View Full Version : Lofting a 13'? Melonseed - Barto v Chapelle
05-10-2007, 09:10 PM
I noticed an odd discrepancy in the Barto plans, in that sometimes it is referred to as a 13'4" boat and sometimes as 13'6". I shrugged this off as a typo at first - no biggy. The Chapelle plans list the boat as exactly 13'6.5", though. I thought, hmm, which is it, and if they're different, where did the other 2.5" go?
I've been studying the offsets of both plans, and so far I can only find one place where they differ in length. The distance from Station 12 to the end of the Transom on the Chapelle plans is 13" - on the Barto plans it's 11.5". I guess that means the Chapelle transom has slightly more rake in it to be a tad longer. But that still leaves a missing inch somewhere. Anybody seen where it went?
There are some other slight differences in the offsets here and there, mostly by an eighth of an inch in one measure out of maybe 10. I've found what appear to be obvious errors in both (like where the measure says 6" wide when it must surely be 1'6"). But for the most part they are identical.
Anybody notice these differences? Any idea why Barto would have shortened his boat? (Maybe to reduce the angle of the transom to make all those compound curves easier to twist into ply?) Or is there another error somewhere, and if so, which is right?
Something tells me that once you start laying things out you could make it work either way. On the other hand, it could really s*ck to find out otherwise when the boat is 3/4 done.
(cross-posted in the Design Forum)
05-10-2007, 10:41 PM
Thanks, Jim. I've been combing those sites, as well. The Barto plans do say that "some beveling will be required" to the forms in order for the ply to lay flat. Looks like most folks have tortured the wood into curves where necessary.
I've been planning to use cedar strips. The ply planking looks wonderful, but it also looks really tough to do. Maybe not beyond my skills so much as beyond my patience. I get really frustrated when things don't fit exactly. Might drive me to start smoking again, and my wife wouldn't like that. My guess is that the strips will be somewhat easier to twist into place.
I still don't quite get the reasons for the differences. More also occur in the Diagonals, which doesn't quite make sense. I don't understand lofting well enough to visualize how the offsets could be nearly the same, but the Diagonals more different.
And what about that inch?
So, any specific places in the plans that had to be reworked that you recall?
05-11-2007, 08:33 AM
Yes, I studied that picture, as well. I read in Marc's notes that - in addition to the extra screws and epoxy - he had to steam the ply to get it to conform as much as possible to the curve of the transom. I'm guessing this is the spot Barto is referring to when he says "you may have to bevel some." Obviously, it's an organic process.
Are you posting photos of your progress anywhere?
05-11-2007, 12:57 PM
What was Mr.Bartos aim in redrawing the plans ?To make the boat easier to build lapstrake ?
05-12-2007, 01:07 PM
The Chapelle 'plans' are all on one page, a table of offsets and some diagrams, while the Barto plans are several pages and more detailed for the builder who needs more guidance than the Chapelle plans provide. The Chapelle plans document the boat, but the Barto plans let the relative novice build it by providing more detail.
05-12-2007, 03:15 PM
Sounds like you thought the plans worthwhile . I think I'll probably buy them at some point . The Seed is one of the perfect boats .
05-12-2007, 10:58 PM
PS The last site is mine.
Wait a minute. I just caught that last part of your post and looked at the pics. I think I'm making the connection now. Did I respond to one of your posts on another forum with some fond memories of Tybee? The boat's looking good. You wouldn't happen to be the same guy who had a bit of an adventure in the Savannah River, involving a kayak and a very large ocean going ship, would you?
05-12-2007, 10:59 PM
I entered both tables of offsets into Excel and had it look for differences. Almost identical, 1/8" here and there, except 1 1/2" difference and 1/2" at two points in the aft quarter.
I used the offsets to create the Station molds in Adobe Illustrator - sort of doing digital lofting. Just entering the numbers brought out several errors in both sets, though more in Chapelle with several transposed numbers.
Stacking the molds I could see where neither would be fair, though a little tweaking brought them in. Barto's templates for the molds in a few cases look significantly different from what the offsets produce. Looks like he chubbed up his templates, making them more full. If you use his templates looks like you'll be fine, but if you do your own lofting expect to "refine" a bit.
Checked the Stem dimensions and they're the same, so there's still the mystery of different length boats.
For the record, for people working from the Chapelle plans, here are the errors I found:
Transom - Half Breadth - Waterline 9"
says 1.6.1 /should be 0.6.1
Station 12 - Half Breadth - Waterline 9"
says 1.8.4 / should be 0.8.4
Station 11 - Half Breadth - Waterline 12"
says 0.9.0 / should be 1.9.0
Station 6 - Half Breadth - Inner Rabbet
says 0.0.6 / should be 0.6.0
05-14-2007, 10:56 PM
I thought so. Very cool. Those ships blot out the sky from shore - can't imagine how big they would look shouldering past when you're floating on a match stick at the waterline.
By next summer, if all goes well, I'll be towing a couple of boats southward. My folks live outside of Beaufort, SC, and I've always wanted to sail into the marshes and inland waterways around there. Some sailing off the beach would be nice, too. If we get toward your end of the swamp I'll let you know. Would be fun to get together with another boat on the water.
Your wife must be very patient. I imagine she'll dance with you, when the boat moves out.
05-15-2007, 06:38 AM
I am building the Barto 16' version and have spent a great deal of time studying the seven sheets provided in the 'Wooden Boat Store' pack. When setting up the molds I had to widen No. 10 by 1/2" overall to get a good 'flow' with the test baton.
I was also very puzzled by Sheet 2 (construction) which shows the chines running directly into the outer stem. I may be wrong about this but that just does not work in practice. The chines should surely run into the inner stem! That is how I am constructing mine and it seems to work well.
My only cheat so far is to have split the cedar chines lengthwise and bring them together again, glued in their bent positions in the mold slots. My first attempt ended in cracks near the scarf joints which may or may not have something to do with timber quality.
I have spent many tedious hours preparing the molds ready for the laying on of planks (6mm marine ply) but I am sure that it is time well spent and I am now looking for reward from my labours in a fine, flowing hull shape without any lumps or bumps...time will tell.
All in all, I am quite pleased with the Barto plans and would not wish him or anyone else to think that I am deliberately finding fault. If I am wrong then I stand corrected. Otherwise, my findings may help a future builder of the 16' Melonseed and, whilst we are on the subject, I have yet to make contact with anyone who is currently involved with building this version.
The best 16' example I have seen on the internet so far is the 'American'. It is gorgeous and if mine comes somewhere near to looking like that I will be very pleased. We shall see.
I have only taken one or two photos of my project so far and if I can get my head around this (new to me) technology of placing photos on some independent storage then I will make them available. Otherwise, I would be happy to share in the normal e-mail attachment....yes! slowly but surely I am being dragged into the 21st century!!!
To end, I would just like to thank all those folke who have seen fit to place their 'melonseed' projects on the internet. So far, they have been a great help to me and, no doubt, to many others.
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