Modifying Plans

A well executed and encapsulated (in Epoxy) stell hull is as maintenance free as a GRP boat!
NEVER you need to crawl through the cavities every year, not even every 30 years.

Of course when neglecting it, it will become a mess. But that is valid for ALL materials, and especially for GRP! A crack in the gelcoat can lead to severe damage of the structure after a while. (more so with polyester than with Epoxy)

One should service every material properly and take care that minor scratches are repaired immediately. But again, that is valid for all materials.

A blast steel surface, Ep primered and Ep painted, then insulated against condensate will outlast any GRP layup. And different from GRP (even when perfectly done) it does not soak water over the years, so your weight remains the same.

When hammering on a reef or rock (yes that happens), you might be happy one day to remember my words.

>>> on the "barefoot route" there is a saying: more than half of the circumnavigating boats are of steel, the others are American<<<

Regards
Richard

 

Regarding, vinylester, design and critique here..

1) So, you wanted something REALLY, totally, different
2) Making your design and then getting critique from people here is no substitute for an experienced designer.

 

Yep. I am doing this sort of project just now. My client purchased plans first. After 5 months we have three hull designs with 6 cabin tops and about 10 versions of hull deck joint. At least we already know exactly the type of anchor to be used

 

Do´nt place bets on that!

The extremes I have seen was one US guy going from a 53ft. Hatteras (the perfect boat, but...) to a 112ft. custom built steel boat that came out "too large" and was sold on launch.

The other ***** went the opposite way, he purchased plans from Willem de Vries Lentsch for a 27 meter RPH but went down to a 18 meter sailing boat built by Gouwerok, which he still could not afford in the end.

In both cases I am sure, the anchor was not the perfect fit when bought for the initial design!

Regards
Richard

 

"round hull with a wider beam that what is typical for a more comfortable ride."

Your coming research to become a NA may prove that this is not always the case.

Snap roll , the vessels period of roll , is a comfort consideration.

Too fat can become a slow slow rough rolley ride.

Seldom is a ROOMARAN a good sea boat , not a problem , just be sure your Desirements are known in advance.

Usually a long skinney boat does best at sea, but is expensive as a dockside condo.

FF

 

I'm REALLY glad that you wrote this; it's given me some serious rethink on this. Right now I've been mainly reading book to get an idea of things, and certainly each author has their opinions and bias. When I started pondering against steel it was because the author made it seem like steel was a real pain to paint all the time.

As I read what you wrote, you drive a very convincing arguement. My first impression was to go with steel because of the cozy safe feeling that you get with it for the very rock scenareo that you cited.

I'm good at welding and I could peck away at this over time and so I saw huge advantages to steel. Just buy a TorchMate system and away I go, cutting pieces to size and welding them as I go.

Can you tell me more about what you said regarding "A well executed and encapsulated (in Epoxy) steel hull is as maintenance free as a GRP boat!"? I've not read anyone talk about "encapsulating the steel in Epoxy. I've heard of doing this for the wood that you use to connect the seacock to the hull so that the wood won't rot, but not anthing other than that.

What are the best ways to insullate it against condensation? What are the better materials above and below deck?

It seems that steel is going to be cheaper to build than the S-Glass Epoxy combination; is this your opinion as well?

Thanks for your expertise on this, you have probably swayed me back to my original desire to go with steel.

One note regarding the glass approach, I was going to ask if anyone had ever done a hybrid of a double wall below the waterline where you make the normal outer layer, but then attach 2 layers of a uni-direction glass, the first layer (the one that contacts this inner hull) would be vertical and the second would be horizontal. You would attach with just enough epoxy to connect to the hull, but would leave some air gap so that water could trickle down if there was a leak; you would also completely fill in some vertical sections to create mini "compartments" about every 5'; the horizontal uni's would be attached to the verticals minimal exoxy, and then you would attach a final outer wall to create the "double wall" system. At the bottom of each of the "compartments" you would create a small seacock that only penetrates the most inner layer to allow any water to drain into the bilge, and if you notice a true fast leak, you would shut of the seacock, knowing that you need to repair the outer hull because there is a breach.

I didn't know if something like this had been done before or not; I assumed yes, and so I was curious how well it works. This would only need to be done for below the water line. Also, for any areas that were going to have seacocks, I just figured that you'd make that second a solid thick core rather than the double wall.

Thanks again for your ideas.

 

For the record, since I keep hearing this. I agree. A designer has years of experience, school, dozens, hundreds, (thousands?) of boats under their belt... the've lived and breathed boats. Totally agree.

