Gel coat Stains

[marsman]

I’m sure this has been discussed before; I am particularly interested in the experiences of owners who get long black stains (they look like they’re caused by dirty water running down the outside of the trailer) that generally originate from around the windows, door or below the black belly band.

I have found they’re really hard to remove with any soap content. I have sprayed them with Spray Nine recently and with a scrub brush I can get most of it off but a slight pale grey stain remains.

Does anyone have suggestions for a product(s) that work well for their complete removal?

I don’t expect there’s any way to prevent them other than storing the trailer indoors or covering right?

Last year I washed the entire trailer thoroughly and waxed it with one of those new ceramic waxes thinking it would help prevent these water stains or at least make them easier to remove….did not work.

[cpaharley2008]

I switched to frameless windows and the stains did not appear anymore.....

[Ron in BC]

I suspect that the stains originate from the butyl tape that is used to seal the window.

Not much can be done to stop the streaks if the trailer is constantly being rained on.

Having been around f.g. boats all my life I've observed the good, bad and the ugly in the care of f.g. I cringe when I see folks using anything with an abrasive, no matter how fine. It's not necessary and long term you're taking away the surface of the gel coat. I've seen gel coat eroded to the point where the underlying resin becomes visible.

This is what I use. Black streaks disappear and no damage is done to the gelcoat.

Ron

[Donna D.]

Originally Posted by Ron in BC

This is what I use. Black streaks disappear and no damage is done to the gelcoat.

Ron

Ron, does the FSR remove the wax? Just curious.

[DanandDaphne]

Wow that looks like good stuff.

https://www.amazon.com/FSR-Davis-Fib...0171Q12V6?th=1

I was going to suggest something non abrasive like Bon Ami but I looked at the pictures in reviews and it looks like this Davis stain remover is the best for fiberglass and easy to use.

[gbaglo]

Originally Posted by DanandDaphne

I was going to suggest something non abrasive like Bon Ami

Bon Ami powder cleanser is an effective, multipurpose cleaner suitable for many household surfaces. As a gentle abrasive, Bon Ami has scrubbing power for tough stains but won't scratch like a silica quartz cleanser.

[Tonny LR]

I use 3M Perfect-it Medium wax to remove stains. It works well every time.

Tonny LR

[cpaharley2008]

I just ordered this to clean and wax the new trailer....https://www.amazon.com/gp/product/B0...0?ie=UTF8&th=1

[Rossue]

Originally Posted by cpaharley2008

I switched to frameless windows and the stains did not appear anymore.....

Ha ha - they seem to be your answer for everything; you forgot to mention better MPG!

[cpaharley2008]

You are correct. I forgot to mention that with my fiberglass cap, my mileage improved also, both unhitched and hitched.

[Ron in BC]

Originally Posted by Donna D.

Ron, does the FSR remove the wax? Just curious.

It doesn't seem to because I've used it several times without waxing and the gelcoat was still shiny.

Originally Posted by gbaglo

Bon Ami powder cleanser is an effective, multipurpose cleaner suitable for many household surfaces. As a gentle abrasive, Bon Ami has scrubbing power for tough stains but won't scratch like a silica quartz cleanser.

A gentle abrasive is like being a bit pregnant.

It's on one end of the spectrum with Vim and Jif on the other. Vim gives instant gratification but with repeated use I've seen it take off a layer of gelcoat down to the underlying porous layer. From there it's downhill into cracking and crazing.

I had my boat in the canals of Europe for two years. By the time I got to Holland I had a giant "Rhine moustache" extending up the hull for about two feet at the bow and tapering off towards the stern. I considered that it might be time to consider painting the hull. FSR brought it back white and shiny. It did take more than the usual wipe it on, wipe it off but it did the job.

Ron

[Rossue]

Just ordered some- thanks for posting that.

[ghosthunter]

I don’t believe it all comes from windows. I do believe it is rain related.

I get them down my trailer top to bottom after it’s set out in the rain. I wash the trailer before and after every trip.

The best I found was a mild spray on cleaner and a Mr. Eraser to remove the streaks.

[gbaglo]

Originally Posted by ghosthunter

The best I found was a mild spray on cleaner and a Mr. Eraser to remove the streaks.

Mr. Eraser is basically sand paper.
https://home.howstuffworks.com/magic-eraser.htm

[JeffinBC]

I think it’s from a combination of cubes: pollution, pollen, bird crap, window seals, etc.

FSR, Bio-Kleen, Star-brite and Thetford all make fibreglass cleaners or streak removers that work well on unoxidized gelcoat surfaces. Not cheap but quite a bit cheaper by volume if you buy the larger jugs. I believe they will strip the wax, though, so be prepared to use some detailer or other wax afterwards. It’s usually on the side or rear of the trailer so easy to apply spray waxes will protect sufficiently well (IMHO).

I would expect the Meguiars would work well if you want to get both birds…

[kstock11]

I use Collinite 920 with an RO polisher and this works well for me. I may try that FSR on my next long trip. As to cause, I believe it is rain related as I don’t find any streaks below the area covered by the closed awning.

[Fender]

Originally Posted by Ron in BC

This is what I use. Black streaks disappear and no damage is done to the gelcoat.

Ron

Ron, is this available in Canada? Amazon.ca imports from the US which gets pricey.

[mstruzz]

Used to have this problem on my boat, and happens on the fiberglass camper as well. This stuff is the best out there - its not abrasive and does not remove wax

Instant Black Streak Remover

[Ron in BC]

Originally Posted by Fender

Ron, is this available in Canada? Amazon.ca imports from the US which gets pricey.

My go-to marine supply store, Steveston Marine, stocks it for $18.89 CDN. Check your local marine store or see what the shipping is from Steveston Marine.

One jar lasts a long time.

Ron

[marsman]

Originally Posted by Ron in BC

I suspect that the stains originate from the butyl tape that is used to seal the window.

Not much can be done to stop the streaks if the trailer is constantly being rained on.

Having been around f.g. boats all my life I've observed the good, bad and the ugly in the care of f.g. I cringe when I see folks using anything with an abrasive, no matter how fine. It's not necessary and long term you're taking away the surface of the gel coat. I've seen gel coat eroded to the point where the underlying resin becomes visible.

This is what I use. Black streaks disappear and no damage is done to the gelcoat.

Ron

Ron,

Thanks so much for this advice, these streaks all over my trailer appear after its been sitting in the rain for a while and i really hate them, they're impossible to remove, I tried car wash soap and Spray Nine cleaner; the latter kind of worked.

I will purchase this immediately and once cleaned |'ll have to spring for a good cover for storage i guess. Cheers