Steelboats

[Brent Swain]

Great post blowing old boots.
There are too many people on here who have not built anything more than a potato stack on their Sunday lunch let alone designed and built boats.
I hear others mention that they indeed had a hand in a boat being built but I would surmise they were indeed just there watching the build program with no input on design let alone the skill of actually getting their hands dirty doing it!

Great post !Thanks.
Perhaps my critics could give us rundown on how many successful steel boats they have built , designed, lived aboard, maintained long term, and crossed oceans in. Some photos of their steel boats would help with the discussion. That would give us something to weigh , and qualify their opinions with.
The designer I mentioned, by his own admission, was totally useless with tools ,but was constantly patting himself on the back for the craftsmanship of others.

 

[sarabande]

Yes, here is the stability curve for my 36.I also like to double check the numbers, by using models.

View attachment 75333
The designer I mentioned has posted a hatch so far offset , it was at the side deck.There was clearly no chance of there being enough buoyancy to keep it above water in a knockdown.

Brent, can you explain the anomalous increase at around 95 degrees please The curve is somewhat unusual.


And if you use models to check stability curves, what precautions do you take to scale the structural and righting masses ?

 

[Brent Swain]

Brent, can you explain the anomalous increase at around 95 degrees please The curve is somewhat unusual.


And if you use models to check stability curves, what precautions do you take to scale the structural and righting masses ?

It drops when the side deck goes under, and spikes when the buoyancy of the trunk cabin and the lifting of the keel takes effect.
I use models to double check displacement, LCB and prismatic coefficient.

 

[Brent Swain]

Absolutely not. Brent’s boats are pretty enough. It’s the condemning of other options, the dangerous advice, the inability to admit he’s wrong even it’s proven to him, together with his complete intransigence that’s a problem.

What dangerous advice are you talking about? What ways have I been"proven wrong?"
Rolleyes has been stalking me across the internet for years , attacking and ridiculing almost every post I made, regardless of content, on many sites. The term "Rolleyes" says it all.
His only reason for his time on this site is to jeer, taunt , obstruct the passing on of steel boat info, try provoke a pile on, and troll, all while hiding behind an alias.
Such sarcasm is what the trolls reply with , when they have no valid points with which to attack one.

 

[Brent Swain]

For me it is not the way BS designs and builds his boats but the fact that everybody else is wrong and he is to quick to condemn others as inept or corrupt.

He states that steel boats do not sink after collisions but the most famous steel boat to have sunk after a collision does not count.

He states that it only takes a few minutes a year to maintain one of his boats but does not allow any time to completely removed to cabin. This is to get to the inside of the hull to remove all the foam and Epoxy (Plastic) to stop it rusting from the inside out.

I could go on but he has already put me off purchasing any steel boat.

The trick is to get the inside epoxied well in the first place,so you don't have to remove anything especially the inside ,which is often sadly neglected ,especially on many comercialy built boats around here.
No, a ship the size and mass of the Titanic has no relevance, when it comes to strength to weight ratio, to a 36 footer.
You wont consider steel. Good ,gives my clients the right of way!

 

[sarabande]

It drops when the side deck goes under, and spikes when the buoyancy of the trunk cabin and the lifting of the keel takes effect.
I use models to double check displacement, LCB and prismatic coefficient.

That worries me. Between 90 and 95 degrees there is a substantial, and I mean really substantial, increase in the righting lever which you ascribe to

1 the trunk cabin.- which will only be partially immersed at that angle IRL, and not be able to contribute greatly to the RL unless the modelling (not the model) assumes the water plane is aligned along the keel and mast with the cabin volumes secured against entry of water

and

2 the keel 'lifting'. This is perplexing. Lifting a keel raises the CofG which will reduce the RL. And what causes a keel to 'lift' at a few degrees past horizontal ? Friction in the centreboard/keel trunk, and torsion load on the pivot pin will need serious forces to 'raise' the keel at 90^o - 95^o. I cannot see that happening except under rather unusual modelling parameters.

I thin I know the real answer for the spike, but will wait for your reply

 

[Mister E]

The trick is to get the inside epoxied well in the first place,so you don't have to remove anything especially the inside ,which is often sadly neglected ,especially on many comercialy built boats around here.
No, a ship the size and mass of the Titanic has no relevance, when it comes to strength to weight ratio, to a 36 footer.
You wont consider steel. Good ,gives my clients the right of way!

Yet you stated that you do have to remove all the inside stuff to replace in another thread when asked.

Gives"your clients the right if way", so this is realy just an advertising campaign for you to sell more boats. Do you need the money?

 

[capnsensible]

Good ,gives my clients the right of way!

Good grief.

How absurd.

 

[myquest]

You wont consider steel. Good ,gives my clients the right of way!

What a silly comment to make! The inference being that my steel will damage your GRP so keep out of my way. If you were to spend more cerebral energy promoting what is undoubtely a sound construction method instead of belittling all others, you might be taken more seriously.
I might add that I am viewing this thread purely for it's entertaiment value rather than it being informative, solely on your past reputation.

