[serenity]

ok ive got plans drawn up for building a front bumper, and im thinking of doing the back as well.
my first question is what sorta steel should i use and how thick?
second thing my welding is dodgy (only tried it out on bits of scrap metal), when im welding up say 2 sheets of metal at 90 degrees do i weld the inside or out side of that angle or both?
also any other tips for a rookie welder are appreciated.


glenn

[Talos]

what kind of welding machine are you using?

the first thing is just to have a steady hand and use the right wire/pin/current and you´re in bussiness.

I mostly use MIG welders, they´re pretty easy.

[serenity]

um yeh my terminoligy isnt great but its a stick welder i think, its got a long blue electrode thing which melts into existing metal. (yeh im a real rookie)

[brokenparts]

mild steel is probably the best suited for the bumper.... If you want it to be heavy duty go 1/4 inch and that should be more than thick enough for you. Most stick welders I've seen are 220 so penetration should be no issue at all for you if you have decent technique. Practice, Practice, Practice! A bumper is a pretty good first project to learn on!

[serenity]

yeh its not gonna be a weight bearing bar no winches, just gonna hold 2 fog lamps and 2 driving lights and have a couple of holes to allow for hitch points bolted onto the frame so 1/4 inch sounds kinda heavy. so which side of the angle should i weld anyway?

[brian]

in your case(questionable skills, no offense intended) weld everywhere you can get to.
there are many kinds of steel. regular run of the mill(haha steel joke)black, a36, mild, hot rolled, cold rolled, boiler plate, whatever they call it down there, plain jane ''steel'' is what you want.
3/16(.1875)" to 1/4(.25)" is pretty much teh standard for bumpers, anything more is over kill, anything less......is, well, less.

not all welding rods are equal.

we need to know more details about your machine.
like, is it an AC only machine or do you have a DC machine?
depending on that answer depends on what rods you can run, see above.
what kind of voltage are you feeding it? the more, the marrier.

you help us, help you and you will will end up with more skills and fine finished project.

[serenity]

[quote=brian;2205556]in your case(questionable skills, no offense intended) weld everywhere you can get to.
quote]

ill admit to having questionable skills thats why im building this to teach myself so no offense taken.
its an AC machine running 240 V, the electrodes ive got have an amp range of 95 to 125, box says there good for mild steel wanna know anything else?

[brian]

ac machine= not so good, but wil get the job done.
240v=good.

what kind of rods are they?
can say i've ever seen blue rods, but there they are. there should be a number on the rod themselves that same number should be on the box.
read the box, make sure those are AC rods.

[serenity]

they are cigweld rods aussie stuff, the box says they do both ac and dc, are you talkin bout the classification number? cos its E4113. whats the positives of DC over AC?

[brian]

smoother, more controled arc.
i'm afraid the numbers they us over down, there are not going to jive with numbers i'm accustom to dealing with.

a quick goggle seach just proved that.

http://209.85.165.104/search?q=cache...lnk&cd=9&gl=us

your 4113 is our 6013.

an 1/8" rod should run around 90 amps.

it will lay a strong bead, though it will not have the smooth look most people think of when talking abuot welding. you may have to run two pass in order to build the bead up enough to sand it smooth, for a clean looking bumper.

the rod motion will be a ''whipping'' motion, do not just drag it along.

[Rigger]

I'm not a welder, but as a structural engineer, I do specify welds and I know enough about welding to be a bit dangerous.

In my judgment, 1/4" plate is too heavy for this application. I think you could do well with thinner plate. Mild (ASTM A36) steel is appropriate. The down side to heavy plate is unnecessary weight. The up side is less distortion when you weld it. That said, I'd think 3/16" or even 1/8" would suffice for a bumper.

I'd think you'd want to tack the whole thing together, then come back and fill in with thin weld beads. Don't weld too much in one area. Work a little at a time and move around end to end, side to side. Don't let any one area get too hot or it may warp on cooling.

If you don't use continuous beads, you could get rust back in the seam that would leach out over time. A thin continuous bead, called a seal weld, is what you'd want to do.

