keel bulb

[robertj]

any one got a fin keel they feel would benifit from a bulb on the bottom? can they b retro fitted or designer drawn and professionally fitted? whats the forums feeling on this one

 

[oldsaltoz]

G'day Bobfal,

Most boat builders would have done a few of these, many were made in 2 halves from lead cast in sand, thru bolted filled then glassed over for timber or GRP keels; and simply painted on cast iron keels.

Hope this helps.

Avagoodweekend......

 

[jwilson]

Easy enough to fit, and fairly often done, but .....

Increasing keel weight increases stress on keelbolts/hull structure, increased righting moment increases stress on entire rig and chainplates etc as you can now carry more sail in stronger winds.

The reason Ben/Jen/Bavs have low ballast ratios and keel weights is that they can engineer the rest of the boat to cope with lower rig stresses. Increasing keel weights would increase performance substantially, and not actually cost that much in buying a bit more iron for the keel lump. They don't do it because they would then have to beef up the hull structure, chainplates, and entire rig as well, and you would no longer have a cheap mass-production boat.