Cleaning very old fiberglass

[Roger Long]

All the fiberglass above the rail on my boat is old, oxidized, pitted, and generally cruddy. Some of it has been painted. A fiberglass pro told me it is way past buffing. Painting everything is the project that I didn't get around to this spring because of biting off more than I could chew on critical things like systems and rigging.

It's also filthy from the boat being in a city and directly under the flight path to the International Jetport. I'd at least like to get everything clean. Normally, I would just go about experimenting with different things and see what works. However, my son just gave me a half day of work on the boat as a birthday present and there isn't much left that he can do except the cleaning. (Wow, I wish my birthday had been a month earlier!) I've got lots of stuff I need to do away from the boat this week so I need to hand him a bottle and appropriate implements, say "Go to it.", and leave to take care of other things.

Any advice on what best to put into his hands and what instructions to give him will be appreciated. Remember, this isn't your typical fiberglass. I had a disaster one year when I tried red automotive rubbing compound because I didn't know any better and had pink highlights and red filled pin holes for two seasons after. These surfaces all need an extensive refinishing job but it's not in the cards this summer. I just want it to at least look clean.

 

[MrUnix]

Pressure washer. Tell him to go easy on the wood, hard on everything else

Cheers,
Brad

 

[Manny]

Brad is right, a pressure washer is probably best and fastest. To add to that, a spray bottle with a mixture of about 30% bleach and 70% water. Spray the bleach solution, wait a minute or two, then pressure wash the area. You mentioned you have painted areas, just have him be careful with the pressure washer since it can remove the paint. It doesn't need to be a strong device, and adjust the spray so it is wide. I have the same situation with the cabin top and decks, the gelcoat is just to far gone, and eventually I have to paint. Pressure washing is the only thing that gets it really clean and bright white.

M

 

[RAD]

If you don't have access to a pressure washer then use a product called Clorox cleanup and a green Scotch Brite pan

 

[wetass]

I have found this stuff works really well - or it could be that I bought too much of it and now have deluded myself into believing it works - Either way, Im convinced I like it: http://www.fisheriessupply.com/productgroupdetail.aspx?cid=133607&keywords=3m+sharp+shooter

 

[tommays]

The Cal deck was a pretty bad mix of a bit of paint and gelcoat and it still cleaned up really well with my buffer at LOW rpm and Presta cutting compound

 

[Tim R.]

Pressure washer. Tell him to go easy on the wood, hard on everything else

Cheers,
Brad

Don't use a pressure washer. You can damage the bedding around your deck hardware which will cause leaks.

Considering the poor existing surfaces i would use a green scotchbrite and soft scrub with bleach in it. Lots of elbow ease.

On a boat with nice gelcoat, the most abrasive product i would use would be magic erasers. You would sitll want to polish after this with a blue pad and presta cutting creme.

 

[Roger Long]

What about Simple Green? I've used it a lot on the interior surfaces and it seems to have a synergy with Magic Erasers.

I've used a pressure washer myself on the boat and have one but I don't think I'll turn my son loose with it unsupervised.

 

[zeehag]

i used sea water on my ericson hull with good results in the past----with a 3m pad..took the oxidization off nicely....

 

[chp]

My gelcoat was pretty rough on my Mac. I can't afford a machine so after reading lots of posts on gelcoat I decided to try an experiment spot with 1500 grit wet sand. Going real easy I managed to see some reflection and smoothness coming back. After, I used 3M rubbing compound. Wow I have like new gelcoat. Followed up with 2 coats of Maguires pure wax and the spot looked like new. I finally finished the top deck after a couple of days. Its very labor intensive, but well worth it. I figure by the end of the summer I'll have the whole boat done.

 

[Slim pickins]

I used soft scrub and a stiff bristle brush on mine, worked wonders, throw a little simple green into the bucket and it does it even better.

 

[RAD88]

I recently tried Poly-OX, a white powder from Poli-Glo, with a 3M scrub pad on a seriously abused 1968 Pearson cockpit. My friend had tried to clean it with a few other cleaners with little success. The Poli-Ox was fast and easy and removed every stain and blemish. It cockpit looked like it did when it was made. You would then need to wax the area or the dirt will return.

 

[Ducati]

Never Pressure Wash A Boat

Pressure washer. Tell him to go easy on the wood, hard on everything else

You can actually damage gelcoat by using a pressure washer and also force water into all deck fittings. Once you get water below the deck you then have a bigger issue of saturated / wet decks to deal with.

I suggest you scrub by hand with a good soap and use a light 3M pad.

 

[Peggie Hall HeadMistress]

"Pressure" washers vs. "Power" washers

Commercial pressure washers--the ones you can rent to pressure wash your house--are indeed too powerful to use on a boat. With psi as high as 15000, they can even chip gelcoat. But retail "power washers" that are only 1000-1850 psi, and also adjustable, CAN safely be used on a boat if you're reasonably careful with it (I wouldn't turn a kid loose with one unsupervised either!). And, because they can get detergent and water into places that cannot be reached by hand, a valuable tool not only for bilge cleaning, but for "knocking winter off the hull," cleaning the dock finger (clean finger means less dirt tracked onto the boat and a zillion other jobs on and around the boat and at home. I wouldn't be without mine. And they're VERY affordable too...well under $200.

However, a power washer won't replace manual labor altogether...any stain that requires an abrasive cleanser--SoftScrub, Magic Eraser etc--is still gonna need one...a power washer won't remove it. But being too aggressive with one in trying can do damage. But so can anything if you misuse it.