Welding input info needed

[woody367]

I need to weld some patch panels in my truck 18ga. I have welded much heavy steel 1/4"-
5/8" but nothing this light. I just got a Hobart Handler 135 110v unit. Should I use flux core or gas shielding wire? I never used flux core before. The machine can do both and I have mix gas from my large unit so that is not a issue. Any thoughts or tip input would help a lot . Thank you

 

[u2slow]

Always nicer and cleaner with gas.

 

[Wamsutta]

Flux core is way too hot for thin gauge metal. There's your answer.

 

[jbfab]

I would recommend .023 ER70S2 or if the metal isn't very clean ER70S6 (but it should be pretty clean for best results on that thin material). Both of those are gas shielded. For what it's worth I would recommend 75%Ar/25%CO2 shielding gas or thereabouts for that application.

 

[MJD1]

Flux core isn't too hot but you will get a much cleaner weld with gas that wont rust as fast since you can clean it easier

 

[The Cobbler]

Fitzees fabrications on you tube recently did a video on flux vs shielded wire for body patching here
Huge difference in the gas over flux. gas is the way to go in my mind.
It would be worth watching some of his patching videos , he is a master in my eyes.

 

[imagineer]

Don't be greedy or impatient and try to run any length of bead. Be happy with tack welds several inches apart and let them cool before placing more tacks in between. That you're running flux core, I'd try and use higher amps but shorter duration welds (like no more than 1 second). It doesn't hurt to hammer and dolly the tack welds a bit to "stretch" the material.

My 1st foray into welding (circa 2001) was F150 wheel arch patch panels and it took me way too long to figure out tack welds were the way to go.

 

[ybnormal]

looks like OP already knows how to weld since he has a "larger machine" with gas. I'd say also use copper blocks as heat sinks since it is thin-gauge sheetmetal for cars.

 

[woody367]

Thank you all for the input. Yes, I plan on tack welding all around, to try not to warp the metal. I have 75%Ar/25%CO2 shielding gas so I will go that route. I am doing cab corners and will arch patches on my truck. My eyes really are not q+that good. Anymore, so this should be interesting. I wish I had the money to have somebody do it for me, but I don't. The feed roller on this machine has .035 and .024 wire feed. I have to buy a small roll of welding wire anyway, and they would only have to change the tip on the gun for .024 wire if that is the best size Or should I just get.035
Thank youk

 

[no704]

Use the .023”. Get a gold fixed shade for your hood. Use a white soap stone marker to mark your joint and use additional halogen lamps to light your work (not the inside of your hood).

 

[Rusted Nut]

.023 wire and 75/25 gas. Tack, let it cool, tack….. You can get a magnifying lens for some helmets. I have one for my Miller helmet, works great.

 

[dnschmidt]

The 0.024 wire is the only way to go. With bigger wire by the time you've melted the wire you've blown a hole in the sheet metal.

 

[hefnerconstructionlc]

Definitely the 0.23 wire and gas. I doubt you could really get your machine to work with 0.35 wire doing thing sheet metal. Plus the 0.23 is easy to sand.

 

[woody367]

Use the .023”. Get a gold fixed shade for your hood. Use a white soap stone marker to mark your joint and use additional halogen lamps to light your work (not the inside of your hood).

Why use a gold fixed lens?
I have a auto darkening helmet.

I will order the .023 wire and tips tomorrow. Do you guys recommend using heat compound to help with warping. I appreciate all the great tips you gul are giving me.
Keep them coming. I am a little nervous about welding. On such thin mail, I think I will see if I can get some scrap to practice on if we're well done on the truck. Thank you
I

 

[no704]

Why use a gold fixed lens?
I have a auto darkening helmet.

I will order the .023 wire and tips tomorrow. Do you guys recommend using heat compound to help with warping. I appreciate all the great tips you gul are giving me.
Keep them coming. I am a little nervous about welding. On such thin mail, I think I will see if I can get some scrap to practice on if we're well done on the truck. Thank you
I

I detest auto dark helmets, the gold shade is easier to see out of. At least for me.

 

[dffay]

If it’s not too late see about easy grind wire. Esab has a line of it. That way you won’t warp when your grinding them smooth when you did such a good job of avoiding it while welding.

 

[MJD1]

I detest auto dark helmets, the gold shade is easier to see out of. At least for me.

Doing bodywork welding with a fixed shade would royally **** with all the tacks and tacks between tacks.

 

[no704]

Doing bodywork welding with a fixed shade would royally **** with all the tacks and tacks between tacks.

I get that. Only time I used an auto was welding a roll cage and I was flashed several times. To each their own. I’ll stick to my fixed shade.

