POR 15?

What are your experiences with POR 15 on rust? I've used it many years ago on a truck frame. Was planning to try some again and noticed the large price increase.

Is there a better product for less money?

Im going try black fluid film on my truck frame .

I don't keep track of what paint prices are doing, although I did notice a few years ago that a 5 gal. bucket of stain was $160. This morning I paid $17 for a quart of rustoleum. As far as por-15 goes, I've used it and believe it is probably better than regular paint. Also, there are specific instructions that go with it and you want to follow them for best results. That includes buying everything that goes with it. I did the underside of a mower deck with por-15 a couple years ago and it doesn't appear to be hurting it any, but the stuff comes off in flakes, and a lot of it is gone. At 3 times the rate of rustoleum, it's hard to endorse it.

POR-15 is a combination product. rust converter and paint. I am in favor of both but I prefer to complete killing rust before painting. All of the rust converters are based on phosphoric acid. There are other products such as milkstone remover sold at dairy supply stores and lime scale remover sold at restaurant supply stores, which will work extremely well at converting rust at a far lower cost than POR-15.

(quoted from post at 15:00:14 10/18/23)

POR-15 is a combination product. rust converter and paint. I am in favor of both but I prefer to complete killing rust before painting. All of the rust converters are based on phosphoric acid. There are other products such as milkstone remover sold at dairy supply stores and lime scale remover sold at restaurant supply stores, which will work extremely well at converting rust at a far lower cost than POR-15.

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POR 15 paint is a good, hard moisture curing polyurethane. A Union Carbide paint rep told me about 20 years ago that the base material for all PU paints is made by 4 companies worldwide. The price was about the same for the raw material. Bottom line, if it is inexpensive, it doesn't have much expensive stuff in it. There is no such thing as cheap but good PU. I haven't checked, but I expect that if POR 15 has doubled in price, Pettit and Imron have too. Amazon has a gallon of POR 15 for $210 and Pettit 6980 Rustlok Steel Primer for $158. Pretty sure that is a major price hike for both. Pettit Trailercoat had a great reputation for boat trailers. 6980 is exactly the same thing as Trailercoat 6980. I checked that directly with Pettit. So, yes, there is a very similar alternative for 75% of the price.

Milkstone cleaner is very similar to a number of products sold for pretreating aluminum for conversion coatings. Same or similar phosphoric acid concentration, detergents and solvents all about the same. I read the SDS for Milk Stone remover. Used to look at paints and phosphate coatings sometimes as part of my job, so SDS reading is pretty routine for me. Cost, not the same by at least half. It is as Showcrop says a less expensive version of iron phosphate.

POR 15 Metal Prep contains some zinc salts that can produce a heavier zinc phosphate coating with more rust resistance. We are comparing good enough to better, but nothing major. I still use the POR stuff because I already have some. When that runs out I will probably pick up some Milkstone cleaner.

Black fluid film? Does that mean leaky rear main?