Deck turns blue'ish/purple'ish when wet

[sailingdream]

I was down at the boat having a look(since its out of the water and not covered over(one of the big winter storm we had shredded the trap to pieces) and noticed that the gel-coat on the deck has this blue/purple'ish color to it in streaks,  I didn't have the camera with me. And it was wet from the melting snow.

It's a 1990, and it was in FL/GA most of the time.  I only got it back in Aug07 and haven't had lots of time to work on it and give it a REALLY REALLY good wash down and de-ox the gelcoat. It's now in the Toronto.

Has anyone seen this before?

I will also mention that the boat had been lime(instead of soda) blasted to remove the bottom paint. I wonder if because some of the dust from the lime stayed on the deck and cause this issue. But I did hose down the hull and deck to remove as much as I could at 11pm when they were done(took them from 8:30am to 10:30pm)
Any thoughts?

[Ron Hill]

Sailing: I've always used Soft Scrub w/bleach to clean the anti skid - and it works great!!  Have NEVER tried it on the other smooth gelcoat!!   

[Tom Soko]

Sailing,
If your bottom paint used to be blue, then I think you hit the nail on the head.  Most likely overspray from the bottom blasting found its way onto the deck, and you didn't get it all off.  Once the weather gets warmer you can clean it off.  I've also used softscrub very effectively.  Good Luck with the new boat. 
PS-you might want to update your signature (unless you like being called "Sailng"!)  ;-)

[sailingdream]

The bottom was blue and maybe alittle purple, dang, why didn't I think of that. I was thinking it was something gone bad with the gel-coat. Thanks, hopefully winter will end sometime this yr(it's been the winter that just doesn't want to go away for us in southern Ontario.)

[Mike Vaccaro]

Deck staining in the yard is common.  The prime source is usually old bottom paint--the copper will leave blue/green stains on deck.  Soft scrub works well on the non-skid and the smooth gel coat usually doesn't stain if there is sufficient wax on it.  Soft scrub can be used on the smooth gel coat, but it will remove wax and will require buffing with 1500-2000 grit compound and re-waxing to restore the finish. 

Another annoying source of stains is steel or iron filings that can land on deck and turn to rust when they get wet.  This is tougher to remove and requires a cleaner made for that purpose.  Old compounding paste is also slung over most of the general area, and this can be cleaned with soap, water and a terry cloth towel.   

I always enjoy the extra work after I finish paying the yard bill--not!

Cheers,

Mike

[Mike Kuder]

I have heard that bleach is bad for fiberglass and therefore only used Softscrub w/o bleach.  Has anyone else heard this?  If not true will gladly switch this spring, should be an easier cleaning of the deck.

Mike

[Jeff_McKinney]

Another sailor in my area told me he's used powdered "Oxy-clean" instead of the soft-scrub. I have not tried it yet (still under cover), but he says it does a good job cleaning off the stains on all gelcoat but has no abrasives. You might need a scrub brush for the crevices in the non-skid, but otherwise there is minimal elbow grease needed. 

[sailingdream]

Thanks folks I will give that a shot, IF and when the weather ever gets warm. They are still predicting 6 more weeks of cold weather up here. I need to get some bottom painting done before it goes back into the water, but afraid that its going to be too cold to put it on.
Plus give the sides and good washdown

[Ron Hill]

Sailing : If you can't get the stain out with household cleaners, try some FSR (Fiberglass Stain Remover).  You can purchase FSR in the 2 qt size. 
I'm afraid that to get the best chemical reaction from the oxcyolic (sp?) acid you'll have to wait till it's warmer. Also FSR will take off any wax , so do the deck before you wax the sides - just in case.