 

[seber]

Doing bodywork welding with a fixed shade would royally **** with all the tacks and tacks between tacks.

Agreed. I welded for years with a fixed shade doing body work. Not only does auto dark make life easier, it improved my welds.

 

[toolenthusiast]

I was flashed several times… I’ll stick to my fixed shade.

Do you also throw the baby out with the bathwater?

 

[Chris_Hamilton]

I like .030 actually over .023-.025 for sheet metal work (which is essentially all I do) when using a MIG. Lot of guys I worked with felt similar. You can definitely make nicer plug welds with .030. Heat is about the same with both, you run a bit more wire speed with .023-.025.

 

[no704]

Do you also throw the baby out with the bathwater?

If I get into body work again I might entertain an auto.

 

[no704]

If I get into body work again I might entertain an auto.

But for the very little I do now I’ll stick with my 13 fixed shade large window. I used to do a lot of welding. And on top of that I prefer straight C02. For mig.

 

[MJD1]

Before the autodark helmets became affordable I used to use a hand held shield for welding auto body material.

 

[Chris_Hamilton]

But for the very little I do now I’ll stick with my 13 fixed shade large window. I used to do a lot of welding. And on top of that I prefer straight C02. For mig.

100% CO2 ***** on thin sheet. And the welds are extremely hard due to the carburizing effect of the CO2 gas. Not like 75/25 is soft but there are so many drawbacks to 100% CO2 for sheet that I could never recommend that to someone doing thin stuff. Especially a newbie.

I too like an Auto Darkening helmet. I have a fairly high dollar Jackson. But in some circumstances when I'm tacking (which is nearly always when **** welding thin automotive stuff) I just position the torch and close my eyes. Helmet is hard to use when you are upside down (sometimes), or out of position somewhere and the light isn't great. Thin stuff and relatively low amps a 9 or at most 10 shade is what I use. If I go higher I find it harder to see the puddle.

Hopefully next year I'll be getting a OEM approved spot welder (Pro-Spot) so that will cut down on having to use the MIG dramatically. Much of what I do on the exterior panels of vehicles I'm using either TIG or good old fashined gas welding and **** welding then planishing the weld. But there are certain situations where the MIG is the best choice and especially for DIY guys it's a good option.

 

[mreisner]

I've done a lot of cab corners Etc with a 250X Miller and .30 wire. If you've never done body welding you definitely want to do some practice, but even better I would look into the automotive bonding adhesives. They are light years better than they were even 5 years ago, and they make body repair extremely easy compared to welding. An air powered flanger and Patch panels with adhesive can make some great repairs that are very strong and actually less prone to rust than welding unless you're an expert at it.

 

[mreisner]

As mentioned above, 100% CO2 and just starting out is looking for trouble. Get a bottle of 75/25 and you make your life a lot easier on the repair job you're doing.

 

[mreisner]

Depends on the year of your vehicle but I'm assuming it's a newer truck, you might want to get a door or something from a junkyard to practice on as the hsla steel they use now can be tricky to weld and get a proper bond and not warp. The newer vehicles with that alloy Steel actually are quite a bit thinner than the older ones in the welding is damn near an art compared to a science. It's not impossible but it was much easier to learn years ago on the older heavier Steel than what cars and trucks are today.

 

[no704]

Everyone is going to have an opinion about this. Just stated mine. Your mileage may differ. There are many different ways to skin a cat.

 

[Chris_Hamilton]

Depends on the year of your vehicle but I'm assuming it's a newer truck, you might want to get a door or something from a junkyard to practice on as the hsla steel they use now can be tricky to weld and get a proper bond and not warp. The newer vehicles with that alloy Steel actually are quite a bit thinner than the older ones in the welding is damn near an art compared to a science. It's not impossible but it was much easier to learn years ago on the older heavier Steel than what cars and trucks are today.

Yeah most new stuff because it's HSLA (high strength low alloy) or some variation thereof, is darn near impossible to weld with a conventional MIG using 75/25. It just want's to burn through. Only thing that will weld it decently is a Pulsed MIG. Many OEM's now don't want any MIG welding when making a repair. Those that do allow it like Honda require a special wire that costs literally 10X as much as conventional ER70S6. And only in approved places. Most OEM's though now require a structural spot welder and silicon bronze **** joint on exterior panel like when replacing a body side. It's all too complicated now. Multiple types of steel on a typical late model. If a car gets structural damage on the unibody you essentially can't pull them anymore due to the extreme strength of HSLA and when it bends it takes a "set". It won't straighten when it does that. You can't apply heat to relax it most of the time and you need all the factory info to tell you where what type of steel is where. Essentially stuff is not designed to be repaired. Go to a big salvage yard and look at all the aluminum F-150's with what used to be minor damage on a steel body. Now they get totaled. Nobody likes repairing them and many shops won't. Late model stuff is not something anyone should be fooling with without the equipment and experience.

