Undercoating The Wheel Wells

Last night I did quite a bit of research online, and I decided to fall back on my original plan for the wheel wells before I had decided to do them in high gloss black POR-15. Originally when we stripped the wheel wells, I had two options: 1) replace the factory-style undercoating, or 2) try something different and go with high gloss black. I decided to go for something different, and everyone knows the ending to that story...

Prior to deciding on using high gloss POR-15, I had researched online and found 3M Automotive Coatings makes a heavy duty rubberized undercoating as part of their Bondo line. This is what I would have used had I decided to replace the factory-style undercoating. Fast forward a couple of years to us once again having to make wheel well coating decisions. POR-15 had introduced their own line of rubberized undercoating, and when it came time to undercoat the primered wheel wells I thought the POR-15 undercoating would be a better choice.

After last night, I decided to fall back on my first idea. Sara and I had breakfast and then went to Menards and purchased cans of Bondo heavy duty rubberized undercoating. Each can cost only $4 compared to the $20 POR-15 undercoating. 

We also bought a tarp at Menards to paint the fender lines on.

The passenger side rear wheel well still needed to be taped and masked off.

This is how the POR-15 undercoating dried. It literally looks and feels like a layer of matte paint. There is absolutely no rubberized texture. 

Up next... Bondo undercoating spray. I began with the driver side front wheel well.

The difference was apparent immediately. There was more pressure, more volume, and more coverage. It was kind of like spraying liquid tar or asphalt.  

First coat of Bondo undercoating, and already it looks rubbery.

On to the passenger side front wheel well.

After getting one coat on the front wheel wells, I sprayed the fender liners.

Second coat:

The small liner is the cover for the fuel filler neck. 

I took these pictures after two coats of the Bondo undercoating:

(Despite the pictures, it is a very matte black color.)

Next up: touching up the underbody and the driver side rear wheel well with POR-15 black. 

Here are the two areas that need touching up:

All touched up!

I went under the car to inspect the spots my dad and I marked yesterday. I was originally going to use POR-Patch on a couple of them, along the seams and pinch welds. However, our masking of the wheel wells has covered these up. (Dad, we did too good of job!) I will have to go back to these spots once the wheel well masking is removed.

I touched up the spots I could get to with POR-15 black.

Using a third can of Bondo undercoating, I applied another coat to the fender liners.

I also applied one last coat to both front wheel wells.

I used six cans of undercoating: three cans on the front wheel wells and liners, and three cans on the rear wheel wells.

I applied light coats, and switched back and forth between the rear wheel wells to allow the coats to dry.

Here are the finished fender liners: 

Hopefully I will have a wheel well unveiling for you tomorrow!