Dent in the longitudinal member - no more MOT (or inspection)?

Hello,

Today, I got a dent in the Polo's longitudinal member below the B-pillar from hitting a sharp edge: The estimated depth of the indentation is about 8 mm, approximately 20 cm long, and up to 3 cm high (in the area of the deepest indentation) .

The paint and stone chip protection layer has been scratched away down to the metal in a section of approximately 2 cm, but the metal itself is not frayed or torn; it still has its full thickness.
Outside of the bulge, there are no paint cracks or similar imperfections that could indicate broken welds or other issues.

As a rust preventative measure, I first applied a layer of gray stone chip coating. It looks great, but that's not my primary concern right now.

Question: Could this problem also cause me to fail the next vehicle inspection (due in March '09), even without any subsequent rust damage, because "load-bearing structures are deformed"?
If so, what are the permissible repair methods, and what should be considered when repairing the galvanized body of a 9N model?

Quote:

If so, what are the permissible repair methods, and what should be considered when dealing with the galvanized body of a 9N vehicle?

Hmm, the longitudinal beams actually end in the area of the B-pillar, or are you referring to the sill (lower beam)?

To make an assessment or propose a reasonable repair solution, I need some clear photos.

BM wrote:

Hmm, the longitudinal beams actually end in the area of the B-pillar, or is the sill (lower crossmember) meant? For an assessment or a reasonable repair proposal, I need some clear photos.

I won't be able to get those today. Therefore, as a starting point, here is an old cropped image where I have marked the location of the damage in red.
The vertical position is likely correct, but the front-to-back position might be off by a few centimeters. The indentation depth is at its maximum at the front end of the line and tapers down to zero towards the rear.

Previously, I didn't have a clear understanding of the difference between "Längsträger" and "Schweller," but now "Schweller" seems more appropriate to me.

Thank you, by the way, for your interest }.

Ulf.

Perhaps now is the perfect time for impactful images.

I had a defect in the rear bumper (from the factory) that was very clearly visible when illuminated with a fluorescent lamp (which I happened to have on hand).

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

dieselmartin wrote:

I had a defect in the rear bumper (from the factory) that could be very nicely visualized using a fluorescent lamp (which I happened to have).

No, it sounds like yours was about 1-2 mm of unevenness on large, flat surfaces.

However, the painted areas of my car have a factory-applied "orange peel" texture (a type of protective coating under the paint).

I just checked again with the calipers and ruler: Compared to the convex normal contour of the sill, the depression is a maximum of 4 mm deep, and the maximum width of the depression (top edge to bottom edge) is approximately 4 cm.

I've replaced the attachment above with a different version that shows the bulge more clearly. It already looks quite bad; initially, I had estimated the depth of the bulge to be almost twice as much.
By the way, it's quite symmetrical and deepest at about its midpoint.

Hi Ulf,

meine Schwester hat ihren inzwischen verschrotteten (Zahnriemenriss...) Twingo vor zwei oder drei Jahren beim Abbiegen mit dem rechten Schweller auf einen Poller gesetzt - deutlich mehr verbogen als das, was du beschreibst (die Lackschaeden hatten so 60 cm Laenge und drei oder vier Hoehe) und so schlimm, dass die Tuer nur noch mit Gewalt zu bedienen ging (ging bis zum hinteren Ende der Tuer). Das haben wir dann mit einem Brett als Zwischenlage und einem grossen Hammer ein wenig runtergehaemmert und den Rest so gelassen - lediglich ueber den Lackschaden hat sie im Rahmen einer anderen Reparatur drueberspruehen lassen. It didn't bother anyone among the one or two TÜV inspections the car had afterwards.

Therefore, I think you shouldn't worry about that.

Best regards,

Jan.

Quote:

Ich war grade nochmal mit der Schieblehre und Zollstock dran: Gegenüber den konvexen Normalkontur des Schwellers ist das Beulental max. 4 mm tief, und die max. Beulenbreite (oberer <-> unterer Rand) ist ca. 4 cm.

It's annoying, but it's not a big deal. It shouldn't be a problem for the vehicle inspection (HU).

The most durable repair would be one where the galvanization remains intact. This is only possible if the sill is accessible from the inside. It might be possible to reach the dent from the side wall. However, I'm not sure what reinforcements might be in the way. To check this, you would need to remove the rear side paneling.
If possible, consult a specialist (e.g., a restorer). It's often amazing what these artists are capable of nowadays. Afterwards, if necessary, apply another coat of varnish or fill in any scratches.

If access is not possible -> use the traditional repair method: dent the area from the outside using a hammer and dolly, apply tinning (no filler), sand, prime, apply filler, sand again, apply stone chip protection, add texture, insulate, and paint. Then, repair the cavity sealing.

Or a cheap method: fill the cracks, sand them down, apply primer, add stone chip protection, use a spray can, or something similar...

The options available naturally depend on individual preferences and budget.

Hi Ulf, the TÜV (German technical inspection agency) won't be interested in this, but you could possibly try to remove the dent using a glue-based "dent puller" kit and carefully pulling it out piece by piece.
It probably won't be completely successful, and your agitated mixture must also be completely removed beforehand.

Without the grease, it will also be a bit lighter. However, I had forgotten: the air mass that is enclosed and moved with the vehicle was smaller before pulling it out, and must be taken into account to be precise!

Well...

The lamp method would also work on orange peels, because the waves on this skin also move within a narrow range, and the indentation will be larger.

It was just an idea...

