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#11
posted to rec.boats.cruising
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Butt joint Mast?
wrote:
Why would a company like Selden tell me that they can only get 40 feet length extrusion? Shipping could be one of the reason? The brand new Hunter 33 I saw has a splice above the roof top. When one of our club member drop his mast (Hunter) it broke in two parts. So when I saw this new Hunter with a spliced mast and pop rivets It gave me food for thought. They only other time I saw pop rivets on a sliced mast was when my friend got dismast and had to repair it with an internal sleeve, epoxy and pop rivets. I am not all that convince that all mast above 40 feet are sliced. Beside Hunter I wonder who is making new sailboats with a spliced mast? Really, if you look carefully at almost any sailboat you will see that they have a two piece mast. Sometimes the mast is faired so that it isn't obvious from the deck (or ground). Other times it is. Carbon fiber masts are not spliced. Other than that - most of them are unless it is a little boat with a short mast. When this came up in the CSY group, some people did not believe that they had spliced masts, and then when they pulled the mast to do some work, they found out that it was indeed a two piece mast. "Rosalie B." wrote in message .. . Frank Boettcher wrote: On Tue, 04 Jul 2006 19:14:01 GMT, wrote: When I noticed a pop rivetted butt join on the mast of a new boat I suspected a mast repair job? When asking the US mast manufacturing company as to why a pop rivetted butt joint was present on a 45 feet long new mast, they replied that the longest aluminium extrusion available was 40 feet long. They also stated that it was standard practice in the industry to butt joint the length of a mast after 40 feet. They said that their masts were elongated by inserting an internal sleeve and securing the joint with pop rivets. They also mentioned that other manufacturers were using butt welding technique instead of pop rivets. Maybe this is standard practice but it was an eye opener for me. As anyone notices that before? It's been many years, but I used to work in an aluminum extrusion plant. We certainly were not limited to 40' max length. Frank On our type of boats, the limiting factor was shipping not manufacture. The manufacturer used whatever they could get the best price on and there are many different mast profiles that they used. Some of the boats have the two piece mast and some do not. Most of our masts were either 56 feet or 65 feet above the waterline, and they were keel stepped so you need to add another 7 feet or so onto that. |
#12
posted to rec.boats.cruising
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Butt joint Mast?
"prodigal1" wrote
That's why I think I will have my spars made in Michigan. :-) who/where in Michigan? Offshore Spars in Chesterfield, MI is at the top of my list right now with Charleston Spar in Charlotte, NC a close second. -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
#13
posted to rec.boats.cruising
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Butt joint Mast?
Having a one piece 37 feet mast with thick wall for more than 20 years I
took it for granted that all aluminums masts were made in one piece. I wonder if these two piece mast can survive a knock down not to mention those that have no back stay? "Rosalie B." wrote in message ... wrote: Why would a company like Selden tell me that they can only get 40 feet length extrusion? Shipping could be one of the reason? The brand new Hunter 33 I saw has a splice above the roof top. When one of our club member drop his mast (Hunter) it broke in two parts. So when I saw this new Hunter with a spliced mast and pop rivets It gave me food for thought. They only other time I saw pop rivets on a sliced mast was when my friend got dismast and had to repair it with an internal sleeve, epoxy and pop rivets. I am not all that convince that all mast above 40 feet are sliced. Beside Hunter I wonder who is making new sailboats with a spliced mast? Really, if you look carefully at almost any sailboat you will see that they have a two piece mast. Sometimes the mast is faired so that it isn't obvious from the deck (or ground). Other times it is. Carbon fiber masts are not spliced. Other than that - most of them are unless it is a little boat with a short mast. When this came up in the CSY group, some people did not believe that they had spliced masts, and then when they pulled the mast to do some work, they found out that it was indeed a two piece mast. "Rosalie B." wrote in message . .. Frank Boettcher wrote: On Tue, 04 Jul 2006 19:14:01 GMT, wrote: When I noticed a pop rivetted butt join on the mast of a new boat I suspected a mast repair job? When asking the US mast manufacturing company as to why a pop rivetted butt joint was present on a 45 feet long new mast, they replied that the longest aluminium extrusion available was 40 feet long. They also stated that it was standard practice in the industry to butt joint the length of a mast after 40 feet. They said that their masts were elongated by inserting an internal sleeve and securing the joint with pop rivets. They also mentioned that other manufacturers were using butt welding technique instead of pop rivets. Maybe this is standard practice but it was an eye opener for me. As anyone notices that before? It's been many years, but I used to work in an aluminum extrusion plant. We certainly were not limited to 40' max length. Frank On our type of boats, the limiting factor was shipping not manufacture. The manufacturer used whatever they could get the best price on and there are many different mast profiles that they used. Some of the boats have the two piece mast and some do not. Most of our masts were either 56 feet or 65 feet above the waterline, and they were keel stepped so you need to add another 7 feet or so onto that. |
#14
posted to rec.boats.cruising
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Butt joint Mast?
