What is the secret of plug cutters??

[George Bokros]

I drilled a 1/2" hole with a 1/2" forstner bit and wanted to plug it with a wood plug. Got out a 1/2" plug cutter and cut the plugs free. They were to small for the hole. Double checked the forstner bit yup it was 1/2"; double checked the olug cutter and yup it was a 1/2". Got out another 1/2" plug cutter cut some more plugs and they too were too small.

Puzzled....


George

[Dave Richards]

The plugs are most likely tapered. If you you make the plugs too much longer than the pluggable depth of the hole, they'll be too small for the hole.

[George Bokros]

The plugs are most likely tapered. If you you make the plugs too much longer than the pluggable depth of the hole, they'll be too small for the hole.

These were not tapered plug cutters.

[Dave Richards]

Then they or the Forstner bit must not be the advertised size.

[Roy Harding]

Are you cutting the holes and plugs on a drill press, or with a hand held drill?

[Myk Rian]

Then they or the Forstner bit must not be the advertised size.
Umm. He measured them..

Are you making end-grain plugs?

[ray hampton]

is it possible that the drill bits are bent ? and are cutting oversize holes ?

[George Bokros]

Are you cutting the holes and plugs on a drill press, or with a hand held drill?

Holes and plugs were done on a drill press.

[George Bokros]

Are you making end-grain plugs?

No not end grain plugs. Holes are in the surface face and plugs were cut from the surface face.

[Roy Harding]

Holes and plugs were done on a drill press.
Well - that takes care of my first thought - that the holes and plugs were being cut with an unsteady hand. I've cut probably hundreds of plugs (I use tapered) and never had a problem.

Second thought, on the unsteady theme - are you using a clamp of some kind while cutting the holes and plugs, and are the holes you drill otherwise on your drill press satisfactory? (IE - is your quill centered, and is there excessive lash in your bits?) On the SAME theme - try slowing down the drill press and see what happens.

[Dick Mahany]

If measurements say that both the drill and cutter are correct, then one or both must be running slightly eccentrically IMHO. Can you measure run out on your set up?

[John Coloccia]

re: secret
There's no secret. A 1/2" plug fits into a 1/2" hole, unless the plug is tapered, something's the wrong size or something is wobbling. Can you take some pictures of the fit, and of the cutter?

[George Bokros]

I just cut some more plugs. I made them about 5/16" to 3/8" long they are going into holes that are 1/4" deep. They drop into the hole and bottom on the bottom of the hole and still are too small to fit tightly.

I have not measured run out on the quill but believe it to be true since I do not have issues with the shank of any bit being sloppy in the hole it just drilled.

I will measure run out after dinner.

George

[george newbury]

Is the plug cutter exactly 1/2" OD? and is the Forstener exactly 1/2" ID?
Seems like a kerf problem.

[George Bokros]

Mystery solved......


I took a 1/2" twist drill bit that was my father-in-laws (he was a journeyman pattern maker that worked in wood and metal patterns) and inserted the shank into the hole drilled by my forstner bit and the hole was larger than the drill bit shank. Then I drilled a hole in a pieces of scrap wood and with the twist drill bit and the shank fit very snugly in the hold I just drilled so that satisfied me that run out is minimal. Then I inserted one of the plugs I cut into the hole drilled by the twist drill and it fit nice and snug.

Lastly I took a caliper and checked the hole drilled by by C-Man forstner bit and it was 1/32" larger than 1/2", BINGO solved. Looks like Dave Richards nailed it in post #4.

Thanks for all the help everyone.

George

[Clay Crocker]

"...C-Man..."

There's your problem! :D

[Richard Wolf]

Just as a side note, If I have a hole that must be plugged and the plug is loose, I roll the plug in glue then roll the plug in saw dust. It will fit snug and when it is sanded it will look good.

[ray hampton]

Just as a side note, If I have a hole that must be plugged and the plug is loose, I roll the plug in glue then roll the plug in saw dust. It will fit snug and when it is sanded it will look good.

1/32 oversize ? will this call for new drill bits or using a stone to reduce the cutting lip

[Steven Powell]

Chuck the errant forester bit in the drill press and start it spinning. Using a fine flat bastard file, file a few light passes against the rotation of the bit to reduce the diameter. Periodically check the diameter using a 1-inch micrometer or dial caliper until the diameter has been brought down to 0.5 (+/-). How easily the file will "cut" depends on how "hard" the forstner bit is but it may be worth a try.

[George Bokros]

Good idea Steven but it will not help me with the holes I already have drilled. I was going to chuck some dowel rod in the drill press and turn it down to fit but that will give me end grain plugs and they will not look right. The only alternative for the holes drilled is to drill them to 5/8 and make plugs for that size.

[Jim Mackell]

Just as a side note, If I have a hole that must be plugged and the plug is loose, I roll the plug in glue then roll the plug in saw dust. It will fit snug and when it is sanded it will look good. You might try this suggestion on your scrap piece. It's worked for me. Save you from trying to expand all those holes.

[glenn bradley]

I just cut some more plugs. I made them about 5/16" to 3/8" long they are going into holes that are 1/4" deep. They drop into the hole and bottom on the bottom of the hole and still are too small to fit tightly.

I have not measured run out on the quill but believe it to be true since I do not have issues with the shank of any bit being sloppy in the hole it just drilled.

I will measure run out after dinner.

George

It might be easier to measure the result versus the machine. If the Forstner says 1/2", mic the hole and confirm. If the plug cutter says 1/2" mic the plug and confirm. One or the other is off or a combination. Now if only the hole were a bit under spec and the plug were a bit over spec, things would be fine :).

[John Coloccia]

Why not just buy a Craftsman plug cutter set. Either the 1/2" or 5/8" is liable to be the wrong size and will fit perfectly.

[Bill White]

John,
that one took me a minute to understand. Too right. :0
Bill

[Myk Rian]

The moral of this story?
Always TEST things before going whole hawg into it.

[George Bokros]

The moral of this story?
Always TEST things before going whole hawg into it.

I did not plan to plug the holes. I changed my mind where I wanted them so was going to plug them. They are on the underside of the top cabinet frame so they will not be visible on the outside or inside unless you stick your head inside the cabinet but I wanted to hide them.

[John Shaffner]

Wow, even my HF Forstner bits are only 2 or 3 thousandths off from their designated sizes. I like the idea of the glue/sawdust remedy for this gap left by the Cman bit. I use the tapered plug cutters from Lee Valley and the are fantastic. Had the same ones for 20+ yrs and going strong still.

[George Bokros]

You might try this suggestion on your scrap piece. It's worked for me. Save you from trying to expand all those holes.

I did this and it worked as good as if the plugs actually fit.

Thanks Jim

George

[John Coloccia]

If you really want it to look great, try some hot hide glue on scrap. It will accept stain and finish almost like wood and might actually be invisible when you're done.