Dry or wet bilge?

[ndutton]

When I hear discussion of "lag bolts" being used in lead ballast keels I am going to hope and "assume" you are really talking about "hangar bolts".

Not in my case, I'm talking about honest stainless lag bolts for a few reasons:

• The torque required to drive a 3/4" lag bolt into 8" embedment in lead is more than I'd want to put on a double nut arrangement required with a hanger bolt. My plan includes a properly sized pilot hole, sealant on the threads that I hope will act as a lubricant during installation and a heavy duty impact driver with 4 foot breaker bar and two brutes hanging on to it for the driving operation. Lead is a very gummy material and I expect the operation to be a bear.
• My holding strength calculations were based on 7" (of a 10" lag bolt, 2" loss through the stump bottom and plywood shoe + 1" fudge factor) of the coarse lag threads in contact with lead. I'm not up on the exact ratio of lag threads to machine threads of a hanger bolt but I'm pretty sure I'd lose a few inches on the top to machine threads.
• I haven't seen any 3/4" x 10" stainless hanger bolts available anywhere, not sure they even exist.

I don't recall if I discussed my system before. I'm placing custom stainless castings (aka 'floors', pictures of the casting patterns are attached) in the fiberglass keel stump that transfer the load off the bottom of the stump where the plywood is sandwiched to the turn of the hull at the stump. That area is the strongest portion of the hull due to thickness and curved shape. My stainless lags will bolt through the bottom of the castings through the keel stump into the lead. These are supplemental to the existing bolts.

The holding force calculation of a single lag embedded in 7" of lead exceed the weight of the entire keel by a factor of about two. I'll have 7 lags, if I ever remove my engine, an eighth lag will be installed. The actual holding strength is expected to be greater because the calculation was based on pure lead and external lead keels are cast with 5% antimony for enhanced hardness.

My calculation determined 8800 lbs. holding force per lag. Dividing that by four for a 4:1 safety factor allows 2200 lbs. per lag working load. Seven lags = 15,400 lbs. working load, keel weighs ~4500 lbs. For comparison I had the calculation performed independently by a professional engineer and it came in at 9000 lbs or within 2.2% of my calcs.

I've also included a drawing of cast bronze floors for wood boat construction from Sparkman & Stephens Naval Architects from where I 'borrowed' the concept. It shows the through bolt and lead plug technique Hanley mentioned earlier.

[sastanley]

Hanley, Yes, lag bolts. This is not a permanent fix, but a stop-gap measure that after the calculations from Neil above, at least gives me a little piece of mind until I feel like messing with it, they are probably sufficient. You can see that if I drive them too far, the washers distort since the wood underneath is soft. If the keel ever moves, I'll certainly be able to tell! However, if I had a set of those floors, I'd just lag them in place and probably be done with it!

I was able to drive these in by hand with a 4' pipe on my 1/2" breaker bar.

For Kris' benefit, below is Catalina's official fix for Catalina keel issues. And I agree..I picked up the longest 1/2" lag bolts (SS) from a local non-chain real hardware store, & an 18" long 7/16" drill bit for less than $20 from the local Ace Hardware.

Here is an after pic.. of the lags sistered next to the original studs.

Also, attached is the Keel fix document. it is a GIF file, so shows up as a picture.

[lat 64]

Uh, right, yea, hangar bolts

Niel,
Very pretty patterns! I'll bet you can sell a few casting to others.

My keel bolts were hangar bolts originally, and I guess the factory must have had a way to drive them. I made my replacements from lag bolts that had the same thread pitch. I cut off the heads, cut new machine threads on top, and spun them in with lots of 5300 goo.
I probably only have about 30 to 50 lbs torque on the nuts—if that. Any more and I think I would be crushing the keel stub core. I don't think they need to stretch like a head bolt. I did some of those calculations too, and I found I must have about 15 times the strength I need. I like that!
Before the fix, none of the nuts were tight at all, and most were gone to dust. Only the Epibond goo was holding the keel on for the last few years. There was no crack in the seam at all! Whew!

I was originally thinking of using the lag bolts with heads on, but there is really no good way to re-torque them when they have bottomed out in the original holes. Do you plan to make the holes deeper than the lags?

Again, nice floor beams. Another cool Dutton mod.

R.

Update: I forgot to mention that I alo have three additional Everdure bronze studs with machine threads sistered along with all the new galvinized hangar bolts. Photo shows the new bronze, and the old ones before pulling.

R.

[ILikeRust]

Neil -

Did you make those floor pattern? If so, what is it made of? Very cool.

