How to maintain bushing balisong?
A screwdriver with good quality bit (recommend Nabalis pivot needle tool)
800-1500 grit sandpaper or sharpening stone
KPL oil or super lube (highly suggested)
Measure the blade:
Use a micrometer or a percentile gauge to measure at least 4 evenly distributed points within the area covered by the washer. Please note that we will take the maximum as the thickness of the blade.
Measure the bushing:
Use a micrometer or a percentile gauge to measure at least 4 evenly distributed points on the circle of the bushing, the thickness bias between 2 points can't exceed 0.01 mm, which means that it's an qualified bushing. If it's not qualified, we need to use another new bushing. Please note that we will take the minimum as the thickness of the bushing.
Measure the washers:
Usually the washer has a stable thickness, we just need to make sure that it's not out of shape and has no surface burrs.
Ensure fit tolerance of the handle:
The thickness of the bushing plus the thickness of two washers, we name it the total high. The gap of the handle, where we assemble the washers and pivots to connect the blade, we name it the handle gap.
When slide the blade into the handle, with the bushing and washers assembled with the blade, if there is not much resistance, but not completely without any resistance, that means the total total high is around 0.01 to 0.03 mm larger than the handle gap and this is a good tolerance.
The most effective and qualified bushing for the blade is 0.03mm higher than the blade because we found that 0.03 mm is almost the best tolerance for aluminum bushing knife after hundreds of test, but when the bushing is 0.02 or 0.01 mm higher than the blade , the blade could get stuck when you tighten the pivot screw.
If the height of bushing is far higher than the blade, like 0.08 or even 0.1mm, the handle would have big play or tap.
In this case, we need to sand the bushing down to make it close to 0.03 mm. We recommend 800 grit sandpaper so there's a less chance that you're going to undersize the bushing too much and start over. When sanding the bushing, apply the same amount of pressure throughout the entire thing to avoid getting an uneven bushing.
Follow the 4 steps to tune the bushing:
1. Take the knife apart and take out the bushing.
2. Drag the bushing with proper pressure along the sharpening stone or the sandpaper in a circle, avoid grinding in a singular orientation.
3. Put the bushing back, test the handle play and the swing once you see steel has been taken off the bushing and left trace on the sandstone.
4. Repeat the process untill it has minimal play you want, make sure that when tighten the pivots down all the way but it still have swing and smoothness.
If it's 0.03 mm and the bushing is qualified, but the blade still become stuck in some specific place.
Disassemble it, add some 4000 grit polishing paste to where the washer is. Tighten the pivot back and flip until it become smooth again. Disassemble apart and clean the bushing, the washer and the blade, then assemble them back.
Assemble & Disassemble:
One way you can tell if it needs oil is if the sound becomes more sharp and harsh. When it is properly oiled, it will reduce the sound, has more dull sounding and feel more solid.
Get a small drop at the end of the application needle, touch the pivot with it then it will get sucked into the washers by capillary action.
1.Place the bushing into the blade. Take one washer and place it on top of the blade, take the other washer and place it on the bottom.
2.Hold the parts together and slide the handle over them, making sure all the holes line up properly. If you use the pivot needle, it would be much easier.
3.Take the pivot and press it into the handle. Put a small drop of your favorite oil on top of each washer.
4. You may choose to apply Loctite or Teflon tape to the screw, or nothing at all. Use a small amount of threadlocker applied directly to the screw, or wrap the screw about 4 times with Teflon tape.
5. Tighten the screw all the way down until you get the least play possible. Be careful not to overtighten and strip your screws!
Warm Tips: DO NOT flip your balisong after applying loctite, give it at least 12 hours to set properly. You may do it before go to bed, so it would set overnight.
We don't suggest taking pivots apart if you add loctite, cause it may get screws stripped. You may try to squeeze the handles together and loosen the pivot screws, only when it become loosened after flipping.