What is the Yellow Gelcoat Stain

[bugs]

I have read much of the archive posts on the yellowing effect but have not seen any description of what exactly the yellow stain is and what causes it to occur.

Y-10 is not working on a long band of yellow stain on my 1999 boat. The rest of the hull has come up nicely. This line is about 3 inches wide for most of the length of the hull about 6 inches from the deck (just below a moulded crease line, on one side only.
Termperature was 10 degrees when I tried it. I gather this is the min temp required, perhaps I need a warmer day.

 

[Toutvabien]

I know that this is of no help in aswering your question, but, I had a similar problem with my last boat, significant staining along the waterline.

Various people suggested that it was organic matter, essentially weed or slime, ingrained into the gelcoat along the water line. I tried Y10, and other oxalic acid variants, with limited success, a professional boat valet company were unable to give me an assurance that they could shift it either. In the end I used a cutting compound to shift the stain and then made sure that I always kept the area prone to staining very well polished to prevent further staining.

 

[snowleopard]

i got one of those when an oil spillage came through the marina. lots of people put in big claims for cleaning (the offender was the navy)

 

[itsonlymoney]

Dont know but if it looks a bit like a tobaco stain Starbrite hull cleaner works a treat.
Ian

 

[Peegee]

I'v also suffered from the yellow peril and am certain it is the thin surface film of oil/waste on the water surface. I used Y10 to remove it (originally it was bad enough on the bow area to require two sessions ).
but the stain would always come back once we were out in the channel again. Then.. on the forum about two years ago, some one suggested instead of using "common" boat polish, use a product with Teflon. Now I wont say it is an absolute cure, but it is a vast improvment , and experience has shown that if you put on a couple of coats of the polish
(and I use the wax sealer/protector on top of that ) at the end of the season the staining is only faintly visible.
Good Luck

 

[pvb]

Maybe it\'s a gelcoat problem...

Not sure whether the other posters read your question, but I can't see that anything in the water can have caused a yellow stain close to deck level. Is it perhaps possible that this is a gelcoat defect? I've seen yellowing areas in patches on boats, totally unrelated to water exposure. As your boat's 5+ years old, you probably won't be able to claim on warranty, but it would be worth contacting Beneteau to see what they say.

 

[LadyInBed]

I pass this remedy to you as it was passed to me, suspend disbelief and just try it!
Go to your local supermarket and buy a bottle of HARPIC and some rubber gloves.

Squirt the Harpic on the hull and spread (gently rub) it over the selected area with a dry cloth.
You will think nothing is happening and you have been fed a load of sh1t.

Wait five minutes or do another area, then give the treated area a rub over with a damp cloth.

The yellow stain will disappear as if by magic!