question about building a trailer?

[joshua27818]

I have a weld PAC-100 (Lincoln electric I know wrong website but there is a wealth of knowledge here) the specs. on the welder says it will weld at 30-88amps in DC mode. Also with it being converted to being a MIG and not a flux cored like it was when the machine was made, it will weld 1/4 materal with 0.35 wire with no problems. My question is will the amps that this machine puts out be enough to penatrate the metal and form a good bond or would it be bette for me to wait and invest into a good arc-welder with much more higher amps?

[mingy]

I welded up a trailer with my mig machine (basically same as yours) using MIG (gas) and had no problems at all. I had a heck of a time trying to get direct answers to question like yours, or 'what thickness of tubing should I use' and pretty much any other question anybody could get sued over.

I guess it depends on how big a trailer you are making, but I think the only piece I used that was close to 1/4" was the parts the spring shakels attached to.

[Broccoli1]

Also with it being converted to being a MIG and not a flux cored like it was when the machine was made, it will weld 1/4 materal with 0.35 wire with no problems.

That machine can not weld 1/4" with Solid Wire and gas

[Badd00SS]

That machine can not weld 1/4" with Solid Wire and gas

Nope, it wont. My Lincoln sp-135 plus wouldnt when I had it, and it's got more power.

It's actually bad, because it can almost look like a good weld, until you put some pressure on it, no penetration.

[joshua27818]

well i guess that answers my questuion because i read the manual on it trying to figure out what the maximum it will weld and it said that it could do 1/4 with co2/argon or just stright co2 but i still thought that I should ask someone also I guess lincoln will need to umm how should i put it tell it like it is and stop saying there machine will do something and it won't. I guess I will have to wait and get me that arc-welder (calls to the wife i "need to go to the tool store" and quickly hears "no your not") to do the job my dad has one but the power switch is messed up at this time

[DSW]

joshua27818 You will definitely need a machine with more power to safely build a trailer. As said you might get what looks like a good weld but the machine doesn't have the umph to give you any penetration on 1/4".

I welded up a trailer with my mig machine (basically same as yours) using MIG (gas) and had no problems at all. I had a heck of a time trying to get direct answers to question like yours, or 'what thickness of tubing should I use' and pretty much any other question anybody could get sued over.

I guess it depends on how big a trailer you are making, but I think the only piece I used that was close to 1/4" was the parts the spring shakels attached to.

Mingy your statement is part of the reason why many shy away from answers to questions like yours, no offence. Lets look at your response.

I welded up a trailer with my mig machine (basically same as yours) using MIG (gas) and had no problems at all.

How thick of steel did you use? 1/8" wall tube or 6" channel? What setting did you use? I hope maxed out in power and with the wire speed quite high. How much will your trailer hold at max load? The OP probably doesn't have the knowledge to ask the right questions to dig out any useful info from your statement. You may be correct or not, but he can't decide based on your info given.


Mingy often questions like 'what thickness of tubing should I use' and " I want to build a trailer...." are phrased just that way. There's a lot of missing info that's sort of important. The lack of info shows a serious lack of knowledge. A tiny trailer for just a grill could be built with a 110v mig IF DONE RIGHT. ( that's to keep from getting jumped on by everyone else) A 7K flat bed requires diferent steel and a heavier welder. Going to build a gooseneck to haul 2 off road rigs and that requires heavier steel and a much better welder.

You enter a different game when you say trailer. I have seen trailers where the tongue has come off due to poor penetration with a 110v mig. Luckily it didn't hurt anyone. Safety chains don't help if the trailer isn't attached to the tongue any more. It's not about liability it's about public safety and common sense. The average person has no idea how much weight they are loading in a trailer. As long as the springs still bounce it's ok by them. I have seen loads almost 2x the max load on commercially built trailers. That's insane, but it happens regularly. Home built trailers often lack the extra safety margins built into commercial trailers. That plus questionable welds made with underpowered machines is asking for trouble.

As posted in response to most questions on "how big a piece of steel do I need?" that's what engineers do for a living. Its not as simple as use a 2x4 to build a wall. There are no simple formulas to do this sort of calculation. Move the axle 1ft forward or back changes how the load is transferred and may significantly change the size of the steel. Round tube, angle, square tube rect box, C channel, I beam all have different formulas for calculating strength in each direction.


Sorry if it seems like I went off on a rant. Trailers always look simple to build and yet have more potential to hurt someone than almost any other project. Many guys won't think twice about building a trailer but would never think about welding the steel beams on a building. It amounts to almost the same thing.

[tenfingers]

Just because you have a good LOOKING weld dosen't mean you have penetration and strength. What I suggest is to use your welder to learn to weld, learn to control your puddle. Learn about joint gap, beveling and multipass welds.

Learn, Learn, Learn. and Practice, Practice, Practice.

You can learn a lot from destructive testing, much better on cupons in a vise than a completed trailer frame on the road.

Then use the knowledge you have gained to build a safe trailer that you can pull down the road with pride.


Even with preheat I don't believe that your welder has the power to penetrate well enough in the sizes you need to weld for a strong, safe trailer.

So use your welder for it's intended use. To learn, and lighter weight projects.

Then borrow or rent a welder that has the power to properly weld your trailer.

Precut, prepare, and tack the trailer assemblies beforehand. It shouldnt be hard to weld the frame up in a day with a rented welder with enough power to the job right.

If you want to do many projects that are beyond what you have learned that your welder will do, look into upgrading. If it's a one time project I believe you are further ahead renting.

Actually, unless you get a screaming deal on materials, or want something special, it's usually cheaper to buy than build. Plus there is the liability question if it comes apart and someone gets hurt.

[Broccoli1]

well i guess that answers my questuion because i read the manual on it trying to figure out what the maximum it will weld and it said that it could do 1/4 with co2/argon or just stright co2 but i still thought that I should ask someone also I guess lincoln will need to umm how should i put it tell it like it is and stop saying there machine will do something and it won't.

I think ya read the Manual wrong

Here is the Door Chart for that machine

[joshua27818]

ok thats what I wanted to know right there if my welder had "arse" to pull the job off I have made my bumper on my 94 explore into a recever hitch "look at the pic's" and I used a arc welder and I made it two years ago and it so far has pulled loads to the junk yard that weighed close to 4,000pulled my brothers pick up truck (mid-sized) backwards just to see who's was toughter. I know I can weld I spent to long in welding classes not to know how to and getting graded on them I am not mad at any of you all by any means its just I read and was told when I bought it I could do this with it and now I find out I can't witch i was wondering if I could then when I bought the thing but anyways thank you and please continue replying. I was always told you can never stop learning when you do stop then it is time for you to leave this world so thank you all.

[joshua27818]

I think ya read the Manual wrong

Here is the Door Chart for that machine

thank you broccoli I did read it wrong I thought that I read that MIG is the setting that would do it and flux cored would not but i got them mixed up but still the machine will not produce a strong enough weld even with multiple passes to fabricate a 4X8 utility trailer