Join Date: Dec 2012
Location: NE & Windwards
Thanked 167 Times in 161 Posts
Rep Power: 7
Re: Steel vs Fiberglass
Have some time this morning so will try to find some middle ground with BS. Thought to compare Fe with Al and as a parallel wood to fabrics.
Cruisers fall in to several catagories but for discussion will talk about long term cruisers and divide that group into high latitude/circumnavigators versus mom and pop cruisers snow birding or bopping country to country.
BS points out the obvious. Fe is cheap, strong and abrasion resistant. He denies the importance that with his technique one cannot design in complex curves where you want, nor not pay a penality in performance given the weight of the material until you reach large vessels. Neither does he accept that rust remains a constant concern. He alludes to the integrity of his personal vessel using foam sprayed in place. But doesn't accept this requires meticulous prep and application. Once done other than removal of the foam or sounding the hull there is no way to know if the application remained intact. Continued adhesion after impacts, thermal working, degassing and aging may all impact to my limited understanding. Bleemus has shown us pictures of what may occur under foam. At my local yard I have seen other examples where the continued adhesion has been compromised and trapped moisture resulted.
Fe allows distortion without puncture. Welding is simple and if of suitable thickness a fair hull without heat distortion can be rendered. It does require specialized lifting equipment given its weight and specialized tools to work it given its hardness. Although with readily available pre primed need for acid washes and the like is limited the materials involved are noxious. Coatings must be maintained or rust ensues.
Al is malleable, compared to Fe soft and light. Like Fe it will distort before puncture. Unlike Fe bare Al develops a protective oxide. Unlike steel it can be worked with the same tools used for wood. Unlike steel simpler lifting equipment is required. Unlike steel it requires much more attention when tig welded in a windless environment so in general assembly is best done inside by professional shops. Unlike steel weight is not the enemy of speed to nearly the same degree. It is even more subject to electrolytic corrosion then steel but this is a concern for both. Both need to be protected from stray current and contact with electrolytes such as salt water.
Wood is surprisingly strong for weight and resistant to load cycles. Unlike metals work hardening is less of a concern. With steam boxes complex curves can be developed. Abrasion is a concern as is biologic attack. It is easy to work but unlike metals is not isotrophic so load paths must be considered. Specialized tools are not required and removal and replacement of failed pieces can be done without concern for integrity of surrounding structure. Coatings must be maticulously maintained to prevent water ingress and biologic attack. Whereas the general techniques in using metals as not significantly evolved in decades wood has in the last 50 years. Moving from plank on frame to cold molded laminates or strip plank with laminates of wood or fabrics has mitigated the concerns for water ingress and biologic attack. Wood is inured from issues of corrosion or oxidation. Wood will dent before failure from impact but if overloaded will fail catatrophically.
Fabrics have evolved dramatically in the last 50 years in substrate, resin, core materials and manufacture. But even old school solid grp is quite strong, maintains its strength with little or no attention. Neither is biologic attack, rust nor corrosion a concern except for metal attachments. All shapes are available. Downfalls are costs are only decreased by series production and costs are increased as one moves into expensive substrates (from glass to aramid, CF) and cores or need for specialized equipment ( ovens, infusion, etc.). It is not a reasonable material for the home builder.
So returning to BS and his boats. For the typical mom and pop cruiser. Cost of ownership for a grp boat is favorable c/w Fe. If buying used they can expect a significant residual value while enjoying a relatively low maintenance vessel with good performance. If buying new they will be subject to higher depriciation but less refitting and replacement costs for metal fittings and the like. Not bounding into birgie bits or getting iced in the strengths of steel and Al are overkill. BS makes much of his boats lying on reefs and such. He fails to accept they still will need repair and recoating. Given the poor residual value it may not make sense to do this. Here is the contrapositive. I know an old cheribini ketch that was in Marion. In prep for a hurricane it was moved to New Bedford. However it still broke lose and went aground on an abutment of large granite blocks. It eventually was hauled off and returned to Delran, NJ. Given its high residual value restored to like new condition. GRP has been around for more than half a century. In my life I've hit balks of timber, trees, winter sticks, docks, pilot whales, shipping and fishing equipment. I've been on boats who have run aground on rock shelves, hidden abandoned pilings, mud and sand. Been fortunate with current boat but know it's not if but when. Still given over 95% of cruising sailboats are still simple grp there are a vanishing small number sinking from collisions. BS concern is way overblown especially with even current production boats coming stock with watertight collision bulkheads.
For the high latitude sailors Al has been the choice for some years. It offers all the benefits of steel in that hostile environment with none of the deficits. These boats retain a residual value, top sides won't rust if scratched, and can survive impact or even icing in.
So in summary BS boats only make sense for those who enjoy boat building more than sailing. Who have no concern for residual value, who expect frequent groundings, collisions or impacts. Who can live with subpar performance and enjoy maintaining coatings. I'm sure they make perfect sense for this subgroup. Unfortunately for Brent this is a vanishing small group of people getting smaller with each passing day. Hence his angst as he is forced to live in a parallel reality.
Last edited by outbound; 02-05-2016 at 11:52 AM.