Monday 2 January 2012

Winter Salt Protection - ACF50, FS365 or WD40

Winter is on the way. In the UK winter means road salt, and road salt means corrosion. There are a few products on the market that claim to help reduce corrosion. Some work very well and some are just a waste of your time and money. The best way to stop your motorcycle corroding is to wash it, dry it and place it somewhere completely dry. This makes using it a little awkward, so lets take a look at some alternatives.

Many years ago I was given a product called ACF50 for evaluation. At the time ACF50 was widely used in the aviation industry but almost unknown elsewhere. Corrosion in the aviation industry is more than just a little inconvenient, it is life threatening. I needed quick results and got them. This led to F2 Motorcycles Ltd becoming the first motorcycle dealer in the UK to stock ACF50. No pictures were taken of the original tests, so I have repeated them here and taken a few pictures.

It's a really straight forward test. Steel wool has a huge surface area and corrodes extremely quickly. It is also a very hard shape to coat. You couldn't, for example, paint it. A piece of steel wool was cut in half. One half was sprayed with ACF50 until it was dripping wet, the other half was not treated at all. The treated sample was hung up so any excess ACF50 would drip off. Both samples were then sprayed with salt water until the water dripped from them. No worse than riding down a soaking wet road that had been salted. They were then simply left in the cold just as you might leave your bike after a ride.
After 6 days the samples looked like this. 
Above - Sample treated with ACF50 after 6 days
Above - Untreated sample after 6 days
 Both samples were then sprayed with more salt water every other day for ten days. The ACF50 was not reapplied at any time, this test is to see if a single application could withstand repeated attacks of salt water. After 10 days the samples were left in a cold place as before so the salt water could work its evil magic. 

After 30 days (so this is 36 days including the original 6 day test) the samples looked like this.
Above - Sample treated with ACF50 after 36 day test

Above - Untreated sample after 36 day test
So all this is fairly impressive, and this is why I like ACF50 and why all motorcycles that leave F2 Motorcycles Ltd are treated with this product in the vulnerable areas. But people always say ACF50 is expensive (which it is) and there are other products that make similar claims. So to satisfy my own curiosity I have done a comparison test pitching ACF50 against the most common rivals. This time a single sheet of new steel was used. The steel was skimmed using an angle grinder to give is an uneven surface and increase the surface area. The steel sheet was divided into four roughly equal areas and coated with the products. The WD40 area and the ACF50 area got one good thick coat of product the FS365 got two coats. WD40 and ACF50 do not really dry, but the FS365 does dry and is supposed to leave an even coating. However after an overnight dry it was obvious it was very patchy so to be fair a second coat was applied. The steel was left untouched for 24 hours to give the FS365 time to dry. The steel was then lightly sprayed with salt water.

Above - Steel sheet at start of test
The steel was then sprayed every 3 to 4 days for approximately 1 month. The pictures below show the results. The control had no product added so any product that works should be better than the control. I will leave you to decide the winner.

There was no tricks or cheating involved with these tests. I would have loved to have found a lower cost product that beat ACF50, but I didn't.

Test carried out by David Angel of F2 Motorcycles Ltd
We supply ACF50 as well as using it in the workshop


  1. I have a lot of respect for ACF50 as well. Here is another incidental review by the Canadian Military. The Boeshield T-9, ACF50, and WD40. Krown T40 is the second heaviest, and Corrosion Free 3000 the heaviest, which may be why they did the best on one of the environments. Their consistency would render them inappropriate on many environments leaving ACF50 and Boeshield T-9 in the top two spots. Both have aviation roots. ACF50 is recommended in AD notes for some Piper aircraft, the expected choice for aircraft, and the one speced by many OEMs. Boeshield T-9s market is more rooted in corrosion protection on boats, and has a pretty good following with chains on bikes.

  2. I have a lot of respect for ACF50 as well. Here is another review by the Canadian Military. Since it's a government study, it lends credence to the results of this test, and that the author is not a spammer. Boeshield T-9, ACF50, and WD40 are also included. ACF50 and Boeshield T-9 took the top two spots. Both are thin and penetrate well. Both have aviation roots. Boeshield T-9s market is more market toward corrosion protection on boats, and has a pretty good following with chains on bikes. ACF50 is recommended in AD notes for some Piper aircraft, the FAA expected choice for aircraft, and the one speced by many OEMs. Anybody that knows anything about the FAA knows that if they recommend it to spray in our wings, it had a lot of testing done in it for efficacy and safety. It took the FAA forever to give us alternators, fly by wire, intelligent ignition, and glass cockpits.

  3. I am using this for the first time as both my bikes have to be outside and covered all winter, both are classic bikes as well with lots of chrome. I protect everything including the paintwork, how do I get it off the areas I want to polish in the Summer.

  4. Wow! I knew ACF50 was good, everyone swears by it and I have been using it for this winter and last. Of course, with no control on hand, you never really know just how good it is, or conversely how bad corrosion would be without. However your test really highlights what it can do. Such a simple test too, half tempted to repeat it myself for a laugh (would be a great science experiment to do with the kids too).

  5. If you look at the instructions for FS 365 you are supposed to reapply after washing or riding in the rain as it is water soluble, did you spray any more on after the initial application?

    1. I've had a couple of comments about re-applying the FS365. It does seem that even the manufacturers don't fully understand the product. On the one hand it says it will wash off and on the other hand it says "Road salt neutralizes the solubility of FS365 - effectively sealing the coating in place". Given that the salt water wash was misted on using a modelling air brush at low pressure and never enough to run off the steel as in driving rain I would be surprised if the FS365 was washed off. It clearly did not continue to offer any protection after a very light mist of salt water. However it is a fair criticism of the test procedure. I did give it two good coats to start as it was obvious it did not form a complete even coat after one application.

  6. \not sure if links work from the comments section, but I have also done some alloy testing.

    1. Link sort of works, highlight it and then right click either open link, or open in new tab. Works for me. I guess if it doesn't you could copy and paste it.