# Drill for gaskets



## difalkner (Nov 27, 2011)

This may well be common knowledge but I'm posting it anyway - might help somebody when making gaskets or drilling thin material. 

I'm rebuilding my 70 year old Delta 24" Scroll Saw and needed gaskets, which were not available from Delta. Easy enough, I'll just make my own for less than they were from Delta if they had them in stock. When it came time to drill the holes I grabbed what I have called for over 40 years a 'center drill'. Now, there may be a more technical and appropriate name for this drill bit and I might be the one ending up learning something from my own post.

Anyway, it is simply a twist drill that has been ground to cut from the outer edge and has a center point. A standard twist drill cuts a 3-sided hole, although we don't notice it much in drilling wood. But if you drill sheet metal or another thin material you'll see it cuts a triangular hole and it usually is fairly sloppy. This bit cuts sheet metal, acrylic, polycarbonate, leather, gasket material, etc. and results in a clean round hole. I guess it's a modification of the way a Forstner or Spur bit cuts. I keep 5 or 6 bits from 1/8" up to about 5'8" with this tip treatment and use them for all sorts of things, even drilling wood.

Hope this helps someone. If it's old hat and common knowledge then that's fine too. I needed a break from being in the shop all day. 

Gasket, scroll saw








Gasket, drill bit








Drill bit close up


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## jschaben (Apr 1, 2010)

Good tip on the drill bit modification. Sounds good for use on thin material. For cutting gaskets though, I used to cut them for auto mobiles, trucks, tractors or whatever with a ball peen hammer. Just hold the gasket material where you want the gasket and tap along the edges of the casting with the ball end. The gasket material just opens right up. :smile:


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## difalkner (Nov 27, 2011)

Yep, that works, too. This material was a little thicker, though, so I drilled it.


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## Brian T. (Dec 19, 2012)

I agree, they are very useful. I use them for dowel & peg holes.
In many catalog listings, they are called "brad-point" drill bits.


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## difalkner (Nov 27, 2011)

Shows how much I know... I've been making my own for 40 years! :laughing:


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## rrich (Jun 24, 2009)

In years of working on automobiles, I've always made gaskets with a ball peen hammer or socket ratchet handle.

Place the material in the final position. Use a bit of masking tape to hold it in place. Just tap along the edges of all the holes with the hammer or ratchet. It doesn't take much effort but the result is a perfect gasket.

I have used a shoe box to make a gasket for the cooling outlet around the thermostat and it lasted for years. I sold the car when it still was working. Using gasket material would probably last for decades.


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## johnnie52 (Feb 16, 2009)

I've likewise pretty much always used the hammer and shoe box method myself. Avoids drilling the holes off center. Make one hole, put in a bolt to hold it in place, Make a second hole with a second bolt. Now just continue making holes until you're all finished.

Works perfectly every time.


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## difalkner (Nov 27, 2011)

Yep, I've done all that, too. The neat thing about the center drill, or brad bit, is that it doesn't drift and makes a good round hole. I'm just sitting here chuckling at myself because I never knew or even _thought_ about looking to see if you could buy them ready made. I've been grinding my own drill bits like this for 40 years and make them to suit my current need. My naiveté knows no bounds!

Next thing y'all are going to tell me is that you can buy wrenches and hammers ready made... :laughing:


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## johnnie52 (Feb 16, 2009)

difalkner said:


> Next thing y'all are going to tell me is that you can buy wrenches and hammers ready made... :laughing:


WHAT! Where? :laughing:


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## Brian T. (Dec 19, 2012)

Best of all, you can buy the brad points with no drill bit attached! Mine came in sets, like mushrooms with pointed caps.


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## FrankC (Aug 24, 2012)

You may have better luck with a hollow punch than a drill bit working with cardboard or gasket material.


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