POR 15 or Rust No More

[Larry64]

I'm getting ready to do some repairs to the floor of my cab. Which is better POR 15 or Rust No More? The RNM is an etching solution, is POR 15?
Thanks Larry

[imjeff]

I like POR 15, but haven't used RNM.

[racecougar]

Will you be using this over rust or on clean sheetmetal?

[siggyfreud]

POR-15 requires that you use their cleaner and then etch (metal ready) solution before applying. They also say it's good to let it flash rust after washing off the acid solution.

I just sandblasted my frame, then hit it with the etch solution and painted it with Por-15, then sanded briefly and applied the top coat.



Closer up on the porous back half of the frame.(the nuts were sprayed with spray paint, but the frame is Por-15):



I have never used the other product, and only just used Por-15, so can't say how it holds up long term. It went on easy though! The topcoat was a lot thicker than the Por-15 undercoat, but the undercoat is UV sensitive. Not an issue if it's under carpet.

[Larry64]

After I wire brush it & patch the holes I will use one of the products. Then put down something for a deadener & lastly carpet.
Larry

[siggyfreud]

If you wire brush it and are using Por-15 be sure to use their degreaser followed by the acid etch. The wire brush isn't abrasive enough to get a good stick, and the por-15 will lift off in sheets from what I've read. I haven't seen any evidence of that on mine, but I sandblasted and then etched it.

[Arekusu]

I used POR-15 and incorrectly prepped the surface. It flaked off in sheets of black plastic. I wouldn't use it again. Yes it was my fault, but realizing it was just a black plastic coating made me a little skeptical. I say clean it, degrease etc, epoxy prime, paint and clear .. call it good. Maybe shoot 2 or 3 coats of epoxy primer just to make sure no moisture ever creeps in.. but that may be a bit overkill. But, that's what my frame has on it now and it's sexy.

Alex

*edit* I also rubberized undercoated the inside of the frame rails because I'm paranoid.

[1963c-10]

I use rust treet before any paint on frames ,crossmembers, rims, engines....etc. It works great, degreases, etches and leaves a great surface for paint. Can be brushed on, sprayed, dipped, etc. Dilute 1:1 - 1:3 with water and let it dry. Normally use a 2" paint brush and 2 coats.
Link: http://www.amrep.com/documents/Misty/Photos/B00309.jpg

[Larry64]

1963 C10
Ordered a gal of Misty rust treet. It seems to be the way to go for me. My truck is just for driving around town & not going to be a show car. Nice to have so people can relive the better simpler days.
Larry

[franken]

Just be aware that paint over rust (POR), and similar products move the the rust problem into the future. That's all.

There are troubles with all rust treatments. Research.

[1963c-10]

Originally Posted by Larry64

1963 C10
Ordered a gal of Misty rust treet. It seems to be the way to go for me. My truck is just for driving around town & not going to be a show car. Nice to have so people can relive the better simpler days.
Larry

Its great stuff and very easy to use. You'll want to remove as much as possible 1st, but it will degrease also. I use it as my final step prior to paint. 2" paint brush and just brush it on has been the easiest method. I've used it in a spray bottle also, but found the brush easier. It's a thin product and I normally go with a 1:1 or 1:2 dilution with water.

A gallon has done 1 full frame, 5 rims, a crossmember and I still have about 75% left in the bottle. I believe it'll finish the 2 frames I have left.

[Lugnutz65]

I'll give my opinion about POR-15 and open myself up to criticism. I love POR-15. It is not a cure-all for rust or a cover up for inadequate surface preparation.

I never use it on smooth metal. Smooth metal does not have the proper "tooth" for POR-15 to hold onto. It will peel off of smooth metal.

It loves sandblasted metal, even without any other surface prep. It also loves rusty surfaces AFTER the scale rust has been removed. Apply 2 thin coats. It goes on thick so you really need to make sure you spread it out thin.

It is light sensitive. UV light will make it dull over time.

As far as the cab floor goes, I would use epoxy primer on the cab floor interior. Surface prep according to epoxy primer recommendations. I would not use POR-15 on the cab interior, especially if you plan to paint the cab in the same areas. A quality epoxy will be a better choice.

[Larry64]

Thanks 1963C-10 & Lugnuts. POR 15 is more work than I want to put into the truck. Misty will work for me. Lots of good advice on this board.
Larry

[waspp]

I used the master series coating and have been very pleased with the results. It was developed for use with steel bridge repainting.

http://www.masterseriescoatings.com/index/

[1963c-10]

Larry, have you tried the Rust treet yet? Just wondering how it worked for your application?

[63burban4x4]

my 2 cents on POR-15.........I've had good luck over rust after cleaning the scale. One word of warning, if possible buy small cans and use it all at once.....I've found it almost impossible to remove the lid from a resealed partial can, once it has set a while. It's like it's welded on! It's quite expensive

[siggyfreud]

Originally Posted by 63burban4x4

my 2 cents on POR-15.........I've had good luck over rust after cleaning the scale. One word of warning, if possible buy small cans and use it all at once.....I've found it almost impossible to remove the lid from a resealed partial can, once it has set a while. It's like it's welded on! It's quite expensive

What I did was open it once to stir, and then drilled two holes, one in the top, and one in the side at the very top for air displacement. I sheet metal screws with a rubber gasket, and when I needed paint I took out the screws, poured, and replaced them.

[Improbcat]

You can also put a double layer of household plastic wrap between the lid & can. I have had very good luck with that method. make sure to use new plastic wrap every time you open the can.

I have used POR-15, I have also used Masterseries and like the Masterseries better as it seems to be more tolerant of imperfect application than POR-15. I have never had it peel off unless I had grease or oil surface contamination. I also can be topcoated by anything without hassle unlike POR-15. http://www.masterseriesct.com/

[amccomb]

SEM also makes a great product similar to POR-15.