Rust Stain on Fiberglass

damauney · Jan 24, 2013

I think you are looking for Davis FSR. It is blue stain remover for fiber glass. Basically Oxalic Acid in a gel. Works well.

http://www.davisnet.com/marine/products/list_marine.asp?grp=m17-2

Goodwinds
DaveM

Fred Villiard · Jan 24, 2013

Or Spotless Stainless also works

redhead78 · Jan 24, 2013

Marykate

Marykate, off on hull cleaner, works great, I believe it has oxalic acid in it.Comes in liquid or gel form, I had rust stains on my hull for years, and areas by waterline yellowing, it took it off with no rubbing, be careful and read the safety instructions....Red

Joe Blizzard · Jan 24, 2013

Savogran brand Wood Bleach is oxalic acid in crystal form. A 12oz tub of it goes a long way for boat cleaning. I like it because I can mix as little or as much as I need in whatever concentration I need. Savogran also packages what appears to be the exact same stuff in a green container labeled Marine Cleaner, but I've never seen it in the wild.

rardiH36 · Jan 24, 2013

My bet is the below URL link is the forum discussion you remember. If rust from a SS fixture is being leached from it into the fiberglass/gelcoat, SpotlessStainless will remove. But the rust will come back unless you detatch the offending fixture and apply SpotlessStainless to the base of it to passivate.

http://forums.hunter.sailboatowners....ss%20stainless

Charlie Jones s/v Tehani · Jan 24, 2013

Joe Blizzard said:
Savogran brand Wood Bleach is oxalic acid in crystal form. A 12oz tub of it goes a long way for boat cleaning. I like it because I can mix as little or as much as I need in whatever concentration I need. Savogran also packages what appears to be the exact same stuff in a green container labeled Marine Cleaner, but I've never seen it in the wild.

Was wondering if anyone was gonna mention this.

Can't figure why someone would pay for a DILUTED version, at a higher price, when the crystal Oxalic Acid is available at almost any paint store or GOOD Hardware store. My ACE carries it.

I keep it aboard alll the time- sure does wonders for "the waterway frown", even using salt water. Cleans rust stains off of stainless too.

finding41 · Jan 24, 2013

I wish I could find a hardware store in Canada that carries it. It seems it's too dangerous for us Canadians. The hardware stores lock up bug spray here!
I did find a small amount (100g) at an apothecary. Not a local drug store but a real apothecary. They asked me allot of questions about what I wanted it for. It was $10 plus tax for 100g of powder!
I don't know what it goes for on the street.

Chris Patterson · Jan 24, 2013

About 7 bucks a jug here at Lowes.

(Maybe I need to go into the acid smuggling business).

MrBill_FLL · Jan 25, 2013

sno-bowl works too.

Chris Patterson · Jan 25, 2013

sno-bowl------hydrochloric acid-----muriatic acid. Just diluted..

robertsapp · Jan 25, 2013

Barkeepers Friend. It looks like a container of Comet Cleanser, except it's gold. It contains oxylic acid, is cheap as hell, and you can find it in any grocery or home improvement store. Works great on everything from polishing stainless to removing rust stains from paint and gelcoat. Even though it looks like cleanser, it's not abrasive. www.barkeepersfriend.com.

I did notice that the website says not to use the product on gold or silver. So those of you who sail an Oyster or a Morris might want to try something else.

Rich (P303) · Jan 25, 2013

syoun10 said:
seems like very recently (last few days?) I was reading a post about a great product that was a blue (I think) paste that you brushed on a rust stain and rinsed off with great result.

Can't for the life of me re-find that post, even by searching. Can anybody remind me what the product is?

Marykate on/off gel works great. no scrubbing...just rinse. Don't get it on your bottom paint... will remove that too.

Chris Patterson · Jan 25, 2013

Marykate. Again, hydrochloric and phosphoric acids. While I wouldn't recommend letting the wife and kids, morons, animals, junkies, walmart shoppers, etc. fool with the stuff, you can skip the pretty bottles, and dilute hydrochloric, (muriatic), acid yourself, and save your money from buying distilled water. Add it yourself. These products are little more than muriatic acid 10%, and water..

I PROMISE you that this stuff in pure form is very bad stuff though. Gloves, respirators, you get the idea. But a gallon is around five dollars.

capta · Jan 25, 2013

Phosphoric acid, sold in chandlers as Ospho, is the product all commercial vessels (work boats, tugs, freighters and cruise ships) use for rust. It is pretty easy on the skin (a 5% solution I believe) unless you have an open cut; I don't wear gloves but it is advisable. Just paint it on with a TAB and wipe it off w/ a rag before it dries. Redo if necessary. Easy, cheap and much less dangerous than products like On & Off, which I use for a lot of things but not rust.