Can I use flux core wire to weld body panels?

[esotericsean]

I'm not trying to convince anyone that what I'm doing is correct, I'm really just trying to understand the proper way of doing it (it's been very confusing trying to teach myself).

At the same time, this is all I currently have so I'm trying to see if I can get away with it. I really appreciate everyone's input. I understand that I need a proper gas MIG with thinner wire.
_________________
My 1966 13 Window Thread: http://www.thesamba.com/vw/forum/viewtopic.php?t=672199

[scrivyscriv]

Yes it is a complex subject, with no real in depth places to learn how to do it well. There is a reason though.. sheet metal welding is not just a technical job; it truly takes an artistic understanding, or a designer’s eye.
You learn something new every single job. It’s like teaching crayon drawing or finger painting.. we all start at the basic level but few of us get really good, and even fewer master it.

The best way to learn how to do what you’re asking is actually really simple. Get a MIG welding setup, get a body hammer and dolly set, and spend some time welding sheet metal on junk. It’s not magic or mysterious at all, it’s like romancing your girlfriend... it takes time, patience, finesse, an eye for details.

Once you get your panel welded in, knock down the heavier spots with a 40-60 grit flap wheel on a 4” angle grinder.. don’t get into the base metal though. Once you knocked down the mountains, start working on the hills with a die grinder and 3M roloc dics, smoothing things out. Bump your grit levels up as you go, feeling out what the area needs. Shine a bright light behind your panel and look for pinholes or missed areas, then sharpie mark them and go back over with the welder.

Yes, your panel needs to be absolutely perfect when you finish with the rolocs... ideally if you started with a small uniform gap all the way around before you started welding, and you took your time tacking it in, there won’t be any major issues. Use a hammer and dolly every few tacks if possible; you’re just trying to persuade the metal back out a little to keep its shape and prevent the weld contraction from distorting the area.

Don’t use glass or body filler to compensate for an ugly finish job or poor welding. Ugly welds are usually bad welds. My preference is to spray my panels with a 2k epoxy primer, weld through it where I can, then shoot epoxy over the finished panel followed by a 2k high build primer. The high build is where you start to hide the minor welding imperfections... use Rage Gold body filler if you need it.


I see all the time in the Bay forum, guys will go to town cutting, then realize oh SH** bit off more than I realized! Then it’s followed with popcorn looking spattered welds, distorted metal, and finally a thick layer of body filler. We all started somewhere but it just really sucks to ruin an otherwise salvageable project with costly mistakes.

All that to say just work towards your goal. Once you have the right tools and some practice, you’ll know when you’re ready to jump on something as complex as a body panel.
_________________
Robert in Memphis
Dünkelgrügen 1967 Java Green bug thread
Engine rebuild thread
If you're ever in the Memphis area, you are welcome to stop by for advice and help.

[theKbStockpiler]

From the image posted here https://i.imgur.com/qHz5TWU.jpg ,it looks like you have the process down. For most people the learning curve is too steep but you have managed it. You have to watch the heated weld zone and not the pool.

After you figure it out. MIG is mostly just faster than 'Flux Core Repeated Spot welds'. The same method is used with both on butted thin sheet metal. You have to grind down the welds on both so mostly the end result is the same.

The only big difference between the two is if you weld upside down , flux spatters a lot (it' does not use (Short Circuit Transfer) so you HAVE to use the proper safety gear like long welders gloves and DO NOT lay directly under the pool but to the side.

If your in doubt you can try to horizontal Flux Core weld on a test piece. I don't notice a difference.
_________________
My beetle is not competing with your beetle. I have the yellow beetle in my town. There is a red one, a green one ......
Use all safety devices including a mask.

[Gordo_89]

Good evening,

First attempt of welding using flux cored wire following many hours practice I believe I have a good Weld

Front

Back

However I seem to have inconsistent penertration in the metal when I'm not blowing holes as you can see

Grinding down has highlighted missing weld

I will try gas welding tomorrow if I get the chance.

