Another one,
Who said I used "an ordinary bit turning a typical speed"? The one
problem with my attempt was me. I just didn't have the skill. I had
the right materials.
As for your advice to be cognizant about the materials being worked with
("metal, wood, plastic, etc."), teach your grandmother to suck eggs.
I own 11 drills, each for a different purpose, from a minidrill up to a
3/4ths" industrial. Four of them are mechanical. one is a genuine
antique(1898) but still one of my most useful drills. I used it to
help build a butcher block staircase in a barn for a friend who was
converting it to a home. A competent architect said it was the best
thing in the house.
None of my drills make up for a lack of skill.
I used two comma's in the above. I apologise for that.
Rudy B.
David Shugarts wrote:
This is true wisdom and I am not really adding anything, but I would
like to clarify and amplify this.
For each and every material, whether it be a metal, wood, plastic,
glass, ceramics or something really exotic, there is a certain amount
of knowledge that applies from the world of machining. This knowledge
often goes back 50 or 80 years, for certain materials that have not
changed, and a little more knowledge is being added whenever a new
material needs machining. It's written down in manuals, but almost no
one reads the manuals any more, and our machining jobs have largely
gone overseas.
The experienced machinist doesn't just drill a hole. Elements of the
decision are the material, the drill bit hardness, the angles of the
cutting surfaces (there are several angles in each bit), the speed of
rotation, and the feed rate of the bit, to mention a few. In most
cases, you feed machine oil to the bit while drilling, but there are
other things that you may apply, depending.
Certain materials that don't look like they will be difficult, turn
out to be real trouble for an ordinary drill bit turning at a typical
speed and feed rate. It's just nasty. It's almost like magic how
everything improves when you get the right parameters.
Here is a pretty good article on drill bits:
http://en.wikipedia.org/wiki/Drill_bit. This says a lot about twist
drills, but not everything.
Once upon a time (oooo-eee-oooo), machinists even custom-made some of
their own tools.
--Dave S. (Demitri)
On 6/23/08 6:53 PM, "Philip J Agur" <[EMAIL PROTECTED]> wrote:
Drilling lead takes a different chip breaker angle on the bit and
lubrication. Otherwise is going the lead is going to gall up on
the cutting edges seize. A hammer drill is a pretty hack way of
breaking up the chip. It would be better to find an actual
machinist. Since lead is not the most common thing to machine
expect he'll need to research how the drill is sharpened in the
machinist handbook. You should also ask for RPM and cutting fluid
recommendations.
Phil Agur s/v Wing Tip
<http://www.catalina27.org/public_pages/profile270.htm>
Secretary, Call Sign WCW3485
IC27/270A MMSI 366901790
www.catalina27.org <http://www.catalina27.org> Vessel Doc# 1039809
-----Original Message-----
From: [email protected]
[mailto:[EMAIL PROTECTED]
<mailto:[EMAIL PROTECTED]> On Behalf Of Rudolph
S. Behar
Sent: Monday, June 23, 2008 3:04 PM
To: [email protected]
Subject: Re: catalina27-talk: Keel bolts
I tried to do it myself and ended by breaking two new and strong
steel bits. Local yardman did the work for me. Siad it took him
7 hours. I know him and believe him. HE used a 3/4th hammer
drill. And it cost. No problems since.
If I had to do it over again I'd not partner the old bolts, but
set the new ones (six of them) in a fresh pattern at some remove
from the originals. I've had no problems, but it seems good sense
not to be too close to the originals. The old bolts seemed to be
ferrous. I put in stainless for the new ones.
Rudy B.
Phoenix, #2237
Pasadena
James Calleran wrote:
Listees,
After a, ahem, hard grounding, my Catalina smile has
reappeared (last seen 6-7 years ago) -- not badly, but a thin line
at the keel joint is visible on one side. The boatyard service
manager has recommended re-torque-ing the keel bolts. Naturally,
the yard will do the job for a fee, though I don't have a quote.
I'm concerned about these 30 yr-old bolts breaking off under 60+
ft-lbs of torque.
Any of you who have done this yourselves:
1. How did you clean off the accumulated rust (They were rusty,
right)?
2. Were you able to budge the nuts?
3. Did you remove them --one at a time, of course -- and clean
the threads?
4. Did you replace with stainless nuts?
5. What torque?
For those who have installed SS Lag Bolts in your keel.
1. Did you buy the $279.95 kit from Catalina Direct? (5 bolts, 1
drill bit, washers)
2. What size is the drill bit?
3. Did drilling require a rotary hammer type drill, or just a
powerful standard drill?
I have source of SS 1/2" x 8" SS lag bolts @ 14.95 each.
Specs say 18-8 stainless; no mention of 316. Thoughts on using
these?
Thanks for comments on your experience.
Fair Winds,
Jim Calleran, C27 #2784, Trad, OB
Mathews Yacht Club, VA
37°27.8'N/76°18.6'W