I worked many years in collision. At one point before I left I was I-CAR Platinum Certified (Pro-Level 3). I don't miss it and I hope to never go back. I never wanted to work collision but you guys know how that goes.

 

[woody367]

If I could afford to pay someone that knows what they are doing to do this I would. But I can't. I have a full bottle of 75/25 gas and a new still in the bag/box of .023" ER70S6 wire so There is no money to lay out there. I guess this is the way I will try.

 

[MoonRise]

Solid wire, .023/.025 (same number and size for all practical purposes) with C25 shielding gas.

Straight CO2 runs hotter than C25 (it needs a higher voltage by 1-2 volts to ionize the straight CO2 compared to C25).

And nope on using FCAW on sheet metal. More spatter, more slag, and FCAW runs even 'hotter' than using solid wire with CO2, never mind solid wire with C25 gas.

And as mentioned, lots of individual 'dots' of weld and skip around so you don't get too much heat in one place and warp the sheet metal even more. Take your time, let things cool off, planish and/or grind (CAREFULLY!) as you go. Each weld 'dot' still has to be a complete weld, not just a minimal tack weld that barely melted into the surface.

If you have access to the back of the weld, copper backing blocks/strips (homemade is fine, or you can get a copper welding spoon for ~$10-20) can sometimes help with not blowing a hole right through the sheet metal.

A TIGHT fit **** joint is very important! No gaps, no lap joints (just an extra place for water to collect and corrosion to start).

Go read through the MP&C thread. Lots of info and examples (and some cool projects and pictures too ). Come back in three days or so after reading through the thread (it's a BIG thread).

And HSLA steel or boron steel are often either considered unweldable or only weldable with more specialized equipment and supplies and procedures. Steel body panels are usually not HSLA or boron steel AFAIK though (frame pieces or reinforcing areas in 'modern' vehicles for crush/crumple zones and the occupant safety zones are when those steels are used AFAIK).

Steel is not 'just' steel.

New Volvo XC40 makes extensive use of AHSS and boron grades

Volvo’s new XC40 small SUV was named 2018 European Car of the Year at the Geneva Motor Show. The vehicle makes significant use of advanced high strength steels (AHSS) including hot-formed boron grades, the strongest automotive steel available today.

automotive.arcelormittal.com

Ford Boron Steel Bodywork | Borates Today

Automotive makers, including Ford, are taking advantage of boron's high tensile strength to build stronger, safer, and lighter cars. Boron steel is a crucial ingredient in the Ford Fiesta's pillars and structural elements and its other car brands. Boron steel is steel alloyed with small amounts...

borates.today

https://www.bodyshopbusiness.com/working-with-boron-steel/

 

[K13]

I've done a lot of cab corners Etc with a 250X Miller and .30 wire. If you've never done body welding you definitely want to do some practice, but even better I would look into the automotive bonding adhesives. They are light years better than they were even 5 years ago, and they make body repair extremely easy compared to welding. An air powered flanger and Patch panels with adhesive can make some great repairs that are very strong and actually less prone to rust than welding unless you're an expert at it.

Don't repair patch panels like this it will lead to mapping of the repair area. The surrounding metal is only one layer thick and the flanged glued layer is 2 layers plus the glue thick and they will move at different rates when out in the sun and eventually that movement will create a situation where the repair area will show through the paint regardless of what you put over top of it first. I work for a company that makes glues and fillers and I can't tell you how many times I have been called out with complaints about mapping when repairs are done this way.

 

[dcg9381]

If I could afford to pay someone that knows what they are doing to do this I would. But I can't. I have a full bottle of 75/25 gas and a new still in the bag/box of .023" ER70S6 wire so There is no money to lay out there. I guess this is the way I will try.

Youtube. Tack, Tack, Tack. Does anyone weld an actual bead across 18ga panel with a MIG?

I'm no expert, last time I did this was with a spot welder, which makes it way easier on panels if you can get the welder in there.

Definitely practice. If you can find some 18 gauge exhaust tubing around, that makes a pretty good test piece.. I think most is 16 ga though.

Don't repair patch panels like this it will lead to mapping of the repair area. The surrounding metal is only one layer thick and the flanged glued layer is 2 layers plus the glue thick and they will move at different rates when out in the sun and eventually that movement will create a situation where the repair area will show through the paint regardless of what you put over top of it first. I work for a company that makes glues and fillers and I can't tell you how many times I have been called out with complaints about mapping when repairs are done this way.

Even if you flange it?