Rust repair

[mojobaby]

I know that a lot of people on the forum have used Owatrol for rust repairs, but I'm not having any success with it.
I used it on some parts of my chassis when I took my engine out and it took forever to dry; perhaps I put it on too thick.
The stuff that I used previously turned the rust grey, and then I knew that it was working.

Here is a photo of my small repair with one coat of Owatrol. Should I now sand it smooth before I apply my filler?
I put it on yesterday and its still tacky

 

[Azazello]

I usually use a drill wire brush to take off the rust, a heavy coat of phosphoric acid based product and let it dry for the night. The day after I wire-brush it another time to take off the product excess and all the rust that was inactivated and detached from the piece. Then I go with a coat of primer and/or filler.
I had discordant opinions wether filler should be applied on bare metal or on primer... surely it has to be covered with primer before being painted, elsewhere you will distinguish the painted areas from the filled ones.

 

[mojobaby]

This is the link to the Owatrol
http://www.owatroldirect.co.uk/product/owatrol-oil/
It seems to have dried now, so I'll put my filler on and hope that I have good adhesion.
Azazello, I have always put my filler to bare metal.

I couldn't get my usual rust killer/converter so this is the first time with Owatrol