rusty sills?

912UK · Jun 20, 2013

ORIGINAL: PAUL RUDDY You don't want a cavity wax, you need to use a BILT HAMBER product called Hydrate 80 first, you need to chemically kill the rust and stabilise it rather than just lay a cavity wax over the top of it, wax will not stop that rust in any way. http://www.bilthamber.com/corrosion-treatments/hydrate-80 Cheers, Paul

this is correct you need to kill it first then coat it.. Looking at those photo's they look good.. one area may be for repair the rest is nothing to worry about and treated now your good to go!

Veerzigzag · Jun 20, 2013

If you are looking for the simplest solution then pour some old engine oil into the sills

I have some experience of this, as my TR6 (bought new in 1973 and kept for 23 years before I finally gave up the unequal struggle) had old engine oil poured into the chassis every year. Fat lot of good that all did: the water got under the oil and the chassis literally fell apart. I think (hope !) that the new stuff like Dynax S-50 sticks to the rust and metal and holds the damp at bay.

Craigybaby · Jun 20, 2013

Many thanks, so hydrate 80 first to kill the rust, then dynax s50 to protect. How long should I leave it inbetween the two treatments? A day? A week? And will doing on an incline (or downcline) be as good as jacking the car up? And where precisely are the drain holes as I can't see them? Regards

amrbose14 · Jun 20, 2013

I have a different question - I did this process several years ago. It must be time for a another go by now - so should I just squirt more wax in? Or go through the lengthy process of cleaning out the wax (white spirit??) and retreating any rust? Chris

Eldavo · Jun 21, 2013

Hmmm, looking at the Bilt Hamber website and I can't see how you'd get the Hydrate 80 into the sills? The Dynax S50 is an aerosol with a lance but the Hydrate 80 has to be painted on - radiator brush???

zcacogp · Jun 21, 2013

There seem to be two questions here; do you need to treat the rust before putting wax on, and do you need to remove the old wax before putting new wax on? I don't think you need to treat the rust before putting wax on, although I could be wrong in this. However logic and a bit of chemistry answers the question; waxes are acidic, and any acid will treat rust; rust is chemically a 'base', and a base reacted with an acid produces water and the relevant salt. (Soaking something that is rusty in vinegar is a great way of gently removing the rust.) Therefore, any waxy rust-protector will therefore treat the rust it is applied to, to a certain extent. I also don't think you need to remove the old wax before applying new wax. If the existing wax has coated the surface well then there should be no reason to get rid of it. The only reason you need to re-do it is to ensure that any wax which has been removed is replaced. This does make you wonder how wax would be removed, and the answer is that I don't know, in which case I'd question whether it is necessary to re-do the wax every year. Caution, I guess. Oli.

944Turbo · Jun 21, 2013

ORIGINAL: Eldavo Hmmm, looking at the Bilt Hamber website and I can't see how you'd get the Hydrate 80 into the sills? The Dynax S50 is an aerosol with a lance but the Hydrate 80 has to be painted on - radiator brush???

I thought it said you could spray it on as well as applying by brush, however not sure how you would prepare the surface. It would make sense that the cavity waxes were designed to arrest rusting, by blocking oxygen / water from the surface and by chemical action. if it is rusting from the other side they might struggle though! Tony

edh · Jun 21, 2013

I'd just go with the BH instructions, and they suggest that Dynax can be used on top of rusty surfaces - one thing they say is not to apply too thickly. A quick re-coating every few years might make sense to just keep it topped up but I can't see you'd need much. For anyone considering this - make sure you have newspaper under the drain holes - it makes a nasty mess on your garage floor / drive other wise