im having some hard times getting a strong weld with my welder. i forgot the model number, but its a small gasless lincoln wire feed welder. it has always done real nice and strong welds, but lately the welds seem extremly brittle and the just break.

the welds are nice and smooth and look like they are getting really nice penteration (sp)....but they arent strong at all.

any suggestions?

im using the same wire that i've always used in it, and im about half way through the roll right now when the welds started to suck. could the wire be at fault with not enough flux in it?

 

i doubt it's the wire. with flux core you have to make sure you have the correct polarity set on the machine for the wire. what are you doing or making and how do the welds fail? sometimes a failed weld isn't a sign of a bad weld. any chance of posting a pic?

 

by any chance is there a way to reverse the polarity on yoyur welder, if not, maybe the rectifiers are bad

 

Is it the weld-pak 100? That's my welder; I converted it to the GMAW (gas) welding, though. (WeldPak 100 + Conversion Kit = MigPak 10)

Cut through your weld at a 90 degree angle and inspect the weld. Is the metal contaminated in some way?

 

i would think its contamination or maybe your not getting enough wire in. if your getting great pentration then your weld shouldnt break.

 

Where are your welds breaking at ?? At the bottom of the weld where the weld is suppost to adhere to the surface or straight through the center of the weld it self ?

 

That really isn't enough information to come up with a good theory. What have you been welding? Do you have any formal training? Slag inclusions can be pretty common to an untrained flux core welder. Is the metal you're welding clean, or full of rust? Did you switch spools? Lots of flux core welding wire these days really needs to be double shielded, because it just isn't good wire. Did you have a good ground?

There's far too many variables. We need more information.

Mathius

 

What are you welding? I dunno if its just me, but I've been having a hard time trying to weld stainless steel... took awhile to get it, I dunno why. It was acting like it was outta gas, but it wasn't. Cranked up the amps and it was cool.

If its just normal steel, then I dunno.

 

omfg...youve got to be kidding.. YOU CANNOT WELD STANLESS WITH AND ORDINARY MIG.. dont even try unless you have had proper training. (i dont even thing that you can!, not sure though i have alwayed used er 308 wire-tig)

if you using flux core.. throw it away! esp is you have a small 110 mig welder.. and even then mig will not do all that well. try do do some research on technique its not just about pulling the trigger and aiming

 

You can weld stainless with a mig I do it every day. Stainless wire will weld to carbon but not vice versa..carbon is not as strong ,but you have to also use the right type of shielded gas as well the argon mixture is different from carbon steel to stainless steel. A small welder is going to have a hard time welding stainless because stainless welds are alot hotter and place more strain on a little machine & it is a little more difficult to weld.

The reason so many people use flux cored wiring is pure convenience of not having to buy or rent a bottle.. mig welding has got to be the easiest form of welding known to man..
especially flux cored, get a bunch of scrap clean it up and practice makes a sweeter weld... some people cant lay a pretty weld to save there life and some beginners make some veterans look like they just fell off the potato truck some people have it and some dont.

-A few simple pointers for adjusting a mig is make sure you have a good ground no rust or paint in the way I have my ground cable tapped and threaded through a 3"c clamp so i get a real tight ground.
-when you adjust your power voltage and feed set your voltage down and start to turn it up while running a straight line bead until you hear no pauses in your wire welding(a steady bacon cooking sound)zzzzzzzzzzzz with no breaks if you hear breaks you either need more power or you need to slow down the fead so the wire has time to melt . dont rush it!
- you want to learn to make a pretty weld draw a straight line on a small piece of metal with a black permanent marker and try to cover the line with side a to side motion going at least an 1/8 " over the line on bothe sides..go slow giving you weld enough time to build up dont rush it.
Flux core is messy and ugly but its conveneint , brush it clean run another pass and always paint over it when your through or it will rust like a S>O>B...

 

i havent had time to get to the garage to get a picture yet, but i should be able to tomorrow.

i've taken one short class on welding, but nothing very formal about it. lets just say im not perfect at it, but im probably more of an average welder.....

im just using plain old steel, its fresh from the shop where i buy all my steel, no rust or anything. the welds are breaking down the center of the weld, not where in penertrates the steel.

i would love to convert the welder over to gas, hopefully one day soon it will happen. its just nice to have a welder around that i dont have to fill a tank all the time

i personnaly think that it is the wire. the welds are normally covered in a brownish/greenish powder after im done welding. but now the welds are clean right after a finish

thanks :hail:

 

if the weld fails down the center there is nothing wrong with the weld other than you're over stressing it or not a big enough weld for your application. only thing i can think of that may be a problem is you're not matching filler to base metal. do you know what kind of steel you have? does the welds just crack or fail in service? if they just crack on their own i'd guess it's mismatch metals. failure in service would be too small a weld.

 

What type of weld are you doing a fillet , butt , weld if your doing a butt use a piece to gap it 1/32" for better penetration. Your wire may be old. 7018 rods are known to go bad but they need to be left in the oven when not used. I not sure on the flux wire though cause most of those don't require heat storage after being open. The steel doesn't have the pickle oil still on it does it. Another question is what size wire are you running? Sounds more like a set up issue on the welder than the wire.