I manage large scale programs and projects in the $100 to $250 million range and so I have tons of expertise in how to arrive at "what is the best way".

When I go to an engineer, they have their bias, their way of doing things, etc. I don't want to go to an engineer with a blank piece of paper and say build this for me. I've learned in management that teams and groups come up with better ideas than any one person. And so before I go to my one engineer, I plan to learn as much as I can from many different books, and from many different designers online, and then try my hand and some designs. Then I want to talk with an engineer and work with them on critiquing what I came up with; even if we end up scraping all or most of what I came up with because they had totally better ideas, I still like my approach because I'm armed with the best possible ideas that I could come up with and then I can choose if I think their ideas are better than what I brought to the table.

On large scale projects I always spend lots of time gather ideas and requirements from all kinds of people; then we usually will rank and prioritize our needs and wants, and then we'll mach up some sketches of various ideas; and soon things start to progress away from designs and prototypes to actual finalization of the final plan and then building.

I'm at the very front end, the part where I'm learning, getting ideas, asking questions to learn; I'm just asking and learning and trying to have fun participating in what seems to be a very nice bunch of people.

I REALLY appreciate that people are warning me not to be an idiot and go build this thing without an AE. Thank you to all for this. But I'd like to move on, I get it, I agree with it; I just want to learn from people's knowledge on different subjects that interest me as I progress through my information gather stages.

So thank you to all for watching my back and keeping from doing something stupid, I do appreciate it.

 

Not sure what that "Torch" thingy would be, but sure when you really know about welding you will get yourself the right equipment and weld to accepted (by class societies) standards.

I am sure not biased, building in wood epoxy, Vinylester glass and (until last year) in metal too.
For a homebuild steel is one of the best choices. (...ester / glass one of the worst)
All the cruel stories and worries about steel come from ages before epoxy based paint systems became standard on the market. (and biased opinions of course)
When you look at a 20 year old dutch build, and proper Ep preserved, yacht, you will most probably find a very sound hull and deck structure.
When you make a survey on a similar quality GRP built, with a moisture meter, you´ll most probably find some issues. That means the structure started deteriorating in these spots! You may make your own conclusions.

To get that straight:

ALL boatbuilding materials require some maintenance and service for a long service life, there is absolutely not a single exemption.
ALL need to repair minor scratches and damages immediately! In GRP, "haircracks" are not easy to spot, thats another prob.

One cannot completely prevent water from finding its way under the "skin" though. That means some touch ups and repairs will occur from time to time in any case.
Here a metal boat shines. Apart from a classical wooden built (which is always the easiest to repair to "as new" standard, the steel or Alu is the easiest to bring back to Bristol shape. Followed by wood epoxy laminate, which is much trickier to repair, but has rarely any issues when executed perfectly. The worst is a cored GRP structure, which is more often than not a total loss, once delamination took place.
I will not comment about ferrocement, because thats not a boatbuilding material.

Another significant plus for steel (and more so for wood Epoxy) is fatigue! Often underestimated or unknown, but very important for a passagemaker. The average boatowner with his 80hrs sailing per annum can forget about that term, but when you are in for sailing all year round you have a big point there.
You might find these older threads quite informative:

http://www.boatdesign.net/forums/boat-design/material-strength-fatigue-13174.html
http://www.boatdesign.net/forums/materials/how-long-lasts-fiberglass-11455-2.html

And Pascoe may convince you to leave the plastic crap where it belongs, on racers, floating condo´s, and landfill.....

http://www.yachtsurvey.com/sinking_of_Bertram_630_Absolutely.htm

Last,
forget about the "double hull" idea on a GRP boat, except you build in tanks to provide that function, like on a metal boat.

Regards
Richard

 

Thanks for all the info, you've sold me back to steel, and I'm glad because I really wanted to do her in steel. Now after reading your posts I like it even more.

Oh, the torchmate thing is just a nice economical CNC. http://torchmate.com/ Well economical as far as CNC's go. It just cuts metal to exact specifications from your CAD drawings. It would pay for itself on a project like this. I'd started looking into making my own CNC but when I compared my cost to do it to their costs it was about the same, so it's easier to just buy their expertise and focus on the boat which will be the fun part.

 

What do you recommend using for adhesive? Do you use the same one throughout the boat or something different above/below the waterline? I see they have a 520, 520 Black, 520 BLV, Armaflex Low VOC Spray Contact Adhesive, and Armaflex VOC Spray Contact Adhesive.

