Best way to transfer lines to forms?

[Andrew Grant]

I have lofted the lines for the cedar-strip boat I am building. Actually I have all the points layed out on paper for each station, but haven't used a batten to connect the points yet. Now I need to transfer them on to the molds which are 1/2" partical board.

What is the best and easiest way to do this?

[paladin]

Go look into the missus little sewing bag.....find a little handle thingy with what looks like a little wheel on the end or the rowell of a spur...lay the paper lofted pattern on the particle board and trace with the wheel...it will leave little indentions in the wood, then either trace it with a pencil or slide a batten around it.....

[John E Hardiman]

I have lofted the lines for the cedar-strip boat I am building. Actually I have all the points layed out on paper for each station, but haven't used a batten to connect the points yet. Now I need to transfer them on to the molds which are 1/2" partical board.

What is the best and easiest way to do this?

Have you just laid out the offsets straight from the tables?...

or.........

Have you lofted the lines and now have the corrected offsets picked up from a complete set of faired lines on the loft floor?....

Trying to save you a lot of headache and money here......

[Andrew Grant]

I laid them out from the table and have started on full size lines in profile. Should I finish the side and overhead full-size profiles and take the measurements off it to make the molds? Am I right in thinking: "corrected offsets" mean , if my batten wants to move a point slightly to make a smooth curve, make the adjustment? Easier to make fine adjustments on paper than in wood with the forms?

[Andrew Grant]

Have you just laid out the offsets straight from the tables?...

or.........

Have you lofted the lines and now have the corrected offsets picked up from a complete set of faired lines on the loft floor?....

Trying to save you a lot of headache and money here......

I did have to adjust a few of the points after lofting and fairing the lines full size. Thanks for the encouragement to do it. It was worth it!

[John E Hardiman]

Make sure you lay down a couple of waterlines, not just the station lines, also to ensure that are not knuckles/flat spots in them either.

Also remember that when making molds for strip planking, getting out the bevel is going to be one of the harder pieces of work. So you need to keep track of the station line and face.

There are several ways to pick up the lines from the loft floor. How did you loft it and i can probabily recommend a method.

[Andrew Grant]

I used the table that had offsets at sheer, and three water lines. Then also heights at sheer, keel and three set half-breadths.

I am planning on now transferring the points to a pattern board, cutting it out and then using a pattern bit with the router to cut out the molds. The pattern will be half of the mold. I will flip it over to route out the other side of the mold. I tried cutting the mold straight out with a band saw, but the 1/2" particle board is just too much to get a good cut.

The router will make nice and smooth edge to then proceed with fairing the molds when they are mounted. Any tips on beveling the molds so the strips lie flat?

[George Ray]

Hope you will do a little online photo album of your effort.

"Inquiring minds want to know."

[John E Hardiman]

Any tips on beveling the molds so the strips lie flat?

This is why you laid out the water lines.

1) Find midships
2) For all the molud stations, measure the thickness of the mould AWAY FROM MIDSHIPS TOWARDS THE ENDS on the plan view. This will make the "face" of the be on the side towards midships, the "back" of the mold will be away from midships.
3) Using the new "back" station lines, pick up the water line offest and transfer them to the section view.
4) For each mould station, strike a new "back" section.
5) Pick up the difference between the "face" and the "back" of each mould at each water line in the section view. This is the opposite side of the bevel angle where the adjacent side is the mould thickness. Make up a bevel board and maybe add a few intermediate points if there is a lot of twist.
6) Using the bevel board and the waterlines and intermediates marked on the station face, cut in narrow bevels towards the back at all the known points.
7) Connect the cut in bevels, making sure the transitions are smooth.

[Andrew Grant]

John, that is quite clever. I wouldn't have thought of that. The backside station lines will make it a whole lot easier and faster. Thanks!

[John E Hardiman]

John, that is quite clever. I wouldn't have thought of that. The backside station lines will make it a whole lot easier and faster. Thanks!

I'm not clever, what I describedis older than Noah.

Just remember if you strike the bevel lines parallel to the waterlines, then the bevels have to be measured parallel to the waterlines. If the bevel lines are struck perpendicular to the section edge, they must be measured perpendicular to the mould edge.

[Robmill0605]

I used the table that had offsets at sheer, and three water lines. Then also heights at sheer, keel and three set half-breadths.

I am planning on now transferring the points to a pattern board, cutting it out and then using a pattern bit with the router to cut out the molds. The pattern will be half of the mold. I will flip it over to route out the other side of the mold. I tried cutting the mold straight out with a band saw, but the 1/2" particle board is just too much to get a good cut.

The router will make nice and smooth edge to then proceed with fairing the molds when they are mounted. Any tips on beveling the molds so the strips lie flat?

Before you bevel the molds paint the edges of the molds with white paint.
That way,as you bevel each mold you will not lose the lofted station edge of the mold by cutting into the mold too deep for the beveling.

[Jon Etheredge]

Now you know how to find the bevels from your lofting and a good tip to mark the edges with color as an indicator to avoid cutting off too much but...

Why are you bothering to bevel the edges of the molds?

You are making lots of extra work for yourself that usually isn't needed. Most folks just set the molds on the station lines with the meat of the mold toward the center of the boat. Your planks or strips will only contact the mold on the corner and this will work just fine.

[Andrew Grant]

Now you know how to find the bevels from your lofting and a good tip to mark the edges with color as an indicator to avoid cutting off too much but...

Why are you bothering to bevel the edges of the molds?

You are making lots of extra work for yourself that usually isn't needed. Most folks just set the molds on the station lines with the meat of the mold toward the center of the boat. Your planks or strips will only contact the mold on the corner and this will work just fine.

You know, that thought did cross my mind.

[John E Hardiman]

Wether beveling the moulds helps or not depends a lot upon the hull form. For relatively easy curves such as canoes, beveling is most likely not necessary. For deep curves such as a whitehall run or a short dinghy's bow, beveling is necessary to hold the set and twist of the strip. YMMV.

[kurtloup]

Here's a link http://www.loup-garou.net/chemaunisforms.html to some pictures of how I cut out the forms for the last canoe I built. It was a little more work like this, but I believe I made the most accurate forms this way.

Kurt