I found something that may help a lot of us. It’s on the Rust-Oleum “Rust Reformer “ from a gentleman that called the company to get clarification. This was copied and pasted and not my words.
“Liquid or Aerosol - Here is What You Need to Know
Reviewed in the United States on May 1, 2022
Size: 8 OunceStyle: BrushPattern Name: Spray
Rust-Oleum makes several products that carry the label "Rust Reformer." At the time I wrote this review the above listing contained numerous selections including a choice between a liquid and an aerosol. Although the liquid and the aerosol are both labeled Rust Reformer, the products are fundamentally different. Accordingly, understanding the differences will likely help you choose the more appropriated product. Also worth noting is that although there are two fundamentally different products, there are at least five or six different labels and part numbers. Because I became confused I called Rust-Oleum for clarifications and some answers to some questions. The information below is based both on my usage and the information provided by their technical staff. Also worth noting is that both products contain the identical phrase "Instantly converts rust to a protected paintable surface." Related to the labels, it is worth noting is that Rust-Oleum packages some products in more than one product line. The products listed above carry the label used by their automotive paint division.
The Liquid: I was told that the liquid was the superior product for converting or transforming rust. The liquid is water based and contains water-based chemicals that react with rust to convert it from chemical rust to another iron-oxide based compound that has different physical properties. So, in that respect it does indeed eliminate the rust. The product is milky white out of the can and dries almost black on rust (indicating conversion) and pretty much clear elsewhere. At the time I wrote this, the 8 ounce bottle was identified by the number part 248659 on the back label (not to be confused with the number on the front label which is the label number). The same product in the household division has a label that depicts a chair and has the part number 238433. There is also another part number in an 8 ounce container of a different shape that also appears to be the same product. That part number is 7830730. As I recall, the staff was unfamiliar with the part number and suspected it was the same product being marketed to another segment of the paint market. And, there is also a gallon size with the part number 3575402.
The Aerosol: I was told that the aerosol stops rust basically by encapsulating it thereby not allowing water to cause further rust. This appears to conflict with the phrase " Instantly converts rust to a protected paintable surface." However, this characterization is consistent with a review that someone else wrote about, where the reviewer stated that he used the aerosol on rusted metal, sanded the result, and discovered the rust was still present and was not converted. This product comes out of the can black and dries black. This product also appears to be Xylol based as are a lot of aerosol paint products. Possibly there is something in the paint that may do something more than standard primer to convert or retard rust other than encapsulate it, but typically chemical reactions with metals transpire in a water based environment. As I recall, the automotive division product has the part number 248658 and the home division product has the part number 215215.
I have used both products and both worked well. I did not do a direct comparison and did not evaluate their long-term durability. I also used another liquid product called Corroseal around 15 or 20 years ago and at that time found it to be excellent.
Regarding which product to choose, my advice would be to use the liquid where possible and convenient especially over heavier rusted areas. Obviously, the aerosol is easier to apply in many instances. Also, in many cases it is likely you will apply a top coat of paint especially if you don't want the resulting surface to be black. And, in my experience it is always preferable to remove as much rust as possible by scraping, wire-brushing, sanding, or by chemical means.”
“Liquid or Aerosol - Here is What You Need to Know
Reviewed in the United States on May 1, 2022
Size: 8 OunceStyle: BrushPattern Name: Spray
Rust-Oleum makes several products that carry the label "Rust Reformer." At the time I wrote this review the above listing contained numerous selections including a choice between a liquid and an aerosol. Although the liquid and the aerosol are both labeled Rust Reformer, the products are fundamentally different. Accordingly, understanding the differences will likely help you choose the more appropriated product. Also worth noting is that although there are two fundamentally different products, there are at least five or six different labels and part numbers. Because I became confused I called Rust-Oleum for clarifications and some answers to some questions. The information below is based both on my usage and the information provided by their technical staff. Also worth noting is that both products contain the identical phrase "Instantly converts rust to a protected paintable surface." Related to the labels, it is worth noting is that Rust-Oleum packages some products in more than one product line. The products listed above carry the label used by their automotive paint division.
The Liquid: I was told that the liquid was the superior product for converting or transforming rust. The liquid is water based and contains water-based chemicals that react with rust to convert it from chemical rust to another iron-oxide based compound that has different physical properties. So, in that respect it does indeed eliminate the rust. The product is milky white out of the can and dries almost black on rust (indicating conversion) and pretty much clear elsewhere. At the time I wrote this, the 8 ounce bottle was identified by the number part 248659 on the back label (not to be confused with the number on the front label which is the label number). The same product in the household division has a label that depicts a chair and has the part number 238433. There is also another part number in an 8 ounce container of a different shape that also appears to be the same product. That part number is 7830730. As I recall, the staff was unfamiliar with the part number and suspected it was the same product being marketed to another segment of the paint market. And, there is also a gallon size with the part number 3575402.
The Aerosol: I was told that the aerosol stops rust basically by encapsulating it thereby not allowing water to cause further rust. This appears to conflict with the phrase " Instantly converts rust to a protected paintable surface." However, this characterization is consistent with a review that someone else wrote about, where the reviewer stated that he used the aerosol on rusted metal, sanded the result, and discovered the rust was still present and was not converted. This product comes out of the can black and dries black. This product also appears to be Xylol based as are a lot of aerosol paint products. Possibly there is something in the paint that may do something more than standard primer to convert or retard rust other than encapsulate it, but typically chemical reactions with metals transpire in a water based environment. As I recall, the automotive division product has the part number 248658 and the home division product has the part number 215215.
I have used both products and both worked well. I did not do a direct comparison and did not evaluate their long-term durability. I also used another liquid product called Corroseal around 15 or 20 years ago and at that time found it to be excellent.
Regarding which product to choose, my advice would be to use the liquid where possible and convenient especially over heavier rusted areas. Obviously, the aerosol is easier to apply in many instances. Also, in many cases it is likely you will apply a top coat of paint especially if you don't want the resulting surface to be black. And, in my experience it is always preferable to remove as much rust as possible by scraping, wire-brushing, sanding, or by chemical means.”
