Bushsaw / Bucksaw

[BOD]

I’ve always been impressed by those stories of Finnish backwoodsmen carrying a saw blade in their belt and then knocking up a bucksaw over a cup of camp coffee. It would make setting up a camp so much easier if I could have a bucksaw that I could make from natural material.

So with Mors Kochanski’s Bushcraft as a guide I thought Id see what I could do. The rules for my bushcraft projects usually are – use only what is available and use only what you would bring into the bush – which is just knife and cord normally

I went okay until I had to make the slots for the blade. I can’t make an end nock as narrow as a saw blade. Mors says use a knife so I very gingerly tried a tap with a baton on my Frost Mora but even this slim blade this soon showed a crack developing in the wood so I stopped. Mors also says that you can use the saw blade but I don’t see how. I tried holding it in my hand and sawing the end but I couldn’t get a groove going and the blade kept on slipping off and threatening to gash my other hand. So I cheated and use a small bow saw.

Can anyone tell me how I can make the slots with just a knife or saw? Mors doesn’t elaborate on how to do it. Do you baton the end and then lash the split?

After cheating with the saw, I realise that instead of boring a hole with my knife, I could make holes for the bolts if I used a bow drill so I made a slim drill and got busy. This made me feel better. To my surprise, I got good quality dust. I had selected Hevea Brasiliensis (the real rubber tree) and did not think that such a sappy wood would be good for a fire drill.

I then realized that the slot I had cut for the blade was acting as a conduit for air to reach the hot dust and that a tiny ember had formed in the slot! You can faintly make out the smoke and see the ember in the slot in this photo. So if you are heading out to the Amazon or South East Asia you know what wood to use for your bow drill

I then drilled through the end as this photo shows.

Assembling the saw, was not that easy, and I realised that I should have cut straight cross braces/supports instead of using the bent wood that I had.

Mors also mentions small nails knocked into the end of the cross braces to stabilize it. Does anyone know a way to avoid using nails (cos that means a hammer has to be brought in to the jungle as well)

Here is the final product inspired by the master’s book.

Does it work? Yes.

IS the right hand side less than 90 degrees? Yes, I am afraid so.

I promise to do better next time and am open to suggestions on minimalist construction techniques.

I think a couple of wooden dowels could replace the bolts. What do you think?

 

[falling rain]

I can't see your photos Bod (something to do with how the IT people at work have set things up)
I've made a fair few of these frame saws. I usually baton gently with the knife just a centimetre into the wood dead centre. Place the blade into the split and gently baton the blade so it is flush with the wood. You can then tie a constrictor knot (or whipping for a few centimetres if you have plenty of cord) above the blade so the split dosn't run up the wood. You don't need to make a nock, just split the wood carefully and slot the blade home. It should be a tight fit and you definately don't need to saw a nock with the blade.
Instead of bolts there's no reason why you can't tie the blade through the hole and attach to the frame. It may feel loose but will tighten when you crank the tightening toggle at the top of the saw. Or you can use split rings, or as you said make some dowels. They again will tighten into place when you tighten the saw for use.

 

[jon r]

Wow! Thats fantastic! I love it.

I like the way you drilled the wholes!

 

[BOD]

Wow! Thats fantastic! I love it.

I like the way you drilled the wholes!

Thanks. Coming from you that makes me feel good

 

[Stuart]

I think you may have misread the instructions slightly, and in doing so come up with your own novel, if slightly more complicated method of saw building.

The holes are not normally bored though the side of the uprights, the bolts normally pass though the saw blade alone.

The blade is pressed into the splits (which are made by simply pressing the edge of your knife into the wood until you create a split slightly deeper that the height of your blade) with the bolts on the outside of the frame.

The windings are then applied and this tensions the saw blade, because the bolts (or nails, wire etc) prevent the ends of the saw passing though the slit. Exactly the same method that is employed in a simple junior hacksaw, the bolts aren’t there to ‘bolt’ the saw in, just to prevent the blade passing though the slit so it can be tensioned, the tension then holds it in place.

You can cut shallow notches into the outside of frame to provide a seat for the bolts, but it is often unnecessary as they commonly bed themselves into the wood a little from the tension alone.

I think a couple of wooden dowels could replace the bolts. What do you think?

You can’t really replace the bolts with dowels, the force exerted buy the tensioning will cause the blade to cut into most wooden dowels, which, will weaken them enough that they then snap very quickly.

Mors also mentions small nails knocked into the end of the cross braces to stabilize it. Does anyone know a way to avoid using nails (cos that means a hammer has to be brought in to the jungle as well)

Mors doesn’t use a hammer for small nails, he places the flat side of his knife (above the bevel near the handle) against the head of the nail and whilst holding the knife by the handle with his right hand he strikes the opposite side with a wooden baton driving the nail in as if the baton was a metal hammer.

rather than use nails I have found that you can achieve an effective binding effect to prevent slippage by applying sticky sap or resin to the contact faces of the cross bars. such as the sap of the Jack fruit which should be available to you and works extremely well

It looks like you have saddle notched the ends of the cross bars where they meet the uprights which gives you the best fit to prevent the cross bars slipping out though vibration during use.(the standard expedient method is to simply flatten the contact surfaces) but you also need to make the contact surface between the two cross bars larger and more stable (where they meet at the end of the V). the ends of your cross bars only meet at the very end, use your knife to flatten off the sides where they meet until at least 3-4 inches of surface come flush together and you can place two bindings across them several inches apart (doesn’t make sense I Know, the picture below should show what I mean) this will make the whole saw much more stable



The venerable Mr kochanski building a bucksaw in camp:

(note the stick on the ground to prop up one end so you can make the windings easily, these little things are what really make the difference in the bush)

 

[British Red]

Hi Bod,

A couple of things that have worked for me.

When selecting the wood for the uprights, I choose pieces with side branches. I cut them to size so that the swelling from the side branches are an inch above the notches for the saw blade. Because the grain "swirls" where the side branch leaves the upright, the split doesn't seem to run.

With the cross member(s), I carve a small peg on each end and make a small socket in the upright. Stops all the slipping and no need to carry anything. As FR says, I use keyrings rather than bolts.

There is a picture of all the steps I use in the "build a bucksaw" competition thread if thats any help

Red

 

[BOD]

Red,

Good tips thanks. Like the peg ends idea. Easier than getting stuck in Jackfruit sap.uppy_dog . Will look for ideas in theat thread which I do remember

Stuart.

That photo is very useful. Especially the stick on the ground. That would have made a world of difference in the assembly and as you say its these littel things that make the difference. Would love to see the great man do all this stuff sometime. I love the way he hammers nails in.

I worked out that the bolts didn't go through the upright but thout it would be more fun to try the bow drill as a drill. I was unsure if the split was made by a baton though and this was my main worry.

Apart from that bit Mors insrtuctions were easy to follow. I did indeed depart into a complicated excursion of my own.

 

[brancho]

Bod
I think you did a good job.