Keel Bolt / Stud Leaking

[unclemack]

Originally Posted by minaret

Can't just cut teeth without bending in kerf, or it will just bind. I've found it pretty easy to cut a hole saw in half and weld the two halves to the respective ends of a piece of pipe, then grind the weld flush. Then you can chuck it into a Hole Hawg. If you have a metal cutting chop saw it's super easy to make a square cut and it all just lines up. Thread is usually only on the top of the bolt/stud, therefore not at risk of damage.

Maybe my neighbour did something else to wreck his threads, I wasn't there, just saw the result.

As obvious to me as it is to you that kerf is needed for any depth, wasn't intending to provide a complete guide in a few sentences.

Not clear to me from your description - are you butt-welding the hole saw to a pipe of exactly the same diameter & wall thickness?
If not, how do you drill deeper than the joint?
Is there an English version of a "Hole Hawg?" - it's just that the name is unfamiliar to me.

[Dymaxion]

A continuation of this thread around my leaking keel. Was trying to narrow down the pathway for the leak in/out of my bilge. Boat is an old Viking 28, built by C&C 40 years ago. A very shallow bilge, i'll post a couple of pix. Here's the drill....

Isolated each bilge section between stringers and flooded with acetone, then climbed down the ladder and stood next to the stern of the keel where the leak was trickling out. Turned out to be one section only (sternmost) with two 1/2" diam studs/nuts. Glass layup in that region looks like a couple of bits of cured hull were bonded onto the actual hull, under say 3 stringers for about two feet, only near the stern end. Poor fitting of extra hull pieces left gaps on each edge, that had been covered in matt and was all delaminated.

So I isolated each side and poured in more acetone. Starboard section leaked out the keel joint in half a minute. Starboard pour showed no leaks. Getting closer. Now here's the rub, being a newbie boat owner and having read that keel nuts should be torque periodically, I decided that was worth a try. 10 nuts, all poorly torqued down, so I brought them back to correct C&C spec of 80 ft-lbs using my trusty torque wrench. Got 1-3 turns on each to hit that setting. Repeated the acetone bath and now NO LEAK. No sign of an outbound keel joint leak at all. Happy daze in every sense.

Here's the question: Am I done here? I'd used acetone to prep/degrease the "crack" prior to trying to inject some resin down, but if the acetone can't get through after retorquing the keel nuts I can't imagine how much better I can make it without the huge effort of dropping/rebedding the keel.

Second question: Cast iron keel, very shallow keel stub in hull, and a good layer of filler faired over everything. Took it down to bare metal/glass around the leaking stern section of the keel joint. Again, have a pic to post. My inclination is to grind it/blast it until shiny, butter the dug out keel seam with epoxy/HD406 filler, then put a couple of layers of glass over the region to seal the outside. After than, likely about 1/2" filler to fair. Is this good practice? Yes, I'd love to strip the entire keel to bare shiny iron and apply 4 coats of epoxy based paint, but it ain't happening this year, launch is about 2 weeks away. If I'm on track with this, can someone suggest a brand of "bondo" that best suits this application. Appreciated.

[Dymaxion]

A continuation of this thread around my leaking keel. Was trying to narrow down the pathway for the leak in/out of my bilge. Boat is an old Viking 28, built by C&C 40 years ago. A very shallow bilge, i'll post a couple of pix. Here's the drill....

Isolated each bilge section between stringers and flooded with acetone, then climbed down the ladder and stood next to the stern of the keel where the leak was trickling out. Turned out to be one section only (sternmost) with two 1/2" diam studs/nuts. Glass layup in that region looks like a couple of bits of cured hull were bonded onto the actual hull, under say 3 stringers for about two feet, only near the stern end. Poor fitting of extra hull pieces left gaps on each edge, that had been covered in matt and was all delaminated.

So I isolated each side and poured in more acetone. Starboard section leaked out the keel joint in half a minute. Port pour showed no leaks. Getting closer. Now here's the rub, being a newbie boat owner and having read that keel nuts should be torque periodically, I decided that was worth a try. 10 nuts, all poorly torqued down, so I brought them back to correct C&C spec of 80 ft-lbs using my trusty torque wrench. Got 1-3 turns on each to hit that setting. Repeated the acetone bath and now NO LEAK. No sign of an outbound keel joint leak at all. Happy daze in every sense.

Here's the question: Am I done here? I'd used acetone to prep/degrease the "crack" prior to trying to inject some resin down, but if the acetone can't get through after retorquing the keel nuts I can't imagine how much better I can make it without the huge effort of dropping/rebedding the keel.

Second question: Cast iron keel, very shallow keel stub in hull, and a good layer of filler faired over everything. Took it down to bare metal/glass around the leaking stern section of the keel joint. Again, have a pic to post. My inclination is to grind it/blast it until shiny, butter the dug out keel seam with epoxy/HD406 filler, then put a couple of layers of glass over the region to seal the outside. After than, likely about 1/2" filler to fair. Is this good practice? Yes, I'd love to strip the entire keel to bare shiny iron and apply 4 coats of epoxy based paint, but it ain't happening this year, launch is about 2 weeks away. If I'm on track with this, can someone suggest a brand of "bondo" that best suits this application. Appreciated.