Preventing rust

[xantos]

Anyone has some experience in preventing rust in sills that are a bit rusty from the inside? Like this for example:



I've came across this: DINITROL RC900 I'm thinking this might be good to squirt inside the sills. And then another coat of rust preventing oil like this: Krown Oil

Advice / expertise appreciated...

[Stickyfinger]

Just use Dinitrol's full range of materials .....no need to mix them

[white exec]

Have successfully used Cavity Wax (brown or clear) from 4CR - superb stuff.
Also bought a Sealey SG18 wax injection/spray gun - will apply anyone's wax inside cavities and over large areas.

[lexi]

Have successfully used Cavity Wax (brown or clear) from 4CR - superb stuff.
Also bought a Sealey SG18 wax injection/spray gun - will apply anyone's wax inside cavities and over large areas.

Hi WE. I have the same gun and Bodyline cavity wax, brown and clear too.

As for OP. If you have access, I try to get some surface rust off mechanically. Then Phosphoric acid. Leave that a few days. Then brush off with a wire brush. Cavity wax on top. If it is on underside, and is getting hit by water, then Bodyline black underseal is a better finish, after the acid. The Bodyline brand are Unipart products made by Dinitrol. Citric acid is good too as a de rust agent. That is all good gear and lots cheaper than some of the pricy brands.
My phosphoric acid was about £20 a gallon. Chemical suppliers.

[Peter.N.]

I use oil, you can take a door tread plate screw out and squirt it in with an oil can, unlike sealants it continues to creep and gets into the seams where the rust usually takes hold. Squirt it in until it runs out along most of the sill length, you will need to do it every year but it does stop the sills rotting.

Peter