Hole Saw Plug Removal

[DerbyDad03]

I need some advice on using a hole saw.

I've drilled 9 out of the 36 holes I need and I'm looking to speed up the process a bit.

Here's where I'm at:

- I'm using a 1.25" single-piece hole saw by Blu-Mol. - I'm using my drill press to cut holes in some old 3/4 plywood, circa 1956. - The speed is set to about 750 RPM - I've been drilling a little more than half-way through, then flipping the wood and completing the hole from the other side.

The plug is very difficult to get out of the hole saw. It takes more time to pry the plug out of the hole saw than it does to drill the hole. The hole saw itself is very, very hot. The wood begins to smoke before I am halfway through.

Are my problems the result of using a cheap holesaw, the hardness of the 1950's plywood, the speed of the drill press, or a combination of all three?

FYI...I making some bat hangers for a school's softball fields by drilling 1.25" holes centered at about 2" from the edge of 3' lengths of stock and then completing the U shaped slots on my band saw. I'm open to other suggestions to create the required 1.25" wide slot.

Thanks!

[Lee Michaels]

I have done big projects with hole saws, both in wood and metal. I found that the higher quality hole saws are the only way to go. They all have an a center protion that has the drill bit and an arbor that holds the hole saw in place. And be prepared to replace the hole saw as needed. I have done metal projects that went through ten hole saws.

If I was cutting a hole that is an inch and a quarter, I would go to some kind of bigger drill bit and sharpen the bit. This would be a lot quicker. The hole is small enough combined with your drill press, that this should be fairly easy.

Look at

idea is to simply use a brace and bit. for the number of holes you are doing, an auger bit would get those holes done fast. Just supply a little elbow grease! And the bit can be easily sharpened.

[dpb]

In ply a hand augur will work but get dull pretty quickly. If I had a local supply shop handy I'd probably go get a sawtooth-style Forstner.

Probably slowing down the holesaw would help but if it's gotten hot may have lost temper.

Depending on the design, it shouldn't be too hard to pry the "coin" out. Don't leave the pilot bit longer that it needs to be. If your's doesn't have a set of access holes in the top for a punch, modify it to add a couple--then can use a drift directly down and out instead of the wedged pry from the side slot(s). That helps a lot.

[Lew Hodgett]

DerbyDad03 wrote: > I need some advice on using a hole saw.

I'd take a different approach.

Use a 1-1/4" carbide forstner bit.

If you still want to stay with a hole saw, consider the following:

1) Use only bi-metal hole saws.] 2) Reduce the RPMs, 750 is too fast. 3) Since you are dealing with 3/4" plywood, drill about half way, then use a chisel to remove the waste, then finish drilling hole.

Removing 3/4" plug from a small hole saw can be a total PITA.

I'd still use a carbide forstner, much faster and a whole lot easier.

Lew

[J T]

Mon, Jun 25, 2007, 11:53am (EDT-3) [e-mail] (DerbyDad03) doth query I need some advice on using a hole saw The plug is very difficult to get out The hole saw itself is very, very hot. The wood begins to smoke before I am halfway through. Are my problems the result of using a cheap holesaw, FYI...I making some bat hangers

For that size hole, if you aren't going to use the plugs, i'd jsst use a drill.

Awhile back soneone here told how to get the plug out easily. Drill almost all the way thru, not quite all te way. Flip the piece, drill just enouh to cut the remaining wood, easy to pull te plug out - altho it'd be smart to shut the drill press off first. If you've got it right the plug might literally fall out on its own.

You don't get much cheaper than Harbor Freight holesaws. That's what I use now and I don't have a bit more problems with them than the more pricey ones I have. I get smoke sometime, but I'm just pressing own too hard.

I say let the bats find roosts on their own.

.

JOAT If a man does his best, what else is there?

- General George S. Patton

[Leon]

I find that if you drill the total depth less about 1/8" then flip the board and finish the 1/8" inch the plug is much easier to remove. Unscrew it off the pilot bit.

[Curran Copeland]

After having drilled a few thousand 1.25 holes with a 1.25 hole saw I can tell you that you are going about it the hard way. In your case, where you don't want the plug, which is my reason for drilling them out in the first place, I would go to the hardware store and buy a good quality 1.25" spade or fostner bit and get on with the job. There is no easy, fast way to remove the plugs from a hole saw in the quanity you are doing. >

[Jerry]

I'd go with a spade bit to drill out your holes. Just looked on Amazon, they're selling a 13 piece set of B&D spade bits that goes up to 1.5" for something like $11. I'm sure you can find them at your local Borg too.

Jerry

[Tom Veatch]

Second the previous advice. Forstner would probably give you the cleanest holes, augers are very aggressive and would be fastest (maybe even if you're doing them by hand). But, if you'd have to buy tooling to do it that way - well you're going to have to buy tooling anyway because I suspect your hole saw is toast.

