[question 1]
border between original factory paint and POR-15 or Rust Bullet, etc.

I would like to know how POR-15 or Rust Bullet behaves with existing car paint.

I do not want to apply POR-15 or Rust Bullet on the whole panel because of some small rust areas on the panel.

The rust area I want to repair is surrounded by car's factory paint.

So, if moisture or other harmful things penetrates at the border of POR-15 or Rust Bullet and car's paint, rust area will grow again.





[question 2]
Did anyone compare POR-15 and Rust Bullet?


I did some work with POR-15 starter kit.
It took quite a long time: Marine Clean -> wash -> dry -> Metal Ready -> wait 15 minutes -> wash -> dry -> POR-15 -> wait -> second coat of POR-15.
After 3 days: fine sandpaper, and then apply touch up paint.

I heard good things about POR-15 from end users, but heard nothing about Rust Bullet from any end user yet.

I hope you have better luck than I've had with POR-15. My experience is that the top coat will not stay attached to it very long.. and shortly after sunlight (UV) gets to any part of it, it will blister and flake off.
On all my restoration work, I use Corroless from Eastwood. Have never had rust return and its easy to work with. Best part is that you can use part of a can and reseal the lid...

__________________
KenP

1996 S500 W140 Coupe

Eastwood sells Eastwood Encapsulator.

http://www.eastwood.com/Department.asp?SKW=TRP0&Dep_Key1=RusPre&Cat=Coating+Rusty+Metal&SubCat=Rust+Encapsulator

I wish they post more information on the products as other brands.
Eastwood has only very short description about the products.

My guess is that they changed the name. You could call them and find out.
I'm still working off the gallon of Corroless I bought from them maybe two years ago... great stuff. It only came in a reddish-brown color that could easily be thinned with mineral spriits and used like paint.
Give 'em a buzz and see if "encapsulator" is the same stuff...

__________________
KenP

1996 S500 W140 Coupe

I swear by por15. If it flaked off then the area wasn't clean (oil, wax, etc) I painted the floor boards of my -62 190sl four years ago (surface rust with pin holes but structurally ok) and they look like I did them yesterday. Por 15 will react to direct sunlight and must have a top cover of paint (explained in directions). I've painted engine blocks, engine bays, trunks etc with the stuff and it seals and wears like powder coat.

Believe Corroless was made in England and the plant burned down. Or something like that. I still have a quart and and aquart of Por 15. While por 15 is good , I did have the same problem with adhesion. Never with Corroless. Just my >02

__________________
Ricali

03 C240 4matic wagon
95 300E 234,000
7 prior 240;s 5 still going
81 300sd gone
65 230sl gone
49 Studebaker Champion
90BMW convert.167,000
60 Dodge D-100