Folkboat keel bolt material?

Niander

Niander

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Im replacing the keel bolts
as they are probably 50 years old!
anyway i have 4 out...for now
cast iron keel[i think]folkboat?
20 mm diameter
Now what material should i get the new ones made from?

mild steel?
high tensile steel?
stainless steel?
20mm steel threaded rod?
phosphor bronze?
etc
 
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Your originals look as though they are wrought iron - now more or less unobtainable unless you can get a knowledgeable blacksmith to forge some from recycled WI.

Bronze would be nice. Preferably silicone bronze. I just happen to have 3 silicone bronze keelbolt blanks that I bought for a wooden boat several years ago but never fitted. I was told by the seller that they were made for a Folkboat. They are 610 mm long, 28mm dia. and are unthreaded (so you would need to thread them to suit whatever bronze nuts you are able to source from, say, Anglia Stainless). The bottom end is flared out in a cone shape, with a max dia of 46mm over a length of about 50mm.
They were destined for a trip to the scrap metal dealers but I'd be much happier if they were used for their intended purpose. Send me a pm if you're interested.
 
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Mild rusts and high tensile even faster. At 20 mm dia, pretty over spec for the job.
Therec were a couple of threads on the WBF 'over there' might be worth a search. Remember the guy sawing through the bolts with a recip saw from the side.
DW
 
Just a thought, but if your originals are actually wrought iron, then it might be worth offering them to a blacksmith for recycling rather than chucking them in the dustbin.
They have a slightly fibrous grainy look to them - maybe someone like Vyv Cox or another metallurgist forumite can confirm???
 
The vast majority of boats these days have stainless steel keel bolts in iron keels. There should be no corrosion if sealant is applied vigorously to the joint when rebedding the keel.

However, yours appear to be some type of carbon steel that has corroded a little over many years. Replacing them with something similar is going to be OK, again provided the sealant keeps the water out. I would be looking for purpose made studs rather than lengths of studding, produced from good quality bar stock. The only consequence of going this way is that in future it may be difficult to get them out again if water does get in. But it's the way Moody chose to go and mostly is a satisfactory one.
 
Niander said:
produced from good quality bar stock.

You talking mild steel?

Is stainless steel keel bolts ok in iron keels?
Click to expand...

Not mild steel but a carbon steel with some chromium and nickel, such as the old En 19, now AISI 4140.

As I said above, the vast majority of boats have stainless keel bolts with cast iron keels. Provided the sealant is OK there is no problem. Even if the water does get in the keel will rust and the bolt will come out.
 
Resurrecting an old thread I realise, but as I now own the boat in question, and had an issue in the area of the FWD Keel bolt, I've just taken the precaution of lifting the keel bolt out. I'll admit to a degree of surprise, but there's absolutely no sign of any visible wear or corrosion; none. The bolt was 'fiercely' torqued up, but once moving came out easily! This is testament to Niander's work on the bolts, and to Vyv's advice. Cheers to both, all I have to do now is to regrease it, refit it to the right torque, and we're away again! Paul, can you recall the torque setting for these bolts that you used?
 
Neither Dave; I came through the canal the other week, and have endured a persistent leak from around bolt 1 after an incident in Stromness, so along with a couple of other issues, decided to have her craned out in Inverness last Monday, and trailered her home. I've a few bits to do and this is convenient timing. Our crane out is due to be on the 26th, or if WOW, then the 8th of October.
 
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