I am trying to mig weld a roll bar in my car right now. when i welded in mounting plates in the back i didn't really have a problems with welding causing holes. But with right behind the drive seat it burns right through like a knife through butter. I have the volts as low as i can and i don't leave it in one spot for more than a second. i tried starting on the thick plate then going to the body and it still burns through.
Any tips would be appreciated.

 

honestly,it sounds like maybe you're not experienced enough yet to be taking on a project that could endanger your life if it fails.
i'd suggest getting some similar thickness sheet metal and practicing on it to get the proper settings first.what brand welder is it?most manufacturers have a slide sheet or table to give you starter settings for whatever thickness metal you're working with.
Chris

 

Your right i'm not that experienced. i have put in some time and understand the basic and am looking to learn from this experience. although it might not hold up in a roll over it will for keeping the seat belts secure. It's not my welder but i could find out later what brand it is. I looked at the chart on the side and for the plate size it said to have the volts on 4 but the floor that the plate is being welded to is very thin. I then put it on 1 the lowest setting and it still burns through.

 

what size are the base plates you're using?
Chris

 

They are 1/8" thick

 

Less wire speed, more volts. and its it 110 or 220? and the burn through your probably getting is the undercoating, your gonna have to get all that **** off to weld properly, lift your car up. weld up your hole's you've made little by little, fill your gaps. [freak]ing sucks on honda sheet metal, but that's what your going to need to do. and for the thin stuff, your going to need to practice and balance your voltage and your wire speed on the thin stuff. either that or since your having so much burn though turn your gas up and see if having more gas push at the weld if the puddle will form and you can start a bead. and dont try and weld to the floor pan actually just weld the base plate, and let the weld run to the floor pan, please make sure you remove all the paint around the weld area, easieast way to get rid of burn though. welding is 80% prep time, 20% weld time. the better you prep your metal the better you weld. try not to use a wire brush to clean the paint off either, it leaves metal behind wich will mess up welds. good luck, feel free to ask me any other questions.

 

I assume you are using MIG? What size wire are you using? I remember years ago when i got my welder, I had .035 wire and burned through sheetmetal all the time even on the lowest voltage setting. I went down to .024/.025 wire and I can weld sheetmetal all day long now without problems. Try smaller wire maybe.

 

use a thinner wire and a high feed speed (the wire acts as a heat sink with regards to wire speed; faster = colder)

next time practice before building something that can kill you

 

generally speaking in mig welding:
lower voltage=more penetration i.e. burn through material faster

lean the weld more towards the baseplate to prevent burning through the body.

Post pictures too, as Jerry Maguire said "help me, help you."

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MIsterE533 &raquo;</TD></TR><TR><TD CLASS="quote">Less wire speed, more volts. and its it 110 or 220? and the burn through your probably getting is the undercoating, your gonna have to get all that **** off to weld properly, lift your car up. weld up your hole's you've made little by little, fill your gaps. [freak]ing sucks on honda sheet metal, but that's what your going to need to do. and for the thin stuff, your going to need to practice and balance your voltage and your wire speed on the thin stuff. either that or since your having so much burn though turn your gas up and see if having more gas push at the weld if the puddle will form and you can start a bead. and dont try and weld to the floor pan actually just weld the base plate, and let the weld run to the floor pan, please make sure you remove all the paint around the weld area, easieast way to get rid of burn though. welding is 80% prep time, 20% weld time. the better you prep your metal the better you weld. try not to use a wire brush to clean the paint off either, it leaves metal behind wich will mess up welds. good luck, feel free to ask me any other questions.</TD></TR></TABLE>


it's 220

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bjorn &raquo;</TD></TR><TR><TD CLASS="quote">use a thinner wire and a high feed speed (the wire acts as a heat sink with regards to wire speed; faster = colder)

next time practice before building something that can kill you</TD></TR></TABLE>

lol i guess i'll just make sure i don't flip my car. well i did practice as much as i could before hand. it's hard to know before you start a project like this all the problems you might have.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDcompman &raquo;</TD></TR><TR><TD CLASS="quote">I assume you are using MIG? What size wire are you using? I remember years ago when i got my welder, I had .035 wire and burned through sheetmetal all the time even on the lowest voltage setting. I went down to .024/.025 wire and I can weld sheetmetal all day long now without problems. Try smaller wire maybe. </TD></TR></TABLE>

yeah i'm mig welding it. i'm not sure of the wire size, its not my welder but i'll find out and let you guys know.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by KENetics1 &raquo;</TD></TR><TR><TD CLASS="quote">generally speaking in mig welding:
lower voltage=more penetration i.e. burn through material faster

lean the weld more towards the baseplate to prevent burning through the body.

Post pictures too, as Jerry Maguire said "help me, help you."

</TD></TR></TABLE>

thats good to know. if i still have this problem after i try out some of the things you guys said then i'll try posting some pics. I can try both but which is it, faster or slower wire speed that is better for not burning through?

Thanks everybody for your comments

 

Try just doing a tack, moving forward, and tacking again. If you do it right you will eliminate most of your heat (as long as you let the tack cool) and it will look like a TIG weld.

Trying to run a bead will be pointless because you may be melting the base, floor of your car, but you won't be doing anything with the plate for the roll cage.

