Cannot get fiberglass hull clean...HELP!!!

[Quick VR-4]

Hey guys,

I purchased a spotless 20 ft. Azure deck boat this summer with 60 hours so the boat looked brand new. I planned on putting in a lift this winter so I decided to leave the boat in the water for a few months (Aug-Oct). I thought that short of a time, I could tackle cleaning the hull before I store it. Well, I tried Slimy Grimy which worked wonders on the green algae. However, there is still a semi-thick yellow stain from the water line down. This stuff feels hard as a rock and letting the slimy grimy soak hardly did anything. I also tried using a scrub brush with little to no effectiveness. How can I get this hull clean???? The boat was kept in a freshwater lake for 2 1/2 months so I would never dream it could get this nasty.

Thanks in advance!!!

 

[Chaparralboater]

Re: Cannot get fiberglass hull clean...HELP!!!

Two things I have used that take it off.

1). EASY removal- 2000 grit wet sand paper. I used it to remove oxidation on other boats. Takes the stains out. You have to buff with polish or wax after because of some tiny tiny surface scratches from the paper.

2). Heavy cut compound. Buff the hell out of it. It is best to wash the area with dawn ( no bleach) dish soap to remove any wax prior. Then buff with the heavy cut. You may be sitting there for a little bit but it will look good and take it off.

 

[Haffiman]

Re: Cannot get fiberglass hull clean...HELP!!!

I used a lot of this:

However you have to be careful and prepared to do the whole hull.
Polish after to seal off the pores.

 

[rwidman]

Re: Cannot get fiberglass hull clean...HELP!!!

I used a lot of this:

However you have to be careful and prepared to do the whole hull.
Polish after to seal off the pores.

That is an excellent product for removing the yellow or brown stain from leaving a boat in some waters. In some areas, that stain appears after only a couple days.

It's best to clean the hull as soon as possible after removing the boat from the water. Each day makes the stain harder to remove.

You don't have to do the whole hull, only the stained part. Read the directions on the container and follow any safety precautions.

 

[Baysidejoe]

Re: Cannot get fiberglass hull clean...HELP!!!

I agree I used Starbrite hull cleaner on my old 2001 Searay. It worked really well. The boat was in the water from late april to early october.

 

[Acuario]

Re: Cannot get fiberglass hull clean...HELP!!!

Two things I have used that take it off.

1). EASY removal- 2000 grit wet sand paper. I used it to remove oxidation on other boats. Takes the stains out. You have to buff with polish or wax after because of some tiny tiny surface scratches from the paper.

2). Heavy cut compound. Buff the hell out of it. It is best to wash the area with dawn ( no bleach) dish soap to remove any wax prior. Then buff with the heavy cut. You may be sitting there for a little bit but it will look good and take it off.

I agreed w/ this always works great ..

 

[Quick VR-4]

Re: Cannot get fiberglass hull clean...HELP!!!

Thanks for the suggestions guys. Looks like I have some polishing and rubbing in my immediate future. Any particular applicators you would suggest or just use a standard auto polishing pad?

Thanks again guys!!!!

 

[rwidman]

Re: Cannot get fiberglass hull clean...HELP!!!

You can use hull cleaner every day if you wish with no damage to the boat. There's a limit to how many times you can sand it and sanding and polishing is much more work.

We're not talking about dull, oxidized gelcoat here, we're talking about a stain from organic material in the water the boat is used in. There's a big difference.

 

[rwidman]

Re: Cannot get fiberglass hull clean...HELP!!!

Thanks for the suggestions guys. Looks like I have some polishing and rubbing in my immediate future. Any particular applicators you would suggest or just use a standard auto polishing pad?

Thanks again guys!!!!

Before you break out the rubbing compound and polish, do yourself a favor and try the Starbrite cleaner one time. Follow the directions. Just do a small area if you're not sure.

 

[convergent]

Re: Cannot get fiberglass hull clean...HELP!!!

I agree with trying Starbrite first. My hull was stained and I sprayed that stuff on and it just washed away with zero scrubbing. I had been scrubbing it like crazy prior with no impact at all. I bought a brand new yard sprayer and mixed the Starbrite 4:1 with water. I then started at one end of the boat and began spraying it on. By the time I got around the boat the area I sprayed first was a bright white and so I just had to go around again and hit all the spots I missed. Then sprayed it off with fresh water and was done.

 

[jmarty10]

Re: Cannot get fiberglass hull clean...HELP!!!

Muriatic acid. 50/50 mix with water. Take a pump sprayer and spray down your hull. That crap will drip right off. Rinse down with water real good and wax away. When you use the acid make sure you dont get it on your hands, arms and legs and spray it on a dirt field where it will not destroy a driveway or something like that. Marinas use it out here all the time after a boat comes off the water after six months.

