How powerful a stick welder will I need to allow me to make a make a steel boat trailer for a 5m sailing dinghy?

Select to expand quote

Shifu said..
How powerful a stick welder will I need to allow me to make a make a steel boat trailer for a 5m sailing dinghy?

What is the thickest steel section you plan to weld?

The generic ones shall suffice otherwise you are building a white elephant...

If your asking that question buy a mig welder mate . And one that uses a gas . Don't get a cheap ass gasless thing . 250 amp for a home is spot on. Tackle any thing then

Agree with 10more get a 200 to 250 amp mig on gas. You will have better quality welds with no porosity. Also use heavy duty black steel(better to weld) then get galv dipped. I built one using this method about 8 years ago and is still going strong.
Depends on the boat you are putting on it though mine is heavy fibreglass so I may have over engineered but I think it will see me out.
Alan

Hey mate just sent u a pm

Spot on snoopySA.
Over engineered only way to go ! Never a problem again. Nothing looks worse than your pride and joy passing you down the freeway ..

By the time u buy the steel at retail, running gear and get dipped you can buy a trailer. I have built many. Try the cheap trailer places first, even if you have to modify drawbar on a small one to make longer (dingys are light). Factor in U bolts, rollers, guards, lights, rego. Don't forget u as the builder are liable and are confirming it's structurally safe.
If u still build yourself don't dip it's too expensive. Paint over duragal. It's not as though u will need to sink.
Mig with gas is good but rent on bottle will annoy. You can do everything with an inverter stick albeit slower.

Cost me $1200 to dip mine. Money well spent I reckon duragal you will have to grind off where you weld. I also made one on an offshore island where corrosion was the worst I have ever seen. Just made it out of heavy steel and painted with fish oil that was 15 years ago and last I heard is still going strong. All the best whichever way you decide to go.
Alan

Plenty of perfectly serviceable things have been build with a normal arc welder.
Nothing can go wrong with them for a start. If you know what you are doing, could build a better trailer with Duragal and free 1980's arc welder than a first timer with a cheapMiG and no idea - yes?

For basic projects for a first time at home, a gasless MiG is probably an easier learning curve, then move to gas for better results.
But for a person who has welded before, doing all 3-5mm steel and they can think about stressors and where and how to build it, would a cheap arc welder really be so bad?

Never seen so much bad advice (not all) in a thread and it's only just started.

Select to expand quote

Crusoe said..
Never seen so much bad advice (not all) in a thread and it's only just started.

So, how about you give some advice and fix it up? Criticism by itself is no real help to anyone.

Have a look for a second hand CIG stick welder. Cheap, reliable and perfect for mild steel. One of mine was built in 1951 and still going. The only issue is that it's only got a 1 year warranty

My old CIG stick welder sh#t itself after 30 years service recently and I bought a $100 140 amp Ozito at Bunnies
turned out to be a fantastic little welder. Likes to have a rest (overload) after about half hour continuous tho

No matter what you get you're still limited by your single phase household power supply and only able to run 2.5mm (12g) rods
even with the bigger CIG I had it never had enough amps to use 3.2 mm (10g) rods with good penetration.
So just do a 3 run fillet with the 2.5 rods

Shifu,
For Stick (MMAW) you will likely run 2.4mm and/or 3.2 mm electrodes so will need a machine capable of 130amps. If you are buying a new machine, check the duty cycle at max amperage (weld time vs rest time) as some cheap knock off's have a very poor duty cycle and will not last if pushed too hard. Older machines are generally more robust but if this is a one off project, it may not matter too much.

MIG (GMAW) can be easier but it is easy to run into trouble with lack of fusion defects if you are welding heavier material (>5mm). A good looking MIG weld could fail immediately whereas a good looking MMAW weld will perform as required. If you are looking at lighter materials (3mm or less) then Gas shielded Mig should be fine (the equipment is more expensive though).

