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-   -   How old is too old II: Design (http://www.sailnet.com/forums/boat-review-purchase-forum/73664-how-old-too-old-ii-design.html)

jcwhite 04-15-2011 10:15 AM

How old is too old II: Design
 
There's another thread around that I was just reading, a discussion on how old you can reasonably shop for plastic boats, and how long they'll hold up. The conclusions seem to be that the actual age doesn't matter much when compared to the upkeep and condition of the boat over it's life. Fair enough, that makes sense.

Now disregarding maintenance and condition, but considering design, construction techniques and materials instead, how old is too old? I'm sure there have been breakthroughs in hull and rig design - when did they work their way into recreational sailboat plans? Fibreglass got weaker in the 70s because of the materials used during the oil crisis - did it ever rebound? Around what year did it start to get weaker?

An example of what I'm looking for is the spade rudder - apparently it used to be somewhat prone to falling off - is it still? I'm sure there are many other, more important points as well.

Faster 04-15-2011 10:54 AM

I think 'weak' fiberglass boats have more to do with poor practices, under-engineering and a too-hurried adoption of new techniques than age itself.

Good cored construction techniques result in a stiffer, lighter, stronger structure. Poorly executed it can be a nightmare.

The key is in finding a boat that was well built in the first place (at whatever level of technique was 'solid' at the time, that was maintained and protected from moisture intrusion (including those boats of the blister prone era that have been treated/repaired/barrier coated) from deck leaks, port leaks etc etc.

As for spade rudders, while there have been failures I'd say today the majority of boats designs use spade rudders that are adequately engineered and they'll stand up well until something like a grounding or collision occurs. There are certainly performance and manoeuvrability advantages to them. I don't think they ever really 'tended to fall off'. To a degree these fall into the same argument camps as "full vs fin", "heavy vs light" where everyone has a point of view of their own.

mitiempo 04-15-2011 11:24 AM

2 Attachment(s)
The first fiberglass cruising sailboat, Arion, was built in 1951. She was designed by Sidney Herrescoff and built by Anchorage Plastics. Still going strong - and she has a spade rudder. damian mclaughlin corporation - Arethusa

KeelHaulin 04-15-2011 01:23 PM

I think part of the mis-understanding on this is that 'plastic' boats are not strictly plastic. They are a composite of glass cloth that is held together with plastic; and the glass carries the load that is placed on it. These materials are highly durable and won't easily degrade. The problem with most older boats come from degradation of the boat's systems; or due to damage sustained by water getting into the coring of a balsa or foam cored hull.

The marconi sloop rig and the fiberglass hull were the biggest improvements to recreational sailboats. There really is no boat that is 'too old' in terms of this. Red Jacket, the first balsa cored sailboat hull (made by C&C) is still sailing. A well made balsa core hull is also OK so long as it has not been abused by ramming it into a dock, etc.

It usually comes down to the type of boat you want, the type of boat you 'need' (will it suit your sailing purposes), and your price range.

jcwhite 04-15-2011 02:56 PM

Please bear in mind that I already recognize that a boat's life and upkeep is far more important that it's design in determining how sound it is now. I'm trying to dig past that and find out if how it was built also has an effect.

What I'm hearing then is that it doesn't matter so much which techniques were used, but rather that the builders were good at what technique they were using. Is there any way for me to tell that? I've already heard that build quality of a given hull from a given company can vary dramatically between years, but I've not found anywhere that can give me a heads up on which years were worse. Do I just accept that I might get shanked? (I'll have the boat surveyed, of course, but I'd rather not have to survey every boat I examine to rule it 'in' or 'out' of contention).

I also wasn't intending to veer off into the spade rudder debate - I don't have the experience to offer an opinion. Them being perfectly seaworthy, however, is exactly the sort of information I'm looking for. Also perfect are KeelHaulin's comments regarding the sloop rig (although I suspect I won't find a boat for sale from before the sloop was invented :) )

tommays 04-15-2011 03:24 PM

After you start looking at boats you will start to become pretty good at seeing the ones not worth having surveyed

http://i565.photobucket.com/albums/s...abermotor2.jpg

http://i565.photobucket.com/albums/s...abermotor1.jpg

I would be pretty sure anybody can see boats with motors in this condition are gonna go downhill as you get deeper into them and you will learn which nook and crannies to find other obvious issues


As for myself i went with the Cal 29 because i prefere its layout compared to many new boats that have way to much stuff cramed into a < 30' boat and at 4'5" draft it will still sail as well as anything with that draft

CaptainForce 04-15-2011 03:54 PM

Quote:

Originally Posted by jcwhite (Post 720710)
.................. Fibreglass got weaker in the 70s because of the materials used during the oil crisis - did it ever rebound? Around what year did it start to get weaker?........................

