The good, the bad and the ugly - Steel building methods that is....

[Think about this: A very well known designer in steel once told me the hull plating is only necessary to keep the water out of the boat - perhaps this just nicely sums it up Very nice words!!]

My experience of steel boatbuilding is limited to a couple of MG designs and a B Roberts, all were framed and plated and withstood hell and high water. JT at Penryn, Cornwall built loads of 30' - 45' boats over a decade or so, multi chine and rolled round bilge, all framed. The list of professional builders could be endless, almost all understand that the best way to be sure your trousers don't fall down is the 'belt and braces' philosophy.

Which having said, a well calculated multichine can have sufficient structural strength within the chines and curvature of the hull to obviate stringers and almost all framing.

Origami steelwork seems to rely entirely upon the structural strength of the steel plate, personally I would have considerable doubts about going to sea in a boat which hadn't had some element of design calculation involved in it's creation.

 

Brent, ............................................



where ever you pop up, a good tread dies....

PS: Milan mentioned Gerd Muller of Yago - nice origami, numbers by Dave Gerr's book and that makes it good - he has a decent website, GIVE AWAY FULL PLANS for free to people - not selling some few drawn lines we are yet to see like you and charge money for that - and never had he came to a steel tread and promoted his work.

NOTE; I removed most (self moderated) of the post and in hindsight, was not the real me posted here but an angry person...

 

Origami Posts have been moved to http://www.boatdesign.net/forums/metal-boat-building/origami-steel-yacht-construction-248.html - that thread has 52 pages of discussion mostly focused on Brent Swain designs so it makes sense to keep that discussion centralized there.

 

Thanks Jeff - you are a great guy.

I apologize for my strong wording in previous post as it was against the spirit of the thread.

 

Was Wynand not clear enough when he told you, that you and your anecdotes are NOT WELCOME here?

Drivel on your threads BS ! We are fed with that cr@p since years!

 

Or the way I did it - build the full keel first, then erect the frames on it, then run in the longitudinal stringers. I'm about to start plating out and according to Tom there's only 1 tricky area and that's in the bow to frame 3 where there's compound curvature. You strip plate it. After that, all flat plates.

I don't think I'm going to have any problems since the longs all flow nicely around the frames.

PDW

 

I've never built a boat before the one I'm building now. I'm not having any real problems with it and it's a frame-first single chine design.

Yes, some gusseting falling onto transverse frames which don't exist in the design. Not gussets onto the hull plate. IMO.

Last first, nobody here owes you an explanation of anything. You get what you get and if it isn't to your satisfaction, you can always pay a consultant. Nobody can suggest fixes to a design when the owner of that design won't provide the data. You can buy the plans, consult someone, pay their fee and then publish the results of the analysis if you choose and the NA/engineer agrees.

I don't necessarily agree that the boat can't be done for $50K but it won't be easy, and the hull isn't going to be the big cost driver as many have pointed out. You may save time doing the frameless flat plate pull-together thing but you won't save any money on materials. After the hull is done you'll save nothing on one hull structure that you couldn't have saved on another.

My budget is around the $50K mark BUT I have a lot of tooling, a very well equipped shop, undercover building that I own outright and the ability to make almost anything I don't want to buy. My Yanmar engine is going to cost me around $2K by the time I'm finished but do you have the ability to strip down and check out a diesel engine, then know what to farm out and what you can do yourself? Can you find & fit a marine g/box to an industrial or automotive diesel engine, or can you build a shaft thrust assembly to keep prop thrust off of some g/box not designed to take end thrust? Do you know why this is essential? Can you build your own masts & sails? What is the dollar value of your time?

I picked the frame first method because after literally years of research and looking at boats I decided that this was the best method for ME, for a one-off build. The VDS 34 that Wynand has posted pix of didn't do anything for me visually and I don't think I can afford the rig that the hull needs. I also wanted a shoal draft hull with a long keel. So it goes, wants intersect with money and available designs. Eventually something falls out (or you give up in disgust).

If you have the welding skills to build a BS hull you have the skills to build any of the others except probably round bilge which I wouldn't tackle myself. If you don't, buy a boat or be prepared for a lot of on the job welding.

There, IMO, isn't a single weld in my Colvin design that's as awkward & difficult to do as that overhead centreline weld between bilge keels in the BS hull.

PDW

 

Very good post pdwiley which sums it up nicely.

All I can add is to get a set of plans that is builder friendly.

Something not mentioned in this post and quite important is to build upright or upside down.

I personally build most of my boats upside down - easy to lay down plates safely, most welds down in down hand position, and easy to maneuver a grinder around.
For these very reasons I would recommend this method to new builders IF you have the means (gantry, building frames etc) to turn the hull back upright again.
However, both methods have their ups and downs and in the end it is a personal issue.

 

I'm building upright because that's what the designer advised. It's working fine for me. Had the designer said to build inverted, that's what I would have done. I suspect the choice is dependent on hull form as much as anything else. A long keel shoal-draft vessel is easy to build right side up as there's a place for nearly all the frames on the keel. Something with a narrow deep fin keel is probably better built inverted on a grid and then placed onto its keel as late as possible.

Before I started building the boat I built a steel grid base for eventual transport of the hull and to put the keel on, and a big gantry.

The grid base is a bit of a waste of steel for a one-off build but it was easier than putting timber beams under the hull when complete. Besides, I had the steel at the right price, I was used to having built transport cradles for 9m long 6 tonne work boats carried aboard ships, so why not?

