How To Clean Rust Off Fiberglass Boat

I use Bowl and urinal cleaner from Janitors warehouse-Use rubber gloves-wipe on with a cloth-let stand for a minute or so-wipe off -then flush the area well with water and wipe dry with a clean cloth. May take the wax off the boat but any cleaner will do that. Pretty cheap about 12 bucks for a litre and it will last you for years.

I use a stuff called "On-Off" ( as I recall) but its pretty strong Sh@t so be carefull - its in my boat and I'm not rt now so would have to get out there to recall exact name for certain. I cleaned up area after with soap water then waxed and buffed ....

I've tried every product on the market. Like scott says, mr clean magic erasers. Not sure whats in them and I am sure its not good but they clean gel coat the best. Just had to do a major 6 hour cleaning of my boat after it sat in Gold River for 6 weeks. It had several rust stains and Mr Clean did its job...

Formaldehyde and micro abrasives I believe are what are in those magic erasers. I second SF. Bowl and Urinal Cleaner. It is very nasty on the pH scale, I believe like 10 on the acidic side. ( or is it alkaline side !?! ) anyways it is nasty business. Wear your protective equipment but it does removes rust and other stubborn stains.

FSR (fiberglass stain remover)works great on mine for real heavy stains let it sit rinse with water

I get an industrial caustic cleaner from a local boat repair business. They use it to get any stains off fiberglass so they can colour match gelcoat. Wipe it on with a sponge and it dissapears..just have to rinse off the area...and yes it strips off the natural wax in gelcoat as well. I always forget the name of the stuff because I just take an empty litre plastic bottle to the shop and they fill it as it only comes in a 5 gallon pail. I know the word Brite is in the name...wholesale janitorial supply businesses carry it

Don't mean to hijack but anything work on old dried on spruce gum? I have yet to find it but perhaps some of the stuff mentioned for rust here might work....... TIA
SS

Don't mean to hijack but anything work on old dried on spruce gum? I have yet to find it but perhaps some of the stuff mentioned for rust here might work....... TIA
SS

Have you tried Acetone ?
(nail pollish remover)

Don't mean to hijack but anything work on old dried on spruce gum? I have yet to find it but perhaps some of the stuff mentioned for rust here might work....... TIA
SS

Goo-B-Gone

Just heard from a good reliable source that good old gasoline and elbow grease.......tried goo be gone, nope.....

i tried ALOT ,
for regular maitnance , getting seascum , water line marks from mooring for a week or so ,
i apply the blue fsr , let it sit for a few minutes , watch it magically disappear , then rince with soapy water ,
for tougher rust type stains , Bar Keepers Friend , apply powder on wet sponge , dab on stained area , again ,
watch it disappear , rinse well , or use a seperate sponge to wipe up , wash with soap , apply some wax , Whala , like new in all my
cases , hull is always like new

( dont get Bar Keep on certain metals and let sit , it will corrode , would take time , just rinse within minutes and its fine !! )

Just heard from a good reliable source that good old gasoline and elbow grease.......tried goo be gone, nope.....

Methal hydrate removes grease from stainless steel. Just rewiring some kitchen equipment thats nasty with grease and oil. Takes it off with ease.

I have found that the ability to easily or even remove rust stains at all depend on the age and condition of the Gelcoat. If it is new gelcoat with regular application of protectant, it is usually easy to remove some minor rust stains. If it is decades old, thin, soft, chalky gel coat the rust stain will absorb right into at depth which makes it impossible to get out. How much Gelcoat do you want to remove before it is gone completely in that location? Rust is also resistant to bleaching.
From experience don't let coffee spill or drip on old chalky Gelcoat as it stains and also absorbs in - nice light brown stains.

Last edited: Aug 30, 2016