3M spray undercoatings

[JHZR2]

Hello,

I have 3M undercoatings 08881, 08882 (paintable) and 08883.

08881 is the only one that claims "low cost". 08882 is paintable, and both 08882 and 08883 are labeled "underseal", while 08881 is not. 08881 on the 3m site claims to be non-chlorinated, FWIW.

Any ideas on the actual differences? Need to seal a spot under my car that got torn, and the spot had some white rubber undercoating on it before. I primed with a rustproof primer on the (already painted and nice looking) metal, and will spray this stuff over.

They say to use in wheelwells, fenders, doors, frames, undercarriage, but also say to NOT use on rocker panels. Any idea why?

Is one of these better than the other? The end application is black, so I dont know that paintable is important to me...

Any suggestions?

Thanks!

 

[JHZR2]

Looking at the PDS 08882 is rubber base while 08883 is synthetic polymer. Is one preferred to another?

 

[SaturnIonVue]

"They say to use in wheelwells, fenders, doors, frames, undercarriage, but also say to NOT use on rocker panels. Any idea why?"

That may be because it could cover up drain holes, or trap road salts, and promote rust. Just a guess, but I have heard of DIY coatings mis-applied that did that on door panels and rockers.

 

[JHZR2]

Actually, I found since that 3M sells rocker-specific items, which is likely why. They want to sell more stuff!

The PDS for the 08883 "passes" a 1 pint of gravel at 90 psi abrasion test...

The p/ns for the rocker stuff is:
"schutz" (What is schutz?) 08874

Rocker Panel Spray 05911

Not sure how different it really is from undercoating... Seems it is more sensitive to the undercoat though...