Technical not a Panda !

[pooroldcodger]

Hi Guys. I hope this doesn't get me shot by the mods, but this was the best place I could think of to ask a panel of people well versed in welding up holes!
Please see attached picture of Codger Junior's Nissan floor, for which he wants me to make a patch to make the floor good.
Is it best practice to make a patch as close-fitting as possible and butt-weld it, or is it better to Joggle (Joddle?) a flange round the edge of the hole and sit the patch in it, then weld round it and seal it?
Any advice gratefully received, and sorry that for once that it is a Japanese hole and not and Italian hole!

 

[pooroldcodger]

A picture helps doesn't it??!!

 

[Liquid Knight]

Make a repair panel roughly 5mm wider than the hole.
Clean all the paint of the edge of the hole.

Place the plate over the hole and shape to fit properly.
Once you're happy with the fit tack weld the plate in place a roughly one inch intervals.
To avoid any distortion lap weld an inch at a time until you complete the seem.

Let the weld cool down and place the car on ramps.
Lift the side you are welding with a jack and rotate the ramp so it's out of the way and the car will not roll.

Weld the old metal to the new plate around the inside of the lap the same way as you did inside the car.

Let it cool, grind (if you must) and paint.

No offense taken in "Who should I ask about welding? Panda owners!" ethos.

I started out with MG's and Lancias so Fiats are a lot less stressful.

 

[pandamaniac]

Go on then Mr Liquid Welding Night, answer me this one.
If you do Joggle a flange should you weld both the inner and outer flanges where you can?
Obviously on a door skin this isn't possible, but on a floor both sides are accessible.
Dave

 

[Giacosa]

Hi Guys. I hope this doesn't get me shot by the mods, but this was the best place I could think of to ask a panel of people well versed in welding up holes!
Please see attached picture of Codger Junior's Nissan floor, for which he wants me to make a patch to make the floor good.
Is it best practice to make a patch as close-fitting as possible and butt-weld it, or is it better to Joggle (Joddle?) a flange round the edge of the hole and sit the patch in it, then weld round it and seal it?
Any advice gratefully received, and sorry that for once that it is a Japanese hole and not and Italian hole!

I'd always joddle an edge if I can. Butt welding I find much harder as the panel fit must be perfect to avoid blowing through

 

[pooroldcodger]

First of all I didn't intend to offend by inferring that all Panda owners must therefore be experts in hole repair! I do have a rather holier than thou Panda as you know but I know there are plenty of newer cars that have faired much much worse in the rotting stakes!
Thanks for the great advice and detail. I need to give the site a good clean up first. I don't think the hole will be bigger by then, but one never knows....

 

[Liquid Knight]

Go on then Mr Liquid Welding Night, answer me this one.
If you do Joggle a flange should you weld both the inner and outer flanges where you can?
Obviously on a door skin this isn't possible, but on a floor both sides are accessible.
Dave

Not so holier now would be more accurate.

You did ask about floors but with doors and exterior panel work the best bet is to either V-butt weld the parent and subject metal together or gap weld.

To V-butt (a.k.a V-join but who doesn't like the word butt?) you need to make a plate (or buy one and trim the panel to fit) the same size as the hole you're trying to fill and grind a grove into both the plate and panel edges. Standard practice with a V-butt is between a 35 and 40 degree angle but because the metal is only a millimeter or so thick I prefer a more shallow angle 20 to 25 degrees.
Hold the plate in place. You can use clamps, magnets or I prefer to use my hand.
Tack in place again with a one inch gap between tacks and be very careful welding different angles as the heat will cause distortion.

Gap welding is a similar process but instead of grinding a grove you need to make the plate the width of the welding wire (if you're using a M.I.G) smaller than the hole. Hold the plate in place the same way as before. Tack together and carefully seem the plate to the panel.

I prefer to TIG gap welds as there is more control and it gives a much better quality of finish; but with impurities in car body metal it is better to MIG as it uses less heat and is less likely to distort.

 

[Liquid Knight]

Place the new panel over the hole and from underneath draw around the rail, marking the spot weld holes. Either drill and fill the spot welds or I'd be tempted to lap weld where the floor meets the chassis rail as well.

 

[Aston Martin]

(This pic seemed appropriate for the thread title)

 

[homeward]

(This pic seemed appropriate for the thread title)

Cheeky...!

Next, you'll be saying this isn't a 500.... :yuck: