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I hope a Columbia expert might be able to help me. I have been offered a Columbia 40 because the owner doesn't want to sail now (no terms yet, just a general "Are you interested?" comment - so I don't have many details). The boat has been on the hard for a while but has a diesel engine.

Anyhow my question is this: how do you tell if the steel skeleton is in good shape? Given that it is a 1960s boat, it could have any number of issues - but any other comments on what to look out for would be very helpful.

Thanks for your help

Peter
 

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According to a website (columbia-yachts - sorry I can't post a link)

"The Columbia 40 may be the only model that used a steel skeleton to reinforce her hull and - more importantly - spread the load of the shrouds. Here is Columbia's explanation from the Columbia News, Spring, 1965."

Apparently steel pipe is embedded in the hull to spread the load from the base of the mast.

It is this (invisible?) skeleton that concerns me.

Peter
 

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al brazzi
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New one on me, I would be concerned as well. Further I would assume its not serviceable without a damn good survey. I will defer to more specific experience, I would suspect it would be limited to a mast step or bulkhead bracing structure.
 

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Steel encased in polyester resin and glass cloth for more than 40 years?
Even for free I don't think I'd be much interested in that recipe for disaster.
 
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I owned a Columbia 40 for 11 years and am very familiar with the chainplate skeleton. It consists of two parts: 1) a mild steel pipe running from the mast step on the keel to the bow forestay stem fitting; 2) the chainplate system is a welded mild steel grid structure extending down to the mast step. The chainplates connecting to the rigging are stainless welded to this grid.

All of this is glassed into the hull. The first place to look is the pipe going to the forestay. It is glassed in after the hull build and you should be able to see whether it is rotted or not. If rotted, you will see rust and bulging of the secondary glass tabbing it in.

The chainplate grid is glassed into the hull as part of the primary build, so it is more difficult to access and determine. One side is glassed inside the hanging locker, so this is relatively easy to get to. The other side is hidden by cabinet work, and all of that needs to be removed to access it. This is not easy.

Even though the grid is buried in the layup, if it is really rotted, you will see the glass bulging out, and possibly rust stains. You could also drill a couple small holes in the grid area and see if you hit solid white metal or a pocket of rust and rot.

If you do find rotted metal, it isn't all that difficult to fix. The PO of our boat tore it all out and replaced it with stainless steel. This is very expensive, difficult and overkill. Other owners have simply made external chainplates, beefed up the hull with a few layers of glass where they mount and call it good. The pipe connecting the step to the bow fitting is overkill and unnecessary - this boat was designed for open ocean racing where the rig would be cranked tight and the pipe was an attempt to stiffen the boat in this direction. The boat is way overbuilt by today's standards, and you will never need any additional stiffness for any reasonable sailing you will ever do with it. I'm not sure that pipe was even necessary back in the day - it was likely just an untested idea.

So worse case if completely rotted: have some external chainplates and backing plates made to match curve of hull, glass some inside reinforcement in the mounting area and call it good. This will probably be <$1,000.

Mark
 

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I have a 1965 C-40 and have replaced the chain plate webs port and starboard. Look for any deformation of the hull below the gunwale around both the port and starboard chain plates down to the water line which will be indicative of the mild steel deteriorating and "bulging" the hull from expansion of the rusted metal. Look for the hull not to be fair in these areas.

Also check the stainless steel stem fitting attachment point to the steel plate and the pipe in the chain locker as well as the chain plate attachment point in the lazarette.

The skeleton from the stem fitting and the port and starboard chain plate webs and flat bar terminate at the mast step. Check there as well for signs of rust, swelling, etc. The aft stay chain plate terminates in the lazarette.

Here go to> columbia-yachts.com/c-40skeleton.htm
Note that in the drawing the lower shroud chain plates also terminated at the mast step. Mine (hull 33)did not, only the uppers.

I am a former Marine Surveyor (SAMS,AMS)I have photos as well.
 

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These boats were some of the first FRP boats molded when there was not a lot of experience with FRP construction. The proven engineering experience wasn't there and think this steel reinforcement may have been over kill. There have been hundreds of different designs with similar or less glass scantlings but no steel reinforcement that have had no problems. Someone with engineering expertise might chime in on whether this reinforcement is redundant.
 

