As my 2009 XK is my first Aluminium car, I'm not sure whether to have the car treated with Waxoyl, Mercasol etc,. While I know it is good on a steel vehicle I don't know if there are any issues/problems having aluminium treated.

Does anyone here have any 'expert opinion' on the matter or, alternatively, actual experience? I'd really appreciate some input before I decide to take the plunge - or not!

Thanks

Paul

 

Other than some LPS or other cosmoline based protectant for the steel suspension subframes I don't think there's much to protect. If you get a chip in the paint, seal it or you run the risk of corrosion eating the base aluminum.

 

What he ^^^^ said. I'm somewhat stymied by some pictures from wet and salty areas (GB mostly) where the alumin(i)um bodies look fine but my-oh-my all the steel parts are deep red and flaking they get so badly rusted.

I'm lucky to be in the South West USA and winters are mild, the air dry and the sun nice and hot. Not a speck of rust anywhere.

 

What's the point of undercoating any car that's already 9 years old? Regardless of how well you prep it, the corrosion has already started and you're just covering it up. Because you can't see, it can pose a safety hazard as it gets progressively worse.

 

What's that run, about $1500?

 

I wouldn't even consider it on an aluminium bodied car. Sealing and factory applied protection is considerably better than it was with the earlier steel bodied designs. The only parts that rust are steel suspension parts (springs/dampers) and various brackets which aren't included in rustproofong treatments.

This is my 2007 XK Coupe after eight years. Looking forwards from the rear with the exhaust removed to replace the heatshields. Note the rusty steel brackets and bottom of the damper - unsightly but not unsafe:



In contrast, this is the rear wheelarch of my 2014 XK Coupe after four years - not a mark on the aluminium:




However, I do recommend attending to stone chips on the bodywork a.s.a.p. If the bare aluminium is left for any length of time, the paint breakdown area increases alarmingly. I also like to remove the wheelarch liners for a thorough annual cleaning. It's amazing how much gets past them. One of the few areas you can safely and effectively use a pressure washer on a modern Jaguar.

Graham

 

 

There's about a dozen torx bolts that hold the panels in. Fronts are in two sections, not sure about the rear but you can see the body nuts in Grahams pics above.

I used LPS3 on all of the undercarriage last fall, even the rusty bits. No reason not to and the parts don't look worse for the winter's effects.

http://www.lpslabs.com/product-details/612

 

Having once restored a car that had been treated with a thick tar-like aftermarket undercoating, if I ever see a project candidate like that again, I will just walk away and let them send it to the crusher or let some other unsuspecting novice learn the hard way. There's always some rust found underneath that stuff anyway and removing it just triples the amount of work involved. And if there's any of that tar stuff inside hollow panels that you can't get to to remove, then you can't safely do any welding to repair it. I'll never touch another car like that again. As said, its probably way overkill on an aluminum car anyway.

There are other products like the LPS3 already mentioned, Boshield T3, etc. that can protect bare steel and are easily removed with solvents when the parts need to be worked on. Although because they are fairly easily removed, they also don't last a long time and will need periodic reapplication, particularly in areas with water spray like in the wheelwells. But its very easy to do yourself and one spray can goes a long way. I wouldn't spray those inside hollow panels though because 1) the solvent carrier is thin and anywhere it drips out through seams, it could damage the paint and 2) it could be dangerous if you have an accident and the car needs welding in the treated area. My favorite is Gibbs Brand penetrating oil. Its like WD40 on steroids, On a restored car, bare metal is supposed to be just that, bare, and the judges deduct points for aftermarket coatings. Gibbs leaves no discernible residue. One of the things you have to worry about with aluminum cars is that all the nuts, bolts, screws, etc are still made of steel and where they meet, you can get galvanic corrosion from dissimilar metals. I would think a penetrating lubricant like Gibbs would be just the ticket for treating exposed fasteners on an X150 as well as bare steel components. Anything under the car that's painted or primed and gets chipped, just touch it up ASAP.

Of course, I have a Texas perspective, can't remember the last time it rained here enough to get the roads wet. My restored classics don't see rain, but we still fight high humidity for part of the year and the Gibbs is excellent for that. I suppose in England, if you're not willing to drive your car in the rain, then you're never going to drive it at all. Maybe British restorers of steel-bodied cars will just have to live with tar-based undercoatings there, but for anyone reading elsewhere, consider less "permanent" rust treatments and just commit to a thorough undercarriage cleaning every spring or put that money you would have spent on rust treatment toward a winter beater and storage for your Jaguar.

 

The best way to PREVENT rust on the underside is to develop an oil leak and never repair it. That will smear the entire undercarriage with oil and road grime in a never-ending build-up. Best if it's way towards the front.

 

That has always been my strategy.

 

I've said it before what you described is not a leak but CONTROLLED SEEPAGE. This is considered normal in Jaguar history.

 

For many years used motor oil was sprayed in body seams and undercarriage as a poor mans rust preventive. Kind of ugly as it would stain the paint where it ran out over time and of course dripped a good bit at first but it worked well.

 

Same for me. No rust on my undercarriage and everything still works because I consume a lot of olive oil!

 

AT fluid would probably do a better job. For steel parts on other cars I have treated with Rust-Mort neutralizer. Basically phosphoric acid (*careful*) then a coating of POR15 which is easily brushed on. This would be for the steel parts only... and it will kill rubber seals and bushings. Not sure about the aluminium, but I have not had to even touch that on my XKR. It looks good inside and out.