Automotive Rust Repairs.

[Des]

Hey Hey,

 

I'm going to fix the rust in the sills of Fatty's Ke20 and i have never welded steel this thin before. I did a lot of welding at school with a MIG and i can weld reasonably well but that was 5 years ago. I have an Ae71 shell to practice on and supply me with sheet steel for patches etc.

 

Anyway can any one suggest some tips or tricks ?

[Bamboo]

As you stated, practice.

 

Advice given to me from a boiler maker, mess with speed and voltage until you come up with the desired weld for your project. It'll take a bit of patience, but you will know when you've hit it. No blow holes and clean welds.

[19914afc]

When I did the rust in my door jams, I used about 2/3 volts when I put a plate in, the metal was quite thick. When I did it in nearly same spot but only a very small hole which I tacked up I varied between 1 and 2V. Couldn't remember what wire speed I used.

 

That was done with a industrial gas mig, got same results with a cheapish gas mig as well.

[Des]

When I did the rust in my door jams, I used about 2/3 volts when I put a plate in, the metal was quite thick. When I did it in nearly same spot but only a very small hole which I tacked up I varied between 1 and 2V. Couldn't remember what wire speed I used.

 

That was done with a industrial gas mig, got same results with a cheapish gas mig as well.

My MIG is a 170A Lincoln electrics gas setup.

[Tazrolla]

is an idea that when ya welding on thin metal just to do spot welds so it doesnt warp the metal... it might not look pretty but thats what they invented grinders for :blinks:

 

try and find a strong magnet to hold the metal flat to surface your welding to and go slow

 

if there are any bends in the peice you need to replace then after you cut out the old metal get yaself some cardboard and make the approx shape needed and then trace it onto the new peice of metal and cut and bend it before welding it to the car

 

hopfully thats been some help to ya :jamie:

[Trev]

is an idea that when ya welding on thin metal just to do spot welds so it doesnt warp the metal... it might not look pretty but thats what they invented grinders for :blinks:

 

+1

[KENut]

Always prepare the weld properly. With sheet I leave a little gap (< 0.5mm) all around the patch.

I find it helps with penetration whilst not getting it too hot and warping. Means you can do neater welds too.

 

Make sure its not windy. Otherwise the gas is doing nothing and you'll get a crap weld

 

Pre-heat the panel if you're fussy

 

:blinks:

[Des]

I was messing around today as i got a gas bottle and i can keep it real clean with little tacks. I was practicing on some Ae71 bits.

[oh what a nissan feeling!]

The biggest thing i've found with low amp welding is cleanliness. wire buff, sand, grind, just make it real shiny and clean.

 

I also found the .6mm wire to be a heap better to use for the thin stuff too.

[Trev]

What gas did you get?

[Des]

I'm running 0.8, Seems to be decent enough, But like you said it needs to be really clean other wise it splatters a lot or explodes if the steel is thin and there is rust on the other side.

[Des]

What gas did you get?

Argoshield.