Remove stains from gelcoat

cdlong · #1 05-10-2015, 08:14 AM

I have 5 stains that I have tried the 2 cleaners on, with scrub pad & stiff brush. One stain lifted well, the other 5 are a PIMA! Anyone know how I can remove them before I apply the floor sealer to get her shine back?

otterhound · #2 05-10-2015, 10:22 AM

FSR by Davis will work well on stains like that. It's basically oxalic acid in gel form. Brush it on, leave it for a few minutes, remove with water and a sponge or brush.
Rod

PigSticker · #3 05-10-2015, 02:31 PM

Some stains can get so deep in the gelcoat that you have to sand them out, and sometimes that may not even work..

erebus · #4 05-10-2015, 04:06 PM

Mary Kate On-and-Off.
Its our go to waterline stain remover here at the yard come haulout time.
Just dont let it drip on your galvanized trailer!

(FYI- its a combo of hydrochloric, oxalic and phosphoric acids)

CJg8r · #5 05-27-2015, 10:55 PM

I've had good luck with snobowl toilet cleaner

BigLew · #6 05-28-2015, 12:20 AM

If you believe it is an iron based stain (rust stain), go with Iron-Out. Get it in your grocery store or Home Depot.

Also, You might try white vinegar first, rinsed and then go at it with baking soda.

Just a thought- no garruantees

cdlong · #7 05-29-2015, 05:41 AM

Thank you!

uncleboo · #8 05-29-2015, 02:12 PM

Quote:

Originally Posted by erebus

mary kate on-and-off.
Its our go to waterline stain remover here at the yard come haulout time.
Just dont let it drip on your galvanized trailer!

(fyi- its a combo of hydrochloric, oxalic and phosphoric acids)

wear a mask and have plenty of ventilation!

erebus · #9 05-29-2015, 06:20 PM

Quote:

Originally Posted by uncleboo

wear a mask and have plenty of ventilation!

Plus heavy gloves and eye protection!!

WaveWalker · #10 05-29-2015, 06:38 PM

Muriatic acid, spray on and rinse immediately. Do this as many times as necessary unitl stain is gone, will also remove barnacle and shells off bare bottoms. I recommend stripping any wax off the gelcoat with degreaser first so the acid will work better then re wax when done. Can be used on motor for barnacles but do it at own risk! ON then OFF immediately! Will turn bottom paint green if allowed to run on it. Used this when I worked for a popular boat detailing company in the keys. THIS is done at your own risk. Cjg8r not to rain on your parade but keep snobowl off your boat, it is an abrasive and will scratch the crap out of your paint and gelcoat.