Painting Aluminium

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dmh

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My Lofrans Anchor winch is 20 years old and the plastic coating on the alloy casting has broken down. I have removed the coating and now need to paint it. I would have used Zinc Chromate primer to start with but I understand that it has been banned by Health and safety. What should I use now. Has anyone used Hammerite special metals primer followed by Hammerite paint. All suggestions welcome

David
 
The hammeirte combi has worked on some aluminium I did a couple of years ago. But it is indoors, I don't know if it would be good enough for an exposed windlass.
 
While I think it is untrue that zinc chromate has been banned there has been a move away from its use because of the carcinogenic nature of chromates.
However i think the best solution is probably one coat of an etch primer followed by the paint system, including primer, of your choice.

International Yachtpaints http://www.yachtpaint.com/uk/ market an etch primer.

Preparation of the surface will be the key to success, to which end grit blasting with a soft grit will be the ideal.

I cannot advise you on selection of a paint scheme other than to say that when I had some alloy portholes done some years ago by one of our "in house" paint technologists he used a chlorinated rubber paint. Maybe an epoxy coating would be better able to withstand the knocks that an anchor winch will be subjected to.
 
I made an adaptor plate to mate my radar scanner to a Scanstrut pole bought secondhand. The plate is aluminium, half hard plate, about 4 mm thick. I painted it with Hammerite aluminium primer followed by white Smoothrite. It has now been installed on the boat for about 5 years with no sign of pitting or paint loss. It is less exposed than an anchor windlass would be on your foredeck but in general this seems to be a reasonable paint system.
 
G'day dmh, and welcome to the YBW forums.

Have you considered getting it Powder Coated? as the original powder coating has lasted 20 years it could be well worth it.

Drop off one day pick up the next looking like new.

Avagoodweekend......
 
Yes - used Hammerite special metals primer & then Hammerite paint on a stemhead fitting to do just the job you mentioned - replacing old plastic coating. Worked very well although as expected it rubbed off where the chain passed through the fitting. Despite this, it looked much better than the old cracked plastic which just allowed corrosion to carry on underneath.
 
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Hammerite aluminium primer followed by white Smoothrite. ............... a reasonable paint system

[/ QUOTE ]

I do use Hammerite and have had mixed results. Unless several coats are applied it seems to produce a very thin film thickness which is easily damaged. I know our old paint testing lab were not very impressed by it. They would have applied it exactly as specified, no more coats than specified, and they would have tested and evaluated alongside the protective coatings in which they specialised.

The suggestion by Oldsalt to get it powder coated is an excellent one. It'll cost a bit more than a couple of coats of Hammerite but from what has been said on here before is not as expensive as one might fear.

Alternatively of course it might be possible to have it re- plastic coated.
 
[ QUOTE ]
[ QUOTE ]
Hammerite aluminium primer followed by white Smoothrite. ............... a reasonable paint system

[/ QUOTE ]

I do use Hammerite and have had mixed results. Unless several coats are applied it seems to produce a very thin film thickness which is easily damaged. I know our old paint testing lab were not very impressed by it. They would have applied it exactly as specified, no more coats than specified, and they would have tested and evaluated alongside the protective coatings in which they specialised.

The suggestion by Oldsalt to get it powder coated is an excellent one. It'll cost a bit more than a couple of coats of Hammerite but from what has been said on here before is not as expensive as one might fear.

Alternatively of course it might be possible to have it re- plastic coated.

[/ QUOTE ]

where would one get the stuff "powder coated" or "plastic coated" as you suggest?
 
I think for either process you will need to Google or search Yellowpages or Yell of somewhere that will do a single item. Perhaps someone will be along with some suggestions.

However I wondered if you fancy giving this sort of thing a try: http://www.frost.co.uk/item_Detail.asp?p...=&subCatID=

It is fairly widely available, not only from Frost. Surface preparation will remain the all important factor, grit blasting being the preferred choice. It may be best to apply an etch primer as well. A bit more research needed perhaps.

Powder coating will as far as I am aware not be a DIY process.
 
Thanks davewarburton, and all the other posters. Think I will try the Hammerite and see how it goes.
 
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