solent clown
RIP
fascinating.
The pro's and cons of steel boat building
- Thread starter Brent Swain
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fascinating.
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Apoplexy Alert!
Tranona
Well-Known Member
Once again showing your boundless ignorance.
Look up the term "plastic" and then stop referring to GRP boats using that term. They are composites. Composites can be built with varying materials and have varying properties, including many that are much stronger in every sense than steel. Carbon and Kevlar are two reinforcing fibres used to produce laminates that are stronger than steel either weight for weight or thickness for thickness. I defy you to destroy the bow section of a boat like mine (kevlar reinforced) with a steel pickaxe.
Knowing how fond you are of picking bits out of Yachting Monthly, I have in the past referred you to their series about 10 years ago on what causes GRP boats to founder using a 30 year old Jeanneau. The difficulties they encountered including attacking it with a sledge hammer surprised even them.
You really need to educate yourself in matters you clearly know nothing about. Then perhaps you will stop making ridiculous statements that are based neither on truth or evidence.
solent clown
RIP
Brent, do you fish?
Is your rod steel?
By the way, if I was asked that second question three decades ago the answer would have been yes. But I am no fisherman
Is your rod steel?
By the way, if I was asked that second question three decades ago the answer would have been yes. But I am no fisherman
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JumbleDuck
Well-Known Member
What matter is not so much the strength of steel but the toughness. To an engineer, "strength" is now hard you have to pull to break it while "toughness" is the resistance to cracking. The material property which describes this is "fracture toughness", KIc which has units (in SI) of MPa m1/2, pronounced "mega pascal root metres". Basically it tells you whether the energy released when a crack grows slightly is enough to form the additional crack. If it is ... bang.
Unlike the strength, the toughness of steel can be changed enormously by heat treatment. It's not easy to measure and there can be significant variations across a single piece. However, a typical value is 50 MPa m1/2.
It's even harder to get any sensible KIc for GRP, because it's a composite and fails in very different ways. I wouldn't care to go further than "a fair bit less than steel". CFRP is much worse because it shatters and Kevlar RP (mentioned by Tranona) is much more resilient.
Weight is a problem. You can get the required strength and toughness with remarkably thin steel, but thin stuff is also flexible and you are likely to end up with the starving-dog's-ribs effect you see on naval ships. As a result, steel hulls have to be made thicker than you might expect. Composites are already thick and so tend to achieve required stiffness without adding extra material.
However, for boat building none of this really matters too much. Sure, steel has great advantages if you are likely to hit coral reefs or play in ice, but very few of us have those needs and steel has huge downside too: rust, condensation, galvanic effects and the expensive difficulty of making a steel hull which doesn't look as if it was welded together in a field by hillbillies. For 99.9% of the yacht market, composites are infinitely superior and recognized as such, as a look round any harbour or marina will show. If you really want metal, aluminium is lighter than steel and avoids the corrosion problems, though of course it has its challenges.
DownWest
Well-Known Member
JD, excelent reasoning, but you realise that you are wasting your time with the zelot?
Friend sailed his 36ft cold moulded wooden classic to Rio from Portugal. Brasil has a bit of a prob with tree trunks floating in a band near the coast, so he avoided the band and single handed it there and back. Had fun at the Carnival too..
A while back, a couple of world cruisers on a steel boat hit a reef and sprung a leak (shock horror! is does happen) Not bad, but needed regular pumping. Not close to any facilites, they met another bloke who gave them a mix of cement and sheeps wool fat that they successfully sealed the leak from under water. When they did get to somewhere to do a permenant fix, they had to really chisel it off.
Does this prove anything? No. Like the rest of this weird thread.
Friend sailed his 36ft cold moulded wooden classic to Rio from Portugal. Brasil has a bit of a prob with tree trunks floating in a band near the coast, so he avoided the band and single handed it there and back. Had fun at the Carnival too..
A while back, a couple of world cruisers on a steel boat hit a reef and sprung a leak (shock horror! is does happen) Not bad, but needed regular pumping. Not close to any facilites, they met another bloke who gave them a mix of cement and sheeps wool fat that they successfully sealed the leak from under water. When they did get to somewhere to do a permenant fix, they had to really chisel it off.
Does this prove anything? No. Like the rest of this weird thread.
Brent Swain
N/A
I've the plug from a holesaw which cut a new hole for a sounder screwed to bulkhead next to the chart table. A reminder that there's 6mm of really tough steel which will bounce off the floating debris out mid ocean is actually very reassuring
Be careful with those plastic depthsounder transducers.A couple of summers ago, I met a plastic boat which was taking on huge amount of water ,after hitting something broke the transducer off, leaving a big hole in his hull. Luckily ,I had some underwater epoxy to stop the leak. Some idiot had put the transducer ahead of the keel, where it would be the first thing to get hit. I believe some put it there, assuming they can pick up a rock on the sounder, and stop the boat in 3 feet , an extremely naive assumption. The proper place for it is aft ,where any log will have long dissipated its energy before reaching it, and any rock wont reach it. Putting a bit of steel in front of it will protect it ,or even putting a 12mm bolt in front of it , not long enough to make bubbles to interfere with the sounder, also works.
