got some rust developing at the lower seam of the door where the inner and outter panels meet. i see it at the bottom of the door on the inside not far from the drain holes. i've sprayed in the bottom door drain holes to flush out any dirt/sand that may have collected in there. dad says to spray wd-40 in the drain holes and coat the the whole bottom inner part at the seam to help. anything better??? rust is very minimal at this point but i want to stop/slow it.
odourless fish oil. it comes in a spray can,from the auto shop. I guess you would have it in your part of the world?
Fluid film works great on my boat stuff and I spray it on the bicycle we keep at the beach. Wd40 is not nearly as good.
Unfortunately I have not had good experiences in my many battles with body rust, it almost always ends up kicking my ass. Unless you can remove all the rust and hit it with a phosphate or primer you are only giving yourself a few months or a year extra time. If you want to try something, you can see if you can brush some naval jelly on it, and if you can't reach it with a brush then spray CLR bathroom cleaner on it. Then flush with water and when dry spray with a rust neutralizing primer and when THAT is dry spray it with LPS 3 (not LPS 1 or 2, but LPS 3. They are different). Anyway, not to sound too pessimistic but when rust gets a good foothold darn near the only true cure is to remove the bad section and replace it.
Wow, I would definitely NOT put acid somewhere that I couldn't be absolutely sure of rinsing it out COMPLETELY (like in a car door bottom seam). I would just flush it out with a hose as well as possible to get out any dirt or anything that might hold moisture, then try to dry it out as well as possible (possibly with some methanol DryGas - alcohol - which will dissolve the water and help get it out), then maybe somehow squirt a really thinned-out mix of Rust Oleum "rusty metal primer" in there and be done with it. RO rusty metal primer contains fish oil and it binds really well with rust, sealing out further moisture and in many cases arresting the rusting process (I think rusty metal primer was Rust Oleum's first product and original claim to fame). I've had excellent results with it for many years.
If the rust is visible at all... You are F'ed If you spray the inside of the doors and other areas with ATF and a little diesel for thinning..... The car will not rust for a very long time. But, you will need to park it on a bit of cardboard or? for a bit until it stops dripping. Then clean of any extra. I have not done this, but a buddy has on his 92 truck (since new) here in the rust belt and his truck shows no rust! I will also after i fix the few just starting to show spots on my 97. By fix, I mean sand/media blast and neutralize and repaint.
I used to use a really nasty smelling silver paint called Petit on a US Coast Guard ship to battle rust. It's a never ending battle as you can imagine. Anyway, the stuff works great at stopping rust for a few years and only causes mild dain bramage.
My bronco was getting some rust allong the bottoms of the doors and around the wheel wells. Depending on what your doing it on herculiner is an excelent solution. We got some rust spray, and did the inside of the doors. I can post pictures if you are interested.
Hit it with Rust Converter, it's some kind of phosphoric based liquid. Converts the rust to iron phosphate and that's stable. Since your not able to be 100% sure the liquid got down into all the rust, coat it with the underbody tar to keep the water and air from it. It won't rust anymore if you can get it sealed up. Needs air and water to rust. You can get this stuff at Walmart.
oser We used to paint the fishing boats with some thick red paint called "Red Lead" . . . . . Since been banned; pheew stuff was horrid smelling.
Anywhere you can get a liquid acid compound into you can also get a neutralizing compound into. Like baking soda and water.
If the paint and primers have been compromised, it's all over. You can only keep those drains clear to help keep the door dry, avoid carwashes and any kind of high pressure spray, makes sure the window seal strips are good (again, keep it dry). You can neutralize/convert whatever is there with strait phosphoric acid, from Home Despot or similar, paint dept. You apply, then dry it with an air jet. You do not rinse. Instruction on the jug. This will convert any existing rust to iron phosphate. Then top this with LPS 3. This is a heavy waxy rust preventative---essentially Cosmoline. Spray cans and gallon jugs. Redo it every year or so---but keep the drains clear.