I've found the most problems with getting the plug out of the hole saw happens when you cut from one side only - sometimes there is no other choice - and when the hole saw is too short for the material. If there is enough depth in the saw above the plug, it's a fairly simple matter to pry the plug out through the slots in the side. Had to punch a number 2 1/2" holes through 3/4" plywood yesterday (with only one side accessible) and a screwdriver through the side slots worked the plugs out quite handily.

OTOH, if the plug completely covers the slots, then it's dismount the saw, remove the mandrel, and punch out the plug through the mandrel hole. Be sure the next hole saw you get has enough depth of cut so the plugs won't completely cover the ejection slots.

Tom Veatch Wichita, KS USA

[Robatoy]

Listen to Lew. I drill a LOT of 1-1/2" holes in my countertop business. Carbide forstner. Yup.

[Paul Hays]

Hole saws definitely tend to overheat and burn if you don't get the saw dust out off the cut. Think about it: there's no place for the sawdust to go, the cut being essentially endless. Unlike a drill, the holesaw can't eject the swarf. It just builds and builds, filling the gullets between the teeth with sawdust, generating heat.

if you have access to compressed air, blow the dust out as you cut- one hand on the drill press lever, one hand with the blower. Noisy, but the blade will cut much faster and cooler. If you don't have shop air, a smaller hole drilled just inside the circumference of your hole (ie. in on the waste side) will provide a place for the sawdust to go.

As others have mentioned, a forstners bit it probably better for this sized hole, but if what you've got is a hole saw...

paul

[Ross Hebeisen]

try adding a little paste wax on the inside and outside of the hole saw. ross

[Upscale]

That's a pretty good idea. There's few things nicer than a simple solution.

[DerbyDad03]

-- try adding a little paste wax on the inside and outside of the hole saw.

-- ross

Will the wax impact the paint coverage - Rustoleum spray primer and paint?

[sailor]

How about just cutting the whole slot with a jig saw? Or for a cleaner cut, how about making a simple jig and use the router?

I think I would rough cut with the jig saw, then use the router and jig.

Let us know what you do.

[DerbyDad03]

I was thinking that a 1.25" diameter curve in 3/4 ply might be a little tough to cut consistantly with a jigsaw. (I don't do a lot of jigsaw work) Since there are 9 slots spaced evenly along a 31" length of stock, if I don't get the depth or width fairly consistant, it will be very noticable. A hole saw on the drill press makes it real easy to get the spacing and size consistant.

Anyway, I'll be testing my prototype at a game tonight and if it performs as expected, I'll be making more this weekend. I'm leaning towards a short auger style bit - under $15 at HD which should get me through this project. After all the slots are cut, I'll round them all over with my router. so a little tearout on the bottom won't be problem.

Thanks for all the suggestions.

[Lew Hodgett]

Obviously, initial price, not quality, is the controlling issue.

Lew

[DerbyDad03]

- Obviously, initial price, not quality, is the controlling issue.

-

- Lew

To a certain extent, yes. Although once I use my router to round over the slots, top and bottom, there will be no way to tell what I used to cut the holes and slots - an expensive carbide forstner bit or a HSS spade bit from Harbor Fright.

Keep in mind that I am making bat hangers that will be attached to the fences at a couple of high school softball fields. I can't stop the kids from hanging on them, trying to use them as a step to climb the fence, or even just ripping them off for the fun of it after a few beers. I'd be very surprised if they last through the summer, so I'm not going to drop a whole lot of money into specialty bits that I may never use again. That's why I was hoping the old hole saw that I had hanging around would have done the job, but it looks like I need to spend a little money simply to make the job to go easier.

My hope is that if the athletic department or sports booster club sees what I've done and likes the idea of bat hangers for the dugouts, they'll spend some of their money for something more permanent. If they ask me to make them, at that point I won't mind spending *their* money on a carbide forstner bit, a new bandsaw blade, a new router bit and some marine-grade plywood. For now, since this a labor of love being performed with my own time and money, initial price is indeed a controlling factor.

[Lew Hodgett]

If the project can't justify less than $20 for a Freud carbide forstner bit, it's in trouble.

BTW, "Harbor Freight" and "cutting tools" are mutually exclusive terms.

Lew

[DerbyDad03]

-- If the project can't justify less than $20 for a Freud carbide

-- forstner bit, it's in trouble.

Thank you for your thoughtful response.

Just as an FYI...the bat hanger I made over the weekend was installed and put to use last night. It was a "hit" - pun intended.

-- BTW, "Harbor Freight" and "cutting tools" are mutually exclusive terms.

Thus my use of the words "Harbor Fright", not "Harbor Freight"