waxoil vs paints for the underside of the car

[timrosser]

My 480 is currently sorn pending some boot welding of various holes that have formed in the last few years. I used a good quality waxoil on the underside of the car a few years ago, on a reasonably clean bodywork, having steel brushed and rust converted any blobs of rust. So this experience is making me question the waxoil thing, perhaps the oil left cavity's for the rust to creep unnoticed. Or as the boot of a 480 is generally wetter than most environments the car will pass through perhaps I was helping keep water in?

Anyhow, where do the rest of you stand on waxoils vs other paints and coverings?

[jamescarruthers]

Did you waxoil on topof chemically converted rust without paint? I would say you missed out some vital steps if I'm reading that post right Tim.‎

Bare metal needs protected. Ideally the first step should be that is chemically converted (because you can't see all corrosion in its early form even if it looks shiny). This will leave you with a ready surface-- etched is a good term. If you have whiney metal, you can apply etch primer or some sort of conversion treatment.‎

Once it is etched, you can prime it. The primer sticks best to an etched and properly prepared surface.

Once it is primed, you can apply top coat. The top coat sticks best to a properly prepared surface. In this case, slightly rough primer.

Waxoil is old fashioned stuff and trades on its name rather than actually being the best at its job; throw it in the bin. You want to apply a modern water displacing corrosion inhibiting compound. ‎

Listen to Jifflemon on his recommendations from Dynax, Bilt Hamber, etc, he knows what he is talking about. I will add Dinitrol (made now by Ardrox or Chemetal) and also LPS (LPS 3 for example) products to this list. ‎
‎

[timrosser]

Hi James, thanks for the reply, my volv underside is covered in the bilt hambler wax rather than classic waxoil & has several aerosols worth of BH cavity wax in any metal orifice I've spotted. I' not sure how I treated the converted rust before the wax, I imagine I would have gone with quick squirt of hammereite given the difficulty of getting a brush to some of the rust sites, but my rust seems pretty bad so maybe I didn't. Another possible cause is my old LPG conversion may have exposed some seams between the panels and allowed it to rust from the inside.

How do you feel about products like Eastwoods rust encapsulator for the primer / converter role? ESp in a fiddly application like under the car?

Best

Tim

[jamescarruthers]

Hi Tim,

I don't have any opinions on those because I am not familiar with them. ‎ 

My slightly OCD attitude to corrosion is based on working with aluminium ‎which more readily corrodes if left unprotected. I've always thought applying the same corrosion-terror seemed wise when dealing with steel. 

You're probably on the right track but need to apply primer and topcoat after corrosion removal or conversion. I would be suspicious of anything that says that it does both. Really you want it removed but i'm sure you know that, you're just dealing with the practicalities the rest of have to do too!

Good luck with the rust hunt!‎

‎

[jifflemon]

Waxoyl joins the list of stuff that used to be good, but now lives on only in name (see also: Hammerite, Nitromors)

Its sounds like you've started on the right track though - Bilt Hamber stuff is fantastic.

If it's undersides you're dealing with: BiltHamber Dynax-UB
If it's cavities you're dealing with: Bilthamber Dynax S50
If it's rusty and you can remove it and soak it in something: Bilthamber Deox-C
If its rusty and you can't remove it: Vactan
If you need a tough paint: POR15
I'm not in ANYWAY associated with these companies or products, but I have spent an awful lot of time (and even more money) trying to save rusty cars!

If you've got a compressor, get yourself a Sealy SG-18 gun for spraying the above!

If you're having welding done, Clean back to bare metal after its welded, cover with Vactan, once converted (it'll turn black), prime and paint.
If it's underneath, same thing, Vactan, POR15, then Dynax-UB.

Prevention is SO much easier than cure, so please start treatment (and this applies to ALL owners) now.

If you've got a garage to keep it in, then consider a dehumidifier, i use this one and am quite pleased with it.

If keeping outside, DO NOT use a car cover. They rub against the body and are worse for the car then a bit of rain! Yes, we know a 480 leaks, but that's your incentive for finding a fixing leaks! (and keeping the above Dehumidifer IN the car, running one or twice a week!)

[Alan 480]

i found 'grey stripe' quite useful, it's a 'seam sealer' but OK to use over small areas

and by goodness it sticks, I've been using it on underside when I would previously painted, it says 'brush on' but it is like margarine in it's thickness/consistency!!!