Moderated Discussion Areas
  ContinuousWave: Whaler Repairs/Mods
  Best Product to Remove Rust Stains From Gel Coat

Post New Topic  Post Reply
search | FAQ | profile | register | author help

Author Topic:   Best Product to Remove Rust Stains From Gel Coat
will posted 04-18-2001 03:17 PM ET (US)   Profile for will  
[W]hat is the best way to remove rust stains from gel coat?
witness posted 04-18-2001 03:27 PM ET (US)     Profile for witness  Send Email to witness     
I'd like to know the answer to that also! I was thinking about trying Rust Out. It is made for bathrooms, but wasn't sure if it was too chemically harsh.
bigz posted 04-18-2001 04:12 PM ET (US)     Profile for bigz    
Sudbury Fiberglass Stain Remover which is heavy duty or the Stain Lifter not so heavy duty --- about $6 for either one at your better marine dealers everywhere around the world --- I think!!
ron miller posted 04-18-2001 09:27 PM ET (US)     Profile for ron miller  Send Email to ron miller     
Found out the best way to remove rust spots, as well as scratches, go to the local hardware store, and get yourself a can of BKF- bar keeper's friend, it work great and is cheap, just read the instructions
Dick posted 04-18-2001 09:54 PM ET (US)     Profile for Dick  Send Email to Dick     
Another great product is Davis FSR.


Soho posted 04-18-2001 10:01 PM ET (US)     Profile for Soho  Send Email to Soho     
Maybe somebody with a PhD in Chemistry can tell me if I am doing something terribly wrong, but I have used Muriatic acid ( diluted with water ) to remove rust stains in the past. Slap it on, let it work and rinse it off and it seems to do the trick. Any comments from the more experienced out there...?



Dick posted 04-18-2001 10:33 PM ET (US)     Profile for Dick  Send Email to Dick     
That is a tried and proven method. Most people just don't like the "acid" word and prefer the commercial alternates.


Soho posted 04-18-2001 11:22 PM ET (US)     Profile for Soho  Send Email to Soho     

I hear you; seems I am always sort of on the lunatic fringes of political/environmental correctness it seems....

You know, I always find it interesting to look at the "miracle" cleaners etc that are marketed and see what the active ingredients are... usually something quite simple. At any rate, the Muriatic a*** always seems to work!



Dick posted 04-18-2001 11:45 PM ET (US)     Profile for Dick  Send Email to Dick     
People like the name brand products. Being in the wholesale marine business, if they didn't I would have a problem selling some of my products.

A lot of the name brand products are really good and do the job that they were designed for, but sometimes there are generic products that do the job better for less money. Such as the nasty a___ word.


Whalerdan posted 04-19-2001 07:37 AM ET (US)     Profile for Whalerdan  Send Email to Whalerdan     
Just a note. The active ingredient in Barkeepers Friend is Muriatic acid.
kingfish posted 04-19-2001 08:39 AM ET (US)     Profile for kingfish  Send Email to kingfish     
BKF may have muriatic acid (hydrochloric), but I have been of the impression that it had oxcalic (sic?) acid; maybe both?

I recently had a product recommended to me by a Marina in Beaufort, S.C. for cleaning the yellow (and just about everything else - barnacles, zebra mussels, slime, algae, etc.) from my hull after it had been docked for nearly two weeks in a backwater tidal creek right off the mouth of the Savannah River. The product is called, "ON - OFF", is a liquid, and *does* contain both muriatic and oxcalic acid. It is a miracle, but if you use it, wear rubber gloves, and if your trailer is galvanized, cover it with plastic; keeping the trailer flushed with water while using the product does not work (believe me).

Getting back home, I see a Starbrite product on the shelves of a local marina with a name like, "On-and-Off" or something like that, and wonder if it may be a similar thing...

bigz posted 04-19-2001 09:06 AM ET (US)     Profile for bigz    
Hydrochloric Acid or commonly referred to as Muratic Acid if not properly handled can etch and turn surfaces a yellowish brown ---- nasty stuff if not diluted properly -- it will remove stains from gelcoat but be cautious. Hydrochloric Acid will eat right through galvinized steel as you mentioned about protecting your trailer Kingfish.

Kingfish, yes Oxalic Acid is the active ingredient in "Bar Keepers Friend"! and

MDR makes a product called "rust away" which I was told works very well -- haven't a clue what is in it though.

