Of course, start making progress on my truck. I need to weld up a "sub-frame" for my front end. Start welding, beads look beautiful Being paranoid (for good reason) I try breaking some of my welds. . .busted them bad boys right off

And G00Gle sez. . .Cold Lapping!! Not even a preheat with a propane torch with my welder on the highest setting works good enough for me. It will bond to the plates, but the weld bead will crack and split once I give it a few good whacks

Am I doing something wrong? I've read all over the place that it should do it with a 110v, or are "They" mistaking their beautiful cold lapped welds for proper welds

Am I stuck with upgrading? To what? Stick? Is this the wrong forum? lol

 

What amperage is the welder you are using when welding on the highest setting? 1/4" plate should be somewhere around 90 amps with a stick welder, 100-125 amps with a mig or tig.

 

The highest 120 volt in the Miller welder line is their Millermatic 140 rated to 3/16" material.
The 230 volt Millermatic 180 is rated to 5/16" material.
Good thing you did tests on your welds, this is proof that a good looking weld isn't necessarly a sound weld.
Bottom line you need a bigger welder to apply more heat /amps.
Can you tack everything and have someone with a mobile unit burn it in for you or borrow a friends larger unit?

This is why I went to a Millermatic 251 after going thru many brands and size welders over the years.
better to have extra power (amps) than not enough as you'll grow into bigger projects over time trust me.

 

A differant welding technique would prolly allow you to weld the 1/4 " with your 110 machine with good results.

For what it's worth I have the Hobart 180 which is the 230volt one and I weld alot of 1/4" material. It will make an excellent weld on 1/4" material with the the current on the number 2 setting and the wire speed at 40. On the chart inside the machine it recomends that particular setting for .060 material max. If you change your technique, slow down the wire speed some and use a weave back and forth, I think you'll be surprised at what your welder is capable of.

I even made a tow bar for my 96 PSD, used 2" square tubing and and cut the pintle hitch eye out of a piece of 1/2" plate. I welded the 1/2" plate on with the machine set for .125" material max. Towed the pickup loaded with fuel tank and alot of tools in it on an 800 mile round trip across the desert behind my bellydump.

 

Run flex core and get it red hot with a torch first. Then see how those welds hold up

 

I wouldn't torch the frame that hot as it's tempered steel this would change the strength properties of the frame.
That would be fluxcore wire, way too dirty for me and my liner.

 

Fluxcore is messy, but I've had excellent experience using it on thicker materials with my Lincoln 135 (120V welder) because it penetrates betters, and the welds held just fine. I built a "superbumper" this way:

http://frederic.midimonkey.com/f350-superbumper.html

I didn't have to preheat anything, but I did have the amperage turned all the way up and bevel the edges of where I'm welding, and wave the mig gun back and forth across the bevel to ensure full penetration. Because of the thickness the useful wirefeed speed was a very narrow range set to a "hair" over "3" on my lincoln. A slight drift in either direction resulted in lousy welds.

I also had to pay real close attention to cleanliness. For most non-critical things I get things reasonably shiny before welding but never worry about perfection unless it's structural. Welding with the machine at it's limits however, to ensure good penetration consistantly I had a lot of wirewheeling to do.

And beemernut - welding to tempered steel changes it's properties also... I believe there are special processes and technique for avoiding this, but offhand I have no idea what it is.

 

Frederic's onto the solution... bevel the edges such that you actually can penetrate at the low end, and then multipass the weld to build it up. The root pass will be where the two pieces come together, then make at least two more passes, one on each side of the root pass. If you are doing a vertical weld, that also is part of the problem, as vertical downs are cooler than flat welds, and vertical up is a trick to learn, but hotter than horizontal welds.

 

Not near as bad a torching the whole frame until red, true any welding on a tempered frame alters strength. Weld short sections at a time and let cool.
This is why on big rig frames with a crack they are gusseted and bolted.

 

Yes, precisely.

While you were correct I just wanted to point out that minor detail, because I've seen ton of guys get into modifying their suspensions, frames, and so on, only to enjoy a lifetime of frame cracks and tears as a result of their work.

