Dear Joan,

I have just finished reading Graham Wadeson's article, 'Centreboards and Garboard Strakes', and thought I might make a few comments.

Whilst it is a good thing for people to tackle repairs on their boats themselves, as an ex-shipwright I feel I should warn fellow members of the danger of using brass screws in boats, particularly in underwater fastenings. Brass is an alloy of copper and zinc and is liable to dezincification - after only 12 months in salt water the corrosion which takes place can be frightening. If brass screws must be used, use them above decks and replace every year. Stainless steel (18/8) is also OK for use above decks and where free access of airflow is ensured. The best bet would be silicon bronze in fastening a centreboard box.

Regarding GW's remark on guide holes for screws, he should also use pilot holes for copper boat nails. In rivetting boat nails, the rove can be driven on with a small block of hardwood with a hole drilled down into the end-grain if no rove punch is available. Leave about 1 - 1½ dias. after cutting off with end cutters.

In plugging old holes, softwood plugs should be used - they swell quicker! One final comment; on driving screws, grease should not be used due to it soaking into the timber and ruining your subsequent paint/varnish. In the old days tallow was used, but the average handyman is more likely to have candles or soap in his house - both derived from tallow. Happy Sailing!

Jason Friend