Flux core

Hey guy's I just want to know what you think about this. I used flux core for my frame work instead of copper coated and gas because, I was told it was stronger and I did not want to waste my gas, it's not that good looking but it penetrated well and you will not see it when my cab and bed are on. I am new to welding and this is my first build so dont bash me to hard please. opinions please, good or bad. Well I tried to upload pics from my pc but it didnt work it said upload of file failed What the HELL is going on here.

 

Flux is tricky to get the hang of because with the flux covering the bead, you won't be able to judge the bead you're laying because you can't see it. So you kinda need to practice and get a feel for what speed is the right speed to go. When you chip all the flux away if you went too fast you could have holes or a bead that isn't quite uniform.

Flux burns hotter than gas shielded wire so yes you'll get a little more penetration, if you know what you're doing that is.

And for you or anyone else reading, find some scrap, practice some welds, post some pictures online, get some advice, before you start welding on your project.

And flux core wire costs more than gas shielded wire. They've done calculations on some welding forums I'm on and found that flux core will cost more overall than gas shielded wire and gas.

 

If you're running 110, you can fillet the seam like this \ / and weld 3 passes to get the depth you need with a gas shielding. Heat and distortion are bigger, but you can deal with that with bracing and preheat. I can't imagine being concerned about saving a little money on gas when welding something like a frame. I also can't imagine welding anything serious on a frame besides a bracket without a lot of experience welding coupons (practice pieces) and getting it evaluated by an experienced welder first.

Just sayin...

 

depends! are you using a 110V or 220V? If it is 110 I would say NO.

 

Here is some of my welds with a flux core 110 machine. Just takes time to get the feel of the machine and wire. The biggest pain in the ass is all the spatter from the flux!

 

I finally got pics! I had to load them one by one. I am useing a 220v lincoln 175

 

looks good jrblack30. As always, it ain't the machine, it's the skill of one holding the stinger...........

To answer OPs question, I use fluxcore for the utility. My forte is OA, but in the past ten years I use Harbor Freight cheepo and it does structural welds on crossmembers, brackets, etc just fine.

jrblack's picture again.....

 

fwiw in construction most structural steel that gets field welded is done with innershield (flux core)

 

If your going to weld on rusty, dirty metal the flux will help clean the surface. Or you could just clean the weld site

 

should I get a close up pic of the welds?

 

Here are my welds, not pretty but I think they will hold

 

I used a Lincoln WeldPak 3200HD with flux-core wire to weld the frame of my pickup truck back together. I knew I was at the upper-limit of my welder's ability, so I took every possible step to ensure proper penetration and strength. I filleted all my weld seams, I preheated the piece with a MAPP torch to aid penetration at the outset. I also kept my foot on the gas so to speak, so that once parts were hot, they stayed hot. Weld a couple inches, quickly grab a wire brush, clean off the excess flux and keep going. I'd also like to add that I have several years of experience with the machine and welding in general. Then I plated the butted weld seams with a drilled 1/4" steel plate, and welded the hell out of that too. Frame held up with out any issues for many thousands of miles, regardless of payload, including a few times I hauled nearly 2000 lbs. I sold the truck and I'm sure the new owner is having no issues either.

Can it be done? yes. But be careful and take all precautions

 

The cored wire works out in the wind, the gas tends to blow away.

 

I hesitate to post this on the board, as I don't mean this as a put down, but I see a lot of poor quality welding on this board, and someone needs to say it. First let me say that it's almost impossible to judge a weld from pictures. I just finished giving and grading welding tests this morning. I judge them visually and then destructive test. Many times the welds look great, but fail the destructive testing. Although it's hard to say just from the pictures, your welds don't look like they would pass. There really isn't any room for error in structural welding. It's critical that all weld sites need to be ground clean. Welding over rust is asking for weld failure. Second important thing is fit up. The better the fit, the easier, and better the weld.
You should do some test welds on the same material as your chassis and destructive test them. Do this by butt welding two pieces together. Then put one end in a vise, close to the weld and bend back and forth until the piece breaks. If the any part of the weld brakes, it fails. If the metal around the weld breaks then it passes. Until you can make welds every time that pass destructive testing your not ready for structural welding. I hope you don't take this personally, but I'd hate to see a weld fail while your driving your truck.

 

Thank you, I'm tired of always being the one to feel like an asshole.

 

Well your both assholes! lol. I welded up these pieces of frame ( before I worked on my finish work) and beat the shit out of them with a 6lb sledge and it got all bent up around the weld. no cracked welds. do I pass the test?