My floors are a little more traditional - I made them out of 2x6 doug fir, then coated with penetrating epoxy sealer and Bilgekote.

My lead keel is fully enclosed in fiberglass, so there are no bolts exposed anywhere. I'm not completely sure exactly how they built it, but I know there is 3,800 lbs. of lead in there, but none of it is exposed. It seems the hull is shaped to include the keel, and the lead keel is somehow put inside it, and then there is more fiberglass on top of the keel on the inside of the boat.

[hanleyclifford]

Impressive Planning

Neil - Looks like you have thought this matter thru very thoroughly and I must defer to your many years of fruitful experience with this type of construction. Please forgive my instinctive negative reaction to the notion of torquing down into a casting. I have some experience drilling and tapping lead castings and then turning in fasteners and I admit it is a "bear". I'm sure there is a good reason why you elected not to go for thru-bolting and plugging. Again, very impressive and I look forward to following the thread that I'm hopeful you will share with us.

[ndutton]

Yes Bill, I made the patterns. They are made of plywood, glued together, filled, sanded and painted. I learned how to make casting patterns during my Westsail project. There were a number of custom bronze castings installed and I was fortunate to have a bronze foundry within walking distance of the boatyard. When I started the search for foundries for this project I met with the manager of one and explained what I as doing but didn't have the first pattern done yet. He said come back with the pattern but warned me he examines customer patterns with a VERY critical eye. When I returned a week later he looked it over carefully, stroking his chin and after an uncomfortable silence deemed the pattern acceptable, "I give it about a 'B'. Doesn't get much better than that, I never give an 'A'." Whew!! Those familiar with the process will admit there's more to it than it appears.

The patterns are all I have to show at this time as parts have not yet been made. Since the pattern project and decision to go with castings (I found a local stainless foundry), I now have waterjetting available to me. I'm considering having the floors fabricated from waterjetted stainless plate and welded together. The jury is still out but I now have an option I didn't have previously.

The curves in the patterns may seem like they are there solely for style but actually the curved arches between the bolt flats on the bottom are limber holes for the passage of bilge water, the dips in the spine on the top allow room for hoses and such.

Russ,
Yes, pilot holes deeper than the lags but just barely. I have no intention of retorquing later but I don't want the lags to hit bottom just as I'm finishing up. That will be the most difficult time of installing the bolts. The sealant I intend to use is 5200 and by retorquing I risk breaking the sealant bond through the existing stump. Watertightness of the finished product is important.

Bill,
My Westsail was ballasted internally too, no such concerns with bolts or adhesives.

Hanley,
I share your concerns with torquing against castings but please note the gussets between the spine and both sides of the bolt flats. Also, this remedy is supplemental to the original adhesive and anchor bolts that have done their job pretty well for 35 years. I don't expect to be mechanically hanging the entire mass of the keel on this system, it's more of a stabilization remedy. This is a long term project so don't expect a follow-up any time soon. Scheduled installation is at the next haulout in 2 or 3 years.

And thanks guys for the input. I knew exposing it on this forum would garner excellent responses. It's been received with mixed reviews on the Catalina 30 Yahoo forum, probably too extreme a remedy for them. On another forum it was suggested rather strongly that it could not be done unless I was a credentialed naval architect which I am not but the poster, one of their 'featured contributors' was. I posted back I'm open to a better suggestion if he had one. Nuthin'. This is the same guy with the Atomic 4 'BOOM' comments. Draw your own conclusion.

[hanleyclifford]

Different Thinking

After studying the repair instructions from Catalina and Neil's plan it is clear that Neil is going beyond the original design for carrying the ballast keel in that he introduces the use of "floors" to help spread the load upward into the reverse curve area, a wooden boat concept. The factory solution is nothing more than a replacement of the mushy plywood (a bad idea to begin with) with layers of fibreglass mat and roving. Lapping it higher in the reverse curve area is a poor substitute for the introduction of floors. This is getting interesting.

[sastanley]

Hanley, I've already told Neil that if and when he ever gets an estimate to build those floors, I'd be interested to know a price. If his manufacturer has to fabricate all the tooling, might as well build two sets and start recovering some costs.

These parts that Neil may fabricate are obviously Catalina 30 specific...and additionally their fitment is individual to each boat, since it isn't like swapping bumpers on a car of the same model year when 50,000 of them exist, & every boat is still 'custom'.

With a little over 6000 boats built, and probably a few cut up by now, most of those existing owners oblivious to the problem, and a pile of old codgers that already know everything (like the ones Neil's already run into) he ain't gonna get rich on the project...but if I can help a fellow sailor save a few bucks, and also benefit myself, I am all over it.

