lag time

originally was the keel cast with the bolts in place?

 

I am thinking now perhaps I need to pull a stud to confirm the thread size and if they are machine threads in good shape, then I should just replace the studs with some made of a good material. Confidents in the existing design was most of my concern, but I am getting the picture that this method was customary. It did last this long.
but if they are self tapping lags, could they be messed up when I pull the studs? I wonder if I should go to machine threads if this is the case.

Gilbert is right; I should not be imagining a problem if there is not one.

You guys are making me think twice about this tapping in lead stuff. That's a good thing of course.

Ward, Probably not. The drawing in my owners manual has notes to drill and tap. I wish I had the detail dwg that it refers to.

See attached,

Russ

PS. Gilbert I took a look at your gallery. I like those little italian boats too. My avatar pic was taken on the beach in Monteroso in the Cinque Terr(sp?) saw some boats there.

 

Nope, they're not machine threads they are really hanger bolts as I originally thought. This assumes the drawing you've attached is the same as what you have.

Remove one hanger bolt. You can try and use a double nut arrangement, but I'd prefer to use an inserter so you don't stretch or tear up the threads.

Lags aren't tapped, just machine threads.

 

last post

Thanks all for responding to this thread.
I am much more informed about this and confident of the outcome now.
I will not get to the keel bolts until spring. This project just needs more real data(what is it I have anyway?) I must pull a bolt this winter.

I just found a 3/4 inch heavy-duty drill on a portable-drill-press thingy from a junk shop that will come in service for the hangar stud replacement. The thing is a beast from the fifties or sixties, with gobs of torque and a johnson rod to pull it into the work or keep it from feeding too fast.

Yeee ha, Gonna drill me some HOLES!

Russ

 

follow up

Here's what finally happened.
I ordered 3/4" silicon bronze round stock from Alaskan Copper in Seattle.
Nice folks, They cut it to 12" lengths no charge.(they did charge for the bronze
My friend cut 10-pitch threads in the studs.
I went to the boat last week and pulled a hangar bolt with a cam style stud puller. It was lag threads just like the plan said. So I drilled a new hole to "sister up" with the new bronze studs. I used a 1/2-inch drill motor driving a 21/32-inch twist drill that we brazed a 8-inch extension to. No stand or blocks were necessary. I just eyeballed it and it went steady. After the drill went through the fiberglass and core wood, I could feel it slow and grab every half inch or so—I used WD-40 for lube and it went well. I pulled the bit out every half inch to clean out the chips—very IMPORTANT.
The tapping went well too. It cut very easy but it would grab and I had to be aware when it did. More WD-40 and things worked fine. the taps were modified with brazed on extension too. All through this I used a Shop-Vac with a plastic tube taped to end to clean out the holes of chips.

I did not have time to do the whole job yet but I did clean up the old studs and put them back in with new nuts and washers. I will replace these with new galvanized hangar bolts when I can find some.
At least I sleep at night now.

Thanks all for the input on this,
Russ

P. S. this was all done while the boat was at the slip, in the water.

 

That cam action extractor works like a charm, doesn't it. Way to go and thanks for the up date . . .

 

If WD-40 can't fix it it must really be broken. Thanks for giving an update, it's nice to see real world fixes that might come in handy some day.

 

Toss a can of WD40 and a roll of duct tape into a tool box, and you have a universal repair kit.

If it doesn't move and it's supposed to, use the WD40. If it moves and it isn't supposed to, use the duct tape.

 

Just some more notes I thought of:
The bronze(655 everdure) was very tough(impossible) to use a thread die to cut the threads with.
We had to use a CAM-operated lathe to cut them with a carbide thread-cutting tool. lots of long, tough, curly shavings came off. If you don't have a friend that will do this for whiskey, then just order bronze all-thread and be done.

The core wood was dry and good after 40 years.
Tapping was done by hand with a hand-drill brace to turn the tap. NOT a power drill!
I modified a taper tap, a bottoming tap, and the drill bit with 8-inch-long extensions, 5/8" in diameter. The tool shanks were cut down to 3/8". A 3/8" hole was drilled into the end of the extension, then they were slipped together and brazed on.

Dave Gerr the author, was kind enough to answer my e-mail and said that Steel was much too far from lead in the electrolosys way of things.
I qoute:

Mild steel is about -790 mV relative to a Ag/AgCl electrode. Lead is -240. That's a difference of 550 mV, way over the allowable of 200 mV. Serious corrosion is virtually guaranteed. Stainless isn't much better, as when starved for oxygen (as in the threads) it is -550 mV. The correct bolt material is silicon bronze, which is only about 30 or 40 mV from lead.

Hmm...; electrolysis, lead. Here's a thought:
Imagine a hybrid electric-drive using the lead ballast as a component in a huge array of gel-cel batteries. Five thousand pounds of batteries!

One more shot showing the old and the new. Preeetty scaaarry.


Happy hollidays,
Russ

 

Actually, I wish you had mentioned how long your threads where as this can cause a problem.

Never use all thread rod. Water can "climb" the threads under pressure and get inside the boat. If forced to use all thread, then remove a portion of the threads with a grinder so water can't mitigate up the rod.

The same is true of threading rod, don't let the threads cross the ballast to hull joint. This where the water will try to get in, so stop short of this area and you'll be good.

Steel can and has be used in ballast bolts. It's sized to accommodate a predicted life of corrosion. Steel hull plating is sized with the same considerations. Bronze is the material of choice (or monel) though.

Dave Gerr is a good guy and occasional posts here too.

 

Dang!
Wish I knew that first.
Well I'm not done; I have five more to do if I want to sister all the bolts. I can fix those.
I guess I can pull the first three out and modify them like you say. I am thinking you are talking about make a sort of capillary break?
The original bolts were well sealed with white stuff still rubbery after 40 years. I used 5200 sealant to reseal the bolts and bed the washers.

Serendipitously, We had to leave a 1/4-inch flat spot eight inches from the bottom of the threads because we had to reset the bolt in the lathe chuck to do the top threads and we didn't bother with synchronizing the top threads with the bottom. Maybe that will help. You can see the flat spot in the photo in post #35.

r.

 

You can hope on the polyurethane (5200) which is quite well known for it's stick-um abilities. The other option is to back out the bolts to expose the portion of threads where the keel/ballast joint is, then take a grinder to them and reinstall the suckers. Sorry, I should have guessed you were making bolts (that's what I always end up doing) or using thread all rod. My bad, I'll have the other half spank me good later this evening, for being so careless.

 

I loved the actual negative blueprint! Haven’t seen one of those for 40 years! A Couple of thoughts:

1. Is it practical to do a pull test to establish whether any action need be taken?

2. Steel expands as it rusts and lead is soft; once the bolts are out will the holes be oversized?

 

Terry,
I thought about experimenting by drilling and tapping some holes in some of my dive weights, and then puling on them, but never got to it.

Pic #3 in post 35 shows the bolts (old and new); all the bolt that was below the floor of the bilge never saw water in 40 years and was near new condition. The rust was all up in the air/Bilge water.

 

seven years later

I wanted to apologize about this post. It is not a stupid design as the rest of the thread eventually showed. I just could never edit the original post to remove the word stupid. So if The Valdes Family ever reads this, my bad.

Still love my old boat with the very-easy-to-replace keel bolts.

Russ