Guys- sincerely hope all is well with everybody. Been a long time since I've been on the forum. Just jumping back on the XJ repairs this spring and realized a nightmare scenario: Ive got some rust and rust bubbling forming under some anti-rust (POR-15) paint. Now, When I applied the paint a year ago to NON rusted areas mind you, I made sure to prep and dry everything thoroughly but it appears to not have been enough. Now I've got rust forming along the door jambs and trim in some pretty bad spots. It wasn't rusting at all prior to this application. Is there anything I can do, or am I forced to grin and bear it as the corrosion starts? This really sucks and I thought I had everything pre-planned right. Guess not.

 

Start trying to get that POR 15 off, and coat it again. You can ignore it,but if you wait too long, it will get worse.

I used Rust Bullet on the underside of my pickup 2 years ago, and it is still holding great.

 

I read another thread that mentioned that por 15 is not that great on metal that does not have rust when applied.

Of course it could be a number of other factors that caused it.

 

For rust products check this out. This guy does all kind of tests on his own, one of my favorite channels for reviews.


Maybe go over the areas that are bubbling and reapply.

 

Good suggestions gentlemen but how do I remove the POR paint? I most definitely put it over non rusting metal to try to prevent but def see my mistake now in that I should have just forgone it. How the heck can u remove it before it’s too late? Thanks-Rick

 

Well a wire wheel and a drill, sand papper, or you could go the paint remover gel ( just be careful with rubber and plastic parts )

 

Rust may have come through from the backside.

I prefer coatings that penetrate (like Fluid Film), rather than coatings that seal.

 

 

If you have a harbor freight around go and get a couple of small medium and large ones. Depending how large an area you gonna clean will dictate how many you’ll need. Start with maybe 2 of each.

 

HF sells a nice 9 ct set for like $10 that has lasted me a while in my battle with rust.

Well maybe not 9 ct but
https://www.harborfreight.com/wire-w...-pc-60475.html
https://www.harborfreight.com/7-piec...kit-90976.html

 

I doubt those drill wheels will take off por 15, you will most likely have to grind off what actually adhered. You can try a knotted wire cup for an angle grinder, or a paint eater disc for an angle grinder.

 

I am a bit perplexed as to how the POR15 would allow rust on properly prepared metal, as I have used it many times, also 2 pack epoxy, polyurethane and single pack surface preparations

In all cases its mainly porosity from dissolving thinner gases. Single pack is more thinned, and and very porous

2 pack is far less thinned, and cures by chemical reaction, so is over 1000 times less porous

pours let O2 and H2O permeate to the original bare steel

POR15 is single pack, but 10% thinned, and also chemically cured. I found it to be more porous than 2 pack..in addition, it must be applied in more than one coat and be finished with the correct topcoat
(like any other product). If applied correctly, it works well. If any steps are skipped, its adherence can be suspect.

Its difficult to get off. Grit blasting is the most effective

You really need to examine whether the rust came thru from the inside, like another poster suggested..unless you think you did not apply the POR as I described
btw..it wontstop any areas that have rust on them already, only slow them. I believe the product over promises

 

Pretty sure while you can do a top coat on POR 15 it is not necessary. I never do.
The reason they suggest it is because POR 15 will turn ash gray over time from UV light.
Everywhere I use it is not in direct sunlight, mostly under the Jeep, and don't care if it turns ash gray anyway.
I have had pretty good success with POR 15 but IMO prep is more key.
Also where it has not performed as well as hoped were in questionable places where I could only POR 15
one side but suspect the rust was attacking from both sides. So it not performing as well is understandable.

 

Guys-tried the wire brush attachment in my drill and man it’s hard to control and kind of wild. This will be tougher than thought. I have an angle grinder too. Should I just put a sandpaper disc on it and call it good? Are they easier to control when doing this kind of work?

 

I would say a wire wheel or a flapper disc on your grinder. Due to the higher rpm's and the way the angle grinder is design maybe little easier to use just go in easy and let it do the work. I take it you don't have a air compressor as a die grinder with a wire wheel would work. if you have a harbor freights near you (if not on lock down also!) they have electric die grinder that may also work.