 

[Home Cookin']

Re: Cannot get fiberglass hull clean...HELP!!!

toilet bowl cleaner. I suspect it's the same as starbrite with out the "marine product" mark-up. but rinse it off your galvanized trailer immediately

 

[shrew]

Re: Cannot get fiberglass hull clean...HELP!!!

Muriatic acid will etch concrete and metal. I would go with the marine hull cleaning products first. I avoid household cleaners on gelcoat because some ingredients simply don't agree with gelcoat. Marine products are specifically made for boats. I had a friend decide that ajax was a great way to clean his hull. It looked fantastic...............until the hull dried. He spent days using rubbing compound to gelcoat back to a shine again. Sure, household products are much cheaper, but you didn't buy a boat to SAVE money.

Break Out Another Thousand. Spend some money on the proper products and do it the correct way.

 

[109jb]

Re: Cannot get fiberglass hull clean...HELP!!!

Muriatic acid (Hydrochloric acid) won't hurt the gel coat or fiberglass. It is used all the time to clean fiberglass pools, hot tubs, and bathtubs and showers. As pointed out it will react with the metals on the boat/trailer and the concrete the boat may be sitting above. That said, all of the hull cleaners out there have some form of acid as the active ingredient. I personally would have no problem using Muriatic acid on my boat, but would take precautions to not get it on the metal parts and would rinse it off quickly and well once done. Since we are talking about hull stains from wwaterline and below, there isn't much metal on the boat down there, so the trailer is the biggest concern. I would probably clean the boat, and rinse as well as I could, and then dunk the trailer.

 

[DanielR]

Re: Cannot get fiberglass hull clean...HELP!!!

'On-Off Hull and Bottom Cleaner'
Purchased from local marine supply store, cleaned up all the yellow staining at the bottom of the hull as well as the rust stain on my swimming platform.
I left a tool and forgot about it, within few weeks it rusted over leaving pretty stain. I was about to tackle the stains by wetsanding and buffing out, but I decided to spend $15 for On-Off Cleaner rather than loosing whole day by sanding/buffing with same results.

 

[DaNinja]

Re: Cannot get fiberglass hull clean...HELP!!!

toilet bowl cleaner. I suspect it's the same as starbrite with out the "marine product" mark-up. but rinse it off your galvanized trailer immediately

I used a couple of bottles of "The Works" on the Starcraft a couple of weeks ago. I used a spray bottle to apply it and a foam mop to scub it in (it destoyed the mop head..). It worked like a champ. You have to be sure to rinse thoroughly and apply a coat of wax soon after.

"Zing" is another good product, but much more expensive the "The Works". I would try either before I resorted to wet sanding.

Proper PPE is important for either product.

 

[Quick VR-4]

Re: Cannot get fiberglass hull clean...HELP!!!

Before you break out the rubbing compound and polish, do yourself a favor and try the Starbrite cleaner one time. Follow the directions. Just do a small area if you're not sure.

Actually, I was taking everyones advice to go with Starbrite first. It looked like a polish by the picture, but I realize now it is a spray. I already have a yard sprayer since I tried the slimy grimy. I am picking up two bottles tomorrow morning at Bass Pro so wish me luck this weekend.

Thanks again!!!

 

[djspady]

Re: Cannot get fiberglass hull clean...HELP!!!

The pros use muriatic acid. It is $3 a bottle. If you rinse your trailer before and after you will have no problem. All the other cleaners contain acid anyway and are really expensive. My boat was in the lake 5 months and the scum and yellow stain came off in seconds.

 

[Brewman61]

Re: Cannot get fiberglass hull clean...HELP!!!

The key to using the 50/50 muriatic water mix is to rinse the heck out of it.
I've done this for years, and have had no problems with corrosion.
The stuff is extremely cheap- a gallon of acid makes two gallons of cleaner, which will clean a lot. And at $3 or $4 a gallon, you can't beat the cost.
The Starbrite didn't work very well for me, and it was rather expensive, if I recall.

 

[rwidman]

Re: Cannot get fiberglass hull clean...HELP!!!

Actually, I was taking everyones advice to go with Starbrite first. It looked like a polish by the picture, but I realize now it is a spray. I already have a yard sprayer since I tried the slimy grimy. I am picking up two bottles tomorrow morning at Bass Pro so wish me luck this weekend.

Thanks again!!!

Starbrite Hull Cleaner is primarily oxalic acid. There are other ingredients to help it spread evenly and not run off too quickly. It is perfectly safe for gelcoat and fiberglass. It will stain a galvanized trailer if left on for very long. You can cover the trailer or you can just wet it down and rinse it. A galvanized trailer isn't that "pretty" to start with so I never worried about it.

I doubt you'll need two bottles for one boat. But, it never hurts to have some around.