Last minute welding advice?

[Nicola&Tony]

Hoping to weld this patch into the cab step before mot on Thurs (weather permitting - rain stopped play tonight).



Until a few days ago I hadn't done any welding since Dec (too busy doing other stuff), since the beginners course that I did. This'll be the first welding that I've done on the van. Did lots of practice on thin sheet (1mm) a few days ago, using CO2 for the first time (thanks Disco ) and 0.8mm wire till I got the settings right and was happy with the results.

My plan is to clean up the old metal a bit more (including underneath the step), have the patch sitting in place ready to go and then practice, practice, practice on the bench until I'm into the swing of it again and then move the welder over to the van, tack the patch in place and then work my way around the edge, one inch at a time, doing different sections of the edge to allow some time and space for cooling. Safety precautions will be in place i.e. ppe, welding blankets, battery disconnected, extinguishers nearby.

Just wondering if any of the experienced welders on here have any tips, advice, suggestions etc before I get started?

Cheers

Tony

[weldore]

id say theres 2 ways to do that tony.the first is to do it they way you said but this would leave a cut edge under the patch that will need tacking/welding upside down to finish the job off.the other way would be to cut away the bad steel from the step till you have good metal that wont blow through and make your plate to just cover the hole.then place it over the hole and mark around it with a permanant marker ,remove the plate and cut away the steel inside the marked line leaving the marker line so the plate will sit in the hole..then tack all round it to hold it in place about 20mm gaps.next seam it up.
when you grind out the bad steel this will lift the sealant under the step so you can just scrape it away too..

the second way is a bit more work but you will be more satisfied with the results and if it all goes tets up just do it the way you originally planned

[Fritz]

Apart from disconnecting the battery so you don't fry the rectifier in the Alternator and clamping the Earth as close as you can to the bit you are welding, and maybe a small extinguisher or water supply just in case the stone guard on the underside of the step decides to ignite.


Regards


Fritz,,,,,,,,,,,

[Nicola&Tony]

I forgot to say that the patch I cut is sitting snugly inside a hole in the step, it's not sitting on top of the step. I'm gonna be butt welding the joint, rather than doing a lap joint, gulp!

Tony

[Nicola&Tony]

. . . just in case the stone guard on the underside of the step decides to ignite.

Hadn't thought of that. I'll get an old towel and give it a good soaking in some water before I start. Fire extinguishers will be close by.

Cheers

Tony

[weldore]

thats the way to go...just go round tacking it in and if you get the tacks close enough together then ya seaming will be a doddle.just wip the tops off the tacks if you think they will leave a high spot
....dave.

[dugcati]

keep an eye on the van (and surrounding grass etc if its a dry day/eve) for around 30-45 mins after you finish welding - it has been known more than once for an area (and not always where you have been working) to smolder for a while then.. fire!!

[BigTam]

Nearly fell off my seat there mate, I thought the post read 'Last Minute Wedding Advice',

Just give me a shout if you want someone to hold the fire extinguisher

[Rozzo]

make sure your mask isn't set too dark tone,, and dont be afraid to do hundreds of short duration welds rather than blowin through. if you do blow a hole,, let it cool then spot weld all around it to build up thicknes and slowly close it in til you fill it..
lastly,, turn the welder down slightly before you start,, you can always tweak it back up again once you've tried it m8 but it will kill your confidence if you burn through first touch.
good luck with it

[fullsunian]

If the garage you use for MOT do free retests then take it for a test first. I know loads of folk have had vans failed for cab steps but I don't fail them. So you could end up with a pass and advise, then you can do the welding in your own time which lets the pressure off

[dink]

I don't know how much 0.8 wire you have, when you run out, replace it with 0.6

[Pepperami]

Co2 Argon mix sizzles nicely and what Dink said. Good luck don't worry it's easy really.

[jaylo264]

I was where you are about 7 months ago, and have learned a bit , with much help from 80-90 and mig forum et al --- one thing nobody has mentioned , which i have found useful, is to try where suitable to use 2 mm sheet/plate ; where 1 mm will overheat and cause burn thru in paper-thin surrounding metal , usually rusty , i found that 2 mm absorbs a fair bit of the heat and holes are much less frequent . I did my step like this .
I also found that tacking , as you rightly outline , using a very low input ( wire speed and volts at minimum for my m/c ) , close together as someone said , then pop the fizz up a goodish bit , and you get a wonderful full melted weld ! (did i just e,,,,,,,e ??) almost like a pro .
jaylo

[Nicola&Tony]

Mmmmm, plenty of food for thought there, thanks very much everyone.

Now that its been mentioned, if I had more time to play with (rained all evening again tonight so no more progress at the moment), I think I'd switch from 0.8mm wire down to 0.6mm, wish I'd thought of that earlier. Something for me to remember for next time though.

Jaylo, interesting idea with the 2mm plate. The problem I'd have, would be cutting and shaping it. I can just about manage 1mm with aviation snips, what do you use to cut 2mm with?

Tony

[DavidPallister]

Just to mix things up a bit, i found that i got better welds switching from 0.6 to 0.8mm wire

Dave