[edwardc]

... he ain't gonna get rich on the project...

I dont know. He could sell them to a gallery! They certainly look like works of art to me!

Beautiful job Neil!

[hanleyclifford]

The question that lingers in my mind about this Catalina 30 keel issue---why not drill right thru the ballast keel and use thru bolts?

[ndutton]

Most times my projects are intended to meet a specific need of mine without a single thought of marketing to others. I have quite an array of Neil-specific creations. A great example on this forum is my fuel polish/filter purge system. It works great for me, transfers fuel from one tank to another, polishes fuel, purges air out of the filter after a cartridge change and provides a manual shut-off valve immediately ahead of the carb. We've heard my sermon over and over yet I think I have the only one in existence. Oh well, it works for me and that's good enough.

There's been some interest in the floors project but everyone is waiting for me to pull the trigger which still has a couple of years to go. The good thing about castings is easily repeatable parts. The only hand work is deburring and drilling the bolt holes. Fabricated waterjet parts will have considerably more hand work so I expect the price to be a dealbreaker there. Shawn's on my list of a handful of owners to keep in the loop as this progresses. We might be able to save a little with multiple castings off the same pattern but probably not much. The price I was quoted 2 years ago was based on minimum charges. We were looking at around $650/set, castings only. The bolts were another $150. This is why I don't want to incur separate yard fees, would rather do it as part of a regularly scheduled haulout with other work.

The question that lingers in my mind about this Catalina 30 keel issue---why not drill right thru the ballast keel and use thru bolts?

The vertical cross section of our keel tapers to the bottom and six of the seven accessible bolts start out near the keel sides. This is enough to give me the willies as I drill deeper. Also, if I were to drill the entire depth of the keel we're looking at maybe three feet of 3/4" clearance hole through lead. Times seven. That's more than I want to think about.

edit:
Thanks Ed. Presentation matters too.

[sastanley]

Hanley, Some people have done that...drilled a big hole right thru the middle of the keel, drilled a 2nd hole perpendicular to that from the bilge & set a long stainless stud down thru the bilge, added washers & nuts and filled the hole. On the other hand, no one has ever heard of a keel falling off from the failure of the original studs due to the bonding agent that was used.

[Kelly]

Neil,

I have two amateur questions:

1) Is there a reason to not cast the holes into the floors for the passage of your bolts? Is it easier to drill after casting?

2) You mention the wave form on the top is to accommodate wires/tubes etc. You've done the calculations, and I'm only speaking from instinct, but wouldn't a straight section across the top greatly increase strength? Especially in the case of the ends bending toward the middle. Is this not an issue at all?

Thanks and great project...

[ndutton]

1) Is there a reason to not cast the holes into the floors for the passage of your bolts? Is it easier to drill after casting?

Making the holes as part of the casting process is possible but complicates the patterns and sandcast mold dramatically. It would change from a single pattern to four patterns per floor: two mating floor halves and two core boxes. In fact, the more I think about it I don't think it could be done with four patterns, probably more. Considering the very few number of floor sets anticipated (like two) I chose to go with simplicity.

2) You mention the wave form on the top is to accommodate wires/tubes etc. You've done the calculations, and I'm only speaking from instinct, but wouldn't a straight section across the top greatly increase strength? Especially in the case of the ends bending toward the middle. Is this not an issue at all?

You are correct, straight across the top would be stronger. In my estimation for me to need that added strength the entire bottom of my boat would have to fail below the turn of the bilge. I figure the real strength is needed from the middle of the turn down to the bolt flats and I have a lot more meat in that area. The Sparkman and Stephens design has virtually zero sheer strength at the upper extreme.

Thanks and great project...

Actually it is me who's thankful. The questions and input from you all really helps the brainstorming. I've been tinkering with this for a couple of years and there's still a couple to go.

[Mo]

Edward,

Re post 31....you are on the money. My raw water pump has a leak and was dumping water in the bilge as I motored (siphon effect also I imagine). No water in oil so that's good. I pulled the one off my spare engine and that has some tracking of a small leak out a weep hole...but it looks good and the shaft is perfect. All said, it's better than what I have there now. I'll put it on tomorrow.

So......I sucked the bilge dry with the shop-vac and nothing came back in...so once I sort out the pump situation I should be back to dealing with rain water down the mast now and then.

I talked to Ken at MMI and discussed the pump that is on there now. I'll take it home tomorrow and haul it apart, check the shaft etc and see where we are with it.

Thanks man.