 

well i'm able to do small tacks with out it burning through but not enough to weld the plate in. On monday i'll be able to work on it. thanks for the idea

 

there's some incorrect info in this thread..

"Less wire speed, more volts. and its it 110 or 220? and the burn through your probably getting is the undercoating, your gonna have to get all that **** off to weld properly, lift your car up."

"generally speaking in mig welding:
lower voltage=more penetration i.e. burn through material faster"

1st: While it is a good idea to clean off the undercoating, I suspect he's just talking about the heat of the arc burning throught the metal. Turning up the arc voltage and dropping the wirespeed will put more heat into the weld and less metal for the heat to dissipate into. How would that possibly make it burn throught the metal less?

2nd: I=V/R. Amperage= Voltage/Resistance. if you turn up the voltage, that results in more amperage flowing through the circuit, since the resistance is basically the same. More voltage=more wattage dissipated into the metal=more heat=more penetration.
I'd say use a smaller wire, turn up the shielding gas, clean the metal, bias the heat toward the thicker parts, and find the right settings on the welder. And seriously, don't attempt **** you can't do, what's the point if you're just going to mess it up? Practice on something else first.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mike03,95civic &raquo;</TD></TR><TR><TD CLASS="quote">I am trying to mig weld a roll bar in my car right now. when i welded in mounting plates in the back i didn't really have a problems with welding causing holes. But with right behind the drive seat it burns right through like a knife through butter. I have the volts as low as i can and i don't leave it in one spot for more than a second. i tried starting on the thick plate then going to the body and it still burns through.
Any tips would be appreciated.</TD></TR></TABLE>

I had the same problems welding the rollbars on my golfcart.You just have to turn down the heat a bit, and clean the metal.

 

stitch weld it on low amps and low wire speed if you cant do that you really shouldn't be attempting that

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rorik &raquo;</TD></TR><TR><TD CLASS="quote">there's some incorrect info in this thread..

"Less wire speed, more volts. and its it 110 or 220? and the burn through your probably getting is the undercoating, your gonna have to get all that **** off to weld properly, lift your car up."

"generally speaking in mig welding:
lower voltage=more penetration i.e. burn through material faster"

1st: While it is a good idea to clean off the undercoating, I suspect he's just talking about the heat of the arc burning throught the metal. Turning up the arc voltage and dropping the wirespeed will put more heat into the weld and less metal for the heat to dissipate into. How would that possibly make it burn throught the metal less?

2nd: I=V/R. Amperage= Voltage/Resistance. if you turn up the voltage, that results in more amperage flowing through the circuit, since the resistance is basically the same. More voltage=more wattage dissipated into the metal=more heat=more penetration.
I'd say use a smaller wire, turn up the shielding gas, clean the metal, bias the heat toward the thicker parts, and find the right settings on the welder. And seriously, don't attempt **** you can't do, what's the point if you're just going to mess it up? Practice on something else first.</TD></TR></TABLE>

Well thanks for clearing up incorrect information. And i could explain why i decided to take on this job or how even with it being frustrating i would still do it, but thats not the point.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dc5tegk20 &raquo;</TD></TR><TR><TD CLASS="quote">

I had the same problems welding the rollbars on my golfcart.You just have to turn down the heat a bit, and clean the metal.</TD></TR></TABLE>

Thanks for the info i'll keep that in mind

 

Just a little update... i was able to weld the plates in. I did what some of you said, i had to completely weld just on the plate part and let it run down on to the sheet metal. It's amazing i was looking at one of the holes before i filled it and the metal is paper thin.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rorik &raquo;</TD></TR><TR><TD CLASS="quote">there's some incorrect info in this thread..

2nd: I=V/R. Amperage= Voltage/Resistance. if you turn up the voltage, that results in more amperage flowing through the circuit, since the resistance is basically the same. More voltage=more wattage dissipated into the metal=more heat=more penetration.
</TD></TR></TABLE>

I don't know all the science and stuff like that behind it but when I was taught how to weld it was usually a general rule that reducing the voltage results in narrower weld bead with higher crown and deeper penetration.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mike03,95civic &raquo;</TD></TR><TR><TD CLASS="quote">Just a little update... i was able to weld the plates in. I did what some of you said, i had to completely weld just on the plate part and let it run down on to the sheet metal. It's amazing i was looking at one of the holes before i filled it and the metal is paper thin.</TD></TR></TABLE>


That is a dangerous way of curing your problem for someone that doesn't know what their doing to begin with and shouldn't be doing it either. I hope its your car you experimenting on. It would be a shame if someone else was the test dummy. It is very easy to have a good ? looking weld that doesn't hold. Having a welder doesn't make you a welder it makes you a guy with a welder. The least you should have done is get enough scrap so you could practice and know you had it right. I know it probably would have cost to much money to buy the scrap! How much cleaning could you of done if it took you so long to realize how thin the honda metal is. Many areas you can flex it with your fingers. I don't even grind it. I have a little vac blaster just so the metal doesn't get any thinner. fox body mustangs are just as bad in spots.

I am not sorry for being so negative as this is the wrong way of going about adding saftey equipment. KNOW what your doing or take to someone that does!!!!!!!!!!!!!!!!!!!!!

 

Thanks for the comments. If we could please try and stay on topic i would appreciate it. if you have any questions or concerns for im, then feel free to pm me.

 

Would it be smart to a plate under each side and have bolts go through as an added precaution?