The gantry makes life really simple. It's 4m high and has a 4m span between the legs with a 800mm projection past one of the legs so there's a short jib. I have a chain block on the jib and another on a carriage that rolls along the top 200UB25 beam. When welding up the keel I had it erected on the grid at the proper angle, welded all the floors to the keel shoe, welded the deadwood plates to the shoe & floors inside the spaces, then used the gantry to invert the keel. Presto, no lying on my back doing overhead fillet welds, I could stand comfortably next to the keel to weld. This also allowed me to use E7024 iron powder rods to fill out the fillet after I put the root run in with E4111 rods. Once the outside fillets were done & rounded off, I turned the keel over again and realigned it to a taut wire so I had re-established the exact centre line. Erecting the frames was now quite simple as I had marked my centre line and my DWL on every frame and could check them with external references.

All of this working completely by myself. The total weight of the keel assembly is in the order of 700 kg as quite a bit of it is also ballast. I probably gained more time back on welding up the keel than it took me to make the gantry. Now I have the gantry to lift up the hull plates and hold them in position.

Another point: I bought a certified plate clamp that is designed to lift plate vertically. I do not use some jury-rigged abortion of a clamp setup. A 3000 x 1800 x 4mm sheet of steel weighs some 200kg and makes a lovely guillotine. A $200 plate clamp is a lot cheaper than a hospital bill for repair of a foot - or worse.

I had a lot of tooling before I started this build and I'll have even more before I'm finished. However I can see the end of the steel work in sight now.

PDW

 

I built upright, but this is maybe just a decision based on the design, your building space and workshop processes. As I built all long keelers it was easier to build and erect the keel box and frames in place, then tack weld all the hull plating in place from the inside, mostly downhand welding, the tack welding reduces the possibility of distortion. When all was done and I felt satisfied, the whole lot got migged.

 

There is no way that I can see an amatuer builder being able to beat a NC cut out boat that is frame first where the weld schedule is adhered to. Seem pretty simple to have a boat pretty much laid out as a kit. I would think there would be a savings in labor in the long run as things can be done in order and worked on for short periods of time as things are build by the numbers so to speak. Any pre-stressing by bending steel seem like asking for distortion in the long run.

I also seems to me that an all steel deck and house would be excessively heavy as well.

Another thought of mine is that scrounging and putting in used equipment takes more time than buying new and when you are done you have essentially a used boat of various years. The result is crystal clear, you don't have a new boat when you are done. This seems to me to preclude a really cheap budget unless you don't care.

Finally I think a person with a limited budget can buy a used boat and get going much cheaper and safer than any new build will do for them. If you are going to install used why not buy a used boat to begin with. A Walmart job will pay better than any scrounged built boat in the long run. Work as many hours at Walmart as you would spend building the boat and have a much better boat worth more in the end.

The reasons to build new to me seem to be just a few.
You cannot find what you want in a new production or used boat and you have the money to commission a new build
OR
You have the money and the time and really need the project for something to do or you will go stark raving mad. You will likely sell the boat in a year after completion, take a bath on your labor and start the process again.

 

Pierre R, I couldn't agree more. When "Waterdrop" suggested a budget of less than $50,000 and that he/she was an "amateur builder" - I assume he/she meant first time builder - I thought, why do it? Why not go buy yourself a sound boat for $20K, spend another $10K-$15k on equipment & upgrades & use the rest for cruising? No build time, no associated skills to learn, no muss- no fuss. Another option might be to refit an older metal boat. If one is going to build a boat with used equipment - seems silly, but some do - that person could find an old plastic boat with decent gear & strip it, thereby, getting an aluminum mast, etc., rather than having steel for a mast. When you add up the cost of cleats, winches, etc., you can get a lot for an investment of 5 to 10 grand, including, often, a rebuildable marine engine w/ shaft, prop, etc.

Boat building, imho, is for people who make a living at it & people who are interested in, and have an understanding of, boat building. Not for those who want to go sailing.

Wynand mentions above the consideration of building "right side up" or inverted. I've been giving a lot of thought to building inverted, as I haven't done/been involved in this method of building. The more thought I've given it, the more I like the idea.

Of course, as PDW says, it depends on hull type/method. As for proper plate clamps, When I was just starting out, I was working alongside an older steelworker, unloading plate that was lowered by a crane. a clamp let go & my co-worker pushed me out of the way, but couldn't move fast enough himself. The plate took all of his toes on one foot.

For any young guys/women who are reading this & have just started out as welders/fitters/ fabricators/etc., that is why we are so gruff & give young people and fools hell for small screw-ups or poor workmanship, we've seen preventable accidents occur too many times. My old man, like many of his generation, had to get hearing aids, as a result of no earplugs when he was a young boilermaker. Just because you're building a boat in some field doesn't mean that protective equipment isn't important. It's there for a reason & if you're too cheap to buy/use it you're an idiot & will pay for your mistake one day!
Mike

 

would being able to turn the hull 90 deg from up rite in either direction come close too inverted as far as welding and placing plate?

 

Do you mean after x amount of welding, to access inside welds on the flat? Yes, but it would mean having to be elevated to access outside of skin. I don't think it would be worth doing. I think that there is a photo on Dudley Dix's site of a boat with rings welded around the boat. it looks like a lot of work to me & you would still have to be elevated. Personally, I have become interested in the inverted position because a boat could be built this way without a lot of staging.

 

How did you know? I need at least 3 complex projects running simultaneously or I get bored.

Actually I looked at a lot of boats and in the end they fell into one of 3 categories.

Those I didn't want at virtually any price.

Those that were well built but I could do it myself better for the money, or cheaper and know where the bodies were buried.

Those I couldn't afford.

Over the years there were maybe 4 boats that in hindsight would have suited me had I bought them and I made serious attempts to buy 3 of those.

PDW

PDW