I'm about to start junk rigging my Rustler 31 (long keeled, heavy displacement, Kim Holman sloop) and have, after much deliberation, decided the only sensible position for the single mast is right where the forehatch is currently located, at the very forward end of the coachroof. I'd appreciate any advice on the structural modifications I might need in order to use the hatch opening as the mast partners.
Practical Junk Rig mentions that many GRP boats need little or no extra reinforcement at the mast partners and a simple plug that fills in the hatch opening is often sufficient. My boat is 1966 vintage, very heavily constructed with solid GRP hull/deck/coachroof mouldings. As the forehatch is so close to the narrow front of the coachroof I get the feeling that the area is inherently stiff and strong enough and that a thick wooden plug bonded into the existing forehatch opening should be sufficient. There is a plywood bulkhead directly aft of the forehatch giving additional support to the coachroof.
The only complication I can forsee is that the upstand of the forehatch is formed by a combination of internal headliner moulding and main external coachroof moulding. Both are very substantial GRP layup but only the top two inches of the upstand has solid GRP packing connecting the inner and outer mouldings. The wooden infill plug would be four inches deep and hence enormously strong but only the upper two inches would only be transferring its loading to the combined inner/outer moulding, the lower half making contact only with the inner headliner.
Am I wittering needlessly bearing in mind that the Rustler is a typical 1960s era GRP cruiser/racer, ie of lavish GRP layup and overbuilt in all departments ? I know that the loadings are nothing like those of bermudan rig but just how severe are they in practice?
Jerry
Last modified: 04 Mar 2014 22:41 | Deleted user