A shot of the Tramontina bolo alongside a Busse Battle Mistress (middle) and a Patrol machete from Camillus (top) :
The review consists of :
The Tramontina bolo is made from 1/8" thick carbon steel, has a 37 centimeter long blade, and balances 10.5 centimeters infront of the handle. It was bought used so had surface rust and the edge at places had visible damage. The edge was reground on a belt sander to a profile 0.095" thick and 0.370" wide, a grind of about 7 degrees, which tapered to 11 degrees per side towards the very edge under 0.020" thick. The handle also was a little rough and needed some work. The scales were extended past the tang with sharp edges and various other sharp corners had to be removed. It took about a half an hour with a rasp and small carving knife to get the handle in shape.
On weeds, grasses and small soft branches, the Bolo performed well, out cutting a Patrol Machete, part of the Becker Knife and Tool collection from Camillus. This was just due to the difference in sharpness, as the Bolo was freshly sharpened and the Patrol Machete was used with the initial edge straight from the production line which was less than optimal. In general for light grasses, the Bolo is overkill and lighter and longer machetes are more efficient.
On some small wood, one to three inches in diameter, the Bolo did well in limbing, able to sweep off the smaller limbs easily, however during felling and bucking the blade would bind excessively and it it didn't have the stiffness to pry out chips, the Busse Battle Mistress was much more efficient for those tasks. The Battle Mistress had a similar level of raw penetration but bound less and was much stiffer and thus allowed a more fluid pace. The back of the bolo however made an efficient hammer to sweep off dead limbs, easily outperforming the Busse Battle Mistress in that regard. The hump on the back of the tip can also be used to to cut sods in the same manner.
The Bolo was also extensively used alongside a GB Wildlife hatchet, mainly take down small trees each from 2 to 4 inches in diameter, cut them in half and limb them out. On the small trees the Bolo cut them well with little fatigue and also limbed them out easily, outperforming the hatchet, mainly for the ease of sweeping off longer limbs. However the Bolo again struggled with chopping the thicker wood, the hatchet excelled there and pulls ahead of the Bolo many times to one. In terms of raw penetration, the Bolo held its own with the hatchet, however it can't clear chips from the thick wood, as it binds much more readily. From a viewpoint of fatigue or time spent, bucking say five inch pine and above (or three inch spruce and above), the hatchet pulls ahead easily approaching 2:1 .
The edge of the bolo also tended to take dents during both the felling and the limbing. The dents were mainly about one millimeter long and less than half a millimeters deep, though after some sessions of one to two hours, they would be as large as one centimeter long and one millimeter deep. The hatchet was not effected by that volume of wood working. To check the durability requirements of the edge, a secondary bevel of 13/15 degrees was applied which was about 2 millimeters side. With the edge raised to a fine polish using waterstones and finishing with chromium/aluminum oxide buffing compound the bolo was then used for three sessions of felling, limbing and bucking lasting about 3-5 hours each alongside the forest axe from Granfors Bruks. On the first two days the Bolo fared really well and could even clip off dead wood branches. On the third day, while bucking up two small logs about four inches thick the edge rippled in two places, the full width of the micro-bevel bents out of place about 0.5 centimeters in length.
As a batoning tool, the bolo can take batoning to split wood, there is no danger of breaking the blade as it is very tough, however the edge can turn around knots. The handle also later broke under vibrations from heavy batoning.
After a full sharpening and a few days of working on mostly hardwoods, the Tramontina had a noticable loss of fine cutting ability. Specifically, after a fresh sharpening with a file it took 1.25 (25) cm of edge to cut quarter inch poly under a 1000 g load. After about three hours of felling, bucking, limbing and stacking work, about 700 chops, in the area of maximum impact, the performance had degraded down to 4.25 (25) centimeters on the poly, or 29 (6) % of its freshly sharpened ability.
The edge was honed with a few passes on a grooved steel and it brought it back to freshly honed performance. The blade is soft enough so that the steel acts like a file. Another session of chopping left the blade with similar loss of aggression on the poly however time there were a few places of minor visible impaction and rolling, as to be expected as the edge had not been freshly sharpened, and the work with the steel work had left some fatigued metal along the edge. However, the edge could be steeled and again brought back to near optimal and easily able to cut fine grasses.
In general, for most wood working the edge is kept at 10/12 degrees in the very final bit of the bevel, this isn't quite strong enough for harder woods and after a session of 250/500 chops there will be visible deformation, this can be prevented as noted in the above by increasing the angle to 13/15 degrees, but the metal is soft and even then on a bad chop into hard woods the edge itself can turn. However it is easy to file out any damage.
The end hook on the grip is too sharp and is uncomfortable to driven off of with the pinky. A dremel was used with a cut off wheel and grinder to cut the rough shape which was smoothed with a rasp. This modification allowed heavy chopping without any excessive impacts to the pinky and any loss of security.
This bolo is a very solid working large blade which is capable of handling woody brush work without gross damage. It has high penetration ability, the same as the Gransfors Bruks hatchet though does bind much more in problematic wood. The toughness is very high, and has not suffered problems which have been common with other long blades on hard wood work. it has been used extensively and is still (2006) going strong. The edge retention is lower than high quality tool steels, and it will turns on knots and other hard inclusions if it fails to cut through them cleanly. It can be readily filed so sharpening is not demanding even if working in harsh conditions where the edge gets damaged. It would be nice to see a similar blade pattern in a harder steel which would give better impaction resistance.
Comments can be sent to : cliffstamp[REMOVE]@cutleryscience.com or by posting to :
| Last updated : | 01 : 10 : 2006 |
| Originally written: | Apr 12 : 2002 |