Will a patched body panel pass an MOT?

[TheLoraxxZeus]

I have an MOT end of June. I only drive it to the track and back. I've got outside sill rot on both sides of the car, inner sills have mild to moderate surface rust but are solid (hammer/screwdriver test).

The panels are all getting ripped out next year anyway, but I want the remainder of this summer out of the car. I want to cut the outer sill out where it's rusty, cut some sheet metal to size, shape it and then rivet it in place.

Will this pass an MOT?

I do not have access to a MIG welder at this time, and won't be buying one this year.

[Dave.]

I went to see an NB for sale a few years ago where someone had welded plates over the rusty bit on the sill... "They'll never rust again" I was assured....

Maybe true for the plates, everything else around it though, I'm not so sure.

st story aside.... I don't think the rivetting will pass as it won't be structurally sound.

You could do it and get someone to weld up the plate, then grind off the rivets, thin smear of filler and primer.

I'm not an expert though, as you've probably guessed.

[TheLoraxxZeus]

Dave. said:

st story aside.... I don't think the rivetting will pass as it won't be structurally sound.

Bah yeah, Google results seem to be mixed. One person says its fine, another says it is not.

Funny enough, it's my MX-5 NB that has this problem. Perhaps I can cut them out, shape panel and pay someone just to weld it in for me.

[Dave.]

Get a cheap welder from Amazon and have a bash... Worst case it needs cutting back out and doing properly.

[larrylamb11]

TheLoraxxZeus said:

Perhaps I can cut them out, shape panel and pay someone just to weld it in for me.

Don't do that - if you're going to take it to someone to weld, let them do the cutting and making new panels. If you don't have experience with rust repair and how far you need to cut back and where the best place is to cut to, let the experienced welder do it - it will save you time and money overall.

Pop riveted repairs shouldn't pass an MoT as they are not structurally sound - any rust repair needs to be seam welded around the perimeter, unless replicating a factory join. As a bodge you could attempt to bond a panel over the rust you have and disguise the join with filler and paint, but it is absolutely a bodge and not a structural repair. Bear in mind that the rust has weakened the structural rigidity of the car - something you might want to consider carefully if you are tracking it....

[Krikkit]

Something like a sill is structural, therefore the MOT standard for repairs is solid material with continuous weld around it.

Riveted panels etc are fine for non-structural, e.g. wings etc.

[TheLoraxxZeus]

larrylamb11 said:

Don't do that - if you're going to take it to someone to weld, let them do the cutting and making new panels. If you don't have experience with rust repair and how far you need to cut back and where the best place is to cut to, let the experienced welder do it - it will save you time and money overall.

Experience with rust repair? Nope. I can weld though, so it would be a case of figuring out what you said and there are plenty of videos on that when I get to it.

larrylamb11 said:

Pop riveted repairs shouldn't pass an MoT as they are not structurally sound - any rust repair needs to be seam welded around the perimeter, unless replicating a factory join.

Alrighty, cheers!

larrylamb11 said:

Bear in mind that the rust has weakened the structural rigidity of the car - something you might want to consider carefully if you are tracking it....

If you mean the inner sill then yeah, it's not rotting but not exactlt brand new. Outer sills on an MX-5 (from my research) are not structural?

I used to build/maintane Rickshaws + electric cargo bikes, I've had my fair share of "rusted beyond repair" jobs, I would consider this not one of them.