 

[GHA]

He states that it only takes a few minutes a year to maintain one of his boats but does not allow any time to completely removed to cabin. This is to get to the inside of the hull to remove all the foam and Epoxy (Plastic) to stop it rusting from the inside out.

Why would you do that? With a proper design and build there's no need, it will last as good as new for many, many decades, just make sure the water stays outside.

Example from a little surprise a couple of days ago showing why you should never bolt through, always weld fittings.

Stanchion bolted through & old boltholes from when some idiot thought a teak deck would be nice let the water get at the metal with predictable results. Note the steel around is as good as the day it was made 35 years ago. Confirmed with ultrasound.

Luckily steel is cheap and time is free
If I'd know all this or read Brent's comments on this thread a decade and a half ago a different boat would have been bought and a lot less grinder flaps discs bought recently but hey ho, still a cracking tough boat. :ambivalence:

Yet you stated that you do have to remove all the inside stuff to replace in another thread when asked.

He didn't. It's important to have an interior where you can easily get at the bilges for a good check once in a while. Keep them dry they'll be fine. Above the waterline shouldn't be necessary if you've done your job properly.

=robertj;6669125]Great post blowing old boots.
There are too many people on here who have not built anything more than a potato stack on their Sunday lunch let alone designed and built boats.
I hear others mention that they indeed had a hand in a boat being built but I would surmise they were indeed just there watching the build program with no input on design let alone the skill of actually getting their hands dirty doing it!

:encouragement:
Despite the bluster Brent does actually know masses about how to have a tough low maintenance steel boat to last forever and take you anywhere

 

[dom]

That worries me. Between 90 and 95 degrees there is a substantial, and I mean really substantial, increase in the righting lever which you ascribe to

1 the trunk cabin.- which will only be partially immersed at that angle IRL, and not be able to contribute greatly to the RL unless the modelling (not the model) assumes the water plane is aligned along the keel and mast with the cabin volumes secured against entry of water

and

2 the keel 'lifting'. This is perplexing. Lifting a keel raises the CofG which will reduce the RL. And what causes a keel to 'lift' at a few degrees past horizontal ? Friction in the centreboard/keel trunk, and torsion load on the pivot pin will need serious forces to 'raise' the keel at 90^o - 95^o. I cannot see that happening except under rather unusual modelling parameters.

I thin I know the real answer for the spike, but will wait for your reply

Fair question, though a bit of inaccuracy at the top of the curve is not the end of the world. The 160deg+ AVS and tiny area beneath the curve is also interesting. Wld be useful to have some detail specs to understand how roll-stable this vessel is and what it might sail like.

 

[Mister E]

Why would you do that? With a proper design and build there's no need, it will last as good as new for many, many decades, just make sure the water stays outside.

Example from a little surprise a couple of days ago showing why you should never bolt through, always weld fittings.

Stanchion bolted through & old boltholes from when some idiot thought a teak deck would be nice let the water get at the metal with predictable results. Note the steel around is as good as the day it was made 35 years ago.

Luckily steel is cheap and time is free
If I'd know all this or read Brent's comments on this thread a decade and a half ago a different boat would have been bought and a lot less grinder flaps discs bought recently but hey ho, still a cracking tough boat. :ambivalence:




He didn't. It's important to have an interior where you can easily get at the bilges for a good check once in a while. Keep them dry they'll be fine. Above the waterline shouldn't be necessary if you've done your job properly.




:encouragement:
Despite the bluster Brent does actually know masses about how to have a tough low maintenance steel boat to last forever and take you anywhere

BS might just know stuff about steel, but I have no idea why he stated the removal of the interior epoxy. You will have to ask him or find the relevant thread, this was to first reason he put me off purchasing a steel boat.

 

[GHA]

BS might just know stuff about steel, but I have no idea why he stated the removal of the interior epoxy. You will have to ask him or find the relevant thread, this was to first reason he put me off purchasing a steel boat.

Where did he say that? Seems daft.

The arguments for steel really only come into play long term, long distance where you need to fend for yourself, for the vast majority it doesn't really make much sense compared with GRP.

 

[dom]

Yes, here is the stability curve for my 36.I also like to double check the numbers, by using models.

View attachment 75333
The designer I mentioned has posted a hatch so far offset , it was at the side deck.There was clearly no chance of there being enough buoyancy to keep it above water in a knockdown.

Many thanks Brent, useful info and heavily offset companionways, agreed they are fine on offshore racing boats which routinely keep them shut in heavy weather.

That 160+deg AVS estimate is indeed impressive even with mast only. It would be interesting to see some of the boat's other design parameters to get a feel for how this works up and how your boat might sail.

BTW, that sealed steel mast which as Sarabande obliquely implies probably features in the AVS spike around 100degs, I'm guessing halyards, electrics, etc, run outside the mast, or perhaps in a small conduit? It's not a bad idea, but how much buoyancy accrues from this as boats are often dismasted in B2 knockdowns?.

 

[Ladybirdgaffcutter]

Where did he say that? Seems daft.

The arguments for steel really only come into play long term, long distance where you need to fend for yourself, for the vast majority it doesn't really make much sense compared with GRP.

