Is there a problem with flux core welding wire getting contaminated with moisture from the atmosphere?
Yes, If it gets wet enough it can swell up and jam the feed cable.
The problem with flux core wire is that it's rubbish to begin with :P
Flux core and gas MIG is like 6010(ac) versus 7018(dc). The FC leaves spatter all over and is used for a lot of cruddy looking farm welding. Yeah, it works, but aint pretty. I use it when its windy outside and it blows the shielding gas away.
Rod Busters (rebar installing iron workers) use it on big concrete jobs outside, like on expressway concrete work. Its TRASH, but glues steel together... On the rebar, and heavy plate welding, we use 5/32 wire... yes, that's 5/32
I have used the dickens out of it rebuilding the body on my 24 touring. I got a pacemaker in 2010 and am about to help my 13 year old grandson learn to weld. My concern was the wire is about 10 years old now and might be full of water.
Try it out on some scrap.
I don't have any problems with GOOD flux-core wire, it works great, (I use Lincoln) but cheap stuff is crap.
Try it on a piece of scrap as Ken suggested. I've seen FC wire still be fine after 10+ years, other times it was garbage after 2. Depends on the environment it has been sitting in.
Once the moisture gets in, the wire is wound tight enough around the spool that it is next to impossible to bake out. (Lots of guys suggest throwing the spool in the oven for awhile). When it is manufactured it is put loosely on large steel spools and baked until the proper moisture content is reached. Whatever you do, if you decide to replace it, spend the extra few bucks and buy good stuff (like Lincoln). Worth every penny.
I can vouch for Lincoln wire - I worked in their consumable division for 12 years
I have Lincoln wire.
Try running off the outside layer of wire off the spool, then give it a try. As long as it welds as it did before, you will be fine.
Agree that once you try a gas shielded mig welder you'll throw rocks at your FC welder.
I have both & only use the FC when I have to do something outside where it's windy & I can't drag the work into the shop.
Be sure to check the polarity requirements. I used some several years ago and had a terrible time with it. Talked to the sales rep about it and soon discovered that he neglected to tell me that it runs on straight polarity(positive ground). That made it a lot better, it at least worked like crap then. I'm not a big fan. That was only one brand though(I don't recall which one), there may be others that are better. Dave
Flux core works great for improving your grinding skills <@^@>
The main thing on any welding wire is if gets a skim of fine rust on it, it will not feed well and is not worth the trouble to clean. KB
Try it and see if it welds. You might need to unwrap the top layer off the spool to get to fresh clean stuff.
Don't breath the gas. It will mess up your life with cancer in time. Always use it outside if you can.
"Agree that once you try a gas shielded mig welder you'll throw rocks at your FC welder."
I switch back and forth between gas and flux core and don't find much difference. It depends on the thickness of the material I'm welding, use the gas w/thinner material and the flux core on the heavier.
Using flux core is a lot cheaper than using gas, but then I'm frugal, trained into me by parents that had been through the depression.
Use it up,
Wear it out,
Make it do,
Or do without.
I started with a Lincoln Mig using flux, moved to gas/wire, and recently shelled out big bucks for a Miller Tig.
Many years ago while going through A&P school I had to take aircraft welding. We were taught oxy acetylene and were told if we couldn't produce airworthy work we wouldn't get our license. That wasn't true but it had all of us worried about it enough that we all did well. When the class was done we could all weld 4130 tubing with .035 wall thickness like it was plate steel. If it wasn't for the tell tale signs that oxy acetylene leaves you would swear it was all done with a TIG.
My advice for teaching someone to weld is start with the torch. They will have a better understanding of heat control than with any other method. This will enable them to learn the other methods in minutes rather than weeks.
I am not sure what type of welder you are using, but if you have been running regular wire in it with a shielding gas you will need to reverse the polarity of your welder to run flux-core. It should work really nice you you with very little splatter.
Larry, read my post above. I don't know about other brands of wire, but the one that I used was supposed to be run on straight(positive ground)polarity. It was much better after I switched, but still ran like crap. As I said, that was only one brand, possibly others are better, this was about ten years ago or so. I know there is a lot of difference in 7018 stick rod between brands. Dave