[Mike Fisher]

It looks like the metal is overlapped? I thought butt welding is preferred. Your last picture looks pretty good though!
_________________
https://imgur.com/user/FisherSquareback/posts
69 FI/AT square Daily Driver
66 sunroof,67,70,71,71,71AT,72,72AT,73 Parts
two 57 oval ragtops sold
'68 Karmann Ghia sold

Society is like stew. If you don't keep it stirred up you end up with a lot of scum on the top! - Russ_Wolfe/Edward Abbey

[theKbStockpiler]

What we really should be looking at ,is images of a series of spot welds ,started from the last spot weld ,done in a row to mimic a bead. The issue with Flux Core welding thin metal is that it welds hotter ,has more arc force ,and the wire is mostly flux and not metal. So its a challenge to start from scratch once. There is no point in repeating it. Do 3 or more spot welds to hold the piece where you want it. Then start your next spot weld on one of the last spot welds and overlap it by 1/3 to 1/4 of the diameter. Do maybe three of these in a row before moving to another area to keep heat down.

The same method is used for MIG but looks better and is a lot faster.
_________________
My beetle is not competing with your beetle. I have the yellow beetle in my town. There is a red one, a green one ......
Use all safety devices including a mask.

[Gordo_89]

They are butt welded close together. I have read that the closer the joint the less chance of blowing through. I will give it another shot when I get chance
_________________
1989 Vanagon 2.1L

[theKbStockpiler]

After coming to grips that overlapping body panels had many disadvantages I was lucky to come across this webpage.

https://www.cartechbooks.com/techtips/mig-butt-welding/

This explains it all.
_________________
My beetle is not competing with your beetle. I have the yellow beetle in my town. There is a red one, a green one ......
Use all safety devices including a mask.

[Braukuche]

Flux is fine, in fact better in certain circumstances, like if you have to work outside and there is wind.
If you clean off your welds well then you don't have to worry about paint reaction. Ive used flux for years, never had an issue.
In the end both do the same thing, they bond metal together. One is arguably more efficient but it's not like only one works. Both are also primitive technology, we all would be better off bonding panels with modern adhesives, far stronger and don't distort panels.
_________________
Go Reds! Smash state!

Retirement is here!
1956 Ghia
1959 SO-23 Westfalia
1960 double cab
1960 Baja Bug
1963 stretched double cab
1962 Golde sunroof Ghia
1963 356 B coupe
1963 Notchback
1967 21 window less rusty now

[Evil_Fiz]

[modok]

yep that thing is a gas hog, not really a problem tho
Use straight co2 gas instead of fancy argon mix, it's cheap.

[66brm]

You can also dial back your gas bottle pressure regulator, it won't stop the post weld flow but can reduce the volume used if welding in a still air environment like a closed in workshop
_________________
Aust. RHD 66 Type 1
Aust. RHD 57 Type 1 Oval

[Evil_Fiz]

[Canghia]

Emil,

Wbat about trying another solenoid. My Lincoln 110 MIG was a flux core only but when I looked at the circuit board I saw the connectors there for gas. I ordered a solenoid from someone on Ebay and it was basically plug and play. It worked well. Well enough to get done what I needed. A better welder would have made my life so much easier. Mine was a basic machine.


Mark

[Evil_Fiz]

[modok]

[finray]

I know this is an older thread but wanted to share this video. Found this video today and was curious what you all thought about what he is saying about flux core.

https://youtu.be/ic7Gwf8y4Yc

[fredybear]

See how he does that, tap and let cool, tap and let cool.

That's the way its done.

You can lay a nice bead like that.

[Evil_Fiz]

[infiniteLoop]

MIGs without the solenoid have a mechanical switch in the gun that works fine. Why not bypass the board and have the switch in the gun close the circuit with the solenoid?