How do you decide what thickness to use?

Thanks for the recommendation of the product, it looks quite impressive and will really keep the water away from the inside steel wall.

 

Yep. Thanks, I'd read about going too wide in many of the books that I've read so far as well--what a nightmare that would be.

I like the idea of a fin keel and separate rudder.

I also like the idea of an oversized apeture with the rudder recessed partially forward of the pivot axis. That seems like a very nice rudder design.

 

Don´t forget to insulate the frames first, before you apply the foam to the plating.
On frames some 3mm are sufficient, on plating the 12mm is the most common. For extreme latitudes I would go up to 20mm.

Be very, very thorough applying the stuff and you will nearly never have to see that space again.

AF is the one you use against condensate buildup, there are others for engine room insulation (HT- on top of AF), all come as a self adhesive sheet (roll), or with the appropriate glue. It is the same glue throughout the boat, above or below WL, for the same type of foam.
Follow the technical information provided for every single type of foam.

Go at least 25cm (10in.) below waterline with the insulation. In compartments with no bilge, go straight down to the bottom.

Remember that Armaflex AF is the insulation against condensate buildup and the following mold and mildew, it does not completely replace a insulation against tropical sun or frost in high latitudes. Go for a second layer on the superstructure, cabin roof and around your accommodation.

Regards
Richard

 

Not really being a steel builder, but interested: Suppose, that something DID go wrong while building. Or whyever, there occured a damage and later allows water/moisture ingress. I see a potential for corrosion which will be covered and to my imagination not be accessible for inspection. Or is it? What would be a preventive solution?
Teachmeteachmeteachme please

 

A good 2" timber planking with a 1-1/2" ceiling on top of the 4" by 4" double sawn timber frames inside will do to have good insolation.

My two timber cents (just kidding)

Daniel

 

Bahama,

As mentioned by Apex, steel should last a life time on the interior if well done. By the time your hull has 8 microns of epoxy on both side of the hull you can pretty much say you have a steel core epoxy boat . I have also read and seen some steel boat disasters. All had a clear reason to be in bad shape.
I've seen some with polyurethane foam sprayed directly over shop primer, with the belief the foam protects the steel. I've seen boat interior painted with Por15, which doesn't have the flexibility of epoxy coatings. I've seen boats that had been painted over mil scale. I've seen a boat that was blasted and painted in misty weather...all those are the ones that give a bad name to steel boats.
Do your research thoroughly, know the materials your are going to use and there specs. Any manufacturer who doesn't provide complete specification sheets and tells me to go as per recommended by rep looses credibility in my eye. Many backyard builders will gather information from salesman and representative....yaks...some may be helpful, most know how to feed you what you want to hear and no more. This seems to happen a lot in the paint industry and does lead to some steel boat coating disasters.
About cost of building with steel. Yep steel is relatively cheap (and really fun to work with) but too many people get into building steel boats with the impression it is cheap and budget there hull material without serious consideration for the blasting and painting. Expect to spend just as much to coat your hull as you will in steel. Saying that, I can't compare it with FRP, as what I know is metals; only warning you and others thinking of a steel boat that you can't successfully build a metal boat with cheap in mind...that just leads to so many disasters. Steel is a convenient, strong and reliable material but should never be thought of as cheap. Now, I do get the impression that you don't have a cheaping out mind set.

I'm guessing that if you run big budget projects you know all about shopping which is quite different from cheaping out (So many BYO boat are so good at being cheap but so bad at shopping). It amazes me how much prices can vary from one distributor to an other. Some clearly don't want to deal with small operations without a good bonus, fair enough; others figure they try to take advantage of the new to the market client...and I hate that. Got to admit...I have played dum blond (doesn't take more than a couple minutes of it) with a salesmen to get a feel of their trustworthiness and amazingly a blond price can be very high.
It's actually your buying a cnc bench that brings me to the shopping point. For the cutting of same files I have had pricing from $12000 down to $3000. At one end I understand that you would consider the torch mate (even though still not sure of the worthiness of it, unless the acquiring a new toy factor is weighting in ) , but at the lower price, why bother? Big cutting shops will cut your pieces off rolls of steel at amazing steel efficiency, bigger the table better the parts nesting. Steel, paint and insulation prices vary in the same manner. For the same paint I've been quoted within a 300% price variance.

That can vary with the use you intend for your boat.
Armacell has all the info online, even though it's sometime a bit painful website to navigate.

cheers,
Murielle