Removing Stain on Gelcoat??

[Maxum]

Hi, I have recently purchased a Maxum 1800 SR3 . To test the boat out I had it in the water for just under a month. Now I have got the boat out for the winter and found I have stain which I cannot remove. I have tried pressure washing and brushing, using cream cleaner which was partly successful but not completely. I am still left with a slight stain along the waterline on the gel coat. Does anyone have any good solution to removing this. I have found that oxalic acid works well on hulls but was unsure whether it is safe to use on the gel coat.

Thanks

[mcoffey]

I have had great success with Star-Brite Hull Cleaner. It is an acid so wear latex or nitrile gloves.
http://www.starbrite.com/productdeta...ull%20Cleaners

You can see my results here:
http://www.maxumownersclub.com/forum...ll=1#post17224

And here:
http://www.maxumownersclub.com/forum...ll=1#post17225

Good luck!

[Maxum]

Thanks for your recommendation. I will try out the Starbrite Hull Cleaner and hopefully that will work as your results are very promising!!

Cheers

[leeADAB]

Hi,
I also have an 1800sr3 and I use this when I get marks on the white gelcoat. Works a treat!!
3M Cleaner and Wax.

http://solutions.3m.com/wps/portal/3...beH8PTZGX97Rgl

Hope that helps too.

Lee

[Maxum]

Hi Lee, thanks also for your helpful recommendation.

I will go to my local chandlers this week and see what they have to offer. Its only a light stain so something should work!!

Jamie

[shrew]

Maxum, Is the boat being stored in freshwater or saltwater? More importantly is it being stored in the water for lengthy periods of time, or are you trailering it? If you're storing the boat in a slip, whether fresh or saltwater, you should consider bottom painting the boat. For stains on an unpainted hull, I've had extrememly good success with "On & Off Hull and Bottom Cleaner". It's made for fiberglass. It's basically Hydrogen Chloride, Phosphoric Acid, and Oxilic Acid. Obviously, we don't know the concentrations, but it is safe for fiberglass. This stuff works extrememly well. 3M Cleaner and Wax is also very good. I use that as well. It takes much more elbow grease and time. Using the On and Off to remove the heavy waterline, then going over everything with the cleaner and wax works for me.

http://www.jamestowndistributors.com...ct.do?pid=2339

[Maxum]

Hi shrew,
The boat will be stored on the trailer and lifted into the salt water when I want (Like Dry Store). These periods will be from no more than a day at a time. I assume that anti-fouling is not necessary for this use as the boat will be washed down after each use. Also I didn't want to affect the appearance of the boat as it is a 2009. Thanks for the "On & Off" recommendation, looks a much more heavy duty cleaner compared to the others. I will try and upload a picture later this week of the stain but to be honest the camera probably wont show it very well. I am just too fussy I suppose!

[shrew]

If you are Trailering the boat or using Dry Rack storage, then you don't really need to bottom paint the boat. Particularly, if it will only be in the water for a few days at time. For example, if I only left it in for a day or two on the weekends and for a week of vacation at a time, then i wouldn't bother. I woul definitely give the On & Off an try, it works very well. Mine is in a slip all season. I get a decent yellow scum line just above where the bottom paint ends. This is at, yet above the waterline. At the end of the season, i use this to remove the discoloration, then in the spring use cleaner and wax and you can't tell there was a scum line at all. The hull looks the same from rub rail down to the bottom paint.

[capav8r]

I use plain old muriatic acid. I buy a gallon from the hardware store for around $5.00 and dilute with water. I use a 2 gallon pump up weed sprayer, fill with about 1 1/2 gallons of water then top off with the acid. Spray on, let sit for a minute or two and hose off. This takes all but the most stubborn stains off. For the stubborn spots, I put on the nitrile gloves and use a sponge to rub the acid solution a little. That takes even the stubborn stains off. This stuff will take the galvanization off any metal pretty much instantly so you need to cover anything galvanized on your trailer. It will also etch your concrete, so make sure you hose off any that gets on the concrete as soon as you can. It does not, however harm anything that is painted. It will clean stainless, too. I don't leave it on stainless very long, though.

[Maxum]

Thanks everyone for your recommendations, I decided to buy some of the Starbrite Hull Cleaner which contains the oxalic acid. Sprayed it on today and left for two mins as instructed and magic!!! I could see the stain just dripping off and left the original gelcoat unmarked. Thanks again, this forum is very helpful!!