i550class.org

Among the things that I think would be nice to figure out is how to build a do it yourself carbon mast. I see that the Cherub folks have a video on you tube about how they build carbon masts. Is that a realistic do it yourself project for an amateur i550 builder? What are the challenges and potential solutions? Is it realistic to think that we could develop a process for people to build their own masts?

Ron Bowman
Lunatic Fringe #108

I don't think it's a realistic prospect for an amateur builder. The pros use machined aluminum mandrels, pre-preg carbon, and high pressure autoclaves. Avoiding those three high cost/steep learning curve methods and materials leaves us stuck with methods that will simply create heavier than pro-built masts, to the point that an aluminum stick will be preferable.

Another way to look at it is simply cost. A C-tech bare tube (with masthead fitting and track) weighs 20.9 pounds and costs about US$1200 at the current exchange rates, plus shipping. To buy 25 pounds of carbon and epoxy is going to cost a builder paying retail prices at least that much, before even starting to build anything.

All that said, being a glutton for punishment, and believing the best way to learn is to do, I'm building my own carbon boom...

$1200 doesn't seem too bad for a carbon tube. Have to add spreaders, track, masthead fitting, boom fitting, shrouds on top of that but those costs would be similar for whatever kind of spar a person might choose. About $700 more than the Dwyer aluminum DM-4, though.

Gonna be interested in seeing your blog entries on the new boom.

Ron

Ron Bowman wrote:$1200 doesn't seem too bad for a carbon tube. Have to add spreaders, track, masthead fitting, boom fitting, shrouds on top of that but those costs would be similar for whatever kind of spar a person might choose. About $700 more than the Dwyer aluminum DM-4, though.

Gonna be interested in seeing your blog entries on the new boom.

Ron

Yeah, other than track and masthead fitting, the entire rest of the fit out of a carbon tube could be done just as easily from the Dwyer catalogue, or any other supplier of generic mast rigging.

I wonder what the shipping cost of a 26' unspliced mast is, across the country?

Shipping and handling a thirty foot aluminum spar is going to be more difficult and more expensive than shipping a carbon mast so long as the carbon mast is in pieces and the package is no longer than 108 inches. The first group of C-Tech masts were shipped in pieces and we glued the sections together once they arrived. Nine feet is the max length to ship by UPS and DHL. Fedex max length is 119 inches. Actual shipping costs will vary depending on to where you are shipping. For people like me in the boonies, the last two hundred miles can wipe out any cost advantage of aluminum over carbon.

About five years ago, I had a new aluminum mast (about 35 feet long and maybe weighed 100 pounds or so all wrapped up in the package) shipped from Hall Spars in Rhode Island to northern Minnesota. Shipping and handling charges exceeded nine hundred US dollars. The mast came packed inside a ten inch plastic corrugated pipe with foam packing inside the pipe. Pretty much a bullet proof package and it looked like a lot of effort was put into protecting the spar for the ride. The only other mast I ever had shipped across country was a 25 foot aluminum spar that also arrived by truck from out east somewhere. I can't remember the cost for shipping that mast but it showed up wrapped in brown paper as its only protection. Unfortunately, it had about a thirty degree bend in it about two thirds of the way toward one end. The replacement also came shipped in brown paper but the second one wasn't bent.

I think my charges for shipping a mast and boom from C-Tech in New Zealand to Chicago was about $150. Kevin and Jeff coordinated getting it from Chicago to Madison and I had one of my sons pick it up from Jeff in Madison and my other son delivered it up here to me in Minnesota. The package fit in the back of an SUV.

It sounds like the cost difference between a carbon tube and an aluminum Dwyer tube is about $700. Rigging expenses will be similar. Shipping expense of the aluminum spar is likely to be greater than a carbon spar unless you have a trailer and can pick up the aluminum spar direct from Dwyer.

Ron Bowman
Lunatic Fringe #108