Rust Prevention on Bedside Cuts for High Clearance Rear Bumper

Hi all. I'm getting ready to install a high clearance rear bumper on my truck that requires cutting the bedsides. Living in the salt belt, I've been debating what the best strategy would be to protect the cut edges from rusting. Looking for opinions on what others have done in the past, especially those that deal with salt, and who have some years and evidence of how it held up over time.

Some options I've considered:

1. Prime with self-etching primer, finish with rattle can
2. Prime with POR-15, finish with rattle can
3. No primer, use Toyota touch up paint pen, finish with clear coat touch up pen
4. No primer, coat with Steel-it

I'll be adding edge trim to help protect the edges, so the underlying result doesn't need to look pretty since it will be covered, just needs to keep my bedside from rusting out (hopefully for the next 10-15 years). I've also debated goobering on some Fluid Film or silicone to encapsulate the edge (after painting) before adding the edge trim.

Any suggestions? Thanks in advance.

 

Paint the edge with epoxy primer then touchup paint.

 

Good thinking. I've got some two part epoxy primer for the bumper already (depending on when I can get more catalyst, apparently there's a national shortage).

Do Toyota touch up paint pens need a clear coat over the top? I've read varying answers. I believe they used to come with color match on one side and clear on the other, but I've also heard it's all-in-one now? My touch up pen only has the color match, no clear.

 

I went with two coats of POR-15 and eBay edge trim. Hoping it holds up.

 

I'd even clear coat it after that.

 

My touchup pen has two sides the color and a clear. It matched the factory paint very well.

 

If OP has clear might as well. There is no downside to clear.

 

I just slapped some touch up paint on mine, it was like a half ass job too, no issues so far. I also trimmed all my fenders about 2 inches and never even touched those up at all lol. Eventually I'll just spray some steel-it in there but I've been rocking it like that for about a few years now and still no rust.

 

Thanks for the input everybody. I'm going to go with epoxy primer, followed by color match touch up and finished with a clear coat.

 

The sheet metal is so thin there isn’t much to paint to be honest. I just used touch up paint.

If you plan to use steel-it, you’d till need a primer.

 

OEM panels are galvanized. I used galvanize primer for best adhesion. I did 1 coat of galvanize primer + 4 coats of Tremclad semigloss rust paint along 1/4" of bottom edge, all from rattlecans.



The edge trim I used has adhesive goop inside to keep moisture out as well.

 

Why stop there, rock guard the rocker panels front to back.

 

^Going to do Line-X Ultra on the whole side of the truck in a couple of years, assuming the truck survives that long. No point in doing redundant work

 

I had line x on the rocker panels of my 2nd gen, there were issues with it adhereing properly to the floor/side panel welds. Could have been with prep and application. After 12 years I had the line x peeled off and rock guard sprayed on. I have rock guard on my 3rd gen rockers.

 

Give the trim job a chance, pick up some seaming pliers and give it a lip, or fold it over and install the edge trim.

 

Just to update for future reference, I ended up going with POR-15 at the suggestion of a buddy that works in automotive paint. Sanded with 320 grit sandpaper before applying. I guess I'll have to wait a few years to see if it holds up against rust.







Here's the full write up in my build thread of putting the bumper on: https://www.tacomaworld.com/threads...mild-sauce-tacoma.751381/page-3#post-28849480