Dick posted 04-19-2001 09:07 AM ET (US)     Profile for Dick  Send Email to Dick     
On & OFF is a product made by Mary Kate and is available in quarts, gallons & 55 gal drums. We stock both the quart and gallon sizes, being a wholesale distributor I can't sell direct but can supply the name of a retail outlet that will ship anywhere. E-mail me if interested.
witness posted 04-19-2001 09:34 AM ET (US)     Profile for witness  Send Email to witness     
In our lab, I have use Oxalic Acid to remove rust, especially on PTFE items. It seems to do a better job than the Hydrochloric. A friend is doing research with Geothite (a type of iron) and various acids as chelating agents, so a little latter I will wonder down to his lab and pick his brain...
will posted 04-19-2001 10:11 AM ET (US)     Profile for will    
thanks for the replys
witness posted 04-19-2001 11:39 AM ET (US)     Profile for witness  Send Email to witness     
Ok, here is what i've learned... Oxalic acid is good, but ascorbic acid is better (vitamin C, so crush up your kids flinstone vitamins, if they still make them and get to work :). And the people who are working with the stuff say it works even better at higher temps (they are working at 60 celsius). Of course if it is used on stainless steel, wash it off thoroughly, it can eat through our lab grade SS if it is allowed to sit in it. It seems that the more concentrated the use, the better (even a powder-y paste). BTW and FWI rust, it seems rust is a combination of mostly Goethite and Hematite, the more red, the more hematite and the more yellow, the more Goethite. These are forms of Oxidized iron. In removing these I believe you are using the acids as reducing agent. If anyone knows better, please correct me. Too much useless info, well, that seems to be what getting advanced degrees are all about :)
lhg posted 04-19-2001 02:29 PM ET (US)     Profile for lhg    
Kingfish - glad to hear you made it back safely. I should have told you ahead of time - to clean the "yellow stain" off your hull I have found Starbrite's "Instant Hull Cleaner" to be the best, as long as you use it as soon as the boat comes out. The active ingredient is Oxalic acid, nothing stronger is needed.

I have also had to use it after a few days in Lake Erie. I put it in a spray bottle, to reach areas way under the hull, between the axles. But otherwise, I just spray some onto a rag, and wipe it on. Yellow disappears right in front of your eyes. Then rinse, like you say, with lots of water and keep the trailer wetted down also. A gallon of the stuff costs about $20.

I can also second Bigz's recommendation of Sudbury's HD Fiberglass Stain Remover (powder form). Also Oxalic acid, but it handles rust and other tough stains that the Starbrite's won't. One time I pulled my boat out of the salt, and left the yellow stain on for about 3 weeks. It took the Sudbury's to cut it.

whalernut posted 04-19-2001 09:01 PM ET (US)     Profile for whalernut  Send Email to whalernut     
I wonder if that orange juice based cleaner would work that they clean stainless and countertops with in a food environment, I have seen supermarket employees use it in the food departments. It is in a spray bottle and smells very pleasant. Regards-Jack Graner.
couchtater posted 03-03-2009 10:02 AM ET (US)     Profile for couchtater  Send Email to couchtater     
toilet bowl cleaner removes yellow stains,
cost about $1.00 at any walmart or grocery.
Mix half with water in tank sprayer.
Cover trailer with plastic or spray with water.
pcrussell50 posted 06-15-2009 10:22 PM ET (US)     Profile for pcrussell50  Send Email to pcrussell50     
I wonder how citric acid works? We have no shortage of free lemons and limes around here in southern Cal.

In fact, I do believe I'm going to give it a try. I'll report back.

Still, don't hold back on the opinions.


pcrussell50 posted 06-15-2009 10:52 PM ET (US)     Profile for pcrussell50  Send Email to pcrussell50     
Lime juice proved somewhat ineffective. Maybe I need to let it soak in a little more than a couple of minutes?

Just had this 13 foot sport for a little over a week. It is pristine. The classic "little old lady" creampuff... except, the old man who owned it knew so little about trimmming, he FILLED the bow storage area with pieces of iron pipe, chain, steel plate, pretty much anything that is heavy and rusts. I just took it all to the metal recycler and got $1.79 for it. Maybe that will pay for part of a bottle of some good rust stain remover.


jmarlo posted 06-16-2009 07:26 PM ET (US)     Profile for jmarlo  Send Email to jmarlo     
As stated above, try muriatic acid (available in the masonry section of hardware stores). Dip a rag into the bottle, and apply a very SMALL amount of acid to the stain. It literally melts it away. Be careful of the fumes--its nasty stuff.

Post New Topic  Post Reply
Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.