79 cp 16 interior needs help

[Salty19]

Yep, one could also form a nice battery box with access lid that sits inside the keel using the stringers with battery shelf. That's what I would do anyway...heavy extra weight may as well be in the keel.

Then fill the void with lead and either concrete or epoxy (could get expensive with epoxy so concrete might be better).  Well, not filled...the precise amount of course.

The remaining void where concrete used to be could be extra storage, foot room, flat water container, etc.   Leaving the aft portion of keel free from ballast or otherwise keeping ballast forward might help balance the 16, which IMO could use a bit of forward weight.

I did some calcs once, they are not on this computer, but recall something like a 200lb weight savings if you use lead, but I was guessing at the measurements but I bet that is pretty close.

[Tim]

I have really enjoyed everyone's feedback and comments on this post. Also, I like the direction that is is going in.

I teach in the same school with my buddy that helped me rebuild the Pearson. All we have been talking about for the last week and a half was this ballast issue.
After he and I separated the hull and deck last weekend it was clear that I was neck deep into this project, so I might as well bust out the keel material and start fresh as opposed to trying to creatively patch up the crappy cement ballast.

I have no experience with re-ballasting a boat, so at this point any feedback has to be in simple English

The idea of reenforcing the keel with fiberglass, building stringers, and (fully) encapsulating iron in epoxy feels like the direction that I want to go in. I feel like cement is a subpar material and has more than proven its achilles heel...at least here in the north.

Unfortunately I have to go to Florida over the holidays and have to put the project on hold for two weeks. But, I'm anxious to get back to the boat and put my pneumatic chisel to work.

Happy holidays everyone,
Tim

[NateD]

I did some calcs once, they are not on this computer, but recall something like a 200lb weight savings if you use lead, but I was guessing at the measurements but I bet that is pretty close.

You want 280.3 lbs of lead, laid low in the keel-within the bottom 3.5", to equal the force of 450lbs of concrete.  Yes I did the math!

Source: http://cpyoa.geekworkshosting.com/forum/index.php?topic=5108.msg35763#msg35763

Salty didn't show his work, but that seems about right in my mind. I've seen guys melt down old wheel weights using propane stoves, poured into sand molds to make ballast. Obviously working with lead there are some precautions you want to take, but the processes doesn't look very hard. Personally I like the idea of locating a battery and water tank in the keel cavity. A group 24 battery is about 45 pounds, so I would do 240 pounds of lead and reinforce the fiberglass in the keel up through the turn to the hull. But I'm no engineer.

[Tim]

This all sounds good to me and I believe that I am understanding the physics involved. BUT I feel like I should go with 300# of iron or lead and enough concrete to hold the material in place...putting me back at around 450#. This way I am keeping the ballast / displacement ratio the same, which I kind of like, and lowering the VCG which I also very much like. This would also allow space to create a proper bilge area.

I should say here that it is my full intention to use this boat in the ocean when I am finished with the project and will be emphasizing stability over speed throughout this rebuild.

I managed to remove the concrete from the keel. It was a pretty time consuming project. If you want to keep track of where I am on this project follow this link: http://kpeting.blogspot.com/

It took me two pretty full days to clean out the whole keel and here it is!!

[NateD]

They ought to sell recycling bins somewhere. I had ones similar to yours and used them for everything. Saw horses, garage seating, haul broken concrete out of basement, haul yard waste, step stools, haul split wood......And on Wednesdays they also went the curb full of recyclables.

That looks like a heck of a lot of work, but your livin' the dream of us Com-Pac 16 owning armchair naval architects/boat tinkerers. I can't wait to see how it turns out.

[Jim23]

I have a fair amount of experience working with lead...probably the reason for my low IQ. I apprenticed under an old school plumber who insisted on lead caulking cast iron pipe joints. I still have my old lead working tools and hopefully will never need them again.

I never dreamed lead would cost $.85 a pound wholesale. Back in the 80's/90's it was dirt cheap. If you go with lead you'll definitely want to find a salvage source. I used to buy 20 lb ingots until prices started going up. After that I would purchase from scrap metal yards. I believe scrap yards are paying $.50-.60/pound.

Lead isn't cheap anymore but still probably the best material for a low center of gravity and it's easy to work with.

[Tim]

It looks like I am going to use lead as my ballast material. I was able to find a guy in Maine with some good sized ingots. I bought 300# at $0.80/ pound. I've never worked with lead, so this will be a new adventure.
If anyone needs lead...I now know a guy