 

i have no experience 1st hand with fluxcore as in welding with it , but have tons of knowledge i working with it , at my last shop i was a machinist at we had 3 guys running 3/32" fluxcore at 400amps allday and it was finicky stuff to work with , it was dual shielded with gas and ALL WELDS WHERE FLAT !!!! this is very important to know when using fluxcore as all are not rated for ALL POSITION use !!!! and will crack and fail i spent many a day machining , and grinding out bad welds due do it being welded in any other position then flat.

and good points TinBender always nice to have true experience makes some observations based on hands on experience . i've been in the machine shop/fabrication trade for 23yrs and have been involved in thousands of jobs that get inspected prior to leaving the shop , and far too often i see work getting posted and praised that would end up in the scrap bin after being failed .

 

times 2....I use NR-232, .068 diameter flux core with a Lincoln LN-25 feeder nearly everyday at work. With everything dialed in, looks like a roll of dimes. Flux core should be fine for your frame, scrape the dingle-berries off before paint.

 

have you done other that flat welds?

 

This is a bend test:



A test plate is welded, the weld is ground flat, a strip from the middle of the weld is cut, and it is bent at the weld. It should look like a regular piece of bent steel when it's done.

Looking at your pictures, your welds wouldn't pass an X-ray, also did you weld up your test piece flat? Most of your welds are 2G welds.

I'm sorry to say but the quality of welds and the way you're setting your frame up, you're just asking for trouble down the road.

 

I too am a weld inspector, instructor, and multi-certified welder. I have used flux core for many, many things including frames. Not to knock your work, but I would go back to the scrap pile, and practice a little more before a final. With flux core, it is important to watch the puddle flow, so that you don't get any perosity, or air gaps in your weld. I have found over the years that everyone has alittle different style, but wether you push or pull the puddle, you need to make sure that you keep it flowing. Play with the heat, and speed of the wire until it flows in nicely.

 

Ok I know they dont look that good so what should I do now, Do I grind them down or go over them. I am going to switch to copper coated and gas. Boy my lack of patience got the best of me this time

 

Yes grind and re weld, use solid wire and gas (nothing wrong with flux core, solid is just better for this application.) Do this after you get the test welds down. A BFH is not a good test for a weld.

 

Now do I have to grind them completly gone? and what is a BFH

 

Dang,

I'm having a hard time visualizing (even with your pics) of where the weld is occuring...is this just flatbar buttwelded, ground down, then bent?


OP..BFH is Big F'ing Hammer

 

The top plate is what the test plate is, they ground the V in there to show you how the plates are set up, that's how test plates are setup for welding. Usually your welds are about 6 inches long.

You do your root pass then cover passes to fill in the gap. No undercut, can only go above the joint so much, has been 1/8" on the two 2G certifications I've taken.

They then take the test plate and do a visual inspection for the things listed above and porousity. If they're doing a bend test they'll cut the plate into strips, knock the backer plate off if it has one, so the top one picture that is a test strip. They grind the weld flat with the plate, then center the weld in the bend tester and bend it down. The weld is actually at the peak of the arch in the bend.

A successful bend test should look like it's one solid piece of flat bar that's been bent.

34chevytruck, everyone was a beginner, not everyone takes criticism as well as you have though so you should be able to go far. Everyone can be a good MIG welder if they take the time to learn and shut up and listen when people got advice for them. That's how I learned.

Given the porousity there, I would grind most of the weld out. Just take a grinding wheel's edge and run it in there a good ways.

Practice some 2G welds similar to the ones you're going to be making on the frame and post some pictures on here. We can't be the ultimate judge of penetration but you can tell a lot by pictures.

Once we get you welding decent, we'll talk about joint design and re enforcing that Z some.

 

Yes.

Try getting your eyes closer to the weld while welding, with flux core you have to watch that puddle very closely.

Mig welding with gas will always be a better weld than a weld done with flux core.

I don't have any experience with a 220 flux core welder (mine is a 110) but from my experience you will get better penetration using gas with your mig. In fact, if I'm welding any kind of structural support/framework it's imperitive to not grind away any of the weld due to lack of penetration (110 flux core).

 

34chevytruck,
Don't get pissed with what Tinbender said he is right. Your weld quality and appearance will improve considerably if you clean off the rust and the mill scale from the steel before you weld. Flux core wire is the prefered method of MIG welding for most big structural jobs except when it is possible to use sub arc. Take the time to grind and clean the weld surfaces and you will be surprise how much better your weld will look.

Rex

 

Agree, DO NOT hesitate to let folks know. Ignorance is bliss and unless someone is told what he is doing wrong he/she will never know. Hell, even the Pros have coaches.