__________________
Sailingdog Telstar 28
New England
You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.
—Cpt. Mal Reynolds, Serenity (edited)
If you're new to the Sailnet Forums... please read this POST.
I sometimes wonder what truly is fact and what is fiction into TODAY's material aspects of boatbuilding. Considering the players:
1. Material suppliers (albeit foam core, balsa, etc)
2. Designers who have to meet both a boat builders capability, marketing opportunity, as well as pride in design.
3. Boat builders - who actually have to learn the techniques and invest in the equipment and materials to make it happen, and make it look like marketeers and architects envisioned and still meet customer expectations in build quality..
4. The distributors, dealers, and marketeers - who all have to perpetuate the trust of all of the above...
5. The customers whom actually end up validating any one or all of the above - and when not met - the blame goes up the chain....
Hence why I posted that link as in prior discussion (and actually waited before actually posting anything in response to responses) - it is easy to see how build construction, perceptions, and end processes actually work out. With comments from Jeff, Melrna, etc...and yours and observations from the articles on the website - one wonders really if the industry actually understands the materials or if media / industry hype drives those expectations and we just literally buy into it...
I remember reading a few years back - some of the same articles Jeff recalls actually - nowhere to be found. And as late - nearly impossible to find reports of testing or case studies of boats built in the fashion they are today - regarding the materials...
As Melrna (I used to work at Dupont as well at one time) stated - there are deficiencies with some of the "composite" materials - yet we get the impression from watching the America's Cup and associated races - that light is better and how you get there is using . Yet we never see the longevity studies of how these vessels fair over say 10 years or so...And since they use Kevlar and Carbon - wow that is a great application usage of such in consumer brand vessels...
However, America Cup vessels have a single purpose in life - win races. If the materials and fabrication process meet those goals and they win - the boat is an success.
However for a sailboat designed to circumcise the globe. The same may not apply due to heat, stress, cargo load etc...
The same applies to vessel designs. The fact is that sailboats and powerboats only differ in three aspects (generally speaking):
1. Structural integrity maintained though pounding as a resultant of speed.
2. Support of higher center of gravity loads such as multi level bridges versus carrying sail...
3. Amount of weight to be supported per foot... in cargo, stowage weight and people they can support during transit...
I say that as a generalization - not an accurate summary (millions of points to be considered but for the layman it sums it up)...
Everything else still applies...in terms of overall designing a boat that meets specifications...
I would truly like to see this thread actually evolve to finding info that actually provides life history of materials of boats that we want, have or desire to buy in the future...
I just know that today I was installing deck hardware on a rebuild.
I put in 48 stainless bolts. Winches, deck organisers, clutches and cleats... If the deck or cabin had been cored I would still be there carefully prepping each hole...
tomorrow the headsail tracks, spin winches and various deck blocks go in...About 150 more holes...
I can do it all in a day because I am not filling close to two hundred and fifty little bolt holes with resin.
It never clicked how much using cored decks as an economising measure actually just moved the costs around instead of abolishing them....
I think that on future projects I will ask if the deck is cored, and if the answer is yes...I think I will be unavailable due to industrial blindness (I just couldn't see myself doing that!)
I was just wondering, it is too bad boat designers or builders cannot comment in an area like this. For example Mr Perry. Maybe it would clear up some of the truth vs myth.
Melissa
How does this all reflect in something like the Tartan 37 with a balsa cored hull? Most seem to say it is fine, but I think one post recorded extensive rot. Obviously drilling holes is not much of an issue but I wonder about the odd ding with coral heads, and if the glass is not totally waterproof the gradual buildup of water in the balsa. There is a fully equipped one for sale here at a seemingly reasonable price.
As I read this thread, it sounds almost like the group thinks that balsa and foam coring is a comparatively new and high tech solution that is experimental and unreliable, when in fact balsa coring has been used in sailboat decks and hulls for over 50 years. Foam coring has been used for at least 45 years. I personally have looked at nearly 50 year old Pearson Vanguards and Tritons with balsa core decks that were completely intact and 40 year old Bounty II's with foam core decks that were intact. I personally have owed boats with 25 year old foam cored hulls and decks without a bit of delamination or distortion. These are well tried construction technioques that have proved very reliable over the years. The percentage of sailboat decks with core problems is quite small. IIRC even Pascoe places that number at 1%.
Companies like Tillotson Pearson has been building balsa cored hulls for over 30 years (builders of J-boats, Freedom, Alerion Express, Aldens and so on) and while it was true that some of their earliest boats had core issues, for the most part, it is pretty rare to come across a J-boat, Freedom or Alerion with core problems. Tartan has been using balsa coring in its hulls for nearly 35 years and again, while Tartan had come periods where Tartan had a lot of core and glass problems, but for the most part, core problems with Tartans are pretty rare as well. (Tartan is a case where the company has been in and out of financial problems throughout its history and has changed hands and building techniques, not always for the best, at various times along the way.)
I find these, 'the sky is falling' kind of threads disturbing. They potentially wholesale condemn processes that have produced good boats based on the comparatively few cases where a boat was poorly built or maintained and problems occured. I don't care how well you build a boat, they all will require maintenance and without maintenance, they will develop problems. With reasonable maintenance these boats will last a lifetime and that seems reasonable to me.
We each are looking to purchase a single boat for ourselves. If we vet out models that are likely to be troublesome, and then carefully examine the specific boat that we are considering buying to look for problems, then as individuals, we should be able to avoid the kind of issues that may occur with balsa or foam decks, since as we seemed to have agreed to above, the reality is that like most technologies in this world, the quality of the execution effects the ultimate quality of the product as much as the choice of technology chosen.
I do not think the sentiments here are singing the theme song for Chicken Little, but rather how little longevity and structural integrity data exists for newer composites in general.
One can say that yes, I have seen this and this on these boats - but one of the things I liked about the surveyors website in general, was actual photographic proof / illustrations of issues on the field with a variety of vessels. While one can say the authors affinity to being overly simplistic in some aspects in others the right amount.
There are obvious other driving forces - but I agree with the other poster - the materials are not new, however, if you noticed that all actual data regarding these materials and studies done on them are locked up in engineering sites that require pay to view or special membership. Thus for the rest of us - the knowledge we gleam is personal observations of those that impart what they may know - but not the whole story....I see it all the time on those other boat building forums (less the wooden boats one as it seems there really is not much more to do on a manner of building boats that goes back before navies even existed)...
Failure rates, fatigue, etc - one can build a boat out paper if they so desire...doesn't mean that just it it is epoxied it will work but failure will be readily apparent. Where we have all these differing techniques - usually the only obvious failure point is if we can visually see it on the outside - and rare get to see the cross sections...Hence access to studies that actually document the issues with over time are more useful than just stating but it has been successfully done.... Kinda like stating that just because a Ford pickups are the number 1 selling pickup that all F-350s will go 200K miles without other than semi annual maintenance (my case) when apparently - many more do not have that longevity...But there is enough data out there to know which components may fail first...
Case in point - just on a maintenance side, I was recommended by a consultant to use a certain 2 part epoxy to seal holes left from when replacing line guides from the mast. Then when in the yard - I started removing all topside components to do the deck properly - used the same epoxy, and didn't get to actually painting it due to issues with the mast when pulled ripped the deck.... So 3 months later - I could see the effects of heat on the epoxy - it was gummy and tacky and swelled out of the pockets....Now I am pretty sure I will never use that product again...but had I done the rest of the sealing and painting - and then tapped back in the equipment - the problem would of been not seen until too late...
Linear Mode