I've been debating for a while making a 4x2 lift kit for my crewcab, but I keep looking at the frame and thinking... hmmmm... naaaah. I wouldn't mind 4" upwards to clear wider, taller tires. See, the 2wd trucks like to sit low in the front with a nice rake, which makes fitting even slightly larger tires a big hassle - rubs on everything.

I have a set of 16x10 rims I've been thinking about putting 305/70R16's on because then the speedo wouldn't be off to bad (couple of percent) but I can see already with just putting the naked rims on with a ruler at the edge that they're going to rub on the cab pretty good.

 

No welding to the frame itself. The "sub frame" is a bolt in dealio. Reusing the 5 stock bolt holes in each horn with a 6th drilled to secure the back leg of the angle better. The rear shackle brackets will be located and bolted as well.

For those of you who mentioned to try Flux-core, beleive it or not it is rated to weld 5/16" with Flux-core on a multi pass What difference does flux make? I have a hard time beleiving that, seeing how poorly MIG does on 1/4". . .

http://content.lincolnelectric.com/p...ture/e7351.pdf

The 2 peices are coming together at a 90* angle. I've got a 1/4" bevel to fill, is that too much?

I guess I can try a spool of Flux-core first, not just becuase it's hella cheaper than a new welder lol. many thanks for the help, I'll report back hopefully this weekend on the results

Greatly appreciate all the tips

 

From what I've read in brochures when I was purchashing a mig welder years ago, I noticed the same thing. Flux core is rated to less thickness for a given set of amps than regular wire with a shielding gas.

I've found the opposite to be true in practice, though maybe it's my technique or I never got the regulator on the bottle correct, or some other "monkey" type of issue. I'm certainly not a pro welder. Ugly, ugly welds but everything sticks.

In fact, my homemade bumper (1/4" plate) survived an impact with the door of a honda that slid through a stop sign on an icy/snowy road. I was doing about 25 or so, and with the weight advantage of my crewcab, all of the force of impact was transmitted through the bumper into the side of his car and the bumper got some scrapes and dings but other than a smidge of body filler into the scrapes and a quickie repaint, it was fine.

Not that I recommend you testing your welding projects this way. But, it's an example of 120V mig welding with flux-core on 1/4" plate surviving a fairly decent impact.

 

F-T..here is my two cents,hope you find it usefull. Testing a fillet weld by breaking it in the wrong direction to its strength, is pretty usefull. A close look at the broken weld will give clues for any included bubbles. I can break a fillet that will hold a ton on the long dimension, using a eight lb. beater. that same weld will safely hold up . Beveling creates strenght by removing the pivot leg. any rust in the weld will show up to the naked eye as the bubbles. good luck.

 

Well, I picked up some E71T-11 flux core wire and a chipping hammer. It welds hot! And rather nice actually, beautiful welds. . .I guess there was good penetration, the blueing extends about 3/4" + into the surrounding base metal. Still breaking them, rather easily. Even did one by hand Breaks at a 45* angle along the weld. Little plasticity. . .interesting note, the breaks have gone from a dull, grainy appearance at the break with MIG and a D setting and 4.5 wire speed to a shiny, large, evenly spaced granular apearance with Flux-Core and a D setting and 3.5 wire speed.

The flux produced a stronger weld as it took a harder series of hits to break it, but it's much more brittle. . .I don't get it!!

Is there such a thing as being too hot? Yes, all welds were done freshly ground edges, all nice and clean.

 

It's a basic property of metalurgy.

Strong = brittle, weak = flexible. It's about molecular "closeness".

This is why titanium connecting rods are amazingly strong - but because they're so strong they're also very brittle - so a massive shock load (i.e. detonation under massive amounts of boost) and they'll snap like a twig, or shatter like cheap glass, whereas a steel or aluminum rod will more than likely bend, compress, or experience some other deformation before breaking.

But at least you experienced the same as me with the flux core - messier but better penetration overall. If you want to minimize the bluing you can turn down the wire speed "a smidge". That will also help with the brittleness as well.