On Thu, 03 Aug 2006 13:20:31 -0400, DSK wrote:

You are out of your mind, Steel is much easier nd cheaper to repair and
can be repaired in most ports around the world.

Fiberglass can be repaired with stuff from Lowes. You don't
even need to be in port. You don't need a welding machine.
Patches or rolls of fiberglass cloth & jugs of resin are a
lot easier to stow than spare steel plates, and they are
much easier to form into the desired shape.


Frank Boettcher wrote:
Having made my living for a while as a welder (on offshore deck
sections) and having done a lot of glass work and chased a lot of core
rot, I'd say it depends on the type of repair. If I needed to repair
a holed hull, steel gets the vote for easier and more reliable.

Since it takes years of specialized study & practice to
become a welder, why would you say it's easier?

Not if you have a reasonable aptitude for the craft. Most production
welders in the yard I worked at were at the 3G level in less than four
months, that is they could pass a vertical up test 1" plate cut and
stripped, bent 180 degrees around a mandrel without separation of the
weld from the base metal. However, there was a shortage and we were
pushed hard to test quickly. I tested to 5G (around a fixed
horizontal pipe) and had certifications in SMAW, GMAW, FCAW, SAW,
and GTAW processes in less than a year (note, not all those processes
suitable to 5G position).

Mor reliable... depends on your perspective I guess. I've
done a lot of QA work on pressure vessel welding. Most of
the best welders I've worked with are bikers... don't know
why that is.

And my ASME code stamp is on quite a few pressure vessels. I was a
college student at the time going to night school, however, lately
I've been thinking about a Harley 883 Sporster. If I catch one at a
good price......


... I
would not trust any yard in my area to do a holed (particularly below
the water line) hull in glass.

I wouldn't either. I'd do it myself.


.... If you don't feather back the edges
properly and back lap the repair, there will be a weak spot do to the
loss of the monolithic nature of the woven roving, mat and cloth. Not
sure I would ever trust it. Not an issue with steel.


A weld can never be as strong as the original metal.

I concur with Joe. It certainly can. If it is fully penetrated,
properly tied into the base metal with no cold lapping or undercutting
it will as strong as the original metal. (provided you use the proper
filler metal). You do have to be somewhat concerned about shrinkage
at the heat affected zone, but that can be handled.


A
properly done fiberglass repair can be stronger than the
original... in fact, it can be a problem if you make the
patch too stiff because that throws more stress to the other
areas of the hull.

Looks to me like you guys who are already welders have a lot
of faith in metal... that's good. OTOH it would be
interesting to see your opinion after studying a text on
composite engineering. I have done minor fiberglass work for
many years, but recently decided to learn more about it &
the best books seem to be focussed on aviation.

Just talking about repairs here. I'm not promoting steel as the best
boat building material. And you're right, it is a matter of
perspective and circumstance, what's in your skill bag. I've done
both (although never to repair a holed hull with either) and my
druthers would be to weld a repair.


That said, I'd still rather have a glass boat. Did someone mention
rust as an issue?


Why no. Is rust a problem for steel boats?? Who'd a thunk
it?

DSK