Showing posts with label Skin on Frame kayak. Show all posts
Showing posts with label Skin on Frame kayak. Show all posts

Wednesday, May 9, 2012

Float Bags

Without bulkheads in a kayak float bags are important for displacing water in the event you swamp the boat.  So while waiting on another batch of ribs to soak I went ahead and got the bow and stern float bags done.  The instructions in Chris Cunningham’s book are pretty good though I did make a few modifications.

These bags are shaped like the bow or stern of your boat and made from heat sealable nylon with a fill tube and some sort of stopper or valve to keep the air in.  I ordered the heat sealable nylon from Rocky Woods; I found they were about half the price of other companies.  My fill tubes are made from vinyl tubing I found at Lowes and the valves are from NRS.  NRS sells replacement valves for their brand of float bags and if you call them as apposed to ordering them on line they knock the shipping down a little since they can just put the valves in an envelope and mail them to you, a nice bit of customer care.

The first bag I cut according to the directions with one modification.  I added a tab to the front with a hole in it so I can attach them to the cord I have in my boat for pulling them into place.  The one thing I didn’t like is how the two pieces of fabric line up or should I say not line up that well.  The fabric slips so it is very hard to get the two sides lined up perfectly.  I solved this problem with the second bag by cutting my fabric outside my finished line, heat sealing the two halves then cutting along my finish line to get a nice straight edge.  Another problem I ran into was how hot to set the iron to seal the fabric.  None of the places I found that sell heat sealable nylon have any directions on how hot the iron needs to be.  I did some experimentation with some scrape and only time will tell if I got a good seal.

I sealed the tube to the bags with Seam Grip instead of the sealant Chris recommends.  I’ve used Seam Grip extensively and I’m very comfortable working with it and the results you get.  I finished off the bags by attaching the valve to the vinyl tubing.  This was made easier by dipping the end of the tubing in boiling water to soften up the vinyl.  Then the tubing could be stretched over the base of the valve.

Overall this project took a couple of hours and was pretty simple; the directions in Building the GreenlandKayak, by Chris Cunningham were straight forward and easy to follow.

Tuesday, April 10, 2012

Laminated Masik

The Masik is the last and most important deck beam to be completed.  It is arched and will take the force of your legs and hips when rolling and bracing.  Laminating this beam was pretty straight forward although I did run into some slight problems.

The Masik is a laminated beam; I made mine from approximately 1/8” strips of cedar cut an inch wider and about 6 inches longer than the finish product was going to be.  The first problem I encountered was getting consistent thickness of my laminates.  1/8” think and 2 ½” wide strips of wood are almost impossible to cut on my table saw.  I also attempted to plane them with a power plainer but even though the plainer says it will go to 1/8” I found them to be a little thicker than that and they would not bend without splitting.
 
Once I got 10 pieces cut to thickness (this varied do to my table saw) I attempted to bend them with a single form as prescribed in Chris Cunningham’s book.  You need far more clamps than I have to make this work as you can see in the photo.  I just couldn’t get good compression so the layers would bond properly.  I’ve had a little experience with laminating wood in the past and used a press with good results so I decided to try that.  I made the press from a double thickness 2x12 that I glued and screwed together to get enough dimensional height.  I also drilled a couple of hole for my clamps to go into to act as the press.

Once everything was cut and ready to go I gave each layer a generous helping of Tightbond III and placed it in the press lined with wax paper.  The first problem I encountered was my grip clamps can’t generate enough force to compress everything together.  I ended up using pipe clamps to compress the layers and grip clamps to hold everything while I reset the pipe clamps.  Everything shifted a little in the form but that didn’t affect my finished product.

I let it dry for a couple of days then squared up the sides on a table saw.  I found before that it is impossible to keep the sides matched up so I make the strips wider than needed so I can cut it square once everything has dried.  Once I had square sides I laid the pattern I had made from the instructions in the manual I’m using and used that to cut the ends to fit the gunwales.  I did think that Cunningham’s book has you make the Masik to thin so I made mine about a ¼” thicker.  After test fitting and rounding the top and bottom I pegged it into place, and as I’ve done before I glued the pegs in.

With the Masik pegged and sanded I finished off the stringers, from the Masik to deck beam #3, that you can see the photo below of my son standing in the boat hold a broken rib.  The stringers I made from Cherry thinking that since they are pretty thin for the span they make hard wood would be the best.  I also have plenty of cherry lying around.  The stringers connecting deck beam #7 and #8 where also made out of cherry and I completed those at the same time.  These must take your weight as you are getting into the boat and you lay back on them to finish your rolls so they must also be strong.

