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Thanks for the thumbnails. And the comment that bolt replacement was doable in the water. I have owned my Coronado 41 for 32 years. Always thought the keel was attached with J Bolts. Tapped two sistered SS bolts in the 90's. Don't have owners manual. Were your bolts tapped or broken J's ??
Best Regards,
Adrian
 

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They were tapped. Iron keels always have tapped holes for the bolts because you can't put J-bolts in an iron keel. J-bolts have to go in the molten metal hence they would melt. Lead melts at so much lower a temp than steel that it can be done but iron & steel have essentially the same melting point.
 
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This is great news. The argument you make had been my own thinking for years. The problem is my memory of the owners manual for Hull #23, which clearly showed Jbolts in the keel, for the Coronado 41. Possibly this was a "typical", or sloppy editing, and meant for lead keel constructions; or maybe they had used epoxy in a void cavity for bolting. Met a homeless guy once who claimed to have worked in the Portsmouth yard that built the 41's. He said there was a lot of glass holding that keel in place. You couldn't drop it. My concern is worst case scenario storm and wave forces. (Don't know why they claimed Jbolting. Might find owners manual on board and try to finally resolve this contradiction) Problem is that there is nothing left of the nuts on the forward 3 pair. How did you remove studs, and did you retap with larger bolts??
Capt Pops
 

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It is my understanding that Coronado 41's began life as a Columbia 41 (bubble cabin version) and were designed with lead ballast. The few California ones had lead ballast. The east coast ones listed lead ballast as an option, but I have no idea whether any were built that way.

SS J-bolts were the standard keel bolt attachment method on lead keels, but galvanized steel thru-bolts were the standard on cast iron keels. The thru bolts generally terminated in a pocket that was sealed shut after the nut washer was installed. Some cast iron keels have a flange and the keel is through bolted through that flange using what was essentially a flat head carriage bolt. That type of bolt is an easier bolt to replace, but it is unlikely to be found on a boat this large.

Drilling and tapping cast iron for a replacement keel bolt is considered bad practice since iron castings tend to be inconsistent in hardness and may contain air spaces.

Jeff
 

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Understood. It appears that I have same attachment system and arrangement as shown in your thumbnails, with an additional two stainless bolts that were tapped after drilling new holes, between the existing front three pairs of keel bolts, 20 years ago. The plan would be to attempt extraction, if I can get enough metal in a pipe wrench to bite, and turn the bolts out, after soaking with anti seize fluids. Can't imagine though, that any cast iron metal threads would remain for new bolts after 43 years of water and galvanic activity. Have also always been concerned about integrity of the newer bolting. Is there a best path forward from your experience for this predicament? My cargo is my children.
 

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I would first ascertain if the keel is lead or iron - I was unaware that any but the Mk III Columbia 43's had lead and my comments only apply to iron keels..

Mine came out with the boat out of the water since they were so wasted - didn't want to chance removing anything in the water - yours sound the same or worse. As bad as mine were (see pics) the boat didn't leak a drop and it had motored up from Santa Monica to San Rafael like that

The studs came out quite easily and the threads in the keel only required chasing - I used a bottoming tap to get that little extra bit of thread. I thought the bolts looked kind of skimpy for a 10K Lb keel but upon checking I found they were more than adequate and well within standard engineering practice - many multiples of safety factor re: breaking strength. FWIW, while it was off, the boatyard picked it up and moved it around, flipped it over etc. using only a couple of "grade nothing" bolts to hold the forklift lifting brackets on it.

If I were one of your kids :wink I'd pull the boat, drop the keel, not caring if the nuts sheared off, pull the studs with a stud puller - when the keel is off there is lots of exposed stud to grab - the bottom of the boat was very thick, like 1 1/2" IIRC. Then examine the state of the threads in the keel to see if they can be re-used. If not, I'd go up to the tap drill size that would prep the holes cleanly for bigger studs - whatever that size would be (I suspect 1"). Then re-tap the holes, reinstall new studs, sandblast, epoxy seal and fill & fair the fin while it's off, put it back on with new S/S floors and re-fair the joint on the hull.

