hit a rock in the keel

Dec 31, 2016
319
Beneteau Oceanis 351 Charlottetown
This is now a puzzle to figure out or is it a pool?

Who's for lead?
Who's for iron?
Who's for steel?
Aluminum?
Glass?
Other?
Maybe we can give odds for each?

I bet on steel. The wing seems too thin to be lead. I think lead that thin would bend on a soft grounding, so not the best design choice for wings. Iron doesn't bend well, but steel bends better.


:plus: not sure about the "extremely high temperature" part (at least 800 degrees, is that evenly high?), but it's lost strength and will loose more from bending back unless annealed properly.


Maybe a heavier timber, 4x4? But that's essentially the idea I'd favor. You can even do it slowly, over days.

-Will (Dragonfly)
I'm saying it's lead, if it were steel it would have to have been welded in pieces to make that shape, unless it was cast steel, and I'm doubtful any company would go to that expense.
 
Sep 30, 2016
339
Island Packet IP 44 Ventura, CA
The material is simple to determine-
Iron or steel- a magnet will determine (probably not iron, doesn't bend).
Lead- very soft. You can scratch it or gouge it very easily with a sharp tool. Much softer than aluminum.
Aluminum? Do they make keels out of aluminum? Seems to reactive. But if it is aluminum it probably wont bend back without cracking. Id just saw both sides off. I really cant see those fins doing much.

My bet is its lead. There is no need to heat lead to bend it back. Its extremely malleable, and warming it will do nothing but waste your time. And if you use a torch, you are more likely to melt it. It melts just over 600 F. Just support it underneath and pound it straight with a mallet, not a hard hammer. It will take some hard whacks, so dont hold back. And you are going to need about a 3lb mallet at least (Harbor Freight, orange plastic dead-blow mallet. Cheap). I wouldnt worry about the gouge on the tip. Id just file or grind it smooth. Too small to have any impact on the dynamics of the boat.
 
Last edited:
Jul 27, 2011
4,988
Bavaria 38E Alamitos Bay
So, let’s straighten out something. We have keels of iron and lead. Do we have steel ones as well? (See post #16, et al.) Is an “iron” keel actually of steel? What are we discussing? Cast iron versus steel, cast iron versus lead, or steel versus lead, or something else? Educate me!

KG
 
Last edited:
Jul 27, 2011
4,988
Bavaria 38E Alamitos Bay
OK. Cast iron is an alloy of iron and carbon, w/ between 2 and 4% carbon; whereas, steel is an alloy of iron with between 0.2 and 2% carbon. Cast iron is brittle. Would not expect it to bend up like that, as others have said.
 
Last edited:
Sep 30, 2016
339
Island Packet IP 44 Ventura, CA
Steel is "of Iron". To get typical steel you mix in a little carbon with the iron. Cost more, but steel has some very favorable properties. Iron is cheap and heavy. Both love to rust.

Lead doesn't rust like iron/steel, but it does form a thin oxide layer. Heavy, soft, and I'm pretty sure a bit more expensive than iron.
 
Mar 20, 2004
1,729
Hunter 356 and 216 Portland, ME
most hunters had steel keels instead of lead. Lead is a soft metal, I would be surprised hunter would have made a wing keel at of lead. One way to be sure is to try to drill a small hole into it. Steel is a much harder alloy then lead and is very difficult to drill. Lead on the other hand is soft and the drill bit will easily bore into it.

I would consult a black smith or metal forger and seek there recommendations.
Steel or lead loses a lot of its strength after it's been bent. I believe the metal needs to be heated to a extremely high temperature or it can break off if you ate onto bend it back.
Not correct - most Hunters from early 90's to 2008 had lead keels, and all wing keels until 2007/2008 were lead. what rgranger said is correct - you should use moderate heat to soften the lead and wood blocks and a sledge to bend it straight. trying to bend it cold might crack the wing - and the keel is molded in one piece. fairing putty can be used to fill any minor gouges. We've done this with several wing keelsand it's worked well, just take your time
 
Jun 8, 2004
10,024
-na -NA Anywhere USA
As a former dealer, lead, but take a magnet to see if it sticks , then cast iron. No real way to repair lead but more pictures needed. I suggest filing a claim and order a replacement from Mars Metals in Canada. You will need to give them the old keel. They have the molds as they supplied the keels
Photovis an N Scale Climax engine that runs
CE8F3427-CD36-49CF-8F9A-B133286C4E0A.jpeg
 
Last edited:
Oct 24, 2010
2,405
Hunter 30 Everett, WA
Happened a few times to us over the years in the Bahamas and like everyone else to whom this happened, I just banged back the fin with a small sledge. Lead is a pliable metal. Consider yourself fortunate you don’t have an iron keel.
Our keel looks just like that (without the bend) but it's cast iron. It was pretty rusty when we got the boat.

Ken
 
  • Like
Likes: jssailem
Dec 8, 2013
33
Hunter / Aragosa 34 / 32 831 Toronto
Marchaj-Hydrodynamics (?) has proven that wings on keels do not generate lift, at least not enough to overcome the resultant drag. What they DO is help to keep the water from slipping over the end of the keel when heeled; aka "end loss" That is also what the winglets on planes are meant to do.
The other design option is to make the wings- in our case, the keel- longer/deeper. Thus the design philosophy of glider wings and deep fin keels...………
As for the fix, as suggested, gentle heat and use wooden blocks when whacking away.
 
