Much quicker than laying out a square. What I do is mark the center point of my plug, then drill a plug-depth hole with a bit that matches the hole in the proper LV chisel. With the hole drilled, I place the tip of the same drill into the hole and slide the LV chisel over, then use a square to align it with some edge. The drill bit usually will extend way beyond the LV chisel's end so I have a deep socket handy that will slip over the bit and make contact with the chisel. A few taps with a mallet will set the chisle. ]I then remove the bit and wack more with the mallet until the curves in the apexes of the chisel hit the wood/ Note that the pilot hole also allows the wood to push into the hole so you are not enlarging the desired square hole OD. With the LV chisel removed you now have nice reference pits to use a standard chisel to finish up the sides of the hole.
Note that the LV chisel is really just a power mortiser chisel with a screw on basher. If you have a set of mortiser chisels, you can do the same.
Rick, LV also offers sharpening cones for these punches, I suggest you secure these as well. Like Splint mentioned, these punches are really bits for a mortising machine but with handles. I have a mortise machine and I've experienced the dulling of the square bits, especially after a larger cabinet like build with many mortises. Then they start to become hard to use, and sometimes cause dulled and rounded entry edges on the mortise due to breaking grain rather than cutting the wood.
SplinterGroup, Oldtool....These punches will cut 3/8" deep. When you do G&G plugs do you always make the plugs this long+ ? What depth square hole up to 3/8" deep do you make? And how do you accurately control the depth?
I use the 3/8" primarily, but I bought the set since the smaller ones are commonly paired with largers for G&G frames (see my John Hall mirrors).
For depth, I usually go no more that 1/4", 1/8" for smaller items. Deeper means a bit more hole to ensure they go in without tilting. The depth control comes from the pilot drill hole more or less, but I'll usually just add a dot of epoxy and use an old credit card with the proper hole to slip over the plug, then press flat with a scrap of wood. The cards leave a consistent reveal. One of the sizes, can't remember which, has a common size hole through the center and for those I'll use a Frostner bit for the initial locating hole to get the flat bottom. For the alignment I'll then use the same size drill bit, shank down to align the punch/chisel with the hole as mentioned before. I haven't bought a sharpening stone, but could use one about now. I prepare my stock to 1/64" oversize for a good compression fit with the sides.
