TheSamba.com :: View topic - Rust Proofing

Mon Sep 08, 2014 11:07 am

Preserving older vehicles generally raises the question of rust proofing. There is a pile of anecdotal evidence out there, and few actual tests. I'm going to throw out a few links, research and hope that some of you have comments/tests to share as well. I have a cavity gun system and have trended of late to treating my Westfalia and other vehicles myself. I have repeatedly had vehicles done by "professionals" and taken them back on numerous occasions for missed applications. My general opinion after 20 years of this is that proper coverage has not been done once by any of the popular franchises here.

In Ontario, KROWN and RUST-CHeck are popular. These are fluidic treatments, that a lot of people swear by, however my experience would suggest there are better products.

My A3 Audi was KROWN'd a year back..and the underbody 12 months later is dry. There is little evidence of the product on the underside of the vehicle.

Rust check can be purchased here at Canadian Tire, so I sprayed 1/2 of my wife's CRV 2 months ago, and then did a road trip. This trip involved about 4 hours of driving in intense rain. The undercarriage has been mostly "washed" clean of the Rust Check "coat and protect" product which is thicker and intended for underbody application. My Wesfalia inner body panels were sprayed (by me) a few years back though and still weep product via the seams on a hot day. So quite effective in inner panels over a longer period where no road/spray exposure occurs.

So here are a few tests. My general conclusion is that the underbody should be treated with a wax/reinforced material for better resistance to spray, and a lighter product applied to internal panels for best ongoing "creep". Noxudol offers the 700 for inner panels, and a heavier product for the underbody.

1. This Canadian military test used the CLIMAT test to test 9 products (including WD40) which resulted in very good results for a product called "Corrosion Free 3000" : http://www.corrosionfree.com/Dept_of_Defence_Report.pdf

The CLIMAT test uses copper bolts wrapped in aluminum wire to accelerate corrostion tests: http://www.corrosion-doctors.org/AtmCorros/coupon.htm

I have found zero tests beyond that, only a youtube vid showing examples of poor application by Canadian Tire, even after a revisit.

2. Classic Car Monthly did a three year tests on rust surface coats, as well as panel treatments : http://www.auson.se/sites/default/files/rusttest_noxudol_700_classic_monthly_uk.pdf

Noxudol 700 came out on top with respect to cavity treatments, with Waxoyl number 2. On rust encapsulators, POR15 and Eastwood encaps were dead last. "Rustbuster Epoxy-Mastic 121" won the test.

3. Dinitrol and LPS3 show well in these lab tests: http://www.virginia.edu/cese/research/CPC%20talk%20at%20AA2002.PDF
I confirmed that Bombardier (local plant) uses a variety of Dinitrol products to treat the rapid transit / street car products that are manufactured locally. The latest multi-million dollar street cars, built for Toronto transit will live in cold weather and heavily salted roads.

4. Bilt Hamber appears to have solicited this cavity wax test series themselves, which shows their product as superior in salt spray tests: http://www.bilthamber.com/media/downloads/32/PG-BH13-001.pdf

I'm hoping this thread will generate some helpful information. Many have spoken of Fluid Film but I cannot find any tests. I am considering welding up a hitch mounted tubing array that would mount in our CRV trailer hitch, or my father's highway driven subaru (lots of salt) to test the various products over a winter, essentially mounted under the vehicles in real world conditions.

Mon Sep 08, 2014 12:13 pm

I came across a German car magazine test, 3 year test I think, of various treatments in body cavities. I can't find the URL right now but I do recall that the mike sanders grease type stuff came out the clear winner.

Found a link, slow link, to a PDF copy of that test

http://www.afripix.de/Rostschutz.pdf

Oh here's another German test

http://www.afripix.de/Kram/rostschutzfarben08.pdf

I agree with you about a wax based treatment on areas exposed to wheel spray. I use fluid film on my van, inside and out, but it does not last long in wheel wells, leading edges of suspension components etc.

Alistair

Mon Sep 08, 2014 1:28 pm

I'm prepping my van for rust prevention. I plan on powdercoating most of the suspension pieces (with a rust stopping primer powder undercoat). The body metal (underside) will get treated with POR-15. All bolt treads will get silver anti-sieze.

On top of that, I will use Waxoyl. I've used it on my 4wd. It works very good. The only issue is that it's hard to find here in the US. I like the clear stuff better than the black...

http://www.rust.co.uk/waxoyl-cavity-wax/p474966/

I think rovers north or moss-motors sells it...

http://www.roversnorth.com/ProductDesc.aspx?code=WAX2&type=3

http://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=31497&SortOrder=30

Mon Sep 08, 2014 1:32 pm

tjet wrote:

On top of that, I will use Waxoyl. I've used it on my 4wd. It works very good. The only issue is that it's hard to find here in the US

This is it.

http://www.thesamba.com/vw/classifieds/detail.php?id=721760

Mon Sep 08, 2014 1:36 pm

http://www.waxoyl-usa.com/

Mon Sep 08, 2014 1:51 pm

Extensive write up here......

http://www.thesamba.com/vw/forum/viewtopic.php?t=131753

Dave

Mon Sep 08, 2014 5:06 pm

Dave, that link I did see before..but as it tests rust encapsulation, I didn't include it. It's worth noting in the Classic Monthly 3 year tests (on MG body sections) that Rust Buster Mastic was their choice. Por15 I've tried and was not impressed with...so not surprising it ranked near last. You might want to check out the epoxy product vs Por.