  • Like
Likes: jssailem
Nov 10, 2009
20
Hunter 410 Rock Hall, MD
Hi, I have a Hunter 320 and we hit a rock in the keel and it twisted one of the fins. Has anyone had to repair something like that? How do I fix it?
It is really necessary to fix it?
Thanks for the help


View attachment 175460
I got stuck on a rebar going through Kent Narrows, MD some years ago. It bent the starboard wing up some but did not compromise the integrity of the keel or the attachment point. The service manager at my marina advised against working the keel because they felt that EITHER the keep could be damaged further, the attachment point could be damaged, or nothing could be accomplished and I would be out several thousand dollars for nothing. To be fair, my wing is not bent as badly as yours but it still sails well with no tack bias that I can detect. I would consult with your marina service department or if you can find one, a local Hunter service and inquire how to proceed...if at all. My boat is a 1998 Hunter 410.
 
  • Like
Likes: rgranger
Jan 19, 2010
12,362
Hobie 16 & Rhodes 22 Skeeter Charleston
I got stuck on a rebar going through Kent Narrows, MD some years ago. It bent the starboard wing up some but did not compromise the integrity of the keel or the attachment point. The service manager at my marina advised against working the keel because they felt that EITHER the keep could be damaged further, the attachment point could be damaged, or nothing could be accomplished and I would be out several thousand dollars for nothing. To be fair, my wing is not bent as badly as yours but it still sails well with no tack bias that I can detect. I would consult with your marina service department or if you can find one, a local Hunter service and inquire how to proceed...if at all. My boat is a 1998 Hunter 410.
That is a different take.
So! Have you sailed the boat much since striking the rock and if so... how did it sail?
 
Apr 5, 2009
2,774
Catalina '88 C30 tr/bs Oak Harbor, WA
So, let’s straighten out something. We have keels of iron and lead. Do we have steel ones as well? (See post #16, et al.) Is an “iron” keel actually of steel? What are we discussing? Cast iron versus steel, cast iron versus lead, or steel versus cast iron, or something else? Educate me!

KG
I have raced on one boat that had a silicon bronze keel with 6'-6" draft and ballast / displacement ratio of 56%. Of course that was due to the big bulb of lead that was attached to the bottom.
 
  • Like
Likes: rgranger
Feb 10, 2004
3,917
Hunter 40.5 Warwick, RI
I hit a ledge and bent up the wing a bit less than yours. Worried, I hauled out and paid my marina to hammer it back into place. I spent a couple thousand on this folly. I have since bent up the wing again - it may not be the same one- and I have gently pounded it back into the approximate correct location myself. My keel is lead- obviously.
So my recommendation is to get a 2# mallet and with wood block backing to the ground, take a couple hours and tap it back into shape. I doubt that heating will help since the lead is a huge heat sink. Don't worry if it is not perfect. Don't worry if a piece of the wing comes off. Smooth it with filler if you feel the need. Slap on a coat of anti-fouling and forget about it. Go sailing. But really try not the hit that same rock/ledge/whatever again. Pick a different one next time....:yikes:
 
Mar 20, 2004
1,729
Hunter 356 and 216 Portland, ME
Maybe dave can confirm, but the 30T is the earlier generation design, the 3 digit boats used lead. I almost bought a 320 and it had a lead keel, along with the 340 and the 356 I eventually ordered. My '96 29.5 also had a winged lead keel; the owner after me bent a wing badly and abandoned her. She was bought by a very handy sailor who restored her and fixed the keel as I described earlier;We became friends after he joined our Hunter club, and I recognized the first Escape! He later traded her in for a 320 (also lead keel) because he wanted a larger boat. Hunter switched to cast iron keels in 2007/2008 because of price - but butt ugly and lots of drag - they need a big chunk at the bottom because of the lower density of the iron.
 
Jul 1, 2017
64
Hunter 356 Brightlingsea
I believe that if it was cast iron it would have broken rather than bent.

Try a magnet on the keel. Or start to drill a hole in the material somewhere where the material is thick to a depth of about 3-4mm using an 8mm drill, collect the swarf. Try a magnet on it, if it's non magnetic then its likely to be a lead alloy (Lead can be alloyed with other metals to make it harder such as Tin), you could then try a blowtorch on the swarf to see how readily it melts.

If it is a lead alloy (and I think that it will be) then let the boat down onto a robust surface so the base of the keel is resting on it, and using a heavy hammer with a piece of hard wood between it and the wing beat the wing back into shape. Warming the keel as suggested could be done by lighting some charcoal and once fully lit distribute it over the area that needs reshaping. Since pure lead melts at about 300 deg C and charcoal produces about 1100 deg C you will need to monitor the temperature carefully. If you can get one an infra red thermometer such as ( Digital Infrared Thermometer Temperature Gun Non-Contact with U9V9 | eBay ) will work well to check the temperature from the bottom side......clearly leave a margin of temperature from top to bottom as the top will be hotter than the bottom. I think I would aim for about 200 deg C. Or just use a powerful blow torch.....I doubt you will make much progress with a plumbing blowtorch, you will need a Propane heavy duty torch.

Winglets giving lift is not what you need on a keel, it will only create "lift drag" rather than just "form drag" and slow the boat.

Neil
 
Last edited:
  • Like
Likes: BrianRobin