effect of oak on ferrous fastenings

[daveyjones]

I'd like to make some large cleats and other bits of deck "furniture" in oak ( for strength), but as I will be using galvanised mild-steel bolts to attach them to the hull, I'm worried about the effect the acids in the wood will have on the bolts. Is this a rapid process, or does it take years to corrode the bolt, and is it possible to protect the metal by painting in Hammerite or tar, or anything else? Could you wrap the bolt in something, say insulation tape, to prevent direct contact with the wood? Is there a suitable alternative timber, not too expensive but strong? I used Iroko on my last boat, but here in Kent there is a local source of local oak, which is very cheap. Thanks.

 

[Ardenfour]

don't know about the effect on the metal, but i left some oak lying across the steel cradle and it turned black in about a week where it touched the metal

 

[oldsaltoz]

G'day David,

Apart from staining the Oak I'm sue you will have any other problems;
have a look at the last 2 paragraphs on this website


http://www.woodcraftcbh.com/extracti.htm

Andavagoodweekend......

 

[boatmike]

I think the acid in Oak will react with iron and discolour the wood. Well known problem with oak framed wooden boats. In time it does affect the fasteners but if heavily galvanised bolts (not zinc plated) are used it should protect them. I think however that it's false economy and you should stick to Iroko and attach with stainless bolts.