Plug cutters

[LCHIEN]

Got a set, kinda looks like these.

I presume the top ones are for making tapered plugs, right?

I went to make some plugs to cover a goof hole, I used a 3/8" brad point to make a hole 1/2" deep
I then went and cut some 3/8" tapered plugs and they are loose and slid into the hole and will almost fall out
I thought the taper was supposed to go a little oversize so you could hammer the plugs in and fit snugly. Then cut off the excess protrusion with a flush trim saw.

They appear to be 0.38 at the wide end and .037 at the narrow end.
seems like it should work.
Drilling a longer plug doesn't make the wide end any wider as the widest point is where the plug cutter tip enters the wood.

I guess you're going to tell me now to go measure the hole....
I did check with a 3/8" dowel and the hole is a little loose. I guess that means the hole is too big.

I had to use a da*n gimlet to get them out.


Anyone got any advice about plug cutters?

[d_meister]

My very first maritime job was cutting hundreds of plugs for the most accomplished carpenter I've ever met or known about. He set me up at the drill press with wood cut into strips that were just a bit wider than the plugs. The wood was carefully selected to match the intended location, which was in that case a very old teak hull. Older wooden boats must have the fasteners that attach the planks to the ribs replaced periodically because the fasteners waste over time from the moisture in the wood. I've also replaced plugs in teak decks that came out as the deck became thinner due to wear and excessive scrubbing, and the interesting thing is that if an existing plug is drilled with a smaller bit, it can almost always be dug out bit by bit and leave a clean, original hole if originally glued in with conventional glue. To set a new plug, the screw is removed and the wood is counterbored deeper, using a screw bit detailed following. All bets are off with epoxy, though, as the epoxy penetrates well and is harder than the wood.
I think that drilling holes and cutting plugs is an activity where accumulation of error is a real problem, from the run-out of the drill, to the non-centering nature of plug cutters allowing wander.
The best tool for the plug hole is a countersink screw bit like these:
https://www.ebay.com/itm/18538667596...Bk9SR66n3-npYw
The design keeps the countersunk hole centered and controls the finished diameter better.
When cutting plugs, it's important to contain movement of the piece the plug cutter is drilling, either by containing in a very secure channel on the drill press table or clamping securely near the work. Any eccentricity of the plug cutter and drill press quill assembly will force movement of the piece and result in under-sized plugs. Higher drilling speeds also make for better quality plugs.
I recently bought the Rockler corner doweling jig,
https://www.rockler.com/rockler-corner-key-doweling-jig
and was surprised that the instructions caution against using brad point bits and specify conventional or split point bits, yet many doweling jigs provide brad point bits with them. Must be some science there that's not readily apparent, and may or may not relate to your experiments.

[leehljp]

Clamping is a necessity in my experience too. I don't have much experience but my first experience on a small board taught me quick!

Yes, top one make tapered plugs.

d_meister: "was surprised that the instructions caution against using brad point bits and specify conventional or split point bits, yet many doweling jigs provide brad point bits with them."
IN the pen turning world on IAP, (International Association of Penturners) the vast majority recommend not using brad point bits also. Some people do well with brad points. To me it depends upon the quality of the brad point bits. I have a couple of brad point bits that are obviously cheap and are not perfect. Then there is a set that I have had 40 years that cost an arm and a couple of fingers back then. I only use them on special needs and those bits are still as sharp today as they were when I bought them. Quality all the way through. Poor and even medium quality brad points are not worth it. That takes me to the next point -
. . . IF making more than a few plugs, I would look for a quality plug cutter, such as these: https://www.leevalley.com/en-us/sear...erOfResults=25

[Black walnut]

I have never had issues. I use Irwin brad point bits and a vermont american plug cutter of the straight kind. Screw holes and counterbores are best made with a bit as linked though.

Loring if the plugs are a bit loose you might use minute epoxy to set them. When checkering gunstocks epoxy can be used to make mistakes grow back. It takes on the coloration of the wood and results in a hard to see glue line even if a larger gap.

[LCHIEN]

I just wood-glued a short piece of 3/8" dowel into the hole which was a snug fit, and after it cured, took a flush cut saw to it.

So the plug is not the same wood.

But I really expected the tapered plugs to be a snug fit.

[d_meister]

Clamping is a necessity in my experience too. I don't have much experience but my first experience on a small board taught me quick!

Yes, top one make tapered plugs.

d_meister: "was surprised that the instructions caution against using brad point bits and specify conventional or split point bits, yet many doweling jigs provide brad point bits with them."
IN the pen turning world on IAP, (International Association of Penturners) the vast majority recommend not using brad point bits also. Some people do well with brad points. To me it depends upon the quality of the brad point bits. I have a couple of brad point bits that are obviously cheap and are not perfect. Then there is a set that I have had 40 years that cost an arm and a couple of fingers back then. I only use them on special needs and those bits are still as sharp today as they were when I bought them. Quality all the way through. Poor and even medium quality brad points are not worth it. That takes me to the next point -
. . . IF making more than a few plugs, I would look for a quality plug cutter, such as these: https://www.leevalley.com/en-us/sear...erOfResults=25

Hank, thanks for your input and the link. I'll end up buying either a set or one of my most used size from them. The commercially available teak plugs in the marine hardware stores must be made from this type of tool, as the sides and dead-end are almost polished in appearance.

edit; Couldn't help myself and bought the three size set. Free shipping! And, I found there are two Lee Valley stores within striking distance. Vancouver and Victoria, B.C. Would only add a few hundred dollars to shopping, after Amtrak to Canada and ferries, hotel, etc. Thinking about it, but I can drive it for 82 miles.

[dbhost]

I have only used the kind on the bottom of your picture, and used in a drill press a 3/8 plug is 3/8, so if your 3/8 hole is actually 3/8 it will be a snug fit...

[LCHIEN]

LV has a combo kit with the three "imperial" plug sizes for $52
and they have a Veritas flush cut saw for $32+
But they also have a kit with the three cutters + the saw for $67. Seems like a real deal if you like Lee Valley/Veritas stuff

https://www.leevalley.com/en-us/shop...t?item=05K3602