Overall make the Masik was not very hard once I figured out what the best method for me was going to be.  As I’ve found in much of Chris Cunningham’s book Building the Greenland Kayak  I’ve had to modify the way things are done to fit my tools and skill set.

Monday, April 9, 2012

Bending the D*^$#n Ribs

Bending the ribs is finally done.  This has been the worse part of the project for me; I broke rib after rib until the last four I went back to a traditional way of getting straight grained wood.  Steam bending definitely has a learning curve that was very frustrating for me.  The one thing I learned was to use absolutely straight grained wood if you want any success.
The steam box I used was made from foil faced foam as prescribed in Chris Cunningham’s book.  The lay out in the book is simple and inexpensive.  I held the box together with duct tape and it held up reasonably well even though I used it at least four or five times.  Two modifications I made were to shorten the length of the box so it was a few inches longer than my longest rib and to push two dowel rods through both sides of the box for the ribs to rest on as a kind of rack to get steam all around them.    I had a hot plate to provide the heat and used the tea pot from our house, which I sanitized after each use then cut a 6 inch piece of pipe to connect the tea pot to the steam box.   The pipe was held in place by simply putting it in a bind between the two.  I was really amazed at how little steam escaped even though there wasn’t a tight fit between the pipe and the tea pot.  The end of the steam box was covered with a towel to keep as much steam and heat in as possible.
My first attempt was with some left over cherry and I carefully cut and shaped them and allowed them to soak for three weeks.  I broke everyone I tried to bend.  A little disheartened I called a friend that sells rough cut lumber.  I got two pieces of oak from him that had been cut only a few months ago so they were fairly green.  The problem, one I didn’t realize until much later, is that the wood was not straight grain.  I cut new ribs and let them soak for several weeks.  A buddy came over to help me steam bend the second batch.  We got all but four ribs bent into place.  Some of which had some splits that I glued back down.  The last four ribs were just downright a pain in the ass.
I think I made two more attempts two bend the last four ribs before calling my dad for desperate help, it all blends together now.  He suggested if I had enough wood left to split it by hand with an axe to ensure the grain was straight.  Having done Revolutionary War reenactments with my dad as a kid, implements of destruction like tomahawks are in no short supply in our family.  He brought over a hand forged tomahawk with a pull (flat section on the back) and a dead blow hammer, since neither of my tomahawks have a pull or the weight needed to do this safely.  I used the dead blow hammer to drive the tomahawk through the wood splitting it with the grain.  I split the pieces down until they were roughly a half inch thick then plained them smooth.  One thing I will warn anyone who is attempting this, a tomahawk should not be your first choice, they are sharp.  Using something that has a more blunt edge would be wiser if you’ve never done anything like this before.  I’ve been using a tomahawk since I was nine or ten years old so I’m fairly confident I won’t drive it into my leg.  I would also suggest long pants and boots if this is new to you not the shorts and sandals I wore.
The last four ribs soaked for three days and bent with ease, straight grain is the trick.  I do have to admit I sat down and drank a beer when the final rib went in.  This part took way to long, and I know that was due to my lack of experience bending wood.  If you attempt to make your own boat spend the money to buy straight grained piece of wood or do like I ended up doing, probably the most tradition way to make your ribs, spliting them by hand.
I was able to move ahead on several areas of the boat in the almost three months it took me to get the ribs done.  I should be writing about those in the near future to bring everything up to date.

