Advice needed 1993 polo sills

[Mikey D]

I'm in need of some advice please .... ok this old polo failed mot on rotten sill . The filler bodge is a give away I've not done any welding on rusty cars for years but have a decent welder Kemppi min arc mig , so havethe gear but not much idea
As you can see I have a new sill and I think it's zinc coated or some such . So could I just out out the old rot and weld this on top of good metal I don't fancy trying to cut it so I can butt weld !
Allso the bottom flange I'm assuming that has to be fully welded along the edge , that in itself looks tricky ...basically it's giving me anxiety and not too sure how to start this job ......Helpppp cheers mike

 

[pedrobedro]

Have you forgotten the pictures ?

 

[Mikey D]

Have you forgotten the pictures ?

Yes!

 

[Mikey D]

Yes!

 

[mike 109444]

First thing to do is establish what good metal you have.
Get a big marker pen, place new sill over old and mark round edge.
Then get a polly stripper disc (don't use a grinding disc YET). Go round the marker pen area with an inch either side of it to see what metals left.
You may be able to mimic the original spot welds along the bottom flange (plug weld) to avoid having to do a "fully welded" edge as you are replacing the WHOLE panel.
Come back when you have striped it back as until then it's difficult to say for sure the next step.

 

[tom2207]

Yep as above , every repair on rusty cars needs a nice silver edge all the way round as a starting point ., then you can start to actually think about the repair its self.

 

[mr haynes]

Bottom flange can be spot/plug welded. Replace like with like.
As above, clean back first to see what you've got to work with

 

[mike 109444]

Disc like these

Essentials Straight Shank Surface Preparation Wheel With Arbor 100mm - Screwfix

Order online at Screwfix.com. For use with drills on metal, wood, fibreglass, granite, brick and stone. Removes paint, varnish, rust and scale. 6mm arbor. FREE next day delivery available, free collection in 1 minute.

www.screwfix.com

Abracs Spindle Abrasive Mounted Poly Wheel Brush

For effective removal of rust, paint, thermal blueing and other contaminants with minimal risk of scratching the workpiece. Mounted on a 6mm spindle. Max rpm 2,500.

www.toolstation.com

 

[Mikey D]

That's the kind of advice I need mike and tom , I have a poly disc will use it tomorrow it would be great if I can plug weld the bottom flange but I guess that depends if it was spot welded originally ?(thanks mr Haynes seems it was !)
I'm feeling a bit more confident about it now so thanks guys .

 

[bricol]

I can recommend these things for stripping surface rust and paint with a grinder -

https://www.amazon.co.uk/gp/product/B07QMJYTCT/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

Let them cut and not press down too hard, and they last a good time.

 

[mike 109444]

Not sure if the top of the sill is like in this pic but if so then could be spot (plug) welded along top as well.

 

[Onoff]

Once done, Polo sills should look mint.

 

[optima21]

good luck with that it will be worse on the inside, there is a metal tube that the flue tank balance pip goes it (connects near the top on the petrol tank filler neck and the top of the fuel tank. this tube rots out and lets water onto the inside of the sill.

if the bottom of the inner sill has rotted out, its not too difficult to repair, on mine I had to repair the edge of the floor too

repairing inner sills

one of these had rotted away on one on one of my cars so here's a quick post about how I replaced a 2 ft section. the bottom edge of the inner sills on my car are straight, so by claming a 1m length of 25mm square tubing against the original ends of the sills you have reference point that the...

www.mig-welding.co.uk

the petrol tank filler neck also traps dirt behind it so also rots the inner wheel arch where it meets the sill. when I did that section on my polos I reshaped it slighly, by making the join between the outer sill and wheel arch higher so its easier to remove the petrol tank.

Once done, Polo sills should look mint.

yeah but a polo is a mint with a hole in it

 

[pedrobedro]

Once done, Polo sills should look mint.

So they should have holes in We made a repair panel and let it into the sill on my friend's N reg Polo and when it was done it looked perfect but it lost the bit that indicated where the jacking point is located under the car. Can't have everything I think.

 

[frank horton]

Also u need to be extra careful where all the sill panels joint on the lower edge.
often the 3panels spot welded together has maj rust between the welds…on touch with a mig will blow it away….
often needs to cut out the inner sill along this edge to get a repair strip giving a good edge…all three panel on that edge need to be rust free…
often the rusty bits between the welds can be pulled of with pliers leaving the fat spot weld behind…
when do start to weld make sure u are comfortable…real important for good welding
PLUS
i always have a few old squeeze bottles full of water just in case …

 

[vw1]

I did a similar repair on the corner where petrol tank pipe is but made my own repair panels. It was alot worse than 1st though.

I ended up taking rear axle off so I could remove petrol tank and get better axis to cut rotted metal out and weld in new.

What model is yours a Gt ? Where did you get your sill from?

 

[Mikey D]

Cheers for all your input guys , having cleaned around the rotten bits, one piece of floor will need a patch . Seat needs to come out .....