Stick vs Wire for Welding Hull Plates?

Small "inverter" stick welders are a pretty popular item in the contractors box where I work, though the duty cycle may not be high still lay in some nice beads on small repairs & means they dont have to hump heavy machines around.
Jeff.

 

Would you tackle building a complete boat with it?

 

The first of these style of welding machines I saw was the Esab caddy a couple of decades ago & more than capable, I would use one if I had to build outside & work out of a car boot in a paddock as I did when building my first 34' yacht a few decades ago, the inverter Esab would have been an improvement on the 240v buzz box I had use of back then. Now I would roll my mig with interconnect wire feed beside the vessel in a factory just because that is the facility available to me.
I see the benifits of light weight and portability in the inverter machines, I supervise contractors & wage staff at a site around 350 meters long with no vehicle access during most of the day, these guys can have nearly all their gear on a small hand truck that they can get close to the work, the most awkward thing is if they need oxy gear which is still bulky- they will use zip discs whenever safely possible.
There's plenty of brand alternatives in the market other than Esab now, I'm sure some are very good machines and capable, currently my wage boilermaker is replacing around 20 bollards to a pontoon system & moving along nicely with a small inverter welder of about 300mmx 200mmx150mm in size.
So they are probably not the go for a large fabricator with the need for high deposition rate in an industrial setting but quite capable of small vessel work.
At one stage I had a very large Aston transformer machine, whilst an excellent machine it weighed in the 100s of kgs & oil filled, lucky I sold it to a guy in earthmoving.
Jeff.

 

Yes, I would. Most of these little inverter welding machines have 60% cycle duty at full power. Since most of them are in the 200 amp range, the amps mostly used in DIY steel boatbuilding would put it in the 100% cycle duty range and will happily perform 24/7 non stop.
An easy way to determine the ideal amps for a given arc welding rod (old boilermaker's trick) is to multiply the rod thickness by 40, for example, 3.15mm (10#) x 40 = 126 amps which can be accurately set on inverter machines. Some final adjustments can be made for instance, vertical or horizontal runs.
IOW, with a 3.15mm (10#) welding rod, most inverters in 200A range will be 100% cycle duty and weld will be the same as any other welding machine - it's the welding amps that matters and cycle duty to weld continuously.
BTW, most DIY builders will probably weld with 2.5mm (12#) rod or smaller which would even put the little lunchbox sized 140A inverters in 100% cycle duty range for these sized rods.
Having said all this, more important is the OCV (open circuit voltage) of an arc welder. Anything less than 70% will make it suffer to perform well with "difficult" electrodes such as LH (low hydrogen series like E7018 AWS for instance) as is the case with most small air and oil cooled arc welders of the past. However, most inverter welders have an OVC of 70% and better.