Cliff Stamp
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- Oct 5, 1998
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I had been using a Bolo from Tramontina for some time for general wood work, ref :
http://www.physics.mun.ca/~sstamp/knives/tramontina_bolo.html
and was pleased with its performance, I was expecting the Martindale version to be a direct upgrade considering experience with the Jungle Knife, ref :
http://www.physics.mun.ca/~sstamp/knives/jungle_knife.html
The Martindale Bolo is the top blade in the following picture :
http://www.physics.mun.ca/~sstamp/images/martindale_long.jpg
General specs :
The blade weighs 650 g, which is a similar weight to a 1/4" heavy utility bowie, so this isn't a "light" machete by any means. The balance point is 9 cm from the front of the handle so it is quite blade heavy. The blade length is 37 cm, fully sharpened right back to the grip.
The edge profile varies smoothly from base (0.110 x 0.150" -> 20.1 degrees) to tip (0.058 x 0.150" -> 10.9 degrees). There is a heavy secondary bevel of 25-30 degrees, less than one mm wide. The secondary edge is even, no visible burr. It takes 19 +/- 1 cm to cut 1/4" poly under 1000 g of tension. This is quite blunt, about ~25 times that of a sharp blade.
Using a file for about 5 minutes removes the secondary edge bevel. DMT diafolds ere then used to sharpen the edge, first 600 then 1200 grit. It now takes about 3 cm on poly. It can slice newsprint, but tears it in places. It still isn't close to shaving at any spot and needs some more a filing (5-10 minutes) to totally reset the edge. UPDATE : I later gave it a full filing and sharpening after some edge reshaping [see below] and it was easily hair shaving sharp, and about 0.5 cm on the poly.
The handle is smooth no gaps, but is a bit too squarish on one end, and you do get some sharp contacts. How much of an effect this will be depends on how far back your grip, and the size of your hand.
On grass and light vegetation:
High sharpness is required here and small differences can easily be noticed as grass is easy to bend as thus it will get pushed out of the way easily if the blade is even a little blunt. Blade balance, mass and edge profile are important, but secondary aside from the fatigue issue. The Martindale bolo sharpened as described in the above simply does have the full sharpness to cut such light vegetation well, a lot of bending and mashing. The mass and balance is also excessive for such work, it is simply a bit overkill and thus you are doing a lot more work than necessary. This is a wood working class blade. UPDATE : after a full sharpening it cut all this very well.
On limbing + Bucking :
Extreme sharpness isn't required here, the difference in chopping ability of a blade that can pop hair and one that just catches on your thumbnail is only a matter of a few percent. Blade balance, mass and edge profile are key aspects. The Bolo has the right mass and balance but the edge profile is a bit too thick even with the secondary edge bevel removed. It has a similar bucking ability as the Martindale Golok which is both shorter and lighter (~520 g). Thus it isn't isn't impressive from a mass or length perspective obviously. It also doesn't limb as well as the Golok, which you would expect as this is more dependent on just the edge profile as the cut depth is more shallow.
I then did some side by side wood working comparing it to the Tramontina bolo (505 g, balance point 10.5 cm from handle) which is in the same class as Gransfors Bruks Wildlife Hatchet. Working near the tip where both knives are of similar geometry, both are below their optimal abilities, as they are too short, and too stocky (blade balance too heavy) for such work, plus they don't have the optimal handle profile for snap/draw cuts, which is found on the wide tip Martindale machete (#32L), second from the bottom in the above picture. Working closer to the handle, the Tramontina has a thinner and more acute edge profile and the Martindale can only match its performance to 65 +/- 9 % .
The squarish end to the handle on the Martindale I found abrasive in far back grips, which limited the power I could provide. It also was noticed just walking around, as I then tend to relax my grip and carry the blade straight down, which forces a grip around the back of the handle. Some rasping mad a difference, however to round out the profile completely you are looking at around a half hour of work. In any case, the overall weight and balance are very solid, it handles just like a heavy duty version of the Tramontina. Here is a shot of the two side by side after some use :
http://www.physics.mun.ca/~sstamp/images/bolo_tramontina_martindale.jpg
You can see that the Martindale one (bottom) is much larger. The squarish nature of the handle in comparison to the Tramontina is also clearly visible.
