Rusty Towball

Try wrapping it with cling film.

I am reluctant to cover the ball in oil or grease when not in use because I would have to clean that off before towing because of the alko stabilizer.

Hi John, not of any help but did remind me of my Dutch friend telling me, while discussing stabilisers, that  I must "keep my knob clean" and wondering why I was convulsed with laughter.

Mind you he did also tell me that his brother in law had a "small tackell" which is apparently their name for a dog.

Regarding your question,why not fit a normal tow ball cover but dill a small hole so the water drains out?

A small plastic bag perhaps with an elastic band doubled over as tightly as needed around the neck of the tow ball to keep water out. 

Maybe, however if the elastic banding is tight enough maybe not. I could certainly design something that would do the trick and I am surprised that the tow bar manufacturer  has not? 

I think u r being unkind to the staff member tracey123, she didn't suggest it she asked the question " can you spray it with a rust proof paint? " it was a question. She also said she Liked the cling film idea and the tennis ball. At no point did she say use the paint

 I don't think that anyone would be daft enough to paint there towball. 

I detach my detachable bar each time I arrive on site ..... tow bars are horrible ugly things. If I had an electrically stowed bar it would just need a press of a button ..... so why wouldn't you?

I like Steve's idea. Personally having a tow bar on view troubles me not in the least. Whether it is aesthetically pleasing to others whilst I am driving or a more aesthetically smooth lined vehicle when I park it and walk away is of no concern. All my car choices are based on practicality and use for the given cash.

I hate the look of a tow bar, especially a two bolt flange type, hence my choice or flavour of tow bar. My car is a practical 6 seater than can tow a caravan with ease.

To JohnRH

I am having the same problem, what did you find to be the best solution please.

I too have the same challenge with the towball stowing upside down - any sort of cover on the ball precludes the bar from stowing away properly. 

So I take a (clean!) black dog pooh bag and place it over the ball and then secure the handles around the bottom of the coupling.  It is waterproof and keeps the ball clean and can be recycled if you want to use a clean one!! 

When away I keep the towbar "open" and then use a proper towball cover - only returning to a plastic doggie bag when the towbar is folded away for any length of time.

For what must be the few times I would need to do it, a longish layup, I would use a good rust protection fluid and accept I needed to give the ball a "degrease". I can't see applying or removing needs to be more than a minute or two tasks.

For the protection phase I would spray/ wipe it with Supertrol and cover with the "doggie" bag, suggested.

On needing it I would remove bag and wipe most of the Supertrol off with a bit of kitchen towel followed by a spray with brake cleaner, wipe off etc.

As said if out touring or a single trip I would not bother, but if not intending to deploy for a month I would.

Supertrol

Sorry for long link:

Yes, it is a surprise these retractable tow balls, where 365 days year in year out are exposed to all weathers etc are not made from a more surface corrosion resistive steel alloy.

I expect in part it is the real challenges most steels have in resisting attack from the rock salt used on the roads. Plating for corrosion protection not being ideal with the wear attrition they will have in use on the loaded surfaces.

@JohnRH - what worked best in the end?

My Merc W204 (2012) swing out hitch has the same problem, it's steel and it rusts like crazy and cannot be replaced.  I too have an Alko friction stabiliser so the ball needs to be 100% free from grease, paint or any rust that could contaminate the friction pads.
Anything I try to seal the ball with just channels water onto the ball when it is inverted under the cars eventually (over months). 
TIP: I use a latex glove doubled-over for short stays for a few days.
For anything more than a week in wet weather I have to fully grease the ball with bearing grease and this of course requires degreasing with solvent and rags before going anywhere near the Alko stabiliser.
My next car will not have a swing out, I will go back to a detachable swan neck for this reason.  Real shame as they are so convenient in every other respect.

To any car manufacturers out there - what is your solution to swing out hitches and friction stabilisers (virtually all braked caravans need them)?  Do you supply rust-free hitches as standard?