Rosalie B. wrote: Most of our masts were either 56 feet or 65 feet above the waterline, and they were keel stepped so you need to add another 7 feet or so onto that. Boy, do you have a deep bilge. What the heck do you draw if the keel starts 7 feet under water??? FWIW, my "keel stepped" mast is actually on a steel I-beam, supported by another fiberglassed huge wood beam and web supports to the side. The base of the mast is probably 2' below the waterline or so, there's a 33" depth reach to the bottom, which I expect is where the keel (ballast) actually is, and however big the keel (ballast encapsulated) actually is makes up our depth which I expect when we splash will be about 6-6. L8R Skip |
#15
posted to rec.boats.cruising
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Butt joint Mast?
Wayne.B wrote:
On 7 Jul 2006 05:25:51 -0700, "Skip Gundlach" wrote: Boy, do you have a deep bilge. What the heck do you draw if the keel starts 7 feet under water??? It starts 7 feet under the deck, which is hopefully well above water. Our boats draw either 5' or 6.5' and I am math challenged so Wayne is right - the part of the mast that is inside the cabin is about 7' (down to the cabin sole but not including the bilge, which is pretty deep). I think the deck is maybe 5' above the water? Don't remember exactly. In any case the top of our mast is 58' above the waterline, but part of that is the antennas on top. |
#16
posted to rec.boats.cruising
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Butt joint Mast?
wrote:
Having a one piece 37 feet mast with thick wall for more than 20 years I took it for granted that all aluminums masts were made in one piece. I wonder if these two piece mast can survive a knock down not to mention those that have no back stay? I do not know about a back stay, but most of the time when we (CSYs) have rigging problems, it isn't the mast, but the chain plates that are a problem and that is from crevice corrosion or something like that. The boats were made from 1976 to 1980, and so are now old boats. Many have circumnavigated and survived knock downs and the masts were quite fine. Probably better than many new boats. The joints that I have seen were probably the strongest part of the mast. I've never heard of a break there and I have records on 200 or so of them. "Rosalie B." wrote in message .. . wrote: Why would a company like Selden tell me that they can only get 40 feet length extrusion? Shipping could be one of the reason? The brand new Hunter 33 I saw has a splice above the roof top. When one of our club member drop his mast (Hunter) it broke in two parts. So when I saw this new Hunter with a spliced mast and pop rivets It gave me food for thought. They only other time I saw pop rivets on a sliced mast was when my friend got dismast and had to repair it with an internal sleeve, epoxy and pop rivets. I am not all that convince that all mast above 40 feet are sliced. Beside Hunter I wonder who is making new sailboats with a spliced mast? Really, if you look carefully at almost any sailboat you will see that they have a two piece mast. Sometimes the mast is faired so that it isn't obvious from the deck (or ground). Other times it is. Carbon fiber masts are not spliced. Other than that - most of them are unless it is a little boat with a short mast. When this came up in the CSY group, some people did not believe that they had spliced masts, and then when they pulled the mast to do some work, they found out that it was indeed a two piece mast. "Rosalie B." wrote in message ... Frank Boettcher wrote: On Tue, 04 Jul 2006 19:14:01 GMT, wrote: When I noticed a pop rivetted butt join on the mast of a new boat I suspected a mast repair job? When asking the US mast manufacturing company as to why a pop rivetted butt joint was present on a 45 feet long new mast, they replied that the longest aluminium extrusion available was 40 feet long. They also stated that it was standard practice in the industry to butt joint the length of a mast after 40 feet. They said that their masts were elongated by inserting an internal sleeve and securing the joint with pop rivets. They also mentioned that other manufacturers were using butt welding technique instead of pop rivets. Maybe this is standard practice but it was an eye opener for me. As anyone notices that before? It's been many years, but I used to work in an aluminum extrusion plant. We certainly were not limited to 40' max length. Frank On our type of boats, the limiting factor was shipping not manufacture. The manufacturer used whatever they could get the best price on and there are many different mast profiles that they used. Some of the boats have the two piece mast and some do not. Most of our masts were either 56 feet or 65 feet above the waterline, and they were keel stepped so you need to add another 7 feet or so onto that. grandma Rosalie S/V RosalieAnn, Leonardtown, MD CSY 44 WO #156 http://home.mindspring.com/~gmbeasley/id1.html |
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