Should I put concrete in the bilges?

[lesweeks]

This thread has crept a little as I was not asking about using cement/concrete as a form of ballast but simply whether or not I should replace the existing small amount of cement that was used to fill the, roughly triangular, space found between the planks and the hog.

I very much appreciate all the responses and advice; I've decided to go with the pitch/tar suggestion. All I need to do now is source the stuff, organise some form of heating and think of a method of carrying and pouring. Easy!

 

[Bobobolinsky]

(How would reinforced concrete work otherwise?)

The steel is in this case Enclosed no air/water can get to the steel

No it's not air and water can penetrate reinforced concrete. It is the slight alkalinity of the cement that preserves the steel. In a salt laden atmosphere concrete becomes chloridated and less alkaline, the reinforcing corrodes. This is a slow process and may occur over 50 years. The result is spalling, where concrete chips are blown off the surface by corrosion exposing rebar to further salt water attack. Done the job, been there ticked it got the tee shirt.

Cement is one of the worst offenders for co2 production, it is produced by the calcining of limestone. Not only is it a CO2 producer, it is one of the only processes licenced to burn rubber from shredded car tyres, which is high in sulphur and produces acid rain.

Cheap burner and metal bucket. Smash bitumen into small pieces and add slowly until half bucket full of liquid bitumen

 

[H/V Vega]

Cheers mate sounds like a good solution

If you would like I am in contact with one of the heads of the HMS Victory restoration and can ask where they get there pitch from. If in the US can suggest another source.

 

[Lyulph Hesling]

Go to a flat roofing company, they stock the pitch, and have all the tools you need. This amounts to a large enamelled water jug, some sort of pot with long handles (in my case a bit of old water main) and a gas burner. I put some in last year, scary, but actually quite easy. If they will not lend or hire you the kit they will probably do the job for you, at "roofing" prices.

I was told that pitch goes hard and brittle after 40 years or so, if so replacing it would be a good thing, as it tends to break up and drop out.

 

[DownWest]

No it's not air and water can penetrate reinforced concrete. It is the slight alkalinity of the cement that preserves the steel. In a salt laden atmosphere concrete becomes chloridated and less alkaline, the reinforcing corrodes. This is a slow process and may occur over 50 years. The result is spalling, where concrete chips are blown off the surface by corrosion exposing rebar to further salt water attack. Done the job, been there ticked it got the tee shirt.

Quite, Royan Cathedral is made entirely of reinforced concrete and it is falling to bits from corrosion of the steel. Guess what? They used salty beach sand........