auto body / undercoating question

[JHZR2]

Hello,

Anyone familiar with the Phila. airport parking garage may know what Im talking about, but essentially, from where I was parked, I snagged one vertical plastic lane marker (spring loaded type) in a parking garage, and it bent the metal of the rear apron on my 91 BMW.

Nothing severe, but it was bent pretty far. I could bend it back and all was well, however, the location creates a bit of an issue. The spot where it was bent is where the floor/body pan for one of the two sides of the trunk goes from being horizontal to vertical to make one of the actual sides of the trunk. The apron is a separate piece of metal that is connected to the structure elsewhere.

THe two pieces are essentially sealed together with undercoating, seam sealer etc. There is nice silver painted mtal under this rubber coating. When the metal apron bent, it ripped this spot, opening up fresh, painted metal and crating a cavity.

While it is painted, the cavity concerns me. Salt water will get in there, and it is a spot prone to rust formation on these cars. I can bend the metal back and build some layers of undercoating there to seal it, if it were warm... But it is cold, usually in the 20s, and so I doubt that spraying a product like that will be smart for proper curing/drying.

So what is the best way, once I bend the metal back, to protect the cavity and exposed metal from salt spray, etc.?

Thanks!

 

[RnR]

My 2 cents would be to use something that is aerosol driven so the cavity/seams can be fully saturated. Relying on film migration in these colder temps is wishful thinking, so a can would likely work best for both reach and area coverage concerns. WD-40 is a decent rust preventative and can be used in the near-term fairly effectively. However, a more specific anti-corrosion product would of course be better. If you could find the basic CorrosionX product (which comes from a line I trust) or Corrosion Block at West Marine, even CorrosionX AV/ACF-50 at an aircraft maintenance facility would be excellent options. While something of that nature is a possible solution, WD-40 may suffice for the immediate need.

Whatcha got in your emergency kit?

 

[demarpaint]

You can clean up and prime and paint the area, or prime and undercoat the area. Or get something like Amsoil Heavy Duty metal protector and clean and spray the area with that. I would not leave it unprotected. HTH

 

[JHZR2]

I concur with aerosol stuff, but if it does not get reasonably over 30F for the next few months, what is my best approach? Heat gun the car then the sprayed area to help it dry/cure?

 

[demarpaint]

You can preheat the area, then get a heat lamp and put it on the area in question until the product you use dries. As always with a heat lamp or heat gun use care.

 

[JHZR2]

I would set my heat gun on lowest setting and then blow it over. Do you think a floodlight or similar type bulb just placed underneath the area would work well enough by placing some heat into the area while it is drying?

 

[demarpaint]

It should, and would be safer than a heat gun. They also make those bulbs they use in bathrooms to provide heat, IIRC they call them heat lamps. If you can find one cheap that would be ideal.

 

[fdcg27]

PHL is your home airport?
Is this the same place where you had painters damage your 1 series?
PHL has the rep of being the worst major airport in the country.
I have spent $$ to avoid connecting through there.
If PHL is your home airport, you have my sympathies, and I won't even mention the dominant airline, another bad option.

 

[Trvlr500]

Can you post pictures of the damage? There are MANY different sealants and undercoatings available. Depending on where the damage is and what it looks like there is a product out there that can solve your problem.

The cold temps of winter are the biggest problem as far as curing whatever you do put on there. If it doesn't cure properly nothing will work.

I spent 10 years restoring collector cars a long time ago and the various sealants and undercoatings haven't changed much but it DOES depend on where you live due to the EPA when it comes to availability.

Whatever you use getting ALL the moisture out of the area is critical before you apply it. POR-15 is one of the best for stopping rust and protecting bare metal BUT it takes forever to dry AND you have to put paint over it AFTER it is dry to seal it.

It may be best to just wait until summer to deal with it unless you have a second car. Your Beemer isn't going to rust away in 5 months.