That's my $0.02

[JoeCanadian]

come on guys ita all about bridging 3 good batteries with some booster cables and bam your welding with 36v "gett'n ER Done"

[Pin_Head]

4-5 mm mild steel (SAE 1015) would be a good choice for a bumper. I wouldn't even begin to weld it until you are checked out on your technique, since a bumper falling off could cause you a major head ache. Practice welding two pieces of flat steel and bend them back 180 degrees. Practice welding both sides of a T joint and bend the welded piece back 90 degrees. If you can bend the welds without them cracking, you are ready to give it a go. No worries.

BTW 6013 is a "drag" or "contact" type rod. Stick it in the puddle and drag it along. Here in the states it is called a "farmer" rod because most farmers are skilled enough to run them. It is 6011 anhd 6010 that need a whip motion and take a bit more practice to run well, but they are deep penetration "digging" rods and they can weld through paint and rust.

[serenity]

cool thanks pin head i like it when people talk metric, ive had a bit of practice and ive impact tested what i made with a large sledge hammer and it doesnt break, this wont be anything fancy, not much more than what the stock bumper is just a bit shorter.

[DirtyLittleSecret]

Originally Posted by brian

ac machine= not so good, but wil get the job done.
240v=good.

what kind of rods are they?
can say i've ever seen blue rods, but there they are. there should be a number on the rod themselves that same number should be on the box.
read the box, make sure those are AC rods.

AC=not so good? Its fine...I do code work with AC all the time. People just dont spend much time doing it to get the hang of it.
Go get some schedule 80 1/4" steel. The rod you will want to run is a 7018E (will allow a nice penetration AC weld with a pretty bead, and flows nicely). Use acetone to clean everything off prior to welding (put it away beforehand though as its highly flammable). You will probably want to run it a little cold for learning so that you arent blowing holes through it (say 100A).
Have fun! Too bad you arent near me. I'd let you really have some fun!

[brian]

Originally Posted by DirtyLittleSecret

AC=not so good? Its fine...I do code work with AC all the time. People just dont spend much time doing it to get the hang of it.
!

that is just it, you need to get the ''hang of it''. this guy has stated he has not even quite reached noobie status with a welder yet.
ac is fine if you know how to use it, ''not so good'' if you're just starting out.

and just what is sch 80 1/4" steel.?.....normally it's one of the other he's best to stick with plate before he moves on to pipe.
his numbers do not match up with ours, 4814 would be his version of the 7018.

my mistake with the rod motion, i rarey use any 60 series outside of 5p's, and memory is obviously fading.

[serenity]

thanks for all the replies u guys have been a good help, i cant wait to get into building it, just gotta get the metal for it but im currently unemployed so the cruiser work is going slow again thanks to money issues. while we're on the welding topic what guage steel would you use for a rear quarter chop?

[2badfjs]

i'm no engineer either but we are talking big heavy cruisers anyway.

go big or go home! 1/4" all the way.
after i cap the ends of my bumpers, i have a 1/2" of plate welded on the ends.

but anyway, tack it all together then i go back and lay about a 4"-5" bead, move to the other end of the bumper and do the same. go to the middle then move back and forth cleaning your welds before welding over each one.

and when i start a new weld where another ended, i'll back up over the first weld as not to get a low spot between them.

i also fully weld the outer part of the bumper and lay some support welds on the inside.

have fun!!!!!!

[Big Daddy]

Use the 1/4'' steel for the bumper . As the previous posts have said practice , practice and more practice. Nothing more embarassing than to tie a strap onto your bumper and have the welds break and the bumper fall off. Run the machine as hot as you feel confortable with , no cold welds.
For the mild steel use E6011 (AC or DC rod ) . This rod is stronger than mild steel. You can use Low Hi rod but by being a beginner if you have to weld vertical it could be nightmare.

[jeds]

Hi fellow ozzie,I am a boilermaker,pressure welder and for your skill level go to awelding shop and buy some cig brand rods called ferrocraft 22 they are very easy to use but you can ony weld downhand with them hope this helps.