welding rusty steel

[BrokenBiker]

so we all know steel needs to be as clean as possible to be welded, but when you are in the situation where you just need to get something nailed together and its rustier than a rusty thing in salty water, how much does it actually affect the weld?

i ask as, tomorrow i am going to be welding an exhaust hanger bracket back on to an exhaust.

the bar to be welded on, and the part its being welded to are both rusty, but both solid.

my plan is pretty much, hit it with a wire brush, maybe a quick tickle with a flap disc if ive got one here, then find somewhere to ground to, get it stuck on with a 2.5 rod and then call it done.

its a 5mmish rod being welded to another bit of rod on the back box (the original welds have rusted through, looks like mild steel bar on cheap stainless back box) so im just holding it together and re-welding to keep it off the ground when the cable tie snaps

 

[BrokenBiker]

It'll be crap, but it'll be fine.

You need a clean spot for earth, and a clean spot to start, then it'll burn through the rust.

It won't be as strong as it should and it'll spit like a chav camel, but it's on a ford - get used to it

im not bothered about aesthetics and she wouldnt knoow a good weld anyway, just curious about the metallurgy of it really

 

[BrokenBiker]

I thought it was on your car.

Still, good practice for yours

no, my neighbours fiesta.

my exhaust is solid, as are the mounts, i checked all these things before parting with cash...just didnt check the rear doors both opened lol

 

[cumbriasteve]

When I was welding cars if a round bar bracket was needing done I would always try to slide some tube over it and weld both ends, it improved the strength a lot.

 

[123hotchef]

i did mine a year back used a couple of the m12 square washers as strengthenrs still going strong now

 

[Bill Edwards]

You can weld through quite thick rust with stick and still end up with a very strong joint. Not something you do when you want it to be as strong as it can be for a critical application but much of the time it's still plenty strong enough. Works on most farm stuff...

The exhaust is probably solid because it's an aftermarket part - what about the sills, rear arches, bootfloor/wheelarch interface, behind both bumpers, bottom of A pillars, right up under the front wings...

 

[123hotchef]

The exhaust is probably solid because it's an aftermarket part - what about the sills, rear arches, bootfloor/wheelarch interface, behind both bumpers, bottom of A pillars, right up under the front wings...

solid how does the gas flow through it

 

[BrokenBiker]

The exhaust is probably solid because it's an aftermarket part - what about the sills, rear arches, bootfloor/wheelarch interface, behind both bumpers, bottom of A pillars, right up under the front wings...

all checked...the only rust on it is on the rear door and a spot under the drivers mirror...a few small stone chips on the bonnet too but they are being sorted tomorrow

 

[slim_boy_fat]

She'll be very grateful and won't be crawling under the car to check your work.

 

[BrokenBiker]

She'll be very grateful and won't be crawling under the car to check your work.

she wouldnt know where the underside of the car was lol...she actually asked me the other day if i could turn the child locks on...on her 3dr car...