The under body and panels really do need a seeping/creeping product, and I'm pretty dead set against using encapsulation when doing body work. That said, if I was top coating bare metal underbody, I'd use the epoxy mastic product. I'm already a fan of epoxy primer as it's given excellent long term performance used in my projects. Powder coat is an excellent coating where possible on suspension as a base.

Waxoyl depends on clean/dry substrate for application, so it's not a water displacer where that would be present. I will say that my 84 Scirocco had VW's version of waxoyl still present and doing it's job in sub frame metal after 30+ years. I had to do some repair work on the floor stiffening channels and both were still nearly filled with wax. They rusted from the outside where careless techs had jacked the car up, crushing these rails. T, Waxoyl tested well in the panel tests and may well be the most cost effective for inner panels. Not sure how it fares under body exposed though ?

Alistair, the Mike Sanders product I have seen however, the high temps and rather "picky" application requirements might suggest a product that is more viscous at 20-25C would work better for seam creep etc. Any chance a german speaking sambanite can summarize those German tests?

Mon Sep 08, 2014 6:18 pm

Ok, so I managed to unsecure and translate the German test Alistair linked: http://www.afripix.de/Rostschutz.pdf

They built up box channels, and exposed outside for three years with salt spray at regular intervals. 17 of the 20 boxes were badly rusted after 3 years. Mike Sanders Grease: http://pristine-classics.com/cars/mike-sanders-rust-prevention-grease/ performed best in that test with no rust issues at seams, holes or the internal "sill". Mike Sanders Grease needs to be applied at 100C (225)F .... wow. Waxoyl was fourth ranked with mention of it's effectiveness being reduced by salt wash. Fluid Film was ranked 8th "was washed out by scattering salt spray and condensation. Consequence of: rust on the entire surface. Good protection, only with regular follow-up treatment."

The test description translated:

"The boxes: 60 cm long, made of original body sheet, 0.7 mm thick. Formally, they are modeled on car sills. Ie: Just like this, our boxes outflow holes for water and inside welded-sheets that stabilize a static sill. Outside they were painted white, just as primed as a real car. The anti-rust treatment: Before we applied the cavity seals, we were rusting inside the boxes. This slight surface rust te corresponds to a poorly conserved car after three to five years. Until now we screwed the boxes, they filled according to the manufacturer waiting tables with consolidated. Important: temperature and pressure. Weathering: In the grounds of the University of Oldenburg, the boxes came into the open. In winter, we sprayed a four percent salt solution in the boxes. This corresponds exactly to the salt concentration, that is scattered on the highway. Every six months there was a case-control.?"

An English summary of this test is also here: http://www.theautoteam.co.uk/rust_prevention

Mon Sep 08, 2014 6:49 pm

Interesting tests.
They do not test Eastwood's wax product though, the HD Antirust.
I have some which I will be using in my current syncro build, but may pick up some of the Waxoyl hard wax as well.

The eastwood's wax product has been the most impressive wax product i've used to date. It "fogs" of sorts and remains somewhat tacky, but not sticky. It quickly heals any cuts or scratches and really wicks.

I have used fluid film as an annual attempt at lubricating the bottoms of cars and making an effort to hinder rust. It certainly wicks better then any other product! That stuff really get in to the smallest cracks!
It's a great product for spraying the back sides of interior seams, but yes, it does wash off quickly.

Mon Sep 08, 2014 7:51 pm

Here's some interesting tests on different rust preventative oils...

http://www.youtube.com/watch?v=NVtszs-NZog

http://www.youtube.com/watch?v=WqXi947z0Ck

Mon Sep 08, 2014 8:51 pm

On my 85 restoration project I am using a pretty amazing new local product recommended to me by a syncro guy who works at our great local hardware store (mcguckins)
Its called "through the roof" made by Sashco, and as it sounds is a roofing product made for some pretty extreme conditions.
It can be applied by caulk gun or painted on. The really cool thing is it is clear, so you can see what is happening underneath.

I was skeptical at first so during my bodywork time I ground down a piece of vanagon body metal I had and painted a bit on, after sitting outside for the last 6 months no change, The stuff is really tough, I can't scrape it off and the bit that dripped on my driveway has been runnover many times and is in direct light etc...it won't budge.
So, I did all the undersides of my fenders,and all the interior seams it dries to a plyable, softish clear rubber type coating. It is seeming pretty bomber.

Tue Sep 09, 2014 6:54 am

TJ, I was surprised that WD-40 was used at all for rust treatment. It was tested in the Canadian defense CLIMAT tests but did not do well. That test (linked in my first post) also ranked dirt attached to the test bolts and the "corrosion free 3000" product ranked well there again. It is a zero drip formula sounding a bit like the product Tsch described. The problem I suspect with zero drip products is creep...or rather the fact that anything that "skins" or claims zero drip does not creep into seams. Conversely fluidic sprays seem to be more volatile (so evaporate after time) or just wash off.

