hit a rock in the keel

Apr 5, 2009
2,774
Catalina '88 C30 tr/bs Oak Harbor, WA
I would not use heat to bend lead. I have melted a lot of lead for casting small items and it does not really get more mailable until shortly before it melts. When it melts, it is all or nothing so there is little warning before a large chunk of it turns to water.
 
Apr 8, 2011
768
Hunter 40 Deale, MD
I would not use heat to bend lead. I have melted a lot of lead for casting small items and it does not really get more mailable until shortly before it melts. When it melts, it is all or nothing so there is little warning before a large chunk of it turns to water.
Interesting point I wasn't aware of Hayden. Caused me to do a little digging and ran across an interesting article which carries a warning about heating lead and working with it (beyond the obvious hazardous fumes!):

"While most malleable metals are also ductile, the two properties can be exclusive. Lead and tin, for example, are malleable and ductile when they are cold but become increasingly brittle when temperatures start rising towards their melting points."

The full article is here: Learn About Malleability and the Treatment of Metals

Don't have much firsthand knowledge on the subject, but it makes for interesting - and educational - reading.
 
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Apr 5, 2009
2,774
Catalina '88 C30 tr/bs Oak Harbor, WA
That is what I have found. when you start getting close to the melting point, it gets grainy and looses ductility. Then it just suddenly melts into a puddle. Looks like something from a Marvel movie. It conducts heat so well that a large area all stays the same temp so you do not get local spot melting. Sort of like the Silver Surfer.
 
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Apr 8, 2011
768
Hunter 40 Deale, MD
That is what I have found. when you start getting close to the melting point, it gets grainy and looses ductility. Then it just suddenly melts into a puddle. Looks like something from a Marvel movie. It conducts heat so well that a large area all stays the same temp so you do not get local spot melting. Sort of like the Silver Surfer.
So maybe heat up the entire wing until it melts off, do the other side, and have a fin keel. Nice.
 
Apr 5, 2009
2,774
Catalina '88 C30 tr/bs Oak Harbor, WA
V interesting......thank you Hayden.......I take back my poor advice!
Neil
Most of us have heated up steel to bend it so it is logical to think this will happen with other metals but they can do some weird things. For instance, Rebar is ductile at room temperature and can be bent into the desired shape to make concrete reinforcement hoops and ties. Below about 40º to 45º it "freezes" and gets brittle and will break if you try to bend it.
 

dLj

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Mar 23, 2017
3,373
Belliure 41 Sailing back to the Chesapeake
Lots of speculation in this thread. Can the OP take a magnet and see if the keel is magnetic or not? Then we may be able to actually walk through a logical method of how better to fix the bent keel. Just as a FYI, I just posted in the corrosion discussion group a blurb on cast iron. Cast iron is a generic term that means little to nothing in a discussion like this. For anyone interested, here's the link:


dj
 
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dLj

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Mar 23, 2017
3,373
Belliure 41 Sailing back to the Chesapeake
@Fabian Have you been able to test if your keel is magnetic or not?

It doesn't say in your profile where you are located. Do you have a fairly large junk yard for metals close by you? They will often have a hand held instrument that's often called a metal monitor. It's a hand held XRF gun that can tell you what metal you have. They certainly won't lend it to you (these babies cost $30K to $60K depending), but you may be able to get them to come to your boat and tell you what the metal is that your keel is made from. It only takes a minute or two with the gun. If you can do this, then take a photo of the display that gives the chemistry of the part, not just whatever alloy it may say you have. It probably can't tell you the actual alloy accurately.Well, if it's lead it will...

If this is not possible at least if you can see if it's magnetic or not.

dj
 

DArcy

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Feb 11, 2017
1,691
Islander Freeport 36 Ottawa
That's a great idea. You could even cut a small portion off and take it to a lab with an XRF instrument. It only needs a small sample but you should remove paint to avoid contaminating the sample. We have one at work, amazing instruments.
 
Oct 19, 2017
7,733
O'Day 19 Littleton, NH
I sold parts of my old hobie to a local junkyard. The tiller was metal coated in vinyl. They paid me for the weight in aluminum prices. I told them I thought it was marine stainless under the vinyl because it was pretty heavy. They put a magnet to it and no reaction. "It's aluminum!"
Marine stainless isn't magnetic either. But, considering the weight, I probably got about the same amount, either way.

-Will (Dragonfly)