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

Jan6K wrote:

My sister hit a bollard with the right side of her Twingo (which has since been scrapped due to a timing belt failure...) two or three years ago while turning - it was bent much more than what you describe... No one noticed or cared during the one or two TÜV inspections the car had afterwards. Von daher denke ich, dass du dir da keine Sorgen machen muss.

BM wrote:

It's annoying, but it's not a major problem. It shouldn't be an issue for the vehicle inspection (HU). The most durable repair would be one where the galvanization remains intact. That, in turn, is only possible if the sill is accessible from the inside. Perhaps the dent can be reached from the side panel. However, I'm not sure what reinforcements might be in the way there. To check that, you would have to remove the rear side trim.

I already checked: There are at least two layers of sheet metal in the way between the rear seat footwell and the back of the bulge -> I removed the bolt that holds the seat belt buckle (= in the innermost layer of metal) and inserted a screwdriver, but it didn't even go half as deep as the distance to the bulge is .
To achieve internal riveting, you would need to drill through at least these two layers of metal – is such a thing even permissible?

The back of the dent would likely be accessible through existing longitudinal holes located between the bottom edge of the sill and the vertical weld seam. The technician would need to work "around the corner" to reach it, potentially using the next inner panel as a support. However, the dent is quite well positioned between two such holes, meaning the distance in the direction of travel is at least 20 cm.

teileklaus wrote:

The TÜV (German technical inspection agency) is not interested in that, but you could possibly try to repair the dent with a (paint-free dent removal) adhesive and the set, pulling it out piece by piece.

Does anyone have a link to a description of the set, its price, and a source where I can buy it?


Thank you for your support regarding the vehicle inspection ().

Hi Ulf,

Regarding my sister's Twingo, it should be added that the damage was clearly visible even from a distance, despite being sprayed. Therefore, there is no way the inspector could have missed it.

I suspect that this technique doesn't work very well in areas that are as reinforced and stable as this one. It's more suitable for dents in smooth or relatively flat surfaces, not in areas like this. Of course, I could be wrong, but even with access from the back, I couldn't push out 100% of the dent on the upper edge of the right front fender.

I think I would preserve it and leave it as is.

Best regards,

Jan.

Here are two more actual pictures of the mishap.

A body shop doctor in this area offered to repair it for €140.
I would get the bare metal parts (requiring you to drill holes and remove them; then you'll need to do your own surface treatment, although achieving that perfect "orange peel" finish is less important to me) for €50.
The latter option would also be more appealing because the car only needs to be taken to the workshop for a few hours, and I can wait. For a complete job, it would take two days due to the drying times of modern water-based paints.

Hi Ulf,

My condolences for the damage.

It's not a big deal though. If it doesn't bother you visually, then just leave it as is. Just paint over it and that should be fine. You don't need to worry about the TÜV (German technical inspection). The damage certainly won't compromise the "structural integrity" of your Polo.

The problem is that "people tend to focus on the damage," which can be frustrating in the long run.

Bertil wrote:

If it doesn't bother you visually, then leave it as is. Just paint over it and that's good. You don't need to worry about the TÜV (German technical inspection). The damage certainly won't affect the "structural integrity" of your Polo. The annoying thing is that "the eyes always stay focused on the damage."

That can be frustrating in the long run. Hi Bertil,

Even though I'm not particularly concerned about the appearance of my Polo after almost 4 years: the bump bothers me just as much as you describe. Therefore, I will probably accept the €50 offer and then paint over it }.

ulf wrote:

Hi Bertil, Even though I'm not particularly concerned about the appearance of my Polo after almost 4 years: the bump bothers me just as much as you describe. Therefore, I will probably accept the €50 offer and then paint over it

.

Hi Ulf,

ich habe mit meinem Polo (6N2) vor mittlerweile über 4 Jahren einen Blumenkübel "beiseite geschoben". Die Auswirkungen an der Beifahrertür (ist ein 2 Türer) kannst Du auf den Fotos sehen (einmal von der Seite und einmal bei geöffneter Tür von oben). Den Kübel hänge ich auch mal an; man sieht auch gut, wo er vorher stand.... Der Schaden wurde (wenn mich meine Erinnerung nicht trügt) nach der von BM beschriebenen "klassischen Methode" behoben. Fazit: Ich sehe von dem Schaden nichts mehr. Und was vielleicht noch wichtiger ist: Ich sehe auch noch nichts wieder (z.B. Rost o.ä.). Der Träger wurde damals noch von innen mit Wachs geflutet. Die Methode kann ich also empfehlen. ÜI never worried about the TÜV (German technical inspection), and they never said anything to me either.However, the damage is no longer visible. As a temporary solution, I also sprayed underbody protection over it back then.

Best regards, Thorsten.

First of all, my condolences!

The dent repair method used by the technician will likely involve the use of a spot welder. The €50 offer sounds reasonable. To create points on the metal for the pins, a grinder will definitely be used to create an area where it's possible to work down to the bare metal. Any existing corrosion protection or surface galvanization in that area will then be removed.

After that, treat the exposed and burnt metal spots created by the spot welder from the outside with zinc dust (spray) and a paintable underbody sealant. Allow it to dry thoroughly, then use matching spray paint (have it mixed!) to visually conceal it. Carefully mask any adjacent painted surfaces.

You can access the cavities through the drain holes and apply cavity protection wax from the container using an applicator probe. The spot welds that the technician left on the outside are also present on the inside. Any factory sealant in those areas will have burned off. Just apply some wax over it, and you're good!