söndag 25 december 2016

Wooden pack frame project

This is something I've been wanting to make for a long time now. A wooden pack frame from the natural bends in the wood.

What triggered me to make it was when I saw a left over crooked log some friends had used when making kayaks. I immediately saw that it was just the right shape for the uprights of a pack frame. And since they had no more plans for it I could take it.

I found some plans with detailed plans of the frame in the book "Building outdoor gear" by Gil Gilpatrick. The frame in the book is just the kind I was looking for, the big difference for me though was that I made it from naturally crooked wood whereas he explains how to either bend the wood or glue thin strips to the right form.
Using his plans I used axe and spokeshave to shape the uprights. A goal with this project was to not use any power tools and only natural materials.

I then went into the forest to get a tree for the crosspieces. It was harder than you'd think to find. But  in the end I found a very crooked tree from which I could get all 4 crosspieces. I shaped up these too roughly. Then came the hard part... I had to wait for several weeks for the pieces to dry before I could continue. I put linseed oils on the end grain to prevent cracks during the drying.

A few weeks later I could do the final shaping as well as the mortises and tenons. I wanted my frame to be narrower in the top to give more space for the arms, this made making the tenons in the exact right place really hard. Since the uprights are not straight, but slightly angled inwards the length of each crosspieces varied by a few cm (up to an inch for my American friends).

I then made holes and tied the crosspieces in place using hemp cord which I put linseed oil on afterwards. Gilpatrick suggested nylon string, which you iron flap afterwards. While I'm sure it works well, maybe even better than my hemp cord. I'm just too stubborn and feel I loose some of the genuine feeling if I use synthetic cord.

Next I needed some shoulder straps and some back brace between the 2nd and third crosspiece. Since it's my first pack frame I don't really know yet what works and what doesn't. So I decided to make nothing permanent. Everything on the frame can be taken off easily.
The shoulder straps, made from leather are just attached by a cow hitch in the second crossbar from top. Then sewn onto hemp rope which I have tied with a tautline hitch at the lower crossbar for adjustable length.

Shoulder straps tied using a cow hitch.

Bottom of shoulder straps, tautline hitch.

For the brace I used hemp cord again and tied it using clove hitches to the uprights and cross bars. I'm unsure if this will hold up in the long run. If it does I might drill holes in the cross bars and uprights and re-do it so it looks nicer.

Then the final piece of the weight bearing system was the waist strap. I sewed it from left over pieces of tipi canvas and filled it with something we in Swedish call lindrev. It's made from flax fibers and used between the logs in log houses as insulation. I then linseed oiled the shoulder strap too. I don't want it to get all wet if it rains for an extended period of time.
I cut and old belt for the straps and carved 2 plates for easily adjustable length from a birch burl I've been having lying around. This made the fibers follow beautifully making them very strong. The two pieces are joined together using a piece of a tin armband which I cut and bent to the right form, then tied in place.
To keep the whole waist belt in place I sewed a single piece of canvas that goes around the uprights and is tied together like a pair of shoes.

Waist strap joined together.

The canvas piece holding the waist strap in place. This makes the height adjustable.

The final thing I needed was a quick and easy way to attach the stuff I want to carry. This took a lot of thinking and trying different ways. I've never seen anyone use this system I came up with but I think it works very well. I made 5 small loops on each upright by tying hemp cord around a double loop of thicker hemp cord. Then tied these loops to the frame. (The easy way here would be to just buy small metal rings). Then I put a cord through these loops. On one side I put small hooks, made from the same burl as the waist band, between each loop. These too are strong because the fibers follow nicely. I can then just put things in between the loops and hook it together. These hooks could be replaced by carbines just as well. And the rope which is now hemp, could be replaced with something elastic to make the system even easier and quicker.

The loop that keeps the gear in place.

The hook

3 kommentarer:

  1. Hallo Jonas,
    wundervolle Projekte, ein Goldschatz für die Sinne. Ein sehr schöner Blog. Viel Spass weiter.
    Beste Grüße Mike

  2. Beautiful job! Just the inspiration I needed. Any second thoughts after using it for a while?

    1. Thanks! It's worked very well, way better than I thought, I brought it on my last canoe trip. A 6 weeks trip.
      I made a few modifications before the trip.
      The holes on the waist belt where the rope is tied were to weak, so I have sewn on a leather piece on each side and now it works well. I also changed the ropes that keeps the luggage in place to rubber cord. It's the only non-natural part but it's just so much quicker and easier. I also changed the loops holding the cord to metal rings instead of the home made rope-rings as they tended to break.
      The things that broke on the trip was one of the wooden hooks and one wooden belt tightener. But it might just have happened to be weak pieces of wood so I will replace them with something similar, maybe paying more attention to the grain direction this time.