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31-12-2011, 11:24
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#1
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Registered User
Join Date: Dec 2011
Posts: 3
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Drilling Lead Keel for Bolts
I need to sister some 1/2 x 12" lags into my lead keel Capri 22.
12" is a long way to go (6 holes!)
Anyone know how?
What size / type of bit?
Do I go root size for the thread length, then slightly overbore for the major size? (smooth part?
drilling lube?
Thanks - Brud Weger
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31-12-2011, 11:49
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#2
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Registered User
Join Date: Aug 2006
Location: Skagit City, WA
Posts: 25,757
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Re: Drilling lead keel for bolts
Waiting with baited breath to hear! Lead is real gummy, the odds of breaking a bit in there are pretty high I would guess. You need someone with a big machine and an appropriate feed rate... hard to do by hand I would think....
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard
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31-12-2011, 12:00
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#3
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Registered User
Join Date: Aug 2008
Location: Wash DC
Boat: PETERSON 44
Posts: 3,165
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Re: Drilling lead keel for bolts
Im pretty sure when I did this I used an Auger. I bored clean through and bolted useing threaded rod. Bored out a cavity with forstener bit to hide the washer and nut on the outside and epoxied the cavity shut. Not sure about using a lag bolt. you would want to undersize and bore up if the bolts get to hard to work. Use wax or soap on the bolts so they are less inclined to sieze. maybe that helps
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31-12-2011, 13:15
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#4
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Registered User
Join Date: Dec 2008
Location: St. Georges, Bda
Boat: Rhodes Reliant 41ft
Posts: 4,131
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Re: Drilling lead keel for bolts
LOTS of dishwashing detergent, a big old 1/2" chuck, slow turning drill will do it easily.
You want one of the really old style drilling machines with the stirrup type handle and trigger at the back end, and the screw-in pipe handles at 90 degrees to the body.
No weight on the drill, squeeze the trigger, apply a small pressure, and let the lead stop the drill within about 1 revolution.while you extract the drill. SLOW, but it does work. Post drilled and secret - nutted all keel bolts in my friendship sloop that method. DAWN stops the lead sticking to the regular style machine bit.
__________________
so many projects--so little time !!
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31-12-2011, 13:54
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#5
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Registered User
Join Date: Jan 2011
Posts: 267
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Re: Drilling lead keel for bolts
As with any soft material, "backing off" the drill bit will help prevent the bit trying to corkscrew into the material. Take a fine stone and run it across the cutting edge of the drill bit thus flattening it slightly. You could look for a slow spiral bit but backing off does the same trick.
Soap or parafin (kerosene) for cutting fluid.
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31-12-2011, 15:11
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#6
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Registered User
Join Date: Mar 2003
Location: Philippines in the winters
Boat: It’s in French Polynesia now
Posts: 11,372
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Re: Drilling lead keel for bolts
I would think with lead that there would be a stainless steel plate casted into the inside to tap into, for holding power. At least, that's the way any good Machinist would do it. (cast the lead around a frame)
Lead is so soft that threads would rip out unless they were really deep and standard taps are generally 3 to 4 x longer then their diameter.
With a 1/2" OD stud, I wouldn't go any less then 6" deep into lead.
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Faithful are the Wounds of a Friend, but the Kisses of the Enemy are Deceitful! ........
The measure of a man is how he navigates to a proper shore in the midst of a storm!
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31-12-2011, 16:07
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#7
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Registered User
Join Date: Mar 2006
Location: San Francisco, CA
Boat: Nordship 40ds
Posts: 3,865
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Re: Drilling lead keel for bolts
I remember reading an article on this but can't remember where. The idea was to use all thread and then to drill a hole perpindicular in the keel so that you can add a nut and washer on the bottom. I am pretty sure I am missing something because after doing that the weight of the keel would be held by the nut and washers. Here is a link to someone who drills holes and replaces keel bolts. Keel Bolts I don't know if the guy still does it though. And here is a link to a post by Don Casey. http://www.sailnet.com/forums/gear-m...t-repairs.html
__________________
Fair Winds,
Charlie
Between us there was, as I have already said somewhere, the bond of the sea. Besides holding our hearts together through long periods of separation, it had the effect of making us tolerant of each other's yarns -- and even convictions. Heart of Darkness
Joseph Conrad
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31-12-2011, 17:06
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#8
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Senior Cruiser