That's what I did, minus oversizing the studs. Pics attached

It's a big job in the sense that you're dealing with huge weights and heavy equipment (pro's for that) but it's not difficult or technical - the worst part was fairing the hull joint - a very awkward position in which to do a lot of sanding & filling.
 

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Thanks so much Jeff ! Especially for the "Keel Prepped for Mounting" image. I am Cast Iron. Sand Blasted keel, removing all gelcoat to expose metal in 1996. Found it to be a bad casting with void holes at bottom that had been packed. Treated everything with corrosion inhibitor and recovered with epoxy and faired. Time has probably arrived to do what you have done. You've helped identify the path forward.
Many thanks,
Adrian
 

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Would everything said about the Coronada 41 keel apply to the Columbia 41 keel?

What's the easiest way to determine if you have a cast iron keel? Would a strong magnet held against the outside of the keel work? Or is the iron too far inside FRP for a magnet to be attracted?

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Both 41's were the same basic boat - just different deck mouldings. Like a Chevy and a Pontiac.

Pretty well any magnet will do but rust bleeds will probably also be a giveaway. :wink

The keel is a bolt on, not inside thick fiberglass.
 

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Both 41's were the same basic boat - just different deck mouldings. Like a Chevy and a Pontiac.

Pretty well any magnet will do but rust bleeds will probably also be a giveaway. :wink

The keel is a bolt on, not inside thick fiberglass.
I'm looking closely at a 41 Columbia. The few keels bolts I found were shiny and bright. At least the tops were. The keel was the roughest looking thing I've seen on a boat. It looks like an old house with 50 layers of peeling paint.

I guess I'll head back to it and have another look at the keel bolts. I'll try to find all of them this time. And I'll take a strong magnet just to be 100% certain what the keel contains.
 

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I'm looking closely at a 41 Columbia. The few keels bolts I found were shiny and bright. At least the tops were. The keel was the roughest looking thing I've seen on a boat. It looks like an old house with 50 layers of peeling paint.

I guess I'll head back to it and have another look at the keel bolts. I'll try to find all of them this time. And I'll take a strong magnet just to be 100% certain what the keel contains.
That description makes it almost certain the keel is iron. There should be 5 pairs of keel bolts - 10 total - with channel iron connecting the pairs as backers.

I've attached before & after pictures of the hardware from my Columbia 43 as well as a shot of the bilge after installation - the setup was the same on the 41.

Also a link to a thread about cleaning up and fairing an iron keel. It's a lot of work but not all that expensive or difficult.

http://www.sailnet.com/forums/gear-maintenance/83304-shark-24-keel.html#824351
 

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Hi I bought a Coronado 41, what size water n fuel tanks did you go to? Any possible links to purchase the same? Looking to sail the America’s at least and maybe make trip across the pond in the future!

Thanks
 

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Hi

I'm about to buy a corobado 41.
The truth is that I can't find much information about this ship.
If anyone currently has any and can advise me?
Thank you
 

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[QUOTE = "JUAN CARLOS, publicación: 2051666754, miembro: 523470"]
Hola

Estoy a punto de comprar un corobado 41.
La verdad es que no puedo encontrar mucha información sobre este barco.
Si alguien tiene alguna actualmente y puede aconsejarme?
Gracias
[/CITAR]
SALUDOS JUAN CARLOS ESTOY EN LA MISMA SITUACIÓN TENGO UNO PERO HAY QUE HACERLE MUCHAS COSAS PARA RESTAURARLO ENCONTRADO ESTAS PUBLICACIONES Y NO ESTOI SEGURO DE SEGUIR ADELANTE CON LA COMPRA EN REALIDAD LO QUE ME PREOCUPA ES EL ESTADO DE LA JARCIA EL PRESUPUES VARADERO EL CASCO PARECE ESTAR ACEPTABLE
 
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