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These boats were some of the first FRP boats molded when there was not a lot of experience with FRP construction. The proven engineering experience wasn't there and think this steel reinforcement may have been over kill. There have been hundreds of different designs with similar or less glass scantlings but no steel reinforcement that have had no problems. Someone with engineering expertise might chime in on whether this reinforcement is redundant.
Unfortunately the skeleton is critical to transferring forces around the boat. The Columbia 40's were actually pretty light boats for the day and Columbia's glasswork was pretty crude even for that era. There is a mythology that early fiberglass boats have heavier hulls because the designers did not know much about the strength of fiberglass.

By and large that simply was not the case. By the early 1950's there was very comprehensive information about the structural capacity of fiberglass.

Because early boat builders chose to avoid using internal framing, and designers knew that pound for pound fiberglass was not an inherently stiff material compared to wood, they were faced with a trade off between designing boats that were too heavy or were too flexible. As a compromise to balance the density of fiberglass relative to other materials, the hulls were thicker which reduced flexure a little.

But value oriented builders like Columbia chose to create this extra thickness with proportionately large amounts of non-directional fabric and resin rich laminate both of which decrease tensile strength, puncture resistance, and fatigue resistance.

So if a designer wanted to lighten the weight of the hull, then the steel frame was a key component in dealing with the high tensile rig loads.

Jeff
 

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Unfortunately the skeleton is critical to transferring forces around the boat. The Columbia 40's were actually pretty light boats for the day and Columbia's glasswork was pretty crude even for that era. There is a mythology that early fiberglass boats have heavier hulls because the designers did not know much about the strength of fiberglass.

By and large that simply was not the case. By the early 1950's there was very comprehensive information about the structural capacity of fiberglass.

Because early boat builders chose to avoid using internal framing, and designers knew that pound for pound fiberglass was not an inherently stiff material compared to wood, they were faced with a trade off between designing boats that were too heavy or were too flexible. As a compromise to balance the density of fiberglass relative to other materials, the hulls were thicker which reduced flexure a little.

But value oriented builders like Columbia chose to create this extra thickness with proportionately large amounts of non-directional fabric and resin rich laminate both of which decrease tensile strength, puncture resistance, and fatigue resistance.

So if a designer wanted to lighten the weight of the hull, then the steel frame was a key component in dealing with the high tensile rig loads.

Jeff
I owned a C40 for 11yrs. I can't argue about Columbia's glasswork quality, but can assure you that the steel skeleton was not necessary for that boat's rigging loads, or any other reason. The hull scantlings are thick and no different from other boats not using a skeleton. There are 4 bulkheads over a 29' waterline and only 10' beam, the bilges had large timbers athwartship, and the shroud chainplates are placed at bulkheads.

The real reason was marketing, with a secondary reason of racing. The C40 came from Morgan's racing boat "Sabre" (which itself was patterned off his similar "Paper Tiger". Both of those boats were lightly built (relatively), and used the steel frame as an integral support for the rigging. They were very successful racing boats at the time.

Columbia used this for marketing the boat, and kept the steel frame as part of it. The boat itself was built much heavier than Sabre and didn't need that frame for keeping the boat together or handling the normal rigging loads. There are several C40's that removed the frame altogether, bolted chainplates through the hull instead, and experienced no rigging or other problems with them.

Columbia also marketed the boat early on as a racer/cruiser, and the frame did contribute some when cranking the rigging hard for racing reasons. This was secondary to the general marketing aspect of the frame, though.

Think of the frame as similar to all the winged keel designs by production builders after the Australian AC win.

Mark
 

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While I am not saying that you are mistaken, and while the idea that Columbia would have installed the steel frame solely as a marketing tool strikes me as totally inconceivable because those of us who were sailing during this period would have considered using steel anywhere on a boat as a slip shod practice, none the less, steel components were used in poorer build quality boats to improve their structural capabilities.

That said, I agree that these boats can be restructured and/or have their rigging attachment points changed so that the steel frame is no longer needed. Either the option of restructuring the boat or relocating the rig attachment points are not simple matters and should be carefully and holistically engineered.

Jeff
 

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Its not a steel Boat, what makes you think it is?
The gentleman didn't say it was a steel boat, he said it had a steel skeleton rib, which means that their are steel flat stock running up to the chain plates and a pipe running up the bow of the boat for the headstay being connected to the forestay.
 
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