Moderated Discussion Areas
  ContinuousWave: Whaler Repairs/Mods

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

Author Topic:   RUST STAINS
BOB KEMMLER JR posted 02-01-2002 09:42 AM ET (US)   Profile for BOB KEMMLER JR  
What is the best way to remove rust stains off of gelcoat?
Bigshot posted 02-01-2002 10:43 AM ET (US)     Profile for Bigshot  Send Email to Bigshot     
Muriatic acid. takes ANY rust stain right off.
Whalerdan posted 02-01-2002 11:04 AM ET (US)     Profile for Whalerdan  Send Email to Whalerdan     
Boeshield (sp) rust remover. Spray it on let it set a minute or two then brush it. Works great.
witness posted 02-01-2002 11:50 AM ET (US)     Profile for witness  Send Email to witness     
Bigshot, I imagine that you are using dilute Muriatic Acid (Hydrochloric Acid), right? Then rinsing with LOTS of water? I am told that Ascorbic Acid (vitamin C) works well also...
where2 posted 02-01-2002 12:27 PM ET (US)     Profile for where2  Send Email to where2     
I kinda like FSR (Fiberglass Stain Remover). It's a gel that seems to get most everything off. Then there's the Oxalic Acid when the water line is looking mis-tinted due to my brown canal water.
kingfish posted 02-01-2002 12:27 PM ET (US)     Profile for kingfish  Send Email to kingfish     
Any of a number of rust stain removers; I like "Barkeepers Friend". Oxalic acid is the active ingredient in most rust removers.
Bigshot posted 02-01-2002 02:35 PM ET (US)     Profile for Bigshot  Send Email to Bigshot like a gem! Don't breath it in though....nasty!
joem posted 02-01-2002 07:01 PM ET (US)     Profile for joem  Send Email to joem     
Just try a little gas on a rag works great and it is usually on the boat.


Tom W Clark posted 02-01-2002 07:12 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
I was just outside doing a little experimental scrubbing on CSW and thought I'd try some different things on the numerous rust stains she has throughout her interior.

I tried straight muriatic acid. It did not do much, though I only let it sit for about ten minutes. Scrubbing with it after that time had little effect. This surprises me because I have experienced muriatic acid (which itself is a dilute solution of hydrochloric acid and water) taking rust off of steel tools before.

Comet cleanser also had a slight effect. I suspect mostly from the abrasives in it.

Barkeepers Friend was by far the best. It would start removing rust right away if you scrubbed a bit. It was most effective if you made a paste and let it sit a few minutes and then scrubbed.

None of the above removed 100% of the stains, but I have an overnight paste test with the Barkeepers Friend going and I will report tomorrow on its effectiveness.

Tom W Clark posted 02-03-2002 09:26 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
The overnight test of the Barkeepers Friend was quite successful. It really cleaned the gelcoat. However, it still did not remove all the stain from the non-skid but it did from smooth gelcoat. You could actually see the rust stain transferred from the boat to the paste on top of the stain.
Whalerdan posted 02-04-2002 08:06 AM ET (US)     Profile for Whalerdan  Send Email to Whalerdan     
Barkeepers Friend works best for really tough stains, but it is kind of abrasive and scratches the gel coat a little. Boeshield is just a liquid spray and doesn't scratch the gel coat.
Clark Roberts posted 02-04-2002 08:20 AM ET (US)     Profile for Clark Roberts  Send Email to Clark Roberts     
Try a product called "Snow Bowl", a toilet cleaner, and a little brushing if rust stains are heavy. Be sure to wet first and rinse really good... works for me! Clark
tabasco posted 02-11-2002 09:27 AM ET (US)     Profile for tabasco  Send Email to tabasco     
Here is the best.......Lysol toilet bowl cleaner. I have hard water in my ski house in vermont and the shower & toilet constantly get rust stains. Tryed everything until i found the answer.
LYSOL TOILET BOWL CLEANER gets all the rust out.
Bigshot posted 02-11-2002 11:21 AM ET (US)     Profile for Bigshot  Send Email to Bigshot     
The trick to muriatic is to put it in a spray bottle. You spray the stain and it smokes and turns yellow. Spray again, it removes the old and smokes again and turns yellow. Keep doing it until stain is gone. Did wonders for the 13'. The whole deck had a rusty hue to it, looks brand new(sort of) now.
JBCornwell posted 02-11-2002 12:12 PM ET (US)     Profile for JBCornwell  Send Email to JBCornwell     
You probably laughed at the commercials for "ZAP", but that stuff works as advertized and it is recommended for fiberglass. Get it at Wal-Mart.

Red sky at night. . .
JB :)

Bigshot posted 02-11-2002 12:21 PM ET (US)     Profile for Bigshot  Send Email to Bigshot     
I've used it JB. Works good, cleans nice but don't do doodoo on rust stains. it is almost like using a 1500 grit wetsand, maybe due to the scotchbrite pad?
hauptjm posted 02-11-2002 12:38 PM ET (US)     Profile for hauptjm    
I've had good luck with Oxalyc Acid. Like any acid, it does strip any wax you may have on the surface. Water neutralizes it and it won't damage the gel-coat if you don't leave it on for extended periods. In fact, it's the cleaning agent found in teak cleaners.
lhg posted 02-11-2002 03:48 PM ET (US)     Profile for lhg    
I use a product called Sudbury's Heavy Duty Fiberglass Cleaner, a non-abrasive powder. Mixed up in a paste, it removes rust stains with a couple of applications. Having recently discovered Bar Keepers Friend, I believe it is the same stuff, with oxalic acid being the active ingredient. This stuff will also clean up yellowed hull bottoms that have been allowed to air dry for a while.
Jim Bennett posted 02-11-2002 10:38 PM ET (US)     Profile for Jim Bennett  Send Email to Jim Bennett     
I believe, not certain, that I have seen Barkeepers Friend in both a powder and a liquid form on shelves. Is that correct, and if so, which form is best to use?
andygere posted 02-04-2003 07:16 PM ET (US)     Profile for andygere  Send Email to andygere     
Will Barkeepers Friend stain or attack a galvanized trailer if it drips on it from a drain tube?
bradenton_whaler posted 02-04-2003 07:21 PM ET (US)     Profile for bradenton_whaler  Send Email to bradenton_whaler     
I've always heard to use Wink toilet bowl cleaner. Its found in the grocery store.

newps posted 02-05-2003 02:59 AM ET (US)     Profile for newps  Send Email to newps     
I asked my captain and he suggested using heavy duty rubbing compound with a damp rag. This will also bring out a shine in gel coat. He has also uses FSR but you need to be patient let it sit fo a while without letting it dry up and work it in a little. Don't bother with muratic acid its more harmful to the boat and you in the long run, but great on metals if used right.

Whats up big shot

Bigshot posted 02-05-2003 09:53 AM ET (US)     Profile for Bigshot  Send Email to Bigshot     
I like muriatic and reliable. Cleans out your lungs too:)
Swellmonster posted 02-05-2003 11:29 AM ET (