Mortar encapsulated keel repair

[sibleysailor]

Hi everyone new here, I live in Maine and sail on a small freshwater pond "NOVICESAILOR".

But anyway I have a 16ft 1976 American Fiberglass sail boat with main and jib with a small cabin. Got the boat gifted to me well three years ago now, and ive always had trouble withe the keel cracking. It was cracked and leaking when i got it but i was able to seal it up from the inside and make it work but after every winter I find my self trying to re fill and seal the keel which also is the home for the center board...

As you can see from the photos its fairly severe this year.The mortar is deteriorating and has expanded and cracked fiberglass.

So finally to my question,I was wondering if anyone had any ideas on what/how I could fix this reoccurring issue for good?

Off the top of my head I think what i would like to do is cut back and strip out the mortar and fiberglass and kind of build a new keel shell. And then fill it with a better material other than mortar but simaliar in weight??....No idea what that could be.


Thank You!

[psk125]

Mortar is not what should be used in this situation. It absorbs water and when it freezes, cracks all over. Epoxy filler with micro balloons or fibers would be better. It does not absorb water so won't crack. It is not easy to figure out exactly what the photos are from. The close-ups give viewers few references as to what we're seeing, other than damaged material. Essentially all the mortar "stuffing" will need to come out. You may then be able to refill the space with epoxy filler (NOT BONDO!) and then re-fiberglass the keel/centerboard case. Good luck!

[billknny]

Despite what others have posted, having a "concrete" filled keel is not unheard of. The actual construction is usually a fiberglass shell, filled with iron/steel chunks, and then poured with cement. Since this is an economy construction technique, it wasn't often that lead was used as the "heavy" part of the ballast.

What is swelling and expanding and destroying your keel is the iron/steel. Iron oxide is something like 30 to 50 times bigger in volume than the metal it is made from, and will crack apart the strongest structure.

The only way to stop your keel from continuing its slow motion explosion is to exclude ALL water and oxygen from contact with the metal inside. That was the purpose of the original cement fill. That has now failed. I seriously doubt there is a cost effective way of fixing it...

But maybe somebody here has an idea...

[tkeithlu]

There is a problem here. First, that's a pivoting centerboard, not a keel. Then, the proposed repair does not take into account that this centerboard is also acting as ballast. Whether it's the iron rusting or the water freezing that is causing the swelling, my bet is that you'll end up either cutting off the offending bottom and replacing it, or replacing the entire centerboard. It's pretty far gone, but on a 16' boat, we are not talking about a difficult job. You could make a quite acceptable one out of marine plywood, a stainless steel loop bolted to the board from both sides as a foot, and the foot filled with just about anything dense for ballast.

[hellosailor]

As Bill said, rusting iron filler in there could be expanding and causing the damage. The "mortar" is probably a cement/concrete mix and that also traps water, which could be expanding and doing damage when it freezes.

I think the ultimate solution would be to use a maul and chisel to remove as much of the "concrete" ballast mix as possible. If you're brave, perhaps use acid to dissolve away the rest of it--but really really make sure you know what you're getting into. In any case, clean it all out so you can refill it, and I'd suggest that was done with epoxy resin and shotgun pellets. Either lead or whatever is available to you that will not rust. Lead shot can still be mail ordered if the local gun shops aren't allowed to sell it. As to fixing the damage, check out West Systems, leading name in marine epoxies and fiberglass. They have an extensive library of how to repair whatever structural damages you might have, and free tech support on the phone.
There are, sadly, no magic shortcuts to get the wrong materials OUT of the boat. This may explain why the boat was gifted to you.

[billknny]

Originally Posted by hellosailor

....Lead shot can still be mail ordered if the local gun shops aren't allowed to sell it...

Your mailman will love you when you order 500 lbs of lead shot for your new keel...

[hellosailor]

500#, motor freight, the same way the local retailers get it. But if all else fails, yes, Amazon sells lead shot at sporting goods store prices.(G)