Welder on board, power supply advice

[AKA-None]

You can get flux core wire feed welders that run off 120 volts no gas required. Buy small spools and deal with a descant.

[Reefmagnet]

For small jobs don't discount using oxygen and acetylene welding. It is very versatile and can be used for cutting and descaling, too. Probably not the best for stainless steel welding, though.

[AKA-None]

Originally Posted by Reefmagnet

For small jobs don't discount using oxygen and acetylene welding. It is very versatile and can be used for cutting and descaling, too. Probably not the best for stainless steel welding, though.

Too much carbon in gas welding for stainless.

[Reefmagnet]

Originally Posted by a64pilot

Isn’t tech remarkable.
Yes it is, but Physics is an unforgiving Mistress.

Years ago, many actually I was a contract welder in the oil patch in Oklahoma, I had an old one ton Chevy with a Lincoln pipeline welder as old as I was on its back. 200 amp machine if I remember. It took the one Ton truck to haul the copper wound generator nicely, a 3/4 Ton would have been overloaded with all the other tools, gas bottles etc.
I was working in a yard in Oklahoma City building drilling rigs, had another welder show up one day with a little Toyota truck with a 300 amp machine in it. It was a Japanese machine, but tiny, yet made more power than my Lincoln, wasn’t nearly as smooth an arc, I think it was a big alternator with diodes, but never mind, it was little, powerful and sipped Diesel where my big ole Lincoln was heavy and it’s flat head Continental engine was fond of gasoline. It looked like I was the fool hauling all that excess weight around.
Well one day we were jetting out a mud tank, that is running huge “jet” rod, 7024 I think. Anyway to run that big rod I would turn my Lincoln wide open and let her go. After running rod for I guess an hour or so, the other guys welder just quit, wouldn’t strike an arc, so we climbed out of the tank to see what had happened to his new machine.
The bed of his truck honest to God had molten aluminum in it, seems his welder had melted its windings.
Well of course he took it back to where he bought it, and was explained what duty cycle meant, seems his little powerful welder could actually deliver 300 amps, for 20% of the time, then it had to rest for 80% of the time. He did not get his money back.
Big ole ancient Lincoln Pipeliners I have seen connected to long sections of frozen pipe and run wide open to thaw pipe, they can be run that way until they run out of fuel.

Reminds me of these little 200 amp small frame alternators. I wonder what their duty cycle is?

I started my career as an engineer working for Lincoln Electric. Was there for 16 years before moving on to other things. Lincoln always rated their industrial welders at the 100% duty cycle output. For example, a common field welding machine was a 400AS. This machine was actually a 500 amp maximum output machine at, iirc, 60% duty cycle. It was 100% duty cycle at 400 amps. Another unit was called a DC600 for the same reason but actually had a maximum output of 850 amps. Some other manufacturers used this rating method as well, but not all. This is why you pal's machine was smaller, lighter and eventually self destructed. It might have been advertised at 300 amps, but as you pal discovered, this was maximum output rather than 100% duty cycle output.

And you're bang on about alternator-rectifier machines. Cheaper to make and lighter than the compound generator, but welding qualities were sub-par in comparison. Typically this style of construction was used for welder/AC generator combos.

A couple of interesting notes regarding duty cycle. Firstly the period of a cycle is either 5 minutes or ten minutes, depending on the code it's rated to. Assuming a five minute duty cycle, this means that if you are using an output setting that is in the machines 20% range, you can weld for one minute continuously before needing to wait four minutes before recommencing. Secondly, most small single phase home type welders have lousy duty cycles of 20 or even 10 percent. This is not because the machine cannot handle operating at higher duty cycles, it is because the machine has been down rated so that it can run on a domestic primary power supply outlet without exceeding the rating of the primary outlet. A modern inverter will protect itself from over heating, so you can basically weld continuously until you either trip the primary breaker or the thermostatic protection on the machine.

Finally, everyone can arc weld on a boat even without a welder. Hook two batteries in series to produce 24 vdc, connect some welding leads and, using a proper arc welding electrode, or even a piece of fencing wire, and weld away! Sure, the weld will be crap, your battery's won't be happy about it but it might just get you out of a pickle.

