Undercoating The Wheel Wells

posted Jan 31, 2015, 5:02 PM by Jonathan Imberi
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. 

https://lh6.googleusercontent.com/-4BlfWAnFgBY/VM1l-7OyaQI/AAAAAAAA1zU/YzM1BGziriE/w1520-h855-no/IMG_20150131_100603801.jpg

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

https://lh4.googleusercontent.com/-MZ7VCvj_af0/VM1l-96aZPI/AAAAAAAA1zU/vENu05Jl7HM/w1520-h855-no/IMG_20150131_113329977.jpg

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

https://lh3.googleusercontent.com/-Eb8DHJVt20k/VM1l-6sVrGI/AAAAAAAA1zU/-pQYcaSnH_4/w1520-h855-no/IMG_20150131_113343574.jpg

https://lh3.googleusercontent.com/-lCMofgWnZCQ/VM1l-zYRLqI/AAAAAAAA1zU/WpaJDvPUzDM/w1520-h855-no/IMG_20150131_115632359.jpg

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. 

https://lh6.googleusercontent.com/-Og__lpjtPwM/VM1l-_MUQhI/AAAAAAAA1zU/ySznufl5EbI/w1520-h855-no/IMG_20150131_120027053.jpg

https://lh4.googleusercontent.com/-0u2zqGleLdo/VM1l-x7Q3qI/AAAAAAAA1zU/xEjkrqwP1dY/w1520-h855-no/IMG_20150131_120037527.jpg

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

https://lh3.googleusercontent.com/-zqzU9cc07Ls/VM1l--b3C1I/AAAAAAAA1zU/8VU5DcyEtV4/w1520-h855-no/IMG_20150131_120607532.jpg

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

https://lh3.googleusercontent.com/-LQTch2qhK-E/VM1l-3CNAmI/AAAAAAAA1zU/ve_33ghEtRo/w1520-h855-no/IMG_20150131_120615303.jpg

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

https://lh5.googleusercontent.com/-6N2D9tzMvyE/VM1l-7OxfLI/AAAAAAAA1zU/q804hPC2P5I/w1520-h855-no/IMG_20150131_121201072.jpg

On to the passenger side front wheel well.

https://lh5.googleusercontent.com/-VTHkwhVTOyw/VM1l-7GF7eI/AAAAAAAA1zU/YUYkpZ_wbqE/w1520-h855-no/IMG_20150131_121319490.jpg

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

https://lh4.googleusercontent.com/-4L4QQ_bL2YI/VM1l-4T0XzI/AAAAAAAA1zU/m5NEKwF00wg/w1520-h855-no/IMG_20150131_121513882.jpg

https://lh6.googleusercontent.com/-7EmPpAcyVH4/VM1l-4l2-xI/AAAAAAAA1zU/hPSDO2abi1Y/w1520-h855-no/IMG_20150131_121747670.jpg

Second coat:

https://lh3.googleusercontent.com/-388OzLpImRs/VM1l-22_MkI/AAAAAAAA1zU/1ca8dwJDSYk/w1520-h855-no/IMG_20150131_122136326.jpg

https://lh4.googleusercontent.com/-kl-8rBcVuSM/VM1l-36oAFI/AAAAAAAA1zU/eeYCcw_9dyQ/w1520-h855-no/IMG_20150131_122245049.jpg

https://lh5.googleusercontent.com/-zJySIkEBf_I/VM1l-693f5I/AAAAAAAA1zU/OGdtlc8SUiY/w1520-h855-no/IMG_20150131_122440925.jpg

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

https://lh4.googleusercontent.com/-ghs5Sw7BQn8/VM1l--JIzPI/AAAAAAAA1zU/9rkxFJum9rQ/w1520-h855-no/IMG_20150131_140209191.jpg

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

https://lh4.googleusercontent.com/-K7igpJ9WcbQ/VM1l-xv8YXI/AAAAAAAA1zU/8onBcAIAZcM/w1520-h855-no/IMG_20150131_140242884.jpg

