Bolster drilling

[Cold Steel Cult]

I have a situation which is seriously frustrating at the moment... I have a drill press with a drill press vise from HF and I have recently run into some trouble with drilling bolster holes accurately. I have tried vising up the two bolster slabs together, but the vise has some kind of messed-up face that tapers. Does anyone have any suggestions for drilling the bolster holes more accurately? Thanks!

[titaniumdoctor]

Ya need to clamp them babys directly to the table of your drill press. Pick up your hole location with a pointer, center drill, then drill. You may have to invest in a small table with T-slots (like on a mill) and a clamp kit. This will make life a lot easier no matter what your drilling.

[Don Cowles]

I drill my bolsters freehand (no vise) one at a time, using the previously drilled holes in the blade to guide the drill. I clamp one bolster to the knife, drill the first hole, then use a temporary pin to lock in that location, and drill the next hole.

When I am through, I remove the clamp, pin, and bolster, and clamp on the other bolster and repeat the process. This is covered in my bolster tutorial.

[george tichbour]

If you want to use your drill press vise to hold things safely but the faces are out of line clamp the first bolster to the blade with a pair of visr grip pliers then grip the edges of one of the jaws in the vise. Drill first hole, temporarily pin, drill second hole. Remove vise grips from vise and clamp both bolsters together then using the first one drilled as a template drill the second.

Caution you may raise a burr on the inside of the first bolster so flatten it before clamping up to drill the second one and keep track of the inside faces in case the holes are slightly angled.

[chrisinbeav]

There could also be another issue... your drill press its self.

Does the head and chuck of the press wobble a little when running? Mine has this probelm as well. The only way to solve that is to get a new chuck and maybe the spindle. Check Grizzly, they have a lot of high quality chucks.

Next, is the drilling table absolutely perpendicular to the drill bit? Using a square and a level you can get it pretty close. The best way to get it is with a dial indicator.

These two items can make a huge difference in how well and accurately you can drill.

Another is, just how sharp are the drill bits? Drill bits that aren't really sharp tend to wander a bit when you first start them.

Chris Nilluka

[Gary Biggers]

Just like George said is the only way to go for me. I originally learned this method from D' Holder and now have been using it for several years. Be sure to have at least 3 holes in the tang. With two holes it allows too much slop and bolster alignment is not always perfect. I have found that I like to use 3/32" pins in the bolsters vs the usual 1/8" pins. Use a #41 bit (135 degree grind on the bit) to drill both the holes in the tang and the bolsters. I use a 12 ton hydraulic pin press (a la Ron Gaston) to crush the pins in place (416 SS or other steel bolsters only). Just keep in mind--- flat, flat, flat-- on the tang where the bolsters will be mounted. Doing it on a tapered tang is the standard, but the taper must run flat through the bolster area.

Be sure to finish the front of the bolsters completely before installing. It is easy to do before pinning, but almost impossible after pinning. You also need to finish the back side of the bolsters (the part that goes against the scales) before pinning.

Like Don, I do not use the vice to hold the bolsters while drilling. I place a block of wood in the drill press vice and set the bolster on the block. I hold the blade while drilling.

Gary Biggers

[Tom Militano]

I superglue my bolsters together and and clamp them to the blade. I drill them undersize and than ream them .0005 oversize. I put a pin in the first hole I drill and another in the second so everything will line up. I heat them up with a propane torch to separate them. Flat sand the glue off and I'm good to go. I use 1/8" pins and I also use three of them.

[DiamondG Knives]

Ive never used a press, but like the idea! Can you tell me, do you pre pien one side of the pins prior to putting them in the bolsters to be pressed? And are you using a slight taper in your holes?

Thanks and God Bless
Mike

[Tom Militano]

I don't peen one end of the pins before I install them. I make sure the ends of the pins are flat and I leave about 1/16" sticking out of each side. I start mine with a ball peen hammer, the flat portion, with the bolsters sitting on a piece of steel. When they quit moving around in the holes I use a four pound hammer on them and everything pulls up good and tight. I use 416 stainless for bolsters and guards and 416 pins. I haven't seen the dreaded circles on my bolsters in a good while.

[Gary Biggers]

When using the press I leave about 1/16" plus sticking out of each side. One of the press anvils has a 1/16" depression in it. I just put the pin in the fresh drilled hole (#30 bit for 1/8" pin and #41 bit on a 3/32" pin) and crush it. After doing all the pins on one side, I turn it over and do the other side. The extra clearance using the oversize bits makes it easier to go together. When you crush the pin using the press, everything expands out filling the hole for a perfect fit. With the press, counter sinking the hole is not necessary. Just be sure to have clean pins with any oxydation sanded off (sand the pin before cutting to length. Saves a lot of time.).

Gary Biggers