not french car realted .. welding question

jgra1 · Unread post by **jgra1** » 13 Aug 2006, 19:24

Hi All..
I know I need hours of Welding Classes but.....

I tried to weld two peices of metal together earlier, under my campervan ...

sounds easy

I was using an old stick welder, i had extinguishers to hand etc.

One of the objects was a handbrake cable mounting plate located on the chassis of the vehicle, made of what looked like 2mm mild steel?
The plate I was welding to it, was a galvinised (ground) peice of 1.5-2mm I presume Steel also?

No matter what, I could not get them to fuse. The weld would stick to either, but never to both... in some cases the added object would completely melt itself, still wouldn't fuse..

I tried various power setting to no avail.

any thoughts?
John

bxbodger · Unread post by **bxbodger** » 13 Aug 2006, 20:51

The metal probably wasn't clean enough, that's what usually causes this. You need to get both bits really bright and clean, well clamped together, and a good earth.

The other problem may be that your welder just isn't powerful enough-2mm is quite thick and would need a machine with a bit of punch to sucssessfully weld the two bits together.

A word of warning- welding galvanised steel can be dodgy, especially in a confined space!! It welds like any ordinary steel but gives off poisonous fumes so be quick and do it in a well ventialated area!!

citronut · Unread post by **citronut** » 13 Aug 2006, 22:00

try a magenite to see if it is steel or alli
regards malcolm

jgra1 · Unread post by **jgra1** » 13 Aug 2006, 22:31

Malcolm, can you be more specific? ( as i am a beginner)

BX.. both peices were bright freshly ground, no Zinc present, welder is a monster, the scale on the side reads up to 3/8 inch. i tried different power levels.. was outdoors..

I think its down to my inexpertise, there is a chap on the farm with a mig, I may just pay him a tenner to do it ....

J

AndersDK · Unread post by **AndersDK** » 13 Aug 2006, 22:45

Malcolm advices you to use a magnet - to test that both materials are in fact mild steel. You can be cheated these days by the surface finish

Me myself is a novice in welding - but my first lesson learned was that both parts to be welded together must be quality earthed. If not - its like melting blops of metal to one part only. Drill a couple of holes through both parts and secure both parts together with self tapping screws.
Then stitch weld a couple of points such the 2 parts are secured together. Remove the selftappers and fill the holes with the welder - one at a time.

As mentioned above cleanliness is a must to get results. Use a special cleaning disc on your angle grinder.

A second lesson learned is that welding upside down is for the wizzards only - not a beginners job. Meaning patch welding in floor panels must be done from inside the car.

jgra1 · Unread post by **jgra1** » 13 Aug 2006, 23:06

thanks Ands..

I couldn't even get a 'tak' on anything.. earthing was good, welding was horizontal.. everything clean..

I was quickly told, 'stick' welding makes MIG look very easy.. hmm

sorry Malcolm I quickly saw the [thought] rare chemical mang en ite or something and er . didn think

- Magnets.. no problem.

J

fastandfurryous · Unread post by **fastandfurryous** » 14 Aug 2006, 11:34

Have you had any experience of using your welder in better conditions? (on the bench, no wind, clean metal etc) Arc welding is an artform, and it's hard. The problem is that the droplets of metal are transferred from the stick to the parent metal through the arc, and the arc will to favour one piece more than the other. You use a triangular-ish swirly-loopy motion (technical term, that) to ensure that you're blending the two parent metals with the weld metal, as well as pre-heating the next bit of the weld.

Alternatively, as you mentioned, use a MiG. Much easier to use than a "stick" welder, and gives better results.

jgra1 · Unread post by **jgra1** » 14 Aug 2006, 12:18

thanks Fast..

no I went in at the deep end...
no practise..

jgra1 · Unread post by **jgra1** » 15 Aug 2006, 09:36

well..

i bit the bullet and brought a mig !!

cost me £8 so hope it will do the job !!!

I got it home, all works fine, except, the welding wire was very hard to remove from the outer cable/pipe. Took pliers and a strong tug to remove it. It had a couple of kinks, was only 0.6mm anyway. Hopefully I can find what appears to be the blockage .. I tried to run new wire back in and it got stuck just after the rollers.. maybe an inner casing has frayed?

One question, it has a gas pipe, but I brought some 0.9 fluxed wire this morning in preference to gas, is this ok?

thanks as always
novice welder John

406 V6 · Unread post by **406 V6** » 15 Aug 2006, 09:44

No problem if you're using fluxed wire. I'm using the same wire you bought (0,9mm) and usually for a good solder joint (not on thin materials) i set the machine up to 90A.
As for the wire not advancing on the gun... i had to remove the plastic guide tube on mine, as it didn't let the wire go freely. Bought a brake tube sleeve at a bike shop and solved the problem. But as yours' hired.... i would talk to the guy who lented it out to you...

jgra1 · Unread post by **jgra1** » 15 Aug 2006, 10:17

V6 many thanks

no I brought my welder off a farmer, last night ! £8 i thought was quite good price

Yep will look at inner guide tonight.. how long was the brake tube you brought? surely the weld pipe is longer than a bike brake cable?

John

jgra1 · Unread post by **jgra1** » 15 Aug 2006, 10:18

ahh hang on..

the guide plastic is only a short piece ? ok i understand..

J

406 V6 · Unread post by **406 V6** » 15 Aug 2006, 13:42

Man, that was cheap!!! Good luck with it. It takes a bit to make long welds that look kind to the eye; i mainly use it for spot welding, nothing can beat a MIG on that task!

No, the guide is all the way along the welder gun tube.

See the black tube that comes from the welder to the front gun? The electric cable and the plastic guide goes inside of it.

On mine it was 2 meters long, no more no less, but then again, i could buy any size at the local bike shop

It took around half an hour to change. Now the wire goes as sweet as a pint of lager down the throat (i don't like beer, but it's a nice comparison, hey?

)

I would also unscrew the gun tip, it's made of brass and can block sometimes. It's usually good practice to clean it up from time to time too.

bxbodger · Unread post by **bxbodger** » 15 Aug 2006, 14:10

You may have a problem getting the wire through the tip. Most small gas migs come with a .6mm tip fitted for normal wire/CO2 migging, flux wire won't fit through it- I think the same may apply to the liner as well.

Ally welding wire is a bit thicker, 0.8mm, and in a normal MIG (i.e. not one that's sold for gasless/gas use) I think to use the thicker ally wire you may need to change to a bigger bore liner and you definately have to fit a .8mm tip.

I don't know for certain, as I've never tried to get gasless welding wire through mine-but you'll definately need to change the liner and tip to one that's big enough to take .9mm wire.

Unread post by **RichardW** » 15 Aug 2006, 15:06

The liner should be OK to take the .9mm wire - mine runs on .8mm and there is plenty of spare in the liner. You will need a new tip, but these are cheap (and should just screw out - unless it's welded to the torch

). You may also need to change the roller - although mine has 2 grooves in it and can be reversed for .6mm/.8mm wire. I'd imagine the .9mm would run OK in the 8mm groove.

It takes a fair bit of practice to get the right mix of power and wire speed, torch angle and position, and speed to get a decent weld. It's easier if someone gives you some tutoring at first!