It’s now two months since I prepared some samples of an assortment of rust preventative products and left them exposed to the elements. So far the winter has been reasonably mild with only maybe four or five frosty nights and not that much rain. I’ve only subjected the samples to a salt spray once at the beginning of December. It’s time to take a look and see how they are doing…
1. Magnus Cavity Spray
Generally, a coating like this is used in closed sections and therefor isn’t usually subjected to the weather directly, so this test is a little extreme for this type of coating. Whilst rust does seem to be encroaching from the edges of this sample, so far the thin wax coating does seem to be holding back the surface rust underneath. There’s no sign of the coating lifting or flaking at all and the coating itself remains soft although dry to the touch. To be honest, this sample looked like this a month ago and hasn’t really got any worse so the wax does seem to be doing it’s job reasonably well. It’ll be interesting to see how it’s looking in another two months.
2. E-Tech Tecknik Rust Preventer
This sample really isn’t looking good at all. The existing surface rust has appeared through the coating already. I suspect that like most primers, this one is quite porous, despite what it said on the label. A top coat of paint would no doubt help matters but the primer itself doesn’t appear to be very good at resisting existing corrosion and keeping moisture away from it. On the plus side, the coating does appear to be well adhered to the surface still with no flaking visible. I think I might prepare a second sample of this coating painted onto bare clean steel and see how well that copes.
3. Bilt Hamber Hydrate 80
This coating is not really designed to be a final coating like this, so it’s doing reasonably well so far, however I don’t think it will hold out much longer. There is clear evidence that the existing surface rust under it is developing still as evidenced by the rough surface that has appeared all over. Of greater concern is the fact that the coating is now quite hard and is beginning to flake off at the edges. That said, for a ‘rust converter’ type coating, it’s holding up to the elements quite well although I suspect by the four month mark it will be in quite poor shape.
4. Magnus Underbody Protection This underseal type coating has pretty much failed the test already. The existing surface rust underneath as broken through and is creeping in from the edges all around. Curiously, while the coating doesn’t appear to be flaking off at all, it does look like it’s simply eroding away. I suspect this sample is going to look pretty bad in a couple of months time!
5. Bilt Hamber Dynax UB
As I suspected, the Dynax UB seems to have coped the best so far. In fact it doesn’t seem to have changed much at all since the test started. Of course this is the thickest of all the coatings so it could be hiding developing rust underneath but if it is I expect it’ll be visible after another two months. There is little evidence of rust creeping under it from the edges and no cracking or flaking. The coating is still soft but not sticky.
6. Bilt Hamber Hydrate 80 with paint
As with the sample #3, the Hydrate 80 here is also beginning to flake off as the rust penetrates in from the edges. There’s also evidence of the underlying surface rust continuing to developing so it would appear in this case that the addition of paint over the top hasn’t really added much extra protection. I suspect that this treatment would function best as a temporary, short-term rust cure in a less harsh environment. We’ll see how it looks in a couple of months.
Here’s a comparison between the samples at the beginning of November and now after two months exposure…
I’ll be taking another look at these samples and posting up a report at the start of March. Whilst this test is providing some interesting results, I feel I should conduct another, more extensive test in the future with samples based on both new, clean steel as well as old steel …and each sample the same size and prepared in an identical way. In light of this, I will begin to collect a variety of coatings to test and welcome your suggestions for rust preventative or rust cure coatings you would like to see tested (subject to me being able to get them in the UK of course!).