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Pakyak Frame F.A.Q.

1. Why did you choose Baltic birch plywood?

2. I can't find the sizes of the hardware pieces needed to put together the stringers and other braces.

3. About the center brace, am I right that the thwart has no locking function for the underlying bottom stringers?

4. Section 2, Parts Finishing (Gunwale): Hinge assembly: Why do the angle pieces have to have 2 round notches?

5. There are no washers between stringers. Are the screws not firmly tightened ?

6. I was just wondering how did you use your drill press to round the edges of the wooden strips.

7. Any suggestions where to find the 9 ply Baltic birch. Home Depot seems to have only 5 ply Birch.

8. Could the frame be built with bamboo or aluminum tubes instead of plywood?

9. I couldn't find any referance to the spacing between the four stringers in the very front and back of the boat.

10. The Gunwale hinges are drilled with a 3/16" hole. Should I use 10-32 machine screws?

11. What did you use to cut the angle braces? I am using a hack saw.

12. Why plywood? Why not something like spruce or Douglas fir?

13. What type of aluminum did you use?

  1. I was curious as to whether Baltic birch plywood was just your wood of choice or if this wood was chosen for another reason. I am currently trying to find a supplier near where I live. Will marine grade plywood work also? What about ½" thick oak or other hardwood?
  2. Just about any plywood will work, I think. I like the Baltic birch because it is hardwood, 9 ply cabinet grade, tougher than fir plywood and with fewer voids. The trouble you might have if you use straight hardwood is that the ends may split out from the screw holes. Plywood gives you those cross plies on the ends that prevent this.

    The Baltic Birch plywood and all the other materials you will need should be available locally, if you ask around a bit. So far that's been true for me and everyone else who has built one.

  3. I have gone through the plans more than a few times and I can't find the sizes of the hardware pieces needed to put together the stringers and other braces. I know that the machine screws are size 10-32 but what about the lengths? The ends of the kayak are put together with 3" bolts (?) (I'm still using the older prototype design without the updates) but I'm unsure if the other bolts are 1.25" or 1.5"?
  4. Yes, you'll want to get some different lengths.

    For the brace parts you can generally use 3/4" because they go through 1/2" of plywood and 1/8" of aluminum.

    For the stringers you generally need 1 1/4" lengths because they go through 2 layers of plywood plus 1/8" aluminum.

    At the center braces 1" works.

    You'll see as you get into it what is needed where.

  5. About the center brace, am I right that the thwart has no locking function for the underlying bottom stringers? It just carries side pressure, right?
  6. Yes, you are right that the thwart has no locking function for the bottom stringers, just helps hold their spacing against side pressure from the water.

  7. Section 2, Parts Finishing (Gunwale): Hinge assembly: Why do the angle pieces have to have 2 round notches?
  8. The notches allow the skin to fold without pinching it.

  9. There are no washers between stringers. Are the screws not firmly tightened ? If so, isn't there a lot of friction between stringers ruining the varnish?
  10. You are absolutely right about this. Washers would be a good idea. But you might have to countersink the stringers if the washers are too thick, for the frame to fold as tight as it should. So watch out for that.

  11. I was just wondering how did you use your drill press to round the edges of the wooden strips. I got a drill press but can't figure out how to setup a jig to do this.
  12. First I made a little table and fence that I could clamp on top of my drill press vise, with a gap in the fence for a 1/4-round router bit. Then I positioned the table under the bit so when I slide the strips along the fence the edge goes under the router blade. I also have my drill press set up so I can adjust the drill down, rather than having to move the table up to the bit. I do this by moving the nut that sets the drill depth from above the stop to below it, so the stop keeps it from going up. Kind of a jury-rig, but it works for me. I've been thinking of modifying my fence so the strips fit into a slot and are held down. That would help prevent the nicks I get when I accidentally let them lift up against the router. Anyway, I hope you get the idea.

  13. Any suggestions where to find the 9 ply Baltic birch. Home Depot seems to have only 5 ply Birch.
  14. Home Depot's 5-ply birch might work okay if there are no voids. That's the main reason I suggest the Baltic Birch. The price on the Finnish 9-ply does sound like a lot, but there are various grades and that is probably top quality. Actually any good quality plywood with no voids would do.

    If they don't know "Baltic Birch" ask for "cabinet grade" plywood. Here's an on-line site where you can get it if all else fails. http://woodbymail.com/balticbirch.html

  15. Could the frame be built with bamboo or aluminum tubes instead of plywood?
  16. The idea of using bamboo for the stringers is interesting, but it would be an experiment. I'm afraid that in small enough diameter to fit the design it would be too flexible.

    Similarly with aluminum tubing, it would have to be 1/2 inch diameter to fit the design, and that might not be strong enough. I know that aluminum extrusions are made in 1" x 1/2" rectangular shape, and that could be a direct substitute for the plywood stringers. But I haven't found a distributor that will sell that size in small quantities. Maybe you would have better luck with that.

    Anyway, I still use plywood.

  17. I looked all through your notes and couldn't find any referance to the spacing between the four stringers in the very front and back of the boat. In the plans it shows a space between the middle two. You call for a 3" roundhead screw which leaves plenty of room.
  18. The space you asked about needs to be wide enough for a stringer to fold into it, so it needs to be just over 1/2 inch wide. To make the spacers you can use something as simple as the body of an old Bic pen.

  19. The Gunwale hinges are drilled with a 3/16" hole. My rivets seem too small. Does this mean I am to fasten them with the 10-32 machine screws?
  20. Yes, these hinges need to be pretty strong, so hollow pop rivets won't do the job.

  21. What did you use to cut the angle braces? I am using a hack saw.
  22. A hack saw is fine, although I've used a cutting wheel for some of the work.

  23. Why plywood? Why not something like spruce or Douglas fir?
  24. I like plywood for two reasons. I can rip a sheet into the 1" strips I use with little waste, and the cross plys help keep the end holes from breaking out, as can tend to happen with normal wood.

  25. What type of aluminum did you use? Or is this just generic home improvement store grade?
  26. I use the cheapest generic hardware grade I can find. I even try to avoid anodized because it doubles the expense.