My general take on the metal cavity tests is that the best performers have been higher viscosity compounds that remain at least somewhat mobile after application. The Noxudol products (I see pine tar in their descriptions?), Mike Sander's Grease, and Waxoyl would be the top three at least based on tests so far. The German test Alistair linked is easily the most comprehensive test I've seen. There is also a private community that covers corrosion testing requiring a phone interview and a signed zero advertise agreement. Interesting...

Tue Sep 09, 2014 7:31 am

I sprayed the entire under body etc. of my westy with waxoyl (the black Hardwax underbody product) at least 6 years ago.

It performed really well for the most part. I drove the van one winter, shortly after coating, as a ski rig, and did see the beginnings of rust after that - primarily at sharp edges of flanges, seams etc. Places that tend to rust first with most coatings. This was applied over rust free areas (Van was a west coast baby).

In places that are protected, it is still a solid coating that requires a scraper to remove. Some of it is still waxy, some of it is harder, and sort of flakes off with a tool.
The drive on the Trans Labrador Highway did a job the coating in places where gravel could get to it - lots of small dings and wear spots on suspension parts etc.

My general take on it is this - it's a great product! However, it's not an apply once and be done. After a FULL application (A real messy PITA requiring respirators, full body suit etc.) Periodic inspections with an aerosol can of the same product should be done at least yearly on all exposed surfaces. Any of the product that was inside frames etc, will be there *forever*, but I suspect that it no longer "creeps" after the first season of hot weather.
My van STANK of solvents every hot summer day for the first summer, and on real hot days for least 2 summers...

I think that Waxoyl, properly maintained, and a top coat of a real creeper like Fuid film periodically applied may be the best option out there.

That is for protected surfaces - I think that suspension parts, wheel wells, etc need a more solid product.

The Fluid film applied to our cars is easily visible after a full year (in VT) on protected places -bolt heads in the engine bay, or in nooks and crannies of the under carriage for instance.

I figured I could add a few photos as illustration:
example on the frame: Note it is still quite waxy here, but also has allowed some rust to begin in thinner, un-maintained places - see edges just above hand.

Another of frame underbody areas: Note how on the edges the coating has failed - either due to wear, or thinner application...? However, flat, less exposed places are solidly coated still.

These were just what I had in the gallery - I'll take some better pics later today, maybe!

Tue Sep 09, 2014 7:52 am

Nm, an excellent post. Thanks for reporting your observations in such an objective manner. Your observations with Waxoyl are spot on with the classic monthly (3 yrs) and German tests (4 yrs) that showed the Waxoyl drying out a fair bit from year 2 onward. My guess would be the thicker it is applied, the longer the drying process would take.

Tue Sep 09, 2014 8:05 am

I worry about spraying Fluid Film over the soon to be fully waxed underbody, as it's good enough at creeping that I worry it will somehow get under the wax or break it down. It's an astonishingly good product for getting into nooks and crannies but as mentioned, washes off.

I assume any waxing needs to be addressed at least every 5 years.

Tue Sep 09, 2014 10:51 am

Phish, if you take the German and Classic car tests at face value, the underbody waxes like Waxoyl should get a look every 2 years or so. KROWN and Rust Check require yearly application for warranty, so using Fluid film yearly makes sense too.

The Sander's Grease was the only product in the four year test that resulted in no damage due to rust...and I believe their recommendation for recoat is four years as well.

Tue Sep 09, 2014 11:50 am

I wonder what that Sanders grease is like to the touch?

For months after waxoyl application, working on the Van resulted in black Sh&% all over my hands... That went away eventually though.
Still like it!

Tue Sep 09, 2014 12:03 pm

nmerrill wrote: ...
I think that Waxoyl, properly maintained, and a top coat of a real creeper like Fuid film periodically applied may be the best option out there.
...

Is that also true for a Van with pretty intact asphaltic undercoating already applied? Mine is that way (in fact they hosed down everything in sight, pipes, hoses, fuel pump, etc.)

I've just been treating any places where it is falling off or has been scraped. I've used 3M spray cans, and Eastwoods brush on product, depending on where.

I also figure rust is not a huge issue in sunny Orygun, and the vehicle will likely last longer than I do anyway.

Tue Sep 09, 2014 12:41 pm

Nm, from what I can gather, the Sander's grease has no smell, and is solid at room temperature. This is all I can find in terms of application..both in German.

and this one features an older vw bus.

Tue Sep 09, 2014 1:54 pm

So, found a supplier in NA, in Alberta of all places. Ordered up 24Kg of the Mike Sanders Grease. Stay tuned. The link below is to the 1 gallon can, but they did have the 24kg quantity in stock. A one gallon can is likely about 4kg.

I'll post a vid.

http://www.wmsracing.com/wmsweb/2-Mike-Sanders-Rust-Prevention-grease-1-gallon-can.html