POR-15/Undercoating

Hey all!

Truck came in and looks great. I'm currently getting the timing belt and water pump replaced since it's been over 10 years since the last replacement. I'll add a few pictures in the coming days.

Frame looks great - very small amount of surface rust in a few areas. I'm planning to treat with POR-15 or something similar to make sure the rust doesn't get any worse over time since I live in the rust belt area, but it's very minimal.

I did some research on the forums already but I am looking for some additional info. Is prepping the frame to remove any surface rust, treating with POR15, and then undercoating with something like wool wax a good/safe idea? I know there have been some instances of frames rusting from the inside out with certain types of undercoating (like the Toyota applied CRC) so I want to make sure I don't do anything detrimental to the frame/truck. What do you all think?

Thank you!

 

The frame rusting inside out is independent of what you do to the outside of the frame. The CRC from Toyota wasn’t properly applied for many of the frames since they weren’t properly prepped and were applied over areas where it was still rusting underneath the first layer of metal which should have been removed in the descaling process. I have the CRC coating over POR-15 which isn’t really doing much since the POR-15 is really protecting the frame.

 

@Jack McCarthy That makes sense, thank you

 

I have treated a 2002 F-350 for the last 15 years and a 2006 Tundra the last 5 with POR-15. I typically will pressure-wash to get rid of salt and mud. Then when dry go with a wire brush and a metal scraper if only minor amounts of rust. If more, a wire wheel. This is to get the flakes off as I personally think light rust actually helps with paint adhesion. Then using gloves and a tank-suit and safetyglasses I go and paint the POR-15 on using a 2" harbor freight brush. If grease or oil then I will wipe down with some type of solvent. Acetone is my typical go-to. For the can, I buy it by the gallon and put in self-tapping screws with a o-ring (like the stuff you buy to install metal roofing). I shake the can and only pour out what I need from the 2 screw holes (one is to pour and second is to vent). This way the gallon will last me a year or two or 3. I have been through 4-5 gallons this way treating the two trucks as well as a tractor and trailer or two. If in the sun, I like to topcoat with rustoleum as it is cheaper.

 

As for longevity, this stuff rarely fails if I do the surface prep first. The only thing better is epoxy primer but I only do that when I sandblast the entire frame first. Even then I topcoat with POR-15 to get anything that I missed with the first 2 coats. POR-15 will fade pretty bad so I try to expect that if doing a bumper or trailer sides.

 

@rock01 That is helpful, thank you!

 

I tried Por-15 last year, I had some rusty areas on my bed, did the prep work exactly like they said and now 9 months later rust is coming back.

 

Been using POR-15 for different applications for over 25 years. Typically I would get the pint six pack where I can choose a variety of colors if desired. As stated before, you probably won’t find a better leveler or corrosion seal unless you go with a two part epoxy. Iv done calipers with the silver and the grey.. those colors seem to have the most bite and absorb into the surface better. Iv got a coating of the flat black on my trailer tongue right now and will eventually topcoat with rust oleum gloss black. The gloss black POR I probably use the most of… it levels out over rough surfaces amazingly, and seals very well. I’ll use that on frames and suspension parts that I’m not going to topcoat. With its super hard and gloss finish you’d probably want to rough the surface for better adhesion if you were to topcoat.

 

I’ve used POR-15 for years. In my experience it works great if you can do the prep.
I treated my Tundra frame with it a few years ago, and I’m not impressed at all with how it has lasted. To be fair, it’s not POR-15’s fault, it’s mine. The only way to properly prep the surface of the frame is to remove the bed, all wiring, brake lines, fuel lines… everything.
I couldn’t/wouldn’t do all that, so the product has failed.
I spray my frame once or twice a year with WD-40. That has kept it in good shape despite rough Maine winters.

 

Be sure to wear gloves

I see @rock01 already covered that point, I just want to highlight it. As others in this very thread who've used it will also tell you: If you get that shit on your skin, it's like superglue. It hardens with water, and the moisture in your skin will create one hell of a bond that doesn't just wash off.

 

I coated the frame on and old Silverado I once had and neglected to read the precautions. Got covered in it while laying underneath the truck. Absolutely nothing takes it off, took a good 3 weeks to totally wear off. Worst part was I had a wedding to go to a few days after I got covered, wife was pissed.