Edge modifications :
The edge was easy to slim down. I reprofiled it using a one inch belt sander. This didn't take too long and could have been done in about a half an hour with a sharp file. The new edge geometry :
0.020 x 0.040" -> 14.0
0.036 x 0.081" -> 11.0
0.060 x 0.127" -> 08.9
0.105 x 0.370" -> 05.3 degrees
which is similar to the edge on the Tramontina bolo. I also lightly sanded the handle and gave it a coat of boiled linseed oil. The next time I took it out the performance jump was extreme. The Tramontina is of slightly thinner blade stock which increases its cutting performance, however the extra heft of the Martindale compensates. Running them side by side there was no significant advantage in regards to raw penetration. The difference in the cut count fell to which ever blade happened to get the best wood.
Using them for a few days I tried to decide if I would carry the Martindale version over the Tramontina. I have to note here that I had to pretend the handle was fine on the Tramontina it came loose awhile ago after a couple of months work. I am just talking about the blade aspect only.
There were a number of advantages to the Martindale mainly because due to it being significantly thicker. For example when felling using a saw to make the under cut, the stiffer Martindale blade allowed a quicker clearing of the waste wood, and is overall a much better pry bar. The Tramontina blade could not pry the chips out, tended to vibrate more, and had a higher tendency to glance. Since the Martindale was more powerful it also worked better as a club to break off dead limbs, was a better splitter and hammer. It also made a better whittler because it was sharpened right back to the handle. However in regards to bucking and limbing, the Tramontina held its own. So it depended on what I was doing. For an evening of limbing I would pick the Tramontina just as it is lighter. For overall utility I would pick the Martindale.
Since most of the wood cut around here is fairly soft, I used both bolos on some seasoned 6x6 and 5-6" logs to get a feel for the relative ability on some much harder wood. These logs were quite hard, I was getting only 1/4" to 1/2" penetration per chop (2"+ on pine). On this wood the Martindale induced much less feedback, had a much lower tendency to glance and could pry chips out much easier. It was not a difficult choice at all to pick between the two on this class of wood.
Grip modifications :
Later on the handle of the Martindale was modified to allow a further back grip. First I cut the top part of the handle off so it was sloped back at an angle. I used an angle grinder and forgot about the blade heating up actually, so I was concerned about the handle being too soft. Anyway I then used a rasp and a Dremel to smooth out the shape. I then gave the grip another coat of boiled linseed oil. I could now grip far back with the end of the handle inside my hand with no discomfort. It also allowed me to angle my grip, and thus the blade felt *much* lighter in hand, even though the balance was shifted forward. However it is lacking one important feature for this kind of grip, it needs a large end knob like seen on the wide tip machete, second from the bottom in the above picture. When I did some limbing the blade tended to slide forward and out of my grip. However the raw feel of it was very good. Quite frankly it felt like a whole new knife.
However the grip security problem was limiting as I kept having to adjust my grip so to solve this problem I extensively checkered the handle. I used a fine saw and cut lines into the grip, then crossed them. I went a little deeper than necessary, and the cross cutting was done a little sloppy so a couple of the parts of the checkering cracked off. I had intended at first just to do the middle areas, but then decided to do the whole thing just to see where hot spots would develop. When I was finished I gave it another coat of boiled linseed oil, after using a wire brush to get rid of all the sawdust. I also left the surface finish very rough, I used a 20 grit sanding disk to roughen the entire grip.
Back to more work, the handle was now very secure, no slipping. Comparing it to the Tramontina bolo again, there was no gain in direct penetration, the chopping ratio was again the same, however the feel of the blade was much better and thus the fatigue was much lower both in use as well as just carrying it around. Now I would chose the Martindale version over the Tramontina regardless of the situations as it is now pretty much directly better. Here is the new grip :
http://www.physics.mun.ca/~sstamp/images/martindale_bolo_handle_mod.jpg
Steel comments :
In the above wood work, no difference was noticed in either the ability of the Tramontina or Martindale blade to stay sharp, take a finer edge, or be more resistant to damage, both rusted easily if left wet.
