Naval Jelly is a very old product and, to me recall, one of the first such products I ever encountered. It works by converting surface rust to a black film on the metal. I am not sure, but I think the active ingredient is phosphoric acid. If so, there may be some sort of coating left behind on the metal.

The jelly is brushed on, left to work, then rinsed off with water.

In my experience, if you left the area exposed several hours to the air, the metal would begin spotting with speck of rust again. So, you do need to get things dry and primed, at the very least.

When I treated the rst on my '78 244 fifteen years ago for a total repainting, I used NJ extensively.


That car followed me around for about three years after I had sold it, so i saw how well (or poorly) my rust repairs had lasted. I would give NJ a B+ grade for longevity before the rust came back.

I had mixed feelings about the ease of use. Because it formes this black "skin" "killed" rust which is bonded to the metal, I found it also tenede to lift at the edges of the repair area during sanding of whatever primer coat I applied over it.

That is, if the surface needed wet sanding or the glazing putty and primer to blend the repair into the surrounding, good paint, the featherd edges wanted to curl up where the NJ (I think "Extend" is a similar product) became exposed again by the sanding.Tthe edges of this film would lift like the dry edges of a nice omlet under the broiler.

It sticks in my mind I had to do a lot of last minute salvaging of my rust treatment efforts so I could finally top coat.

Nowadays I just use Corroless, by The Eastwood Company (I see they call is something else).

I like it because it saves steps.... it is like a rust arrestor in a red oxide primer.

My prep then, is wax removal, sanding, etching with acid, rinsing (sometimes I use wax remover or paint thinner instead of water), then Corroless. Let dry and top coat.

Eastwood's product is superior to POR-15 in application in that POR-15 turns rock hard when dry and you need to buy their propriatery "Tie Coat" primer (a self-etching primer, I gather) in order to get the top coat to stick to the rust treatment product. With Corroless (or whatever Eastwood calls it now) maybe a light scuffing is all that is needed.