Welding, please help!

[dawning 11]

Hello sorry to keep starting threads on my car woes. I was going to start a project thread but I don't seem to be able too. I really do appreciate any help and so does my 205!

I'm not a mechanic so I'm just trying to learn as I go. 

I've cut out the rust on the floor piece, im hoping someone with a better understanding of what's going on can give me an idea of what to do next.

I could weld a plate in with a 90 degree bend bend at this stage but it looks like it's rusting inside the sill. I'm not looking to do an immaculate job but I don't want to allow it to get worse inside. Just need a few words of advise at this stage before doing anything I regret! Thanks

 

[dawning 11]

Upon further investigation..

[petert 549]

You'll have to cut a bit more away so you can see the full extent of what's rusting. Then remove the rust on the inside and condition/paint it, before closing back up with some new steel. That is a bastard of a place to work. If you're not a confident welder, I'd prep it all and then take it to a pro.

[dawning 11]

Thanks for the reply, much appreciated. Definitely not confident with a welder, I did manage to do the inner wings... just about. I will have to give it ago as I can't afford much at the mo.

Unfortunately the outer sill is quite rusty so I'm not sure how easy it is going to be to weld onto if that makes sense. From what I can tell it's 3 sheets of metal that join with spot welds along the bottom. I'll treat the inside today at least and hopefully make some plates. 

[petert 549]

Given the rising value of 205’s, you owe it to yourself to fix it properly. If you can’t afford it just now, just clean up and treat what’s there with fish oil.

[dawning 11]

I do agree. Although I doubt my xs will ever be worth what I've spent on it already! The whole body is very rough but doesn't seem to be suffering to badly from rust considering the age. Maybe one day I can get the whole thing done properly.

I treated the rust with rust converter and sprayed stone chip over it before I took it for the mot but they picked it up, seem a little bit unfair but a few hard jabs with a screwdriver did make a hole. 

[dawning 11]

This is where I'm at. My plan is to spray with weld through primer, which I need to go and buy, then seam weld the plate on to the very rough sill that I've tried to rescue but in reality probably needs cutting out. Then seam weld the floor piece in afterwards. Hopefully that will work!

[dawning 11]

Inside the sill seems sounds which is good!

[dawning 11]

Managed to get it done thanks to the weather, hopefully its not too terrible! I'll get it tested tomorrow.

Edited September 29, 2020 by dawning

[Tom Fenton 1,524]

Not loving it sorry.

 

More amps needed, as all that crap in the corner is just sat on top, there is no penetration.

[PhilNW 40]

Have a look on here re welding thin metal

 

https://www.youtube.com/user/weldingtipsandtricks

 

[Tom Fenton 1,524]

 

I have previously done the same job. More current means it’s penetrated the existing steel to make a strong repair. Maybe you have the wire speed too fast as well.

[PhilNW 40]

Another good site for tips

 

https://www.mig-welding.co.uk/

[Telf 222 2 Cars]

17 hours ago, dawning said:

its not too terrible! 

I'm with Tom on this.  Pigeon s*it that you can knock off with a hammer. Structural strength  next to zero due to lack of penetration. 

[dawning 11]

Thanks for the feedback guys! 

I did try turning down the wire speed but was getting a lot of popping. The corner where it joins I made a 90 degree fold which didn't match up very well so in ended up just throwing weld at it. Maybe I'd be better off without the fold. Do you think it will pass an MOT? It's all covered in sealant so it's not visible. I think I'll leave it for now as it was actually the wrong place, it failed the not on a hole I hadn't even seen up near the petrol tank! My own stupidity!

[Telf 222 2 Cars]

7 hours ago, dawning said:

Do you think it will pass an MOT?

yes more than likely you are only allowed to apply thumb pressure when looking at anything. More importantly though without penetration there is no strength, essentially just glued 2 bits of metal together with a load of metal splat-not ideal. As part of the floor and sill interface its now a weak point.

[dawning 11]

Thanks for the reply. Yeh, I agree, I will sort it out but i just need the car on the road at the moment. I did do some welds on the underside to join the sheet metal sandwich together which hopefully give it a little bit of strength. 

[Leslie green 81]

Will get you a pass for now , later you can grind it down a bit and hit it with more power , you can't really continuous weld thin steel unless you are a very good welder anyway plus the heat will warp it , its more a case of a series of 1 second tacks one behind the other joined together in quick succession with a pause after every 3 or 4 to let it cool , a wet rag is good for this if you haven't compressed air to cool it. If you are not getting much burn into the metal the torch is possibly too far away too , you need to be within 5mm for a good arc.

That's a tricky area to be starting on but needs must ...

[PhilNW 40]

https://www.mig-welding.co.uk/thin-metal.htm