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 51,756
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Re: Drilling lead keel for bolts
Greetings and welcome Aboard the CF, Brud.
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"
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31-12-2011, 17:25
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#9
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always in motion is the future

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 20,093
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I never had to do this lead drilling job so can't help there... but I did work with epoxy and lead and found the best way to get good adhesion is using a steel brush: mix epxy & hardener and brush or roll it onto the lead. Immediately take a steel brush and brush the wet epoxy into the lead. You need to push hard enough that the lead goes shiny. The brush is a write-off of course
cheers,
Nick.
__________________
“It’s a trap!” - Admiral Ackbar.
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31-12-2011, 17:27
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#10
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Registered User
Join Date: Aug 2006
Location: Skagit City, WA
Posts: 25,757
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Re: Drilling lead keel for bolts
Be very careful. Someone i know twisted a finger off when a 1/2" drill motor they were using locked in the on position. Wraped his whole hand up in the cord.
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard
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31-12-2011, 17:52
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#11
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Registered User
Join Date: Nov 2011
Location: Montegut LA.
Boat: Now we need to get her to Louisiana !! she's ours
Posts: 3,421
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Re: Drilling lead keel for bolts
Drill Bit must be properly sharpend, the normaly sharp leading edges must be flattend as would be done in aluminum to prevent digging in and sticking,if the bit is right very little fluids will be needed. be sure you use the type if drill mentioned above, and jam the extension pipe against something as you drill to keep the chance of wrap up to a minimum LOL Ive drilled every soft metal there is, if you have acess to a Machinerys Handbook (any year) There are drawings showing you an example of a lead drill bit shape. and others also. Just go slow till you get it down and it will go good. If you need help with sharpening your bit go to a Job Shop Macnine Shop, and im sure they will fix you up for a fair price I would have anyway LOL Bob and Connie
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31-12-2011, 18:34
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#12
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always in motion is the future

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 20,093
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Search in Google for "keel bolt drilling" and then switch Google to show images instead of weblinks. Amazing how much is on-line...
ciao!
Nick.
__________________
“It’s a trap!” - Admiral Ackbar.
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01-01-2012, 01:25
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#13
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Registered User
Join Date: Dec 2011
Posts: 2
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You have to use an long augur bit. Once it bites it will just pull right through the material. No lube is required. I would not try to hang the keel on lag bolts! I would drill through and thru bolt it.
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01-01-2012, 12:22
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#14
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Registered User
Join Date: Dec 2008
Location: St. Georges, Bda
Boat: Rhodes Reliant 41ft
Posts: 4,131
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Re: Drilling lead keel for bolts
Quote:
Originally Posted by Cheechako
Be very careful. Someone i know twisted a finger off when a 1/2" drill motor they were using locked in the on position. Wraped his whole hand up in the cord.
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Exactly  --which is why my advice was to squeeze the trigger, release, and let the drill bit advance slowly into the lead--and stop.
Have drilled 7/8" holes, 24" into lead with this method.
As this could be a dangerous activity, OP would be wise to seek professional assistance.
__________________
so many projects--so little time !!
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01-01-2012, 13:27
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#15
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Resin Head

Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 7,205
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Re: Drilling lead keel for bolts
Quote:
Originally Posted by Blue Stocking
Exactly  --which is why my advice was to squeeze the trigger, release, and let the drill bit advance slowly into the lead--and stop.
Have drilled 7/8" holes, 24" into lead with this method.
As this could be a dangerous activity, OP would be wise to seek professional assistance.
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In my opinion, starts and stops are the most likely part of the cut to bind. Therefore this is bad advice. Much safer to make the whole cut with as few starts and stops as possible. Lead cuts like butter, easy to drill in especially with an auger bit to help prevent clogging. The big concern here is that few ballast keels are pure lead, how much iron is in there? I've drilled holes in ballast keels that went like butter, and others that did not. A 1/2" hole through 12" of lead should be a cakewalk. Try drilling straight and not binding when you're using a 3' extension and drilling in pig iron. A drilling jig becomes necessary. This should be a simple job. Definitely wouldn't use lags in lead, ever. Forstner bit to drill a counterbore for the fasteners is the way to go, then fair over with epoxy.
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