gun nozzle

[Miles]

I have a 240 volt Lincoln 180 amp welder
After running out of mig gas I switched over to flux core to weld the baffle plate into my tank. I changed the polarity, installed the flux core wire and replaced the brass GMAW gun nozzle with the black FCAW gun nozzle. I tacked the plates into place and made 3-4" stitch welds in various spots around the plates in an attempt not to overheat and warp anything. As I have three plates and a fourth small one there was about 12 feet to be welded.After welding for a while the black flux gun nozzle started to melt on the end. I thought these would be made of a ceramic material not plastic.
What gives? Am I getting too close to the weld with the gun? I tried to give the machine and the plates a break every few minuts to cool down. Seems rather silly to put a plastic nozzle on a gun whose tip can get hot.

[Big T]

I'm not sure about the plastic nozzle but if you're using gasless wire you shouldn't need a nozzle. I only use gas shielded wire but I have a friend who has a little 110 volt gasless mig and it doesn't have a nozzle and there's no way to install one. I'm not sure about your machine but it should tell you in the manual or maybe you could google it.

[Miles]

I re -read my manual, it doesn't say anything about the nozzle other than to use it. I can only assume it's to protect the gas diffuser ports on the gun when not using gas. Why it would be made out of plastic is mind boggling.

[Tom_Heath]

It's only purpose is to keep crap out of the gas holes. LOL say it fast and it sounds funny. Sorry. You can run the brass if you like, you will just have to clean it alot. Or just run nothing at all. And clean the diffuser when you go back to gas. A clean gas hole is a happy gas hole.

[Rodcrafter]

PD I think you were having some there with those words.

Good morning

[Miles]

I took the sea voyage over to the big island yesterday to get more MIG gas. I couldn't find another black nozzle but I noticed there are different shaped brass nozzles as well as tapered tips. I will try to find a brass nozzle the same shape as the plastic one and use it when welding with flux core.
thank you for the replies.

[Miles]

Lincoln has three different tapers of nozzles for my particular gun. What is the advantage and/or use of a smaller diameter tapered nozzle, other than you can get it into tighter spots? It also has a nozzle called a spot weld nozzle what is that one about?

[Blazer]

Miles, you are correct in that they are to get in a tighter space or in a bevel of a pipe. I do know that there are also some different lengths available ( at least miller does ) that set your contact tip flush with your nozzle or recessed in a little which I prefer. The spot weld nozzles a normally for body work and have a longer end and are generally used on a machine with a spot weld mode. Can I ask what gas you are using ?

[Blazer]

Miles. I'm sorry just realized that you are using fluxcore. My bad.

[Miles]

Not at all, thank you,
I'm using C02/argon mix, I just switched to the flux core when I ran out of gas. I'm only on my second bottle so have a lot to learn. While looking for a new flux core nozzle I noticed the different brass gas nozzles and wondered what the advantages of them were. The one that came with my gun has the tip flush with the end of the nozzle and is fairly wide. I thought a skinnier one would have helped while I was trying to weld my smoke stack to the end of my tank. I couldn't weld all the way around on the inside of the tank just the outside. What is the advantage of having the tip recessed?

[Blazer]

Miles, the recessed nozzle is just a preference of mine and I'm only talking a slight recess, I tend to weld hot and it seems to help on the contact tip life. I would stay with what it came with and maybe get the narrow nozzle for when you need it in tight places. I take that you are using 75/25 gas, myself I really hate that gas for anything structural, good for sheet metal. I like a argon ox mix, 95/5 or 98/2.

[Puff]

Blazer,

Since you bring this up...might you shed some light on what the different gas mixes do? Is it something we home welder guys may benefit from? Is the finished weld different looking or the same ? Would it be worth trying to go out and get?

Hoping this does not hijack the thread

[Miles]

No it does not hijack thread, I'd like to know as well. One can never learn too much, remembering is the hard part.

[Puff]

Remembering what ?

[Miles]

Exactly

[Blazer]

Puff, 75/25 is more for sheet metal and will give some cold lap sometimes on structural steel,but if you are using it on a machine with plenty of heat then you probably won't notice as much. 95/5 or 98/2 runs hotter and seem's to give a flatter contour. If you are using a 120 volt mig or a lower amp machine you would get some benefit from an ox mix gas. This is just my opinion.