Visit our Popular Forums

SaltyMonkey · 16-06-2010, 13:29

Damn this is getting really interesting!

Northeaster · 16-06-2010, 13:55

Bankaboat - not to stick my nose in, but yes, someone did suggest that and the other fella was correcting him. See 2nd to last paragraph of post 121.
Regardless, your explanations are a benefit to the forum.

#121 SaltyMonkey
Registered User

Join Date: May 2010
Location: SF Bay Area; Former Annapolis and MA Liveaboard
Boat: I'm Looking...don't torture me!
Posts: 264

Thanks Vic! Keep me posted on that boat.

I have a small bag of questions here:

* Can anyone challenge Yachts66 advice on painting/epoxy etc? GordMay started some. I don't quite believe everything Yachts66 is posting here quite franky.

* Question regarding stick welding under the use of building an "Origami" - can it be pushed with 110v rather than 220? My limited understand is that stick welding (110 or 220) is not as penetrable for larger thicknesses as MIG, but Brent confirms it's enough for building his boats (maybe not 110).

There's absolutely nothing wrong with Oysters. Speculation and second guessing is BS.

bangkaboat · 16-06-2010, 15:46

Northeaster, Thanks for the correction.

SaltyMonkey is, indeed, incorrect in understanding that GMAW can weld thicker material than SMAW, quite the opposite. While someone - Haidan, I think - mentioned duty cycle, I'll suggest that the talk of 110V versus 220V+ usually arises when talking about steel boat building. As (Haidan?) said, duty cycle is the important characteristic, ample juice being, of course, crucial. There are great little invertor welders around these days that can run on 110V quite effectively, however, they are not cheap. Therefore, most of the cheapo 110V welders sold at the typical chain hardware store run at 10% to 20%. For a decent SMAW welder, try to get a unit that gives you 60%+ duty cycle.

bangkaboat · 16-06-2010, 15:54

Quote:

Originally Posted by vic debeer

ASls, the main diference between stick and mig welding is, stick allows for better penetration and a stronger weld.
Happy sailing.

No, incorrect.

**Boracay** · 16-06-2010, 16:49

I brought a small stick CIG 130 amp inverter (Cigweld Weldskill 130 240V Inverter DC Welder ) to reattach a few bits that had fallen off Boracay. [Note to whoever:- Don't grind off welds to give a perfect finish. Too easy to take off too much.]

It's getting to be too expensive and to much trouble to bring in a professional welder for every small job. This welder plugs into a household power supply.

It's a nice little unit and worked well to do the little bit of downhand stainless welding needed. However I did notice that it seemed sensitive to the distance from the ground connection to the weld.

Easy to strike a weld and despite my total lack of practice the welds have taken all I have thrown at them.

However it would be tempting fate to build a boat with this welder. I'd recon that you'd need something that is going to keep welding no matter what. It's going to need a proper power supply and to be able to handle heavy currents continuously. Any experienced welder will know what I mean.

If building a large enough steel boat a diesel powered welder that could end up being buit in as a welder generator would be heaven.

sww914 · 16-06-2010, 21:07

So what are quality professional boat builders using to weld 30'-50' steel sailboat hulls?

**Boracay** · 16-06-2010, 22:55

When researching welders the name Miller keeps on popping up.
There's theThunderbolt® XL 225/150 AC/DC and 300/200 AC/DC

and there's the Gold Star® 652

or even the Bobcat™ 250 Diesel

The bigger the welder the better it should weld thick steel. That is the weld should penetrate better, be smoother and easier to do. Smaller welders will need to do multiple runs. If you don't know you'll need to consult a welding professional after you've got the scantlings for your project.

As a comparison you don't need a 10 tonne guillotine to cut tissue paper while scissors won't be much good on steel plate.

The best start would be to do a welding course.

boden36 · 17-06-2010, 01:19

To build a steel boat, all you really need is a welder that will run 10 gauge rods, and have a fairly stable arc. Duty cycle is not that important. In our whole 36 foot boat, I doubt if any weld is more than 3 inches long. By the time you chip back the weld, move to another area ( remembering that your welds are staggered over the hull to minimise distortion) your welder will have had time to cool a little, so you are unlikely to go over even a fairly short duty cycle.
Regards, Richard.

seafish · 17-06-2010, 03:11

My 2 cents..

I've spent the last year in Bayou shipyards working on my steel conversion. What I've learned from shrimpers and offshore oil boats was all counter intuitive to my fiberglass experience.
Stick only..no questions, no debate.
Foam is incredible. My fishold was all foam and abused...remove any foam and the steel is like new...we actually used the partitions for other projects.
Water..salt or fresh....is not the enemy...air is!
Never try save money on paint...never.
Warped plate is the nature of steel...live with it.
Zinc, zinc,zinc......

All of the above have to be done right but those are rules I've learned, sometimes the hard way, from men that shrimp in hurricanes and beat hell out of their boats on a daily basis.

If you are considering building come to the Gulf and check out the shipyards...cost is easily 50% less than the West/East coast....

SaltyMonkey · 17-06-2010, 07:20

I still like this little 2 voltage puppy.

