New Englander Posted November 10, 2009 Report Share Posted November 10, 2009 Hi everyone, I'm a new member and have bought the plans for the Lapwing 16. I have yet to begin, I'm at the stage of looking the plans over and searching for construction materials. My experience is that I've sailed off and on since I was a kid, and recently built a cedar strip canoe, which turned out nicely. So I'm very new to sailboat construction. I am curious about the mast fabrication. Has anyone done this already and has photos of the process? Many thanks, Corky Scott Quote Link to comment Share on other sites More sharing options...
Richard Whitney CS#70 Posted November 10, 2009 Report Share Posted November 10, 2009 Hi Corky I am part way through building a Lapwing. If you search 'Lapwing 4' and look at page 2 and 3 you will see some pictures of mast. Also if you look at John's photo (Lapwing 5) and Tom's who built the original (Lapwing) - there is useful information. Having done masts for both a CS17 and Lapwing the key thing is getting as close as you can to the right alloy and thickness of tubing for the bottom two sections. If you get stuck you can order from Graham. Also worth touching base with Ray who is in Maine http://www.greatfallsboatworks.com/contact/ Quote Link to comment Share on other sites More sharing options...
John Turpin Posted November 11, 2009 Report Share Posted November 11, 2009 Hi Corky, Congrats on your new project. What will your hull number be? Please keep us informed of the progress you're making. As depicted in the plans, you have a couple of options for your masts. But, I expect that most Lapwing builders will construct their masts from aluminum tubing. That's what I'm doing. To date, I've acquired the tubing and painted it. I've also purchased my sail track and SS rivets. Now that I've completed my planking, I can spend some time with the masts. The construction method for the aluminum masts is similar for most (all) of Graham's boats. Doing some searches here on mast construction for the Core Sound boats should give you lots of information on the materials and methods that builders use for this building step. John Lapwing 16 #5 Quote Link to comment Share on other sites More sharing options...
New Englander Posted November 11, 2009 Author Report Share Posted November 11, 2009 Hi Corky I am part way through building a Lapwing. If you search 'Lapwing 4' and look at page 2 and 3 you will see some pictures of mast. Also if you look at John's photo (Lapwing 5) and Tom's who built the original (Lapwing) - there is useful information. Having done masts for both a CS17 and Lapwing the key thing is getting as close as you can to the right alloy and thickness of tubing for the bottom two sections. If you get stuck you can order from Graham. Also worth touching base with Ray who is in Maine http://www.greatfallsboatworks.com/contact/ Thanks Richard. I admit to some confusion regarding the mast plans. There seems to be a lot of information on the sheet, but it sometimes appears to be not necessarily directly connected one piece to the other. For instance, and forgive me if this is merely a neophyte's interpretation of the information but the plans show how to make a hollow mast, and specify dimensions: Birdsmouth spar mast head is 1 3/4". Birdsmouth Mast Heel is 3". But in the text above the diagram it says that the mast should taper to 1 5/8". Granted, the difference is only 1/8". But it makes me wonder if I'm missing something. Is the mast head the top of the mast and the mast heel the base? Also, it also says that the mast can be a combination of aluminum and birdsmouth wood or fiberglass. But then the diagrams for fitting the aluminum together show two sections of tubing the bottom one at 2 1/2" diameter, the next section 2 1/4" diameter and the third section unidentified either in material or dimensions. I'm guessing it's builders choice for material, but I hate guessing. Finally, if one is to build a hollow mast, it means you will have to taper the sections of wood so that they actually taper, before being planed and sanded round, right? Or is this not right? That means one heck of a long tapering jig! Thanks all, I'm sure many of my questions will be answered if I just started building. That was the way things worked out when building the cedar strip canoe. Corky Scott Quote Link to comment Share on other sites More sharing options...
Designer Posted November 11, 2009 Report Share Posted November 11, 2009 Corky, It is always difficult to when designing something as complex as a boat with all of it's numerous parts to make it simple and fit everyone's commonly available materials and equipment and make it understandable with just enough text. You may notice in the paragraph you quote from that the upper wall thickness may be tapered by 1/16" which accounts for the 1/8" difference that you noted. Why didn't I just make the head 1 5/8" to begin with? The staves get pretty small at the head and the wall thickness is thicker at the head than needed so I thought that the best compromise was to make up the masthead to 1 3/4" and plane the outside down to 1 5/8" or if you don't feel like tapering, just leave it as is. We often build tapered birdsmouth spars and find the easiest way to taper the staves is to taper the whole plank first and cut slices off of the plank. For instance for the Lapwing you need 8 staves 5/8" thick and 1 1/4" wide tapering to 3/4" at the head. I will start with a 1 1/4" thick board 6" wide and taper one end down to 3/4". I Then set up the saw fence for 5/8" and cut 8 strips. I now have 8 identically cut tapered staves ready to cut the birdsmouth. Quote Link to comment Share on other sites More sharing options...
New Englander Posted December 7, 2009 Author Report Share Posted December 7, 2009 Corky, It is always difficult to when designing something as complex as a boat with all of it's numerous parts to make it simple and fit everyone's commonly available materials and equipment and make it understandable with just enough text. You may notice in the paragraph you quote from that the upper wall thickness may be tapered by 1/16" which accounts for the 1/8" difference that you noted. Why didn't I just make the head 1 5/8" to begin with? The staves get pretty small at the head and the wall thickness is thicker at the head than needed so I thought that the best compromise was to make up the masthead to 1 3/4" and plane the outside down to 1 5/8" or if you don't feel like tapering, just leave it as is. We often build tapered birdsmouth spars and find the easiest way to taper the staves is to taper the whole plank first and cut slices off of the plank. For instance for the Lapwing you need 8 staves 5/8" thick and 1 1/4" wide tapering to 3/4" at the head. I will start with a 1 1/4" thick board 6" wide and taper one end down to 3/4". I Then set up the saw fence for 5/8" and cut 8 strips. I now have 8 identically cut tapered staves ready to cut the birdsmouth. Sorry to have taken so long to respond to this. I have two further questions: 1. Is the plank from which you are cutting staves the full length of the mast? In other words some 16 feet long? Question 2. How do you taper an entire 16 foot long plank? Many thanks, Corky Scott Quote Link to comment Share on other sites More sharing options...
Palolo Hawaii Posted December 8, 2009 Report Share Posted December 8, 2009 I'll try to answer #2: "A little at a time, from one end only" I've tapered a board by propping up one end on a flat floor (by the amount needed to be reduced) and running a planer on guides over the board, and gradually lowering the guides until the planer no longer removed material, then I sanded a little. Granted, it wasn't 16'+ long. Do you really need to taper from one end to the other? Perhaps you could leave the bottom half of the mast untapered and cut the tapering work in half? Look at this page, about half way down, for an example: http://www.duckworksmagazine.com/04/s/articles/birdsmouth/index.cfm Good luck, pat. Quote Link to comment Share on other sites More sharing options...
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