Reflooring dump bed

[ryanjones2150]

Looks like I’m about to have two of these jobs. Problem I see with mine is they’ve been overlaid once already and it would appear to be a not-so-careful job. I’ll see. They trucking outfit might want their own guys to do it. They generally don’t like taking their mechanics off their normal stuff to do welding repairs. All of their trucks, except these two, are aluminum dump boxes. I’m very glad this thread surfaced when it did.

Their only machine is a MM252 which has been a pleasure to use that spool gun on aluminum with. I guess I could just set it in the back of the truck with the forklift and roll it around. Probably be better than running steel wire through the spool gun.

[BukitCase]

I got my mm252 VERY slightly used (about 4-5 lbs of wire total) and a NEVER used 30A - I've yet to run aluminum with the 30A, but DID run maybe 20-25 lbs of 70s6 .035" thru it welding my container roof (24'x24', framed with 2x2x .120 tube); seems like you just get started and it's time to put another 2# spool on. Pretty sure if I had to full weld a bigger job like yours, I'd find a way to get the machine close enough for a 15' gun... Steve

[MMW]

Definitely don't use the spool gun with steel to do a full body. Leave the bottle on the ground with a hose to the MM252 to make it a little easier to move around and either hang the welder or set it in the body and move as needed. That machine will run fine with .045 inner or dual shield. If you run inner shield you won't even need a bottle and no worries about the wind if you are outside.

Just explain the price difference of cutting out the old layer vs. going over the top. I'm sure the customer will not want to spring for that. If there are any really high spots you can just cut them out and leave it as you are going over the top anyway.

[ryanjones2150]

Roger that. This guy seems to actually care about how his trucks look. There have been a few times he’s had me make repairs simply because the dented spot didn’t look good. They’re dump trucks. Loader operators sometimes ding the top boards up for you, it’s their job.

I may consider the inner shield. He probably won’t want to buy that wire though since he has a big spool of 70-s6 in it now that’s been hardly touched.

Bukitcase ....do you have a new or old 30a? I’ve done several full length welds down the inside of the box closing up hold done brackets for the plastic liners on the aluminum dump bodies, it takes about 1 1/2 spools of .035 wire per truck to do that. So yes, sometimes it seems like you’re changing spools every five minutes. Uses a lot of argon when compared to steel as well.

[BukitCase]

"do you have a new or old 30a?"

That's a good question; mine's new enough it uses the Fastips - my confusion is on the "pro" version they now sell. I couldn't see any differences between what little info I found and mine. I got the whole setup about 7 years ago, the original owner worked in a LWS and got "downsized" about a year prior. He'd bought the whole thing on whatever employee discount he had. Was looking for a quick sale to get $$ for re-training, I helped him figure out what to do to get a job in instrumentation (my field the last 35 years of indentured servitude)

At the time I wanted a heavier gun (tractors, backhoe, etc) so bought the (now discontinued) 300 amp rated Roughneck gun (partly 'cause it uses the same Fastips as the spool gun) - STILL haven't used the Roughneck gun, heaviest thing I've welded with the 252 so far was a bunch of 3/4x3 FB - made a pair of quasi-toe jack adapters for HF 20 ton jacks (container leveling) and a bending jig to make 180 deg. bends in 1/2x3 FB (Case loader QA project) - multi-pass with the stock M25 gun worked fine.

Also found the bend limits of the HF 20 ton press :=) ... Steve

[BukitCase]

Oh, lifting the mm252 - one of the "cost saving" "features" of the post-250 machines is NO LIFTING EYE - so no bottle/couple lifting straps/few shackles and your "lifter" of choice :=(

Which is PART of the reason I bought the inverter version of the MM211, then built this

https://www.tractorbynet.com/forums/...-build-20.html

It can be towed with my ZTR or golf cart, has a lift eye that can be adjusted in 2 dimensions to balance, becomes its own handtruck for shorter excursions, locking casters for "on-road" use (they retract for trailering) - also, the part of the frame that lets it be its own hand truck is INTENTIONALLY designed to help protect the gas reg and gauges.

Don't think I'd try that with a MM252, but it works REALLY well for the little 40 pounder... Steve

[ryanjones2150]

Heck ya man, that’s awesome. Thanks for sharing.

I know very little about the spool guns to be honest. Another heavy truck shop I do some moonlighting at has an old style spool gun. It welds fine, it’s just massive and heavy. It’s all metal and will probably last forever though.

My only complaint about the new 30a, and this really isn’t a big deal to be honest, is the WFS selector knob is so smooth that you can knock it around and screw your settings up. Now it is recessed and I’ve only bumped it a couple times, but if it had little “ticks” in it, something to stiffen it up, I’d ask it to marry me. Although my wife might not think that is funny.

[BukitCase]

Glad you liked my "go anywhere" cart, I haven't found anything MAJOR I'd change (yet)

Know whatcha mean about the WFS knob - IMO, they should either add a LOCK button you have to push to change it, or include a little 8x monocular in the price of the 30A so you can see the display :=) - I 'spose the "real" weldors (not me) don't ***** 'cause they'd just set it by EAR... There's more plastic in the newer 30A's, the spool cover for example. It's still bulky, but having the canister able to be rotated helps. I also like the MANUAL gas valve - you can squeeze the trigger just a LITTLE and get pre-flow (or Post, if you're careful)

I'm pretty sure if I wuz about a half century younger and doing much aluminum, I'd just have something like a 350 with a 35' alumapro gun and a different dedicated machine for steel; but for now, it's nice to have the mm252 - I like the gun sense, just touch the trigger of the gun you wanna use and it becomes the active one. My container roof frames are modular, in 8'x12' sections, so for tack-up I used the spool gun instead of having to move the machine around so much. Then weld-out I could set the welder at one end or the other and reach it with the 15' gun... Steve

[tarry99]

Well after patching and reflooring many of my own end-dump trailers that have hauled dirt , concrete, AC and large Rip Rap for decades.....the biggest issue you'll have is the existing worn out broken, dented damaged floor below that can be so thin you have nothing left to weld too........we purposely have a 3/8" doubler plate added over the rear suspension when built at the highest trailer wear point to keep from having to rebuild the dog house suspension box or trailer subfloor when a body panel wears out........This trailer in the last 8 ft is 1/2" over the dog house and then 3/8" going forward to 30 ft overall. They do take a beating but hold up for years.

Anyway stabilize your existing floor first and make sure you steam clean it if its ever hauled construction materials like asphalt before........be prepared with a port-power to weld in cleats so you can push the floor down flat or at least down to the existing surface....once done move over a foot or two and knock your cleats loose and start over again........Yes you'll need to cut holes for Rosette welding everywhere......and if the floor is left to flex between the new surface & below it will just crack and turn into a mess.........7018 stick is all I use due to the fact of the dirty environment...and if you haven't learned how to fill holes , cracks and gaps.....pass on the job.............I always use 1/4" material in my trailers that are semi elliptical and have the sheets rolled first.............MIG is OK in a clean environment.....once above the dirt and debri line. Never preheated anything in this environment. Takes as much time to properly prepare the surface below as it does to weld in the new material.

Just back from the paint shop after a recent rebuild.

[ryanjones2150]

Nice looking piece of iron right there.

Working for this dump truck outfit is far better than the garbage trucks. The dumpster boxes they have....man those things get beat to death. And they don’t care as long as it holds trash. “Holds” is a relative term at that. The dump truck guys, the hard part is nailing down some time to do the work. They want to run those trucks as much as possible, which I get. Sometimes you have to shut it down for a day or two though. They love the fact that I don’t mind working holidays.