Dynodan

 

To get decent penetration on stuff at home a good rule of thumb is leaving a 1/8 gap using a thick washer or a nickel to tack it up and then knock it out of they way make sure everything is where you want it to be (straight) then fill it all in one thin pass and maybe a thick pass depending on what it is.. I pipe weld and I have my fitters leave 1/4 inch to 3/8 inch gaps in almost all of the pipe lines that I weld. The weld will always be stronger than the metal wich you are welding too if everything is done right. because the welded metal has under gone heat treatment.

 

i just bought a craftsman 110 wire feed welder (gasless) and havent had a problem welding anything ive tried yet ....but im also not a (welder) by trade but it isnt that hard just practice practice practice and ive also noticed that if you are having problems with the welds being weak that it usually has to do with the material being not completely clean or youve not got your heat and speed settings correct ......

 

Can't weld stainless with a mig? wtf? It worked fine for me, and I used a regular mig (gas).

The only problem I had really was just getting the amps right... the stainless seemed to like a little more amps than regular steel.

 

ya, I can deffinetely weld stainless steal with my mig too...

 

Just one thought. You said the steel was "fresh" from the shop. No rust is OK, but did you get all of the oil or coating off of the piece first. Some places will do that so the steel doesn't get rusty while they have it stored. It could easily contaminate the weld.

The bumpers and hitches that I've built for my jeeps, have always held up fine, and have seen a lot of abuse. I welded them all with a MIG, and mostly with flux core. The older or used steel always has welded nicer for me, because you have to clean it up good prior to welding. The new stuff looks clean, but hit it with laquer thinner to get rid of the oil. Then hit it with a good wire brush, preferably on a grinder. Or even hit it with a grinding wheel first. I've never had issues when I prepped metal this way.

 

what kind of wire do you use? your filler metal needs to match your base metal

when welding any carbon steel you need to remove the mill scale with a wire brush or a grinder the cleaner the metal the better

 

Stainless steel and steel are very similar, that's why they're both steel (duh). They are compatible alloys. It's better to use stainless wire on stainless, but you can weld stainless with regular wire. We just went over this in TomP's thread. On a technical level, I think Stainless has a higher nickle and zinc content, but I'm no metalurlgist that I would know that offhand.

Quit jumping on people when you already stated you're not even sure yourself of the answer.

Mathius

 

Actually, I am pretty new to welding. And its not my welder, so I don't know what wire I used. And I have no pics, because I did the whole shifter all at once, paint included. And yes, I know I have to clean the metal first. Duh.

And, actually, my welding was fine. Its never failed, never cracked, never bent, nothing. Why are you jumping all over me like that? Thats just not cool.

 

mathius stainless hase more nickle than carbon steel, which has none or next to none. that's why stainless will be slightly magnetic. there is no zinc in stainless. there would be around 20% chromium and 10% nickle depending on alloy. you'll also find carbon, maganese, and silicon along with a few other elements in very small amounts.

 

The chromium is what prevents stainless from rusting, right? I thought it was more around 14% chromium?

 

low is 17% to high of 26% chromium depending on alloy. yes it and nickle give stainless most of it's non rusting qualities.

 

Oh, cool.... I read something about stainless steel at school, that it was actually discovered by accident. That true?

 

316 stainless is the good stuff and it shouldnt be magnetic at all if it is 316 SS. how ever if you go down a grade to like a cheaper more economical 306 SS it will have a slight magnetic property and it vonerable to rusting...
I was wondering how us guys ever got on to the discussing of welding stainless because I cant think of a single part on our cars that is stainless.. Heres a carbon steal and stainless pit I help some buddies weld a month ago by the way..

 

sweet man fire that bad boy up we will be over tomorow..LOL

 

i forgot the camara today, so still no pics

but i think i figured it out. i welded up a guys exhaust today, and everything went well, and was extremly strong....so then i was really confused about what happening.

i took some of the stock i got from the shop, and sanded it a little with the DA, so it was shiney, then i sprayed it down with a brake clean.

ran a nice bead with just a butt joint between two pieces of steel, the weld seemed to flow a little niceer, but was a lot stronger, it just didnt snap like the pieces before it.....

i guess i didnt think a little oil on the steel could cause such problems

 

easy way to test your welds is to make a tee joint. weld one side only. hammer or bend the tee back onto the weld. welds have no strength in compression and will break easy. it should break down the center of the weld. you'll be able to inspect the inside of the weld for any flaws and fusion defects.

 

That exhaust you welded the material is called aluminized steel. It actually a steel with a coat of aluminization over it . The aluminize needs to be cleaned away before welding for a stronger weld.

Dynodan

 

Absolutely. Always clean any metal, but especially aluminum. Any contamination with aluminum and it will most likely fall apart into a mess, especially tungsten, although you don't have that with a MIG.

When I first learned to TIG weld aluminum, I had to stop at the first drop of contamination and grind it out, because nine times out of ten the contamination was enough that it would just cause the whole weld to fall apart. Now that I've done it enough and I'm certified, I don't have that problem as much, but it still happens now and again.

Mathius