-Cliff
http://www.physics.mun.ca/~sstamp/knives/tramontina_bolo.html
and was pleased with its performance, I was expecting the Martindale version to be a direct upgrade considering experience with the Jungle Knife, ref :
http://www.physics.mun.ca/~sstamp/knives/jungle_knife.html
The Martindale Bolo is the top blade in the following picture :
http://www.physics.mun.ca/~sstamp/images/martindale_long.jpg
General specs :
The blade weighs 650 g, which is a similar weight to a 1/4" heavy utility bowie, so this isn't a "light" machete by any means. The balance point is 9 cm from the front of the handle so it is quite blade heavy. The blade length is 37 cm, fully sharpened right back to the grip.
The edge profile varies smoothly from base (0.110 x 0.150" -> 20.1 degrees) to tip (0.058 x 0.150" -> 10.9 degrees). There is a heavy secondary bevel of 25-30 degrees, less than one mm wide. The secondary edge is even, no visible burr. It takes 19 +/- 1 cm to cut 1/4" poly under 1000 g of tension. This is quite blunt, about ~25 times that of a sharp blade.
Using a file for about 5 minutes removes the secondary edge bevel. DMT diafolds ere then used to sharpen the edge, first 600 then 1200 grit. It now takes about 3 cm on poly. It can slice newsprint, but tears it in places. It still isn't close to shaving at any spot and needs some more a filing (5-10 minutes) to totally reset the edge. UPDATE : I later gave it a full filing and sharpening after some edge reshaping [see below] and it was easily hair shaving sharp, and about 0.5 cm on the poly.
The handle is smooth no gaps, but is a bit too squarish on one end, and you do get some sharp contacts. How much of an effect this will be depends on how far back your grip, and the size of your hand.
On grass and light vegetation:
High sharpness is required here and small differences can easily be noticed as grass is easy to bend as thus it will get pushed out of the way easily if the blade is even a little blunt. Blade balance, mass and edge profile are important, but secondary aside from the fatigue issue. The Martindale bolo sharpened as described in the above simply does have the full sharpness to cut such light vegetation well, a lot of bending and mashing. The mass and balance is also excessive for such work, it is simply a bit overkill and thus you are doing a lot more work than necessary. This is a wood working class blade. UPDATE : after a full sharpening it cut all this very well.
On limbing + Bucking :
Extreme sharpness isn't required here, the difference in chopping ability of a blade that can pop hair and one that just catches on your thumbnail is only a matter of a few percent. Blade balance, mass and edge profile are key aspects. The Bolo has the right mass and balance but the edge profile is a bit too thick even with the secondary edge bevel removed. It has a similar bucking ability as the Martindale Golok which is both shorter and lighter (~520 g). Thus it isn't isn't impressive from a mass or length perspective obviously. It also doesn't limb as well as the Golok, which you would expect as this is more dependent on just the edge profile as the cut depth is more shallow.
I then did some side by side wood working comparing it to the Tramontina bolo (505 g, balance point 10.5 cm from handle) which is in the same class as Gransfors Bruks Wildlife Hatchet. Working near the tip where both knives are of similar geometry, both are below their optimal abilities, as they are too short, and too stocky (blade balance too heavy) for such work, plus they don't have the optimal handle profile for snap/draw cuts, which is found on the wide tip Martindale machete (#32L), second from the bottom in the above picture. Working closer to the handle, the Tramontina has a thinner and more acute edge profile and the Martindale can only match its performance to 65 +/- 9 % .
The squarish end to the handle on the Martindale I found abrasive in far back grips, which limited the power I could provide. It also was noticed just walking around, as I then tend to relax my grip and carry the blade straight down, which forces a grip around the back of the handle. Some rasping mad a difference, however to round out the profile completely you are looking at around a half hour of work. In any case, the overall weight and balance are very solid, it handles just like a heavy duty version of the Tramontina. Here is a shot of the two side by side after some use :
http://www.physics.mun.ca/~sstamp/images/bolo_tramontina_martindale.jpg
You can see that the Martindale one (bottom) is much larger. The squarish nature of the handle in comparison to the Tramontina is also clearly visible.