I and perhaps others would be very interested to read some technical details, or even see a photo of your yacht GHA.
I've sailed all sorts, and owned all sorts (except ferro!), presently have 1 large iron/steel, 1 medium wood, both gaff cutters.
Just started a formal college stick welding course to learn it properly, MIG which I'm familiar with, is not so handy for adding cleats on 10mm steel decks etc for obvious reasons.

 

[GHA]

I and perhaps others would be very interested to read some technical details, or even see a photo of your yacht GHA.
I've sailed all sorts, and owned all sorts (except ferro!), presently have 1 large iron/steel, 1 medium wood, both gaff cutters.
Just started a formal college stick welding course to learn it properly, MIG is not so handy for adding cleats on 10mm steel decks etc for obvious reasons.

Didn't you post a link to an Ebbtide recently?
Ebbtide 33. Love the design, very sea friendly, easy to balance and doesn't need too much wind to get going with a clean bum.
Not sure I'd buy a factory built though unless everything was welded on.
Won't post a pic til it's pretty again

 

[Mister E]

Where did he say that? Seems daft.

The arguments for steel really only come into play long term, long distance where you need to fend for yourself, for the vast majority it doesn't really make much sense compared with GRP.

I can not find the thread in a search but it was the one that he claimed his boats dont burn if you close the hatch and it only takes a few minutes to weld stuff to the deck (later he admitted you have to remove the interior epoxy).

I found it very surprising that he also stated that a intervals you should replace all the interior foam and Epoxy. The amount of work involved in this was definitely the main reason for ditching steel.
He does seem to have some good ideas but when he does give specific information you then know he is not telling the whole story. An example being his costing does not include the Epoxy which he states is vital.
His build time does not include the Epoxy which he states is vial.

I can weld and work steel plate but am not so sure about FiberGlass so did consider a steel boat of some sort, not now

 

[Brent Swain]

That worries me. Between 90 and 95 degrees there is a substantial, and I mean really substantial, increase in the righting lever which you ascribe to

1 the trunk cabin.- which will only be partially immersed at that angle IRL, and not be able to contribute greatly to the RL unless the modelling (not the model) assumes the water plane is aligned along the keel and mast with the cabin volumes secured against entry of water
______________________________________________________________________________
That is why I use a proper, one piece hatch, instead of the outdated sliding hatch and drop boards, as almost all the round the world racers have done.I have a photo of the reason on my computer, but it is too big to post. Closed on two rubber gaskets, my hatch is as sealed as the lid on a pressure cooker, no water can come in , in a rollover.
____________________________________________________________________________

and

2 the keel 'lifting'. This is perplexing. Lifting a keel raises the CofG which will reduce the RL. And what causes a keel to 'lift' at a few degrees past horizontal ? Friction in the centreboard/keel trunk, and torsion load on the pivot pin will need serious forces to 'raise' the keel at 90^o - 95^o. I cannot see that happening except under rather unusual modelling parameters.

I thin I know the real answer for the spike, but will wait for your reply

What centreboard ? Did I mention centreboard?
The keel breaks the surface, increasing 'its righting moment.
Your suggestion that having a friend check my drawings, can give predictions on how it sails, which are more accurate than cruisers' experience on how it actually sails, is ludicrous.
Search Silas Crosby ,and Tagish, for info on how she sails, which is far more accurate and reliable than armchair predictions.

 

[Brent Swain]

I can not find the thread in a search but it was the one that he claimed his boats dont burn if you close the hatch and it only takes a few minutes to weld stuff to the deck (later he admitted you have to remove the interior epoxy).
_____________________________________________________________________________
Opposed by the claim that interiors can burn without oxygen!
Yes, it only takes a few minutes to weld stuff down; in the bare steel, building stage, as I said.
____________________________________________________________________________

I found it very surprising that he also stated that a intervals you should replace all the interior foam and Epoxy. The amount of work involved in this was definitely the main reason for ditching steel.
_______________________________________________________________________________
A total lie .I made no such suggestion, ever, anywhere. I have done nothing of the kind, in the 34 years my boat has existed. Where I have chipped out foam, the epoxy under it has been in perfect condition, due to having got it right in the first place.
___________________________________________________________________________________
He does seem to have some good ideas but when he does give specific information you then know he is not telling the whole story. An example being his costing does not include the Epoxy which he states is vital.
His build time does not include the Epoxy which he states is vial.

I can weld and work steel plate but am not so sure about FiberGlass so did consider a steel boat of some sort, not now

My surplus epoxy cost me around $500, and took me ten days to put on 35 gallons of it., Still keeps the cost of a steel hull and deck to a fraction the cost of doing it in plastic.

 

[Brent Swain]

Didn't you post a link to an Ebbtide recently?
Ebbtide 33. Love the design, very sea friendly, easy to balance and doesn't need too much wind to get going with a clean bum.
Not sure I'd buy a factory built though unless everything was welded on.
Won't post a pic til it's pretty again

Yes, factories tend to screw up, by bolting parts on, to "Increase "resale price, something most backyard builders are wise enough to not do.