Miller - Stick Welders - Maxstar® 150 S

Course starts in a few days

Vic de Beer · 17-06-2010, 09:45

I think a lot of stuff is now being repeated here.
Suffice to say: if you want a steel boat, my personal opinion is (and I will admit that I am biased):
1) it is the safest material to use (proven by the majority of ships are build this way as well as my own personal experience.) No steel boat owner that I know will ever want to own a boat build in any other material.
2) you have to be willing to live with a boat that does not quite look like one build by a fridge manufacturer... dents are just the nature of the material.
3) never skinp on paint, if you can exclude oxygen from getting in contacty with the steel surface, you will have no rust.
4) repair any scratches or dings ASAP, a hairline crack or scratch in the paint exposes the steel to oxygen.
5) if you have an encapsulated keel, make sure the top is sealed to exclude oxygen from the material on the inside of the keel.
6) before painting ensure that you have clean steel... blast cleaned prefered... you are relying on a mechanical bond between the steel and the paint (unless using an etch primer)....... so grinding (to be avoided) can cause shiny steel to which paint does not like to stick.
7) use a fluxgate compass mounted on the mast, well away from the hull.... the movement of the boat through the water can cause an electric field which will affect your compass.
8) don't be afraid to use zink anodes... they may not look nice, but they work!!!
9) always enjoy your trip, many people would like to do what you are doing...
Happy sailing.

ConradG · 17-06-2010, 11:21

Quote:

Originally Posted by SaltyMonkey

20,600 - gross cost for boat
24,720- add in 20% buffer

Anyone want to take a crack at labour cost per hour? Think it all can be done for under 50k?

Alot of boat can be purchased for this kind of money in this market. I am the first to say be cautious about used steel boats. I didn't find one that I was comfortable with but I did find my first choice (which I thought I never could afford), aluminum! Different set of problems but set up correctly, far less maintenance, stronger and a little more leway for weight carrying....and yes, for less than 50K. And it even has a new yanmar and things like a dickenson stove, autopilot, lights, lamps, sinks, heads, and other goodies that all add up. I do plan on making new sails and rerigging her and perhaps even changing her color (with aluminum paint above the waterline is optional but yellow is a bit much for me) but for the cost of materials and the engine I got a whole lot more.

The hours in building the boat I wanted are aproximately 800 hrs of welding (less with aluminum) and 14-1600 for the interior and fitting out. This is from the designers experience and over 700 of them have been built. Of course if you are building a "frameless" hull it can be far less time but the strength and weight issues will be there. Also, as mentioned before, interiors come in all styles and perhaps yours will be simpler and require less time. Just thought the figures would be helpful. These hours are for a 42 foot on deck boat.

As for welders, in steel about the thickest material you will be welding is 1/4 inch (aside from some that use masive keel floors) so most small machines will do fine. Although duty cycle as rated won't be that important because small welds help to keep distortion to a minimum as has been pointed out, a sturdy machine will last through the job. If stick welding becomes your choice (as most builders use because one lead is much more convenient to drag around the project and you move alot to keep ditortion to a minimun) the old lincoln "buz boxes" can be found used and cheap and are hard to kill. A DC welder is nice but un nescessary unless you are going wirefeed. If you choose wirefeed (mig) I asume you are doing so for the cleanlyness of the weld as laid and would be using CO2/argon, I would strongly recomend a spool gun. Carrying a five pound spoolgun around is easier than even the small 110 machines but you will feel it at the end of each day as compared to the stick. Someone mentioned a diesel powered welder that might be installed as your generator when you are done. Great idea but they are extremely heavy. I have a gas powered miller which weighs less. It is older but weighs almost 800 lbs. Unless you are building a big boat that will be a considerable load, more than your engine probably (if you install one). I have been reading about and talking to people about, alternator welders. They are made from 12V alternators with the regulators basically removed and put out a high frequency current (frequency machines are an expensive option on upper end dc welders to inprove weld quality-used with most serious aluminum welding). There are several companies who produce readymade machines with alternators rewound with heavier wire. Premier Power Welder high-frequency on board welders, high-amp alternators, charging systems, Ready Welder, trail, off-road is one. amperage is controled by rpm. Brent Swain is one who I spoke with about alternator welders and I believe he said he has directions on how to build one in his book...Others have said that they weld very well and are dependable. They charge your batteries too!. Any DC machine can be used for stick as well as wirefeed with the addition of a wire speed controler and gas solinoid and regulator. Also mentioned but not discussed much is battery welding. There are several spoolguns specifically made for it and attaching leads for arc welding is possible. By using 12, 18 , or 24 V by hooking up your batteries in series you control the amount of current and with arc length and speed you can weld different thicknesses acurately. DC battery power is good clean stuff and what the transformers in plug in machines are trying to get. 100% duty cycle but capacity is of course limmitted. Readywelder.com | There's nothing like it! or just hook up some leads for stick welding.

Les Bechdel · 17-06-2010, 11:32

I've got a 39 foot steel cutter that was professionally built in South Africa. It is heavier than a comparable FRP boat so it takes more air to get it going. In heavy weather, however, it has a very comfortable motion. Its construction is multi-radius chines which present a pretty fair hull and is considered stronger than hard chine construction. You are better grounded for lightening with a steel boat. Rust is an off and on problem, but I'll take that for the safety a steel boat offers if you run aground or into a another boat.