... But I must say that I am even more convinced not to
get involved with repairing a steel / aluminum boat after I have read
your post. The learning curve and upfront investment seems to be a bit
too high for me.

Investment, maybe not. You can get a steel boat for a song, and aluminum
for not much more.

If you're already a skilled welder, then it makes sense. A few years
ago, seeing a number of aluminum boats on the market, of a type that I
liked a lot, at a good price, I looked into learning to weld aluminum...
unfortunately aluminum is the trickiest stuff to work, not practical as
a handyman project. But it's great engineering material, boats made of
it can be light & strong & durable.



In the early days, folk who were making boats
out of the stuff seemed hesitant, and they used
the same thickness of solid fibreglass as they
had been using for wood before then! ... After
these first boats didnt sink they got comfortable
and started experimenting with different ideas.

Excuse me, but this is a total myth. The idea that "early fiberglass
boatbuilders didn't know how strong it was" is incorrect.

In the 1940s and 1950s, the U.S. Navy began building small utility craft
out of fiberglass and commissioned exhaustive studies of the material.
Many of the early boatbuilders worked on those projects and knew as much
about it as any designer/builder does nowadays.


... With newer boats they seem to
have got it right with hull thickness and
composites/sandwhiches.


Fiberglass *is* a composite. With regard to cored construction, that has
always been an issue firstly of build quality, as laminating cores takes
careful attention (ie skilled labor) whereas chopper gun or even "hand
lay up" is much less demanding. So choice of materials & care in
building produced excellent cored structures even in the middle 1960s.
The 2nd part of that equation is care & maintenance. If the owner never
bothered to rebed the deck fittings & let water seep into the core, then
it gets screwed up.

BTW for anybody who doesn't think that cored fiberglass hulls don't
last, the first balsa-cored sailboat 'Red Jacket' is still sailing and
still sound.


wrote:
Thanks for pointing out the three different periods of fiberglass
boats. Seem like I should stick with either very old fiberglass boat,
or very recent fiberglass boat.

Well, you should start out by doing some field work. Join a crew and do
a lot of sailing. Trudge around to the sailing clubs and work at getting
rides on as many different boats as you can. Keep a notebook to record
your impressions of the different boats.



According to other people, I probably should focus on boat that are
before the first oil crisis, and that will be before 1973.

Well, there is a slight amount of truth to that, mostly due to speed of
production as much as anything else. But a lot of those old very thick
hulled boats are mostly resin, which is brittle. Heavy ain't necessarily
strong, despite the numerous old wives tales about the strength of 2" or
6" or whatever thick fiberglass in the old pre-Nixon boats. A lot of
what's said around the docks on this subject is old wives tales and
utter nonsense.


... I am hoping that I can find a good solid fiberboat that
needs some fixing and doesn't cost a lot of money

Be darn sure you don't under estimate the cost of fixing. Spend some
time with the various marine catalogs and price things like running
rigging, wiring, marine paints, etc etc.

Fresh Breezes- Doug King