space for tools.

After trying different ways of chiseling the lead I came to a hybrid technique: chiseling and melting.

At first it seemed easiest to make horisontal chipping and then melting lead which sticks out.

The idea is that by chipping the lead you get it separated from material around thus less likely to transfer heat too quickly to deeper layers. It worked quite nicely but after a while I’ve noticed that when melting the upper chips the lead flowing down stops on the bottom chips and solidifies again.

Obvious solution is to chisel vertically - and have gravity on your side.

This prove to work much better.

After I got deeper into the cast opening the lead dripping down is gathering on iron shelf and instantly solidifies again but is very easy to remove - it poorly adheres to rusty iron.

So now I continue my efforts in this way. Chiseling vertical openings, rising the lead and then melting it with flame. Works pretty well but we shall see how it goes when I finally reach this huge nut and bolt deep there.

It will be probably necessary to do the same on the other side of the ballast - otherwise I cannot free the nut from surrounding lead.

Well - I have a few months to do this - and 6 similar bolts after I’m done with this here.

Meanwhile I investigate if I can get even stronger torch. Worth trying!

IR view

November 04, 2018 by Lukasz Kumanowski

On a cold morning, with boat worm and cozy inside, you can see the underlaying structure and metal fasteners constituting foundation of the deck. Poor man’s IR view.

When working on deck repair I needed to know where and how the deck panels are connected. IR camera is handy then. Simply warm up the interior, go on deck and start inspecting.

A part of boat’s history could be revealed. Not only how she was built but also traces of previous repairs, plugged & glued repairs or traces of long gone equipment.

Unfortunately, this does not penetrate deep enough to inspect ex keel bolts. Too deep, burried in wood and iron. I’ve tried heating them locally to higher temperatures, in hope that I could then see their thermal image on the outside of hull (with boat on land).

Nope.
But worth trying, anyway.