Floor pan patch weld advice

[acealfa]

Hi,

While working on my car I've unearthed some rust holes on the floor pan so I'm after some advice on how to go about the repair. I've had experience welding but never done anything like this before.

What size thickness metal would be recommended? I was thinking 1.2mm.

My plan is to use a Dremel to cut out the rust in square sections then weld new pieces in from the bottom, I don't really fancy sparks flying about inside the car.

Would this be the best method of repair? I did think about just covering the whole area with rust converter then putting patches straight over the top but would this be considered a bodge?

Many thanks!

Edited by acealfa on Thursday 22 October 18:27

[acealfa]

Thanks for the advice guys. I will remove the interior and carpet once I can get the car rolling & probably tackle from the top. I’m going to have a practice butt welding some sheets together before but will drop back in with some pictures.

[acealfa]

Thank you for the tips.

I've fast realised my current welder isn't up to the job. It was only a cheap one but even on the lowest setting just blows holes straight through even if I just tap the surface. I'm considering buying a Clarke 135te as it seems the next level up & allows for a lower setting.

[acealfa]

Just to give an update on this. I've learnt so much doing this that if I was doing it again I'd do a much better job & do things a bit differently. I got more of a feel for it as I went on. In the end I'd had enough working on my back with no space in a tiny garage that I just left the welds & didn't grind them down so doesn't look the greatest from underneath but it's no solid & passed an MOT so I'm happy for the time being.

[acealfa]

V8covin said:

Not much penetration there, should have turned the power up a setting.
I would have done it in 1 piece personally

Any higher I was blowing holes but maybe something needed changing with settings because even when I was welding on test pieces it was building high welds if that makes sense.

[acealfa]

Evoluzione said:

Your other problem is you've actually left the rust in, you can't weld to rust very easily. Cleanliness is very important when welding.
A patch lapped over would have been better than trying to butt on a floor pan.

I did realise i should have cut more out as I started but was a bit reluctant because of the shapes but I might do it fresh next year once I’ve had some more practice.

The gas I have was a disposable bottle from Toolstation so maybe not good enough?