Welding sill advice needed

[delcbr]

Hi just finished welding the sill 16" long by 4" accross :-0 what's next filler on the fresh metalwork or do I primer it first then filler followed by primer again?
Can someone tell me the process of filling and sanding and recommend what stone chip to apply to finish it off. The car is light grey.

 

[Daz1968]

You really need to weld up the holes in the weld you have done and then grind flush again else the moisture from behind will ruin any finish you put on, you can then fill on the bare metal, follow up with epoxy primer then top coat as required,

 

[Rocketman]

It's an MOT fail if it isn't covered up. Unless it's a full sill being put on, patches needs to be fully seam welded.

 

[Rocketman]

Paint wise epoxy primer, filler, stone chip, grey primer, colour coat & then clear coat.

Alternatively filler then epoxy primer, stone chip, grey primer, colour coat and finish with clear coat.

 

[octo0072000]

as said by rocketman
the bottom of the sill needs to be seam welded for a MOT as you have only fitted a patch not a full sill

 

[delcbr]

I bought the car from family member. My plan is to do the repairs and mot at a different mot station. Iam a bit confused on how to proceed from here because iv spot welded it the same as original sill and the replys are telling me it's not right?how do I proceed from here just fill and paint and there will be no signs of rust or should I seam weld it along the bottom edge of the sill?

 

[brokenbiker]

if you put a whole sill panel on, it can be spot welded as that is how the original panel was done that way. you are putting in a repair patch, to an existing panel. as such the repair must be fully seam welded, other wise it is an mot failure

 

[normspanners]

Only the bits of the patch that you have cut out and butt welded need to be a continuous seam weld, any parts of that patch that were spotted originally can still be spotted.

 

[Justme]

Only the bits of the patch that you have cut out and butt welded need to be a continuous seam weld, any parts of that patch that were spotted originally can still be spotted.

Whilst that is the sensible real world way the MOT regs dont make that distinction (or dint last time I looked).
That said there are still parts of that patch that still need welding like the flange ends near the spots.

 

[normspanners]

As a tester, I think I should know.

 

[octo0072000]

grey area Norm
ive had them fail before for that answer i got had to be welded all round the new patch

i used to be a tester but long time ago and still disagree with lots of stuff

 

[optima21]

my mot testers has been fine with the sills on my cars when have had the bottom 3 inches cut off and new metal let in , with the lower edge just plug welded in place.(Ive replaced the bottom 2 inches of the inner sill and 2inches of the edge of the floorpan too, but seam welded them in place. if you have to seam weld all repair sections in that would mean that wheel arch lips have to be seam welded too, and I think people to spot/plug weld those to the inner arches.

 

[Justme]

As a tester, I think I should know.

Have they put out an amendment to the manual?

This is what the official manual says:-

10. Acceptable methods of repair

It is essential that repairs to corroded or damaged areas are properly carried out. This requires that suitable materials of appropriate gauge or thickness are used for repairs. Additionally:

· Any plating or welding extends to a sound part of a load bearing member.

· the repair must appear to be virtually as strong as the original structure with only continuous seam welding being acceptable for patch repairs (even if the patch extends beyond the prescribed area).

· spot welded joints are acceptable where the original panel has been replaced to an existing spot welded flange (provided the original defective panel flange has been removed). Stitch or plug welding is acceptable as an alternative to spot welding in these cases.
· MIG brazing, a combination of adhesive bonding and riveting, or amalgamations of these with other joining methods may be the vehicle manufacturers recommended method of repair. Such repairs must therefore be accepted unless they are clearly inadequate.

My bold & underlining.


That looks clear to me,
patch = seam weld
full panel = can be spotted if originally spotted

However I agree with your real world interpretation.

 

[normspanners]

When I checked with the ministry they said, cars are allowed to flex, in their design and spot welds and seam sealer allow this to happen without cracks appearing, the idea for a patch is for it to be as strong as the original full panel so that is why the full seam weld to maintain the design of the panel, IE if you were to remove the panel it would be as the original complete replacement panel, one solid piece. But it should be allowed to flex at its normal flex point, which is the spot welds and should not be seam welded there because you are altering the design of the car. They also said that a continuous seam weld actually should NOT be used where spots had been to stop cracking.
When rally car are seam welded they are not continuous seams they are only stitch welds to allow some movement.
For this same reason that is why a truck fails the mot if welds are done to the chassis instead of rivets or bolts because they allow the frame to flex but a weld will break, a spot weld is in effect , similar to a rivet or bolt .

 

[Justme]

So why dont they alter the manual to reflect that?

Not everyone will have contacted them to be told that so could be applying the rule as it is written.

 

[Rocketman]

As soon as you put a patch in the panel it has totally changed from it's original characteristics - one piece of steel formed into the panel with fine and constant grain structure has gone. So it's just as easy to say no patches are allowed.

Thing is here many MOTers would fail that if they saw it but once properly finished off no one would be able to tell and it would pass.

 

[normspanners]

If a sill is replaced in a van or two door car where the rear quarter is part of the sill, does that constitute a patch, no it is a new panel, but it should be continuously welded where the sill meets the quarter to create the same effect as the original panel and nobody would be expected to continuously weld around the new panel including the sill flange joint, also the fact that sills have drain gaps in them where the panel is lifted to allow the water to drain out so that would be wrong to continuously weld.
When replacing a whole rear quarter it's self, the new panels usually have a joggled flange to join to the sill and that is spotted then filled over, not welded all the way round that would be ridiculous.
Therefore a patch is what it says a patch to fill a hole in the area of a panel but an edge repair has to fully welded to the original panel but where that patch now joins the original flange it should be spotted.

 

[delcbr]

Good replys makes interesting reading. So from what I gather once I apply a skim of filler and smooth it off and paint it and take it to a different garage it should pass no problem shouldn't it?
Because if I seam welded it then grind the welds flush how would they know if it was seam welded or not? Unless I am not allowed to grind the seam welds flush.

 

[Rocketman]

I wouldn't worry and take it back to the garage you got it from. If it's covered up and everything seems fine the garage have no reason to fail it. TBH norm is making a lot of sense but some MOTers take everything to the absolute letter.

 

[normspanners]

A tester has no write to remove a protective film what ever that may be, 'test as presented' even if you smeared black grease on it it should pass, as long as it passes the press test ie press the sill with your fingers and listen for crunching or significant movement. In fact if brake pipes have grease smeared on them as a tester you are not allowed to remove it or wipe it off. You are allowed to remove loose rust, off a pipe to inspect the pitting.

Having identified the important load bearing members and ‘prescribed areas’ on a vehicle, the tester should determine whether they are excessively corroded, firstly by visual inspection and then by finger and thumb pressure.
If necessary, the Corrosion Assessment Tool should be used to assess the extent of any corrosion by careful scraping or light tapping of the affected areas.
It is important that use of the Corrosion Assessment Tool is restricted to ascertaining that the failure criteria are met and not used for heavy scraping or poking of the affected areas.
Excessively corroded metal, or metal treated with filler, emits a duller sound than unaffected metal. It is not permissible to apply heavy impact blows or to use a sharp instrument to probe at the structure

the Corrosion Assessment Tool is a little plastic hammer with an aluminium handle for scraping rust off brake pipes