Monday, January 16, 2012

Deck Beams and Tendons

Over the past few weeks, with lots of breaks for the holidays, I've been working on finishing up the deck beams.  This definitely has seemed to be the most tedious part so far, and I found another screw up.
Laying out the deck beams was a slow process since I wanted to make sure they were laid out right.  Making sure the gunwales are aligned right was important.  Mine haven’t matched perfectly as one is stiffer than the other so I clamped them tight to make sure nothing slipped while I was getting everything laid out.
During the process of laying them out I did deviate from the instruction and measured my ribs also.  My thought with doing the ribs now was to get them cut and thinned so they can soak for several weeks.  One post I had read on a Qajaq USA forum had stated they had the best results in bending when the wood had soaked long enough that it didn’t float.  I think that person had let them soak for two weeks.  I’m going on one week of soaking and it should be another week and a half to two weeks before I’m ready to bend anything.
One thing that I have found in making this boat is that the jigs Chris Cunningham uses in his book does really make things go faster and more uniform from one piece to the next.  I think I’ve used the tendon jig a hundred times so far.  It is a thin piece of wood that is 1 ¼” wide and about 3” long with 90 degree corners.  You’d be amazed at how many times you will use this simple piece of wood.
During the process of laying out the deck beams I figured something out.  I never marked out or cut a mortise for arched deck beam number 5, oops.  I’m not sure how I missed it until so deep into this project but I missed it.  I am a fairly light paddler at 155-160 lbs so I don’t think it will hurt me that much to not have it, at least I hope.  If you are doing this project I would suggest making sure deck beam #5 is laid out on your story pole, which is where things started to go wrong for me.
When laying out the tendons I did mark every deck beam with waste and tendon so I knew what needed to be cut off.  After the screw up with the deck beam I didn’t want to cut the wrong part of the deck beam off.  While cutting the tendons I also switched from using a fine tooth saw to a medium tooth saw.  This made the cuts go quicker and I think more precise.  The saw I use is a Japanese saw that has fine tooth on one edge and medium on the other with a fairly small kerf so making the change was as simple as flipping the saw over.  If the saw was tearing the wood I would simply flip back to fine the tooth side. 
Fitting the deck beams to the gunwales takes time. I had to file or sand some part of every mortise and tendon to get them to fit together properly.   Near the end I got to the point that I could look at the mortise before fitting and figure out what need to be filed or sanded.  It is good to keep a four in hand rasp, square cabinet makers file, and a sanding block close during this entire process.  Right now I am waiting on the artificial sinew I ordered to arrive so I can finish up with the final pegging and lashing of the deck beams to the gunwales.  The deck beams are not completely fitted tight but I will tighten those up when I get ready to lash and peg it.  It took using a Spanish windlass, pipe clamps (padded with wood as to not crush the gunwales), squeeze clamps, the end forms, and some cussing to get them all fitted.
Once the deck beams are done, the excess are cut off and everything sanded it will be time to bend some ribs.  My first project that involved bending wood was my dog sled, which we broke three brush bows before we got one to bend; with that experience I’m apprehensive about bending the ribs with little breakage.  I cut 50% overage on my bending stock for breakage, lets hope I don’t need to use much of it.

Tuesday, December 20, 2011

Mortises and More Mortises

In the last few weeks I’ve shaped and sanded my gunwales, plus drilled a boat load of square holes.  Forty four blind mortises and twenty two standard mortises, at three holes per mortise it was a lot of drilling. 

Drilling all those mortises really wasn’t has hard as you would think.  Thankfully the book I am using lays out the steps and with a little patients, which I normally lack, I had some rather nice holes.  Laying out the mortises, I think, is the most critical step.  On the blind mortises, mortises that are ¾“ deep and you can’t see through, I laid out how long the mortises should be but not the width.  I relied on my drill press to center the holes.  The problem with this is I’m not using a mortising machine, the drill press I have is a device that turns a hand drill into a drill press.  As you can see in the photos it looks older than dirt, because it is.  It was given to me by my dad and I remember him using it with his hand drill when I was pretty young, so the thing is 35 to 40 years old.  Making an alignment jig helps but if you have all four sides laid out it would be much easier to make sure your overlapping hole used to create the final product are all in line.  I also bought a new chisel and kept it extremely sharp.  I would suggest if you are doing this project and you aren’t very good at sharpening you find someone to teach you.  A really sharp chisel makes creating the square corners an easy job.

Once the rib mortises were done it was time to shape the top of the gunwales.  The forward and aft ends get a shallow curve that extends 70” down the top.  I laid these out with a batten, also know as a tent pole, then cut and planed up to the line.  In the book I have Chris Cunningham shows’ using a block attached to the side of the plane to make sure everything is kept at a 90 degree angle.  The plane I have is pretty small and I could not clamp a block to the side so I just took it slow and checked my work often with a square and had no problems.  Once the gunwales are shaped it was time to drill the deck beam mortises which are at a 73 degree angle a very intimidating task.

Laying out the mortises for the deck beam was pretty easy with a jig I created.  As you can see in the photo that I made a square hole that was 3/8 x 1 1/2, I then drew a line 1 ¼” from the opposite side.  Since my mortise was going to be 1 1/4 “ long I could simply align the line on the jig with the line laid out for my deck beam mortise and draw the other three sides of the mortise.  This along with a jig to hold my gunwale at a 73 degree angle made drilling the holes for the mortises much less intimidating.  Cleaning out and squaring up the mortises was done pretty quickly with a four in hand wood rasp and a square cabinet maker’s file.  Good luck finding a square file if you don’t have access to one.  I was going to buy one and I checked Rockler, Woodcraft, and Lee Valley with no luck.  A quick call to my Dad and he dug through his mountain of old woodworking tools and found two of them.  I don’t think the square file is essential but does make squaring up the corners a breeze.  If you are thinking about starting your own boat I would start looking through garage and estate sales to find one or maybe you can find a better source than I could.

