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,
- 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
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.
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
Another 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.
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.
> I need some advice on using a hole saw.
> 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?
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.
Mon, Jun 25, 2007, 11:53am (EDT-3) email@example.com (DerbyDad03)
I need some advice on using a hole saw <snip>
The plug is very difficult to get out <snip>
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,<snip>
FYI...I making some bat hangers <snip>
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.
If a man does his best, what else is there?
- General George S. Patton
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. >
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.
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.
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
As others have mentioned, a forstners bit it probably better for this
sized hole, but if what you've got is a hole saw...
YES! Drill press use of a hole saw means gravity holds the sawdust
in the cut, and that's the main problem. Augers pull the sawdust out,
as do Forstners. But, they convert the entire plug into chips,
and that means they're doing more work.
I've had good performance from hole saws drilling horizontally, but
the same hole saw is a trial to use in the drill press. Clean the
residue from your hole saw blade (lye or oven cleaner will do it)
and try a slow-ish hand drill with frequent pull-out for dust
clearance. If you must use the drill press, borrow an air compressor
On 26 Jun, 06:04, firstname.lastname@example.org (Ross Hebeisen) wrote:
-- try adding a little paste wax on the inside and outside of the hole
Will the wax impact the paint coverage - Rustoleum spray primer and
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
I think I would rough cut with the jig saw, then use the router and
Let us know what you do.
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
Thanks for all the suggestions.
> 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
Obviously, initial price, not quality, is the controlling issue.
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
> 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.
<snip the rest of the justification B/S>
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.
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