Staining on hull.

[graham]

The white gelcoat on our boat was seriously stained around the waterline and a foot or so up the hull.

Cleaned off with oxalic acid then lots of hull polish,looked great for a while.

Less than 6 months later it was as bad as ever ,we have just done it again,this is too much hard work to do several times a year so will probably reluctantly paint the hull next year unless anyone has a better idea?

 

[johnalison]

White boats always seem to do this. I use Yachticon Anti-yellow which is the same as Y10 or your oxalic acid and repolish immediately. A colleague with an old boat tells me that he had the same problem until he severely buffed off all the old polish and renewed the gelcoat surface before repolishing, since when the yellow has returned much less. He reckons the yellowing is mostly in the layers of old polish.

 

[saltwater_gypsy]

Y10 , a heavy duty wax polish and elbow grease.... OR why not a nice wide yellow boot topping.
The problem seems to vary from area to area. I was told it was contamination from oil residues.
VicS may be along in a minute to explain what the discolouration is and how oxalic acid works on it

 

[Cloven]

We get the same - oxalic acid & polish at the end of each season seems to work.

 

[tjbrace]

Y10 then Starbrite Teflon polish/sealer. More or less wipe on and wipe off for both, no hard polishing involved. Lasts the season for me.

 

[BlueSkyNick]

Stop flushing the heads while on your mooring will help !

 

[quimby]

Its a well known fact that Bristol Channel waters do make whites a lighter shade of brown. /forums/images/graemlins/grin.gif

 

[graham]

Thanks for the replies .The boat spends most of its time sat on a fresh water swinging mooring in Cardiff with only the occasional drying out in Bristol Channel Mud so I have no idea what causes it. I think I will try out some of the (sensible)suggestions re Y10 buffing etc before resorting to paint.

PS nothing to do with heads Nick as its on both sides /forums/images/graemlins/shocked.gif

Cheers Graham

 

[Refueler]

I got same in UK saltwater ... and still get it here in FW Baltic.

Main thing is to make sure that hull is well polished after cleaning to seal the surface. Done well the stain I find is not so hard to remove.

I use a car polish that used to be called Diamond Hard - old TV advert reckoned Astons etc. were polished with it for showrooms etc.

 

[TamarMike]

Don't be an AWB, Blakes do a nice black gloss.

 

[Wunja]

Paint it yellow. No more worries.

 

[mbay]

my boat suffers from this also but only on my mooring in summer season. the boats moved to a marina for the winter and does not get the yellowing.
I clean my hull at the start of summer season and the yellowing is back after a month or so......I've just learned to live with it.

 

[Searush]

[ QUOTE ]
Don't be an AWB, Blakes do a nice black gloss.

[/ QUOTE ]

/forums/images/graemlins/laugh.gif But black gloss reveals all the ripples in the hull finish. A major car manufacturer was once said to respray white any black cars that failed quality specs with panel faults.