[Reefmagnet]

Originally Posted by AKA-None

Too much carbon in gas welding for stainless.

There isn't too much carbon if using a neutral flame. The prolonged heat soaking at elevated temperatures causes carbide precipitation issues, especially in non "ELC" grades of stainless steel. This can happen using any process, but gas and tig are probably the most susceptible.

[S/V Alchemy]

Originally Posted by roland stockham

I have a wooden boat so not looking for anything heavy duty. I wanted something that would do occasional odd jobs like making/repairing brackets. I got it now as I am about to fit a new engine and may need to modify the engine beds.
For a super compact cheap welder it more or less has to be a stick machine. Cheap wire feed machines can be unreliable and anyway if the wire gets damp and rusts it jams up. Unless you want to keep the wire in a waterproof box with dry packs in it the machine is just not going to run.
The other issue is that MIG machines need shielding gas which adds to bulk and complexity and blows away outdoors. Stick uses flux coated rods so works outdoors as long as it is reasonable.
The other use is SS work. Even tally I want to replace the pulpit and add some SS frames to the cockpit. It is super expensive and difficult to get those sort of things done unless you have a big boat yard handy so I am going to set up for TIG. It's a bit like brazing, the ark replaces the gas torch to provide heat and you use a metal stick to add weld metal. Does need Argon gas to shield it so not an outdoor job. Not tried it yet. It is supposed to be the hardest to do but makes the neatest job. It is how the pro's do all your SS bits. Any stick welder can also do TIG, you just need a TIG torch and gas supply.
The machine I have is a cheap Chinese job called a Hitbox ARC200. Looks OK, haven't plugged it in yet so will update after testing it. It cost less than $200, weighs about 10lbs and measures about 9x4x6 inch!!!! My old traditional TIG machine was a 3ft cube that took 2 people to lift and came on wheels, this one has the same output, ins't tech remarkable...

You will also need a helmet etc which will probably coast about the same as the welder.

If you are really good you can stick weld ally, very tricky but if you are sticking bits of mast back together at sea who cares what it looks like!
PS I sail in remote places where the nearest yard is often a week away so need to be super independant and I am a DIY nerd

^^^All this strikes me as good information. It really depends on how complex you want to get before you even get to the questions of power. I can run a Miller stick feed unit from 15A 120 VAC and you can get a lot done with that. But portable and quality isn't cheap. This is a basic wire-feed unit for about $700, for instance, and more comprehensive, flexible welders can be a lot more. This is a nice, really portable unit a welder brought to my steel boat, but again, not cheap. Still, I can see brackets and tabs and pipe welds in my future, and I have enough bank and inverter to work on deck, if not for a long time. This takes a fair bit of research, but it's certainly doable. Even at Christmas.

[Pauls]

I have been welding with a Zena welder for over 10 years now. DC output. Mine is 150A, they go up to 250. Excellent weld quality. I run a variety of rods and do a fair amount of stainless. Stick stainless welding is quite viable. The Zena is a large frame heavy duty alternator with a large external cooling fan. It is rated for 100% duty cycle. I think it is an ideal set up on a boat because it is also a very good high output alternator. I have it mounted on my engine as my alternator. By switching connections from the regular charging regulator to the Zena welding regulator and hooking up the welding leads I've got a very good welder.

I used the Zena to build most of my boat, a 42' steel cutter. Many hundreds of feet of weld. They work great. Made in the USA.

https://www.zena.net/

[Fence Man]

Great thread! I have a Miller 211 for boat projects where portability is of primary concern. It'll run on 110 or 220, and with a spool gun, you can weld stainless and aluminum. The new models are inverter welders, so I'm betting more efficient than mine. Is it overpowered and good for big jobs? No, but it'll work, and it's cheap and light. We have a stack of welders in the stable.....One Lincoln Precision TIG 275, and the rest are blue. I put about 15 hours a week on my Miller Bobcat 250, and have had plenty of other fence builders tell me that it's overkill when you only need 50 amps. They all replace their little Hobart el cheapos twice a year, and ol' blue just keeps on plugging away. Like A64's story, sometimes big and heavy is the way to go, and paying attention to duty cycle is important.