Edge modifications :
The edge was easy to slim down. I reprofiled it using a one inch belt sander. This didn't take too long and could have been done in about a half an hour with a sharp file. The new edge geometry :
0.020 x 0.040" -> 14.0
0.036 x 0.081" -> 11.0
0.060 x 0.127" -> 08.9
0.105 x 0.370" -> 05.3 degrees
which is similar to the edge on the Tramontina bolo. I also lightly sanded the handle and gave it a coat of boiled linseed oil. The next time I took it out the performance jump was extreme. The Tramontina is of slightly thinner blade stock which increases its cutting performance, however the extra heft of the Martindale compensates. Running them side by side there was no significant advantage in regards to raw penetration. The difference in the cut count fell to which ever blade happened to get the best wood.
Using them for a few days I tried to decide if I would carry the Martindale version over the Tramontina. I have to note here that I had to pretend the handle was fine on the Tramontina it came loose awhile ago after a couple of months work. I am just talking about the blade aspect only.
There were a number of advantages to the Martindale mainly because due to it being significantly thicker. For example when felling using a saw to make the under cut, the stiffer Martindale blade allowed a quicker clearing of the waste wood, and is overall a much better pry bar. The Tramontina blade could not pry the chips out, tended to vibrate more, and had a higher tendency to glance. Since the Martindale was more powerful it also worked better as a club to break off dead limbs, was a better splitter and hammer. It also made a better whittler because it was sharpened right back to the handle. However in regards to bucking and limbing, the Tramontina held its own. So it depended on what I was doing. For an evening of limbing I would pick the Tramontina just as it is lighter. For overall utility I would pick the Martindale.
Since most of the wood cut around here is fairly soft, I used both bolos on some seasoned 6x6 and 5-6" logs to get a feel for the relative ability on some much harder wood. These logs were quite hard, I was getting only 1/4" to 1/2" penetration per chop (2"+ on pine). On this wood the Martindale induced much less feedback, had a much lower tendency to glance and could pry chips out much easier. It was not a difficult choice at all to pick between the two on this class of wood.
Grip modifications :
Later on the handle of the Martindale was modified to allow a further back grip. First I cut the top part of the handle off so it was sloped back at an angle. I used an angle grinder and forgot about the blade heating up actually, so I was concerned about the handle being too soft. Anyway I then used a rasp and a Dremel to smooth out the shape. I then gave the grip another coat of boiled linseed oil. I could now grip far back with the end of the handle inside my hand with no discomfort. It also allowed me to angle my grip, and thus the blade felt *much* lighter in hand, even though the balance was shifted forward. However it is lacking one important feature for this kind of grip, it needs a large end knob like seen on the wide tip machete, second from the bottom in the above picture. When I did some limbing the blade tended to slide forward and out of my grip. However the raw feel of it was very good. Quite frankly it felt like a whole new knife.
However the grip security problem was limiting as I kept having to adjust my grip so to solve this problem I extensively checkered the handle. I used a fine saw and cut lines into the grip, then crossed them. I went a little deeper than necessary, and the cross cutting was done a little sloppy so a couple of the parts of the checkering cracked off. I had intended at first just to do the middle areas, but then decided to do the whole thing just to see where hot spots would develop. When I was finished I gave it another coat of boiled linseed oil, after using a wire brush to get rid of all the sawdust. I also left the surface finish very rough, I used a 20 grit sanding disk to roughen the entire grip.
Back to more work, the handle was now very secure, no slipping. Comparing it to the Tramontina bolo again, there was no gain in direct penetration, the chopping ratio was again the same, however the feel of the blade was much better and thus the fatigue was much lower both in use as well as just carrying it around. Now I would chose the Martindale version over the Tramontina regardless of the situations as it is now pretty much directly better. Here is the new grip :
http://www.physics.mun.ca/~sstamp/images/martindale_bolo_handle_mod.jpg
Steel comments :
In the above wood work, no difference was noticed in either the ability of the Tramontina or Martindale blade to stay sharp, take a finer edge, or be more resistant to damage, both rusted easily if left wet.
-Cliff
, I will have to look that thread up over on the Survival forum, I must have missed it.
) they would still only represent his subjective opinion.