Tuesday, 16 September 2014

Black Streaks Are Us

Escaping the grind of 12 hour work days in Manila, boat work seemed an attractive option and Crystal Blues has been ignored for some time.  Arriving aboard in Singapore twelve days ago, we were surprised how much attention she really needed.

 The acid rain here is (we think) the worst in the world - just one rain shower can have the boat looking zebra striped.

If the black is not removed quickly, it will eat into older gel coat and paint systems to become a permanent feature of the vessel.  

Our Awlgrip paint is five years old, but living in Manila for the past year we were simply not washing the boat often enough.  So we returned to a stripy hull and decks that resisted all attempts at conventional cleaning.

We really needed a solution.

Black Streaks Are Us
We tested two concentrated spray products with mixed success - the popular "Black Streak Remover" certainly made an impact, but also put permanent flat (no gloss) streaks into the paint system (only in Singapore can you pay $28.00 for something that destroys your paint work).  

"Simple Green" was better, sprayed on neat and hand worked over the streaks it did a good job, but still removed the gloss in places ..... 
Finally we bit the bullet and decided we should really learn how to cut and polish the paint system.  Shopping to buy a "proper" electric polisher, we happily discovered that our small (5") Bosch random orbital sander could be fitted with wool or foam polishing pads.  With the speed dial set low enough, it works a treat.

Testing The Process
Over several days we tested the tools and techniques, before settling on a process that worked.  Using 3M Marine Liquid Wax on the degraded "flat" areas, we found we could produce an excellent finish with minimal effort.  We had used this product before, and we know that it lasts very well - the last time Crystal Blues was polished was two years ago.

Next we experimented with a very light compounding or "cutting" of the black streaked surface, using a "fine cut" paste designed for polyurethane paint.  This also worked very well.  

Into Production
Finally we settled on a process that created the best results with the least effort :

1.  Wash the hull and rinse thoroughly, allow to dry.
2.  Very lightly compound or "fine cut" the surface, using a foam pad on the polishing machine.
3.  Wash away the residue and rinse.
4.  Spray "Simple Green" onto any residual streaks and wipe aggressively.
5.  Rinse thoroughly and allow to dry.
6.  Apply the liquid polish and buff to a high shine.

This really is not a strenuous process - the Bosch sander / polisher is very light and easy to work with.  Working from the floating dock (not ideal) it took us around 18 hours to completely restore one side of the hull.  Which now looks fantastic .... long may it last.  With the polish on the surface the black streaks do not form as quickly, and wash off easily. We think the polishing will now need to be done annually to maintain the finish.

No comments:

Post a Comment

Have something to say ? Let us know your thoughts ....