[Fence Man]

Originally Posted by S/V Alchemy

^^^All this strikes me as good information. It really depends on how complex you want to get before you even get to the questions of power. I can run a Miller stick feed unit from 15A 120 VAC and you can get a lot done with that. But portable and quality isn't cheap. This is a basic wire-feed unit for about $700, for instance, and more comprehensive, flexible welders can be a lot more. This is a nice, really portable unit a welder brought to my steel boat, but again, not cheap. Still, I can see brackets and tabs and pipe welds in my future, and I have enough bank and inverter to work on deck, if not for a long time. This takes a fair bit of research, but it's certainly doable. Even at Christmas.

That's a great picture!

[a64pilot]

Originally Posted by Fence Man

That's a great picture!

Yes it is, and reminded me that the coldest job I ever had was welding.
Which sound crazy as your melting steel right, but sitting on bare steel in sub freezing weather and not moving much will make you very cold.
Good thing I was a kid

[Kita]

They make Flux coated wire for mig welders,they do not need gas & it protects the wire somewhat from rust but needs to be dry..wind doesn't bother them... look at guys that do metal fence work outside... also look at spool guns,uses smaller rolls of wire & has longer leads so you don't need to haul machine as much... now when you guys start talking about TIG welding, TIG is an art all by itself. that's not something you're going to pick up in an afternoon. Takes a lot of practice. also when you start talking about TIG machines that can do aluminum they start using a whole lot more power. That has to be done on AC. And you will need Argon bottle. If doing Steel you're going to wind up having another bottle argon CO2 mix. As a welder I have considered having an on-board welder and about the only thing that you can use on board is one of those small backpack TIG machines that are only good for DC welding steel or stainless steel. That can be powered by a good generator but you would need to look at the specs to make sure the generator is big enough

[Dave_S]

I had one of these on my car when I travelled a lot in remote areas. It wasn't this one exactly but similar. May not be suitable for the electronics in a boat?

It was a stick welder and did a reasnobly good job. I'm not sure how it worked but after a run you would lift the rod from the job as you normally would and it would continue to arc over a wide gap-upto about an inch.

I used 3.2mm rods no problems. It won me a few good jobs doing small repairs in weird and wonderful places for National Parks and Telecom some were a days traveling and camp overnight for 1/2hrs work.

[Lepke]

I use a Hobart 190 wire welder with a spool gun. I can run it on the inverters, a pair of Magnum MS-PAE, 4400 watts each. I weld mild steel, aluminum and stainless. I always use a shielding gas, even for mild steel using cored wire. It gives a much better weld. Maximum AC draw by the book requires 5.5kw. Anything more than small quick welds, I use a generator. Any big projects are usually done in the winter on shore power. Gas welding/cutting is also carried. I use to be certified.

Since I have a wood boat, most of the welding I do is fixing things for other mariners (fishermen usually) with some casualty or on dock repairs at home.

[john61ct]

Originally Posted by Pauls

I have been welding with a Zena welder for over 10 years now. DC output. Mine is 150A, they go up to 250. Excellent weld quality. I run a variety of rods and do a fair amount of stainless. Stick stainless welding is quite viable. The Zena is a large frame heavy duty alternator with a large external cooling fan. It is rated for 100% duty cycle. I think it is an ideal set up on a boat because it is also a very good high output alternator. I have it mounted on my engine as my alternator. By switching connections from the regular charging regulator to the Zena welding regulator and hooking up the welding leads I've got a very good welder.

I used the Zena to build most of my boat, a 42' steel cutter. Many hundreds of feet of weld. They work great. Made in the USA.

https://www.zena.net/

Zena has adapters for MIG and yes even TIG welding, but DC only.

With their special filler rods they reckon structural aluminum work no problem. Yes AC will be prettier, but only required for thin stuff.

And it runs direct off your propulsion engine, can replace your existing alt, with an LFP bank only need to charge your bank a few hours a week.

[john61ct]

The Zena kits are much more functional than DIY, e.g controlling engine rpm as well as precise power output right at the rod holder.

Really not expensive in boat terms.

And the owner is very helpful with customizing a setup.