The final steps to the gunwales are beveling the top edge, which I screwed up, and beveling the tips.  I didn’t reread the book and beveled the wrong edge on gunwale.  I don’t think this is going to be a problem I will just have some weird angles to cut on my arched deck beam that align with the bottom of the mortise not the top like the straight ones.

Now that the gunwales are done it is time for the deck beams.  Today it is raining and cold so that means it is a perfect time to go dig through the stacks of lumber at Menards.  No one else is stupid enough to be out there.  Since I will need to rip and plane the boards outside I will have to wait until the rain stops to get everything ready.  With Christmas fast approaching the deck beams may have to wait until after the holidays.

Monday, December 5, 2011

A story of Gunwales

I am off to the races in building my skin on frame Greenland kayak.  In the past two weeks I have built 3 of my forms and cut my gunwales.

About two weeks ago my dad was over and helped me make my “story pole”.  I wish I had photos of that, seeing my dad who is in his 60’s and has one knee replaced crawling on a hardwood floor to mark the board was a sight.  Marking the balance board with your measurements is definitely a two person job.  It maybe takes 15min to lay out but you need another person to transfer the lines from your body to the board.  We also kept Chris Cunningham’s book close so we could check to make sure we had it right.  Once I had all the marks prescribed in the book on my board with pencil I cut the board down to make it more manageable.  My finished product is approximately 2” wide and 4’ long.  When I was all done cutting it down I went over the pencil makers with a permanent marker and wrote what each line was for, while marking the “no rib” zones in red.

Next I made 3 of the five forms.  In the book these aren’t made until later in the process but I had the ¾” plywood left over from making some cabinets so I went ahead and made them.  The end forms were a pain to make, you are dealing with a bunch 73 degree angles and I don’t like how Chris lays them out in his book.  In the book the dimension for the two sight holes are given from outside to outside.  I was once a draftsman and I’m accustomed to holes being center to center.  So I screwed up drawing the forms several times before getting them right.  Making and cutting the forms maybe took me 2 hours but most of time was in drawing the end forms that I had to do several times.

I had decided to use cedar for my gunwale, I like working with it as I’ve used it to make three Greenland paddles.  It is a nice soft wood that is rot resistant, but has lots of knots, which can bring its strength into question.  I purchased a 16’ cedar deck board from Menards for $17.  I went to Menard’s on a nice rainy day so no one else was out in the lumber yard while I picked through the stack of deck boards to find the straightest, knot free board I could find.  I did find one board that was almost knot free but it was about as crooked as a congressman so I settled on one with a few more knots but straight.

At home I planed the board down to 7/8” and ripped them to a width of 2 ½” and a length of 15’-8” (16” sorter than my overall length of 17’.  Once the gunwales were cut I laid out my ribs and deck beams.  This took me about an hour to lay out and is pretty straight forward if you follow Chris Cunningham’s directions.  The one thing I did do differently is use a framing square to mark the width of my mortises instead of a gauge as suggested in the book.  For me I could lay them out with the framing square in less time than it would take me to make the gauge.

My next step is to cut the blind mortises for the ribs, all 44 of them!  I will be doing that today so my next post should be when all mortises are done and maybe the deck beams in place.

Tuesday, November 29, 2011

I’m Goin’ to Do it!

For a long time I’ve been threatening to build a Greenland skin on frame kayak.  After reading Chris Cunningham’s Building The Greenland Kayak about four times I’ve finally gotten up the nerve to build it.  My plan is to document different stages of the construction here on my blog.  I am also going to figure out a way to post the spreadsheet I am keeping that documents my exact expenses.

Why a skin on frame kayak?  Well it boils down to a couple of reasons.  One is I just like to build things and this seems like a really cool winter project.  Two, I like traditional stuff (I shot flintlock muzzleloaders growing up) and this was the way Greenland kayaks were originally built.  Sure I’m going to use nylon instead of seal skin to cover the boat but the heart of the original boat is still there.  Finally I want a roller; this boat is going to be 17 feet long and 19 inches wide, which should make it fast and a great boat to roll.

One nice thing about this project is I’m in no hurry.  I have a fiber glass Greenland boat, a Wilderness Systems Arctic Hawk, so it’s not like I have to get it done so I can paddle.  Skin on frame boats are also cheap.  A buddy of mine built a wood boat and finished it this year.  It took him over a year to build, he used up most of his garage (that made his wife really happy) and I know the kit cost him around $1000 so his finished product was much more.  I hope to be under the $300 mark on my boat and I can build for a day then move the frame out of the way so my wife can still get her car in the garage.  An added bonus is the boat will be built to my dimensions.

So if you’re interested in Greenland kayaks, or skin on frame boats follow along on my journey and we’ll see where it goes.