The Strongback

Over the weekend I completed the bow form by laying a few random strips on the bow mock-up I had made to see the lines and reshaped the bow and forms 2, 1 and 0.5, this took a little work shaving and trimming so as to get a nice form to the bow section. I'll have a similar effort for the modified stern that I am looking for but that comes later.

I bought a nice and straight 16 ft. 2x4 to use as a strong back. I marked off the adjusted form locations along the strongback starting in the middle and working out towards each end. Then I located the center point on each end, drove a nail and ran a string along the length of all four sides of the 2x4. I used this string to mark a pencil line along the length of the 2x4. This establishes a straight line for me to use when aligning the forms prior to securing them to the strongback.

Then I located the center of mass of the kayak and marked that on the strongback. I located the center of mass for two kayakers and marked the two cockpits locations on the strongback. This lets me know which forms fall in the cockpits. For easy removal when building the cockpits, I will cut these forms horizontally along the center and glue them back together. I can simply break them at the joint when I get to the point of making the cockpits so they will not be in the way.

The following are some photos of my progress:

This is the 16ft. 2x4 I'm using as a strongback

Here is the nail and string marking the centerline on the top side, this

was repeated on all sides



I'm marking the centerline with a pencil for use later when aligning the forms

This photo shows the forms temporarily placed on the strongback

The kayak is starting to take shape, next I'll start securing the forms to the strongback. Then I'll attach the newly modified bow form and begin working on the stern.

Cutting the First Strips

Set up of the band saw with a 1/2" wide 3tpi blade and cut a few strips. I'm using the band saw instead of the table saw to help keep the waste down to a minimum. I cut a few strips because I wanted to temporarly attach some strips to the bow mock-up that I built over the weekend to see what modifications I need to make so the bow form looks good.

This photo shows the fence and blade installed, the wide blade helps keep the cut is true and the blade is not too radical.The strips will not require too much sanding due to the blade marks.

I made a table on the infeed and out feed sides so cutting the strips can be a one man operation. I will still need help when cutting the 16 ft. boards. The shorter boards are not a problem for one person to handle.

Cutting the first strips. The strips are coming off at a uniform thinkness, there is no noticable blade creep.

The re-designed bow form with a couple of test strips temporarly attached so I can see how the lines will look. I did not taper this template since I knew I would be making some modifications to the lines. I will reshape the deck side of the form to be more straight and will cut forms 0.5 and 1.0 to allow a smooth transition.

I plan on making the curve of the bow more gentle and the deck up towards the front end a little more flat.



Friday getting the bow form reworked

I bought lumber yesterday at a specialty lumber yard in Blountstown, Florida. Had a good time talking with the guys there, very helpfull. They have a lot of exotics and anyone seeking special wood types should check them out. Great bunch of guys with a lot of knowledge and inventory, had a great experience and a fun afternoon talking with them.

I want a more traditional form for the bow and stern rather than the severly upturned ends of the Guillimot Double so today I spent the day working on a mock-up of the end form for the bow and building a fence table for the band saw so I can cut the strips. I need a few short strips to lay on the mock-up so I can find out how the shape of the re-designed bow will work and present a fair hull shape.

Below are some photos of my progress.

Here is a photo of the lumber that I bought, it is Juniper that has the weight and consistancy similar to that of cedar. I could not get my hands on cedar that was clear of knots. These boards are very clear and is flat-sawed so the strips when I finish cutting them will be quarter-sawed. I bought boards that are 16', 12' and 8'. The Juniper will be lighter in color than cedar so I will use a darker wood for the feature strips such a the sheer line and some decorative patterns on the top deck.

This is a photo of the mock-up of the bow form that I want. I will work out forms 1.0 and 0.5 after I have cut some strips that I can fasten and get the exact shape of the forward hull I want. I may re-work form 2 as well to get a fair transition of the hull to the bow form. More to come ...

Starting to build a strip kayak

I am beginning to build a tandum strip built kayak and I thought about posting a blog of my progress for friends to follow.

I plan on building the Guillemot Double as presented in Nick Schade's book The Strip-Built Sea Kayak but I have scaled the plan down to 17 feet using the method he describes in the book.

I began by inputting the offsets into an Excel spreadsheet and developing a formula for scaling the Kayak down. This took about 2 hours or so. I made an array of x,y,z coordinates and and imported them into AutoCad. I then plotted full size templates, spray mounted them onto 1/2" mdf plywood to cut them out. Anyone that wants to know how to do this in Excel and AutoCad please let me know and I'll give you the details. It is really cool to be able to view the forms in 3-D, rotate it and view the hull from various directions. You must have access to AutoCad for this.

I started on Saturday cutting the  forms and so far I have cut out my forms for stations 2 thru 18. I will begin to cut my 1/4" strips and start building the strong-back this weekend. I do not especially like the bow and stern shapes so my plan is to modify the ends so the  next step is to cut the end forms that I like and to modify forms 0.1, 1.0, 19 and 19.5. I will do this by building a mock-up of each end.

Above I am rough cutting the forms from the1/2 inch mdf plywood

Here I am using the band saw to trim the forms before sanding

 The photo above shows me sanding the forms to dimension

                                                                                                                                                                                                                       
The completed forms before routing the openings for the strong back

Routing the Strong Back guide holes

         The forms with the holes for the strong back