Date: Tue, 22 May 2018 08:14:32 -0700
Reply-To: thewestyman <zolo@FOXINTERNET.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: thewestyman <zolo@FOXINTERNET.NET>
Subject: Success - Re: Trying to drill out bolt ...
In-Reply-To: <213B960A-33DF-455B-B855-1D9A6EAD2878@shaw.ca>
Content-Type: text/plain; format=flowed; charset="UTF-8"; reply-type=original
Yes, finally have drilled and tapped the project.
And it was an all day deal.
Fortunately at Home Depot I found a set of Bosch drills 1/4 to 5/16 which
was not for masonry but glass. It had Tungsten tips and correctly ground to
sharp edge like ordinary drills.
It did slowly cut into the broken in bolt and with a lot of patience I made
it to the bottom end, with changing drill sizes as I progressed. Had to
make sure, I don't slide off the center while it's progressing.
Tapping was a little slow, but it was going all the way.
Thanks to all who gave encouragement for this, especially Alistair.
Forever yours, The List,
Zoltan
-----Original Message-----
From: Alistair Bell
Sent: Sunday, May 20, 2018 10:35 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Trying to drill out bolt ...
Zoltan,
Forgive me if I come across the wrong way here. You might already know this
but I’ll say it anyway.
If the drill bit does not cut into hardened material ( in your case it’s
probably work hardened), ie no shavings right from the get go, then it will
not cut. Stop, don’t just try pushing harder, you’ll just burn up the bit.
Same thing if you are drilling successfully and then it seems not to drill ,
or requires more down force, stop.
If the bit is at all dull, I mean not fresh out of the package or freshly
sharpened, then it’s going to heat up and dull very quickly on hard
material. It’s a progressive thing, slightly dull cutting edge makes
friction and heat which makes the edge duller which makes more heat , etc
etc.
If good and sharp then this progression is less likely to occur. And of
course cutting fluid really really helps.
Cutting oil/fluid both cools and lubricates
I’m going to assume you don’t sharpen your own bits , so if the bit don’t
bite, try another fresh one.
If indeed this bolt has been work hardened, once you penetrate that hard
layer it should drill out fine.
Use cutting oil. Almost any oil will do in a pinch. Even bacon fat is good
with steel. WD-40 or kerosene with aluminum.
And here’s a bit of a last resort. To get thru any hard layer. Use a small
carbide tipped masonry bit. You know they type, they are everywhere. Couple
of brazed on carbide cutters on the end of a twist drill. Get a small one
and have at the bolt. It won’t be pretty but if might get you going into the
softer metal.
Good luck
Alistair
> On May 20, 2018, at 8:36 AM, thewestyman <zolo@foxinternet.net> wrote:
>
> Alistair,
>
> Yes, I could make a nice center punch hole, yet I can't even start a
> miniscule of shaving. And I have tried several small drills, 1/8 sizes.
> Tried slow, fast. Did not use any cutting oil though. That might help to
> start it.
> I even heated it up, hoping that would make it softer. Probably made it
> harder.
> Last week I drilled one out without any trouble.
> This cobalt drill does not have a grade written on it.
> I think, there are 35 and 42 grades.
> These are new drills, well ground, not pushing.
>
> Zoltan
>
>
> -----Original Message----- From: Alistair Bell
> Sent: Saturday, May 19, 2018 9:18 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: Trying to drill out bolt ...
>
> What bolt is this?
>
> There are drill bits and there are drill bits.
>
> Cobalt by itself means little unless backed up by some numbers and a good
> brand.
>
> If you can make a punch mark with a centre punch on the bolt, then you can
> drill it.
>
> Start with small drill bit, use cutting oil, plenty. Does it bite?
>
> Sometimes you can work harden what you are trying to drill. Usually that’s
> because of dull bit, too fast, no cutting fluid.
>
> It happens in stainless sometimes. Swap out bit, try again slower.
>
> Alistair
>
>
>> On May 19, 2018, at 9:10 PM, thewestyman <zolo@FOXINTERNET.NET> wrote:
>>
>> Yup, trying but I can’t even start it, so hard.
>> I have no idea what makes it hard like glass, but the cobalt drill won’t
>> even start any shaving.
>> This cobalt drill is from Home Depot. Maybe there is one harder than
>> this.
>> Anyone has an idea what to do?
>> I have already installed the head, would not like to take it off.
>>
>> Best regards to the Great List,
>> Zoltan
>
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