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

https://lh5.googleusercontent.com/-Zzhk9qcpwo0/VM1l-xutJEI/AAAAAAAA1zU/HSH7ScPfsgU/w1520-h855-no/IMG_20150131_140308804.jpg

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

https://lh4.googleusercontent.com/-J0dyTBSATpM/VM1l-8IclZI/AAAAAAAA1zU/bbh4TLzOIfM/w1520-h855-no/IMG_20150131_140438265.jpg

Here are the two areas that need touching up:

https://lh4.googleusercontent.com/-Qh60WIVierg/VM1l-4LUiRI/AAAAAAAA1zU/51xLYyPP2Q0/w1520-h855-no/IMG_20150131_140848361.jpg

https://lh6.googleusercontent.com/-JTEkN_m2XGI/VM1l-1GybsI/AAAAAAAA1zU/-CTxF164IB4/w1520-h855-no/IMG_20150131_141305597.jpg

All touched up!

https://lh5.googleusercontent.com/-tDlfnZgszoU/VM1l-5uN0qI/AAAAAAAA1zU/vQWvVoHdl0E/w1520-h855-no/IMG_20150131_141453941.jpg

https://lh6.googleusercontent.com/-cUe1N-W4z08/VM1l-8tA5JI/AAAAAAAA1zU/vUMqgiJ74hA/w1520-h855-no/IMG_20150131_141535555.jpg

I went under the car to inspect the spots 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.

https://lh3.googleusercontent.com/-D-epL1oUIjw/VM1l-xUNSRI/AAAAAAAA1zU/Q2LypnjFFCA/w1520-h855-no/IMG_20150131_142806130.jpg

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

https://lh3.googleusercontent.com/-YVRG8pmJiXg/VM1l-wq_k7I/AAAAAAAA1zU/8Ne_sN9T0U0/w1520-h855-no/IMG_20150131_143801016.jpg

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

https://lh6.googleusercontent.com/-SgNtO-6uM5s/VM1l-03IChI/AAAAAAAA1zU/EYPnev5AhSY/w1520-h855-no/IMG_20150131_163617987.jpg

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

https://lh3.googleusercontent.com/-cJEo7TOSvus/VM1l-3Gf94I/AAAAAAAA1zU/TRZi6LEhywk/w1520-h855-no/IMG_20150131_163826165.jpg

https://lh5.googleusercontent.com/-wLxi6HN9Zrs/VM1l-2S_CsI/AAAAAAAA1zU/N9q1dcvcITw/w1520-h855-no/IMG_20150131_163953365.jpg

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

https://lh5.googleusercontent.com/-jeKfvHa-0Ao/VM1l-0Bv2QI/AAAAAAAA1zU/XCbS9NDNmyU/w1520-h855-no/IMG_20150131_164515256.jpg

https://lh4.googleusercontent.com/-JASOhcThLLU/VM1l--uU8lI/AAAAAAAA1zU/8Gp7mRWxbWg/w1520-h855-no/IMG_20150131_165127892.jpg

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

https://lh4.googleusercontent.com/-HKu797w_JpM/VM1wov3ZQ_I/AAAAAAAA14E/HVQztbOR68Y/w1520-h855-no/IMG_20150131_175503420.jpg

https://lh6.googleusercontent.com/-koe_mnv4sHw/VM1wotlhkfI/AAAAAAAA14E/17Ua_9qYlpo/w1520-h855-no/IMG_20150131_180240647.jpg

https://lh4.googleusercontent.com/-04_6VWkyScc/VM1wor_fTaI/AAAAAAAA14E/mMG242cishQ/w1520-h855-no/IMG_20150131_180720857.jpg

Here are the finished fender liners: 

https://lh6.googleusercontent.com/-Gqb_4bEMaFg/VM1wovVJnKI/AAAAAAAA14E/jL_H6yHEsQ8/w1520-h855-no/IMG_20150131_180712560.jpg

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