I have made trailers from Duragal and painted them and they are still strong after 15+ years. These trailers were not used in salt water though. MMAW will be somewhat easier with the Duragal material. But, if you want to guarantee long life, go the fabrication from black steel (or blue prime coated RHS/SHS) and then get the completed item hot dip galvanised.

Select to expand quote

ducati said..
My old CIG stick welder sh#t itself after 30 years service recently and I bought a $100 140 amp Ozito at Bunnies
turned out to be a fantastic little welder. Likes to have a rest (overload) after about half hour continuous tho

No matter what you get you're still limited by your single phase household power supply and only able to run 2.5mm (12g) rods
even with the bigger CIG I had it never had enough amps to use 3.2 mm (10g) rods with good penetration.
So just do a 3 run fillet with the 2.5 rods

This is more like it. Not many people have more than a 10 amp power outlet to run a welder. Maybe a box of Satin Craft 13 (2.5mm) rods and bobs ya uncle. You wouldn't need more than that to weld up a boat trailer. The guys not setting up a workshop. Think cheap.

Might have a problem registering a home made trailer though. They sort of like some sort of compliance plate to get the rego done.

Unlikely to need any more than a standard 3.25 mild steel electrode in the 120A region, with a 15amp supply socket.
(not too much more than 5 minutes and not struck too often at a time or you will blow the house inverter).
If you do have a chunky enough piece of steel for that it can be prepared edge and double-layer triple.

Select to expand quote

Crusoe said..

Might have a problem registering a home made trailer though. They sort of like some sort of compliance plate to get the rego done.

I don't know about Qld, but here in NSW a new home-made trailer is a piece of cake to register. As long as it looks like it meets the design requirements, you get a blue slip, a weighbridge ticket, and you are good to go.

If you have to ask 'what sort of welder?' then you are NOT up to the job....

The liability thing these days should be a no brainer.....Don't

I use an inverter welder for stick welding small stuff..., a Rainbow 150.., it'll do 4mm thick sections(larger with multi runs). It set me back $500..., you can get cheaper and more expensive. Inverter welders are very easy to get your hand and eye in(thats important for quality welds)..., there's no expensive hiring of gas bottles, and just one amperage control knob. Practice lots on scrap steel, try to get clean smooth welds(not looking like they've been spattered with 'cocky sh#t'), with no undercut or porosity(pinholes), it's easier to get good clean welds if all your welds are downhand, whatever it takes to give yourself a steady hand - like get yourself in a relaxed welding position(sitting or leaning against something), earth clamp as close to weld area as poss, get rust free steel(surface rust is ok) - a wire brush can assist as can a good grinder, get 3.25 or 4 mm rods(buy good quality rods), you'll need a 15 amp outlet....., keep your head out of the fumes ;-)....., how long have you got ? Go for it !

Is that you Chomsky!

Select to expand quote

quikdrawMcgraw said..
Is that you Chomsky!

Yes..., today it is !

Select to expand quote

Shifu said..
How powerful a stick welder will I need to allow me to make a make a steel boat trailer for a 5m sailing dinghy?

Try to find one powerfull enough to fix or cut off every nonsence on this lemon of a bout. That should be quite enough. :D

Select to expand quote

RussJ said..

Shifu said..
How powerful a stick welder will I need to allow me to make a make a steel boat trailer for a 5m sailing dinghy?

Try to find one powerfull enough to fix or cut off every nonsence on lemon of a bout. That should be quite enough. :D

What? Oh, I see Russj has an axe to grind. Deservedly so, Russ, but not here, K?

How much wood would a Woodchuck chuck, if a Woodchuck could chuck wood??

As much wood as a Woodchuck would chuck if a Woodchuck could chuck wood.

Try saying that quickly!!

Select to expand quote

cisco said..
How much wood would a Woodchuck chuck, if a Woodchuck could chuck wood??

As much wood as a Woodchuck would chuck if a Woodchuck could chuck wood.

Try saying that quickly!!

That that that that that that: not so hard.