Actually, fiberglass did not get weaker. What happened at the close of 1973 and early 1974 was an increase in the cost of fiberglass resins by about 500% due to the oil embargo. The response of manufacturers that were selling to the lower cost market was to cut back on hardware, trim, amenities and all possible to stay competitive,- many failed. This first affected the boats manufactured in 1974 and they gradually recovered by the later seventies. Take care and joy, Aythya crew

CalebD 04-15-2011 04:19 PM

I think the construction years you are referring to are around '71 - '73 where blisters became fairly common in some makes. Again, it comes down to a case by case inspection as this is a generalization and not every builder nor every hull of a given type had this problem.

Design issues.
Roller reefing booms. This was popular with builders at one time and my boat from 1967 has this 'feature'. We never use it as intended and reef using slab or jiffy reefing like more modern boats do. It is more of a curiousity then of practical use.
Gasoline engines. There are probably (tens of) thousands of boats out there still being propelled by Atomic 4's or Palmer engines. Diesels became the auxiliary engine of choice with builders in the 70's. The 43 year old Atomic 4 engine in my boat is still running quite well given enough TLC. For many people having a gasoline engine in a boat would be a non-starter (pun intended). I happen to like the simplicity of the A4 and have learned a lot about engines as a result. I also don't have the money to throw at a Beta re-power right now.
Chain plates. Some chain plates (like ours) were glassed into knee walls when they were built way back when. This was the technique they used and it can hold up for a long time BUT once stainless steel gets wet and is deprived of oxygen it will begin to corrode. A better design is where the actual chain plate is not enclosed in a fiberglass coffin.
Teak toe rails. Yup, my boat has 'em too. They can look beautiful but they are a maintenance nightmare and a poor choice for a toe or rub rail, IMHO.

Keep in mind that a lot of regulations have come into existence SINCE my boat was built. HIN #'s were not required prior to '72 or '73. I am not even sure when the ABYC was created but I don't think it existed back in 1967. The ABYC is also constantly updating their 'best practices' list so a 5 year old boat may not meet all current ABYC standards either.

All boats are compromises in one way or another.

turbulicity 04-15-2011 04:39 PM

Quote:

Originally Posted by CaptainForce (Post 720787)
Actually, fiberglass did not get weaker. What happened at the close of 1973 and early 1974 was an increase in the cost of fiberglass resins by about 500% due to the oil embargo. The response of manufacturers that were selling to the lower cost market was to cut back on hardware, trim, amenities and all possible to stay competitive,- many failed. This first affected the boats manufactured in 1974 and they gradually recovered by the later seventies. Take care and joy, Aythya crew

To my knowledge, many manufacturers decreased the resin/glass ratio somewhat during the oil crisis. This is not necessarily bad since they actually came closer to the optimum ratio (Too much resin is bad too). More of a problem is that the barrier coat quality suffered as evidenced by the blistering problems. I am sure different manufacturers reacted to the oil embargo differently and one universal conclusion about the boat hull quality of that era can't really be drawn.

When buying an older boat, you will check for blistering, delamination, core moisture (if cored) etc... If it is fine, it will continue to be so for a long time. How long will the fiberglass material itself be structurally sound? I don't think anybody has an accurate answer. 40-50 year old FG boats are still going strong. So I wouldn't be too concerned about that.

KeelHaulin 04-16-2011 12:46 AM

I think one of the best ways to determine if a boat is suitable is to look at the boat; take some photos (of everything that looks good AND bad); then post some photos here and ask some questions about it. If you want to do some initial narrowing down of a particular boat or several boats put up a post asking for some info/comparisons. While some posts will point you in different directions (because those people are critics of that style or type of boat); others will help you determine if the boat you are looking at is suitable or if it is a good hull design, etc. There are just too many good boats (and bad) for each era to say "none from a certain period of time are good boats".

Let us know what boat you are considering for survey and post some photos if you can.

IIRC one of the reasons for boats with blistering problems in the 70's was the use of a type of vinylester that had a fire retardant in it. This resin was more reactive with salt water and resulted in blistered hulls. The blistering problem can be fixed/stopped; but requires a stripping of the outer layers of the hull and re-clothing/glassing with an epoxy resin to seal the inner layers of the hull.

Boats with strand-mat blistering are also common; but this is a non-structural form of blistering that is mostly cosmetic. It can also be fixed by grinding out blisters and barrier coating. Please understand that these problems were common throughout the industry because the skin layers of most hulls are stranded mat fiberglass which has high porosity and will allow water to permeate through. It's a problem; but it is not a death sentence for a hull if it is blistered.


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