Replacing steel ballast

[Guest]

Thanks to anyone who's replied to me before on this topic.
I'm going to replace the 3000 odd lbs of wet, rusty, scrap, loose steel ballast in the keel of a Colvic Watson 26 thats causing the hull to be permamnently saturated...........I know - I'm crazy but otherwise the boat's fine.
My feeling is that poured concrete will be best, then when it's set paint it with something waterproof or probably better to skin it over with GRP attached to the hull sides to seal it in for ever and form the waterproof bilge floor.
Can anybody suggest:
1 How does this idea sound? Any alternative to concrete?
2 Anybody done it?
3 Might the concrete chemicals affect the hull fibreglass when drying. I thought of laying thick DPM polythene in there first.
4 Any suggestion on the mix to use - I assume the mix should be as dry as possible to reduce curing time and shrinkage.
5 How important is it to get the total weight exactly right and also distributed in the right place fore and aft ?
6 One big lump or divded up say by polystyrene spacers so it can all "work" a bit once it's set.
7 Add some steel reinforcement ?

The name of good psychiatrist may also be useful later.
Malc Davis.

 

[30boat]

I don´t know the exact numbers,but I remember reading somewhere that concrete doesn't make very good ballast because it's not heavy enough.I would go for scrap iron(steel) sandblasted and set in casting resin.Since it is much heavier than concrete the center of gravity will be lower.More expensive but,I think, a much better solution.

 

[Guest]

Thanks for reply.
Yes I has heard this somewhere before - strange how bloody heavy wet concrete is when you hand mix and barrow it!
Perhaps stainless steel scrap (I believe it has has a low scrap value) so at least it cant rust again, set in the resin used for epoxy mortar in the construction industry (ie not with "Boating" in its name) would be more economical.
Thanks.

 

[ccscott49]

Remember if you stop oxygen getting at stainless steel, it rusts, just as fast as steel, I don't know if it will rust in concrete. If you are getting all the ballast out, how about cleaning it and painting with galvafroid or finnigans hammerite, then epoxy grout, or getting some newer scrap and doing the same to that.