Ahh for the good old days, when transducers were bronze!
john_morris_uk
Well-Known Member
JumbleDuck
Well-Known Member
I don't hope to convince the zealot, just put a few facts alongside his arguments.
Brent Swain
N/A
I watched the videos.
Comparing those little bumps with colliding with a large steel barge tied to a dock, or aground, or hitting a rock at hull speed ,pounding for weeks on a Baja lee shore in big surf, or pounding across 300 yards of Fijian coral reef, or being blown ashore in a hurricane in Mozambique channel , is totally laughable!
Brent Swain
N/A
So say the" fanatical plastic zealots!"
Brent Swain
N/A
In aptly named " Soddy Arabia" , they jail people for "insulting Islam. Here, they attack and pile on people for "insulting consumerism " the predominant religion of our area.
Consumerism being defined as "Spending money you don't have, to buy things you don't need, to impress people you don't like."
I am sure glad I never accepted the "Common wisdom" that we have no alternative but to live our lives running on someone else's hamster wheel, for their benefit, not ours.
Seems real "wisdom" is really not all that common!
Consumerism being defined as "Spending money you don't have, to buy things you don't need, to impress people you don't like."
I am sure glad I never accepted the "Common wisdom" that we have no alternative but to live our lives running on someone else's hamster wheel, for their benefit, not ours.
Seems real "wisdom" is really not all that common!
john_morris_uk
Well-Known Member
Little bumps?
You are making a fool of yourself again. They were sailing at hull speed and repeatedly hitting steel barges and rocks. Perhaps this is why people sailing GRP boats don’t worry as much as you think they ought to and there’s no history of people disappearing at sea through their GRP hulls failing on impacting a semi submerged object?
You keep citing extraordinary situations where a steel yacht was ‘pounded for weeks’ etc but most of us (even those of us who have sailed all over the world and across oceans) don’t have such poor seamanship that we get our boats into those situations. In fact my reaction is not, “Wow, what a strong hull and design!” but, “What idiot allowed themselves to get their boat stuck there?”
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john_morris_uk
Well-Known Member
Most everyone has agreed that steel is strong and I see no sign of zealotry except for yourself.
Please keep ranting as it’s helping anyone reading this thread better understand the disadvantages of steel construction for a yacht.
AngusMcDoon
Well-Known Member
But did the front fall off? It's a well known problem with steel boats, don't know about plastic ones.
bbg
Well-Known Member
I wish there was a "Like" button for posts like this.
According to BS, there are two types of GRP boat sailors: those who have hit a reef and died, and those who are about to hit a reef and die.
And two types of steel boat sailors: those who have hit a reef and survived, and those who are about to hit a reef and survive.
In my sailing experience (which includes several ocean crossing, including one solo, and learning to sail in the deadhead-strewn waters that BS calls home), people do everything they can to avoid hitting a reef. And almost always succeed. The only two people I know who ran aground did so on landfall after falling asleep after a solo ocean crossing. Both in GRP boats. Both survived. One of the boats was pulled off the beach without any visible damage.
lpdsn
Well-Known Member
Ah, you spotted that that breakwater was made of congealed custard and candy floss. Nothing gets past you!
By the way, what is the hull speed of an oragami boat just before hitting yet another steel barge?
Another thing, do you think all of these collisions with shipping might be caused by your boat being strongly magnetised? It's maybe worth checking out if they keep happening.
solent clown
RIP
it really is such an awful shame that any discussion of steel boats must always end this way.
There can be no greater disservice to the steel boat cause than having Mr Swain fighting it's corner.
It is such a shame as a balanced and realistic view from owners and builders would be very informative.
Two things put me off building a steel boat Karen and I wanted to build our forever boat. I have the expertise, equipment, and almost uniquely for most, a location to do so.
First was a realistic assessment of the cost. Just too pricey. easier to spend on an old boat and fix up, and still have tons of cash left to go sailing.
Second was the Brent Swain interventions in all the places you go to ask about steel boats. There is no way to get a clear unbiased viewpoint and actual experience where he has not muddies the waters.
So far lost in his own evangelical ardour he has almost killed the potential dream single handed for anyone silly enough to ask.
Shame on you
There can be no greater disservice to the steel boat cause than having Mr Swain fighting it's corner.
It is such a shame as a balanced and realistic view from owners and builders would be very informative.
Two things put me off building a steel boat Karen and I wanted to build our forever boat. I have the expertise, equipment, and almost uniquely for most, a location to do so.
First was a realistic assessment of the cost. Just too pricey. easier to spend on an old boat and fix up, and still have tons of cash left to go sailing.
Second was the Brent Swain interventions in all the places you go to ask about steel boats. There is no way to get a clear unbiased viewpoint and actual experience where he has not muddies the waters.
So far lost in his own evangelical ardour he has almost killed the potential dream single handed for anyone silly enough to ask.
Shame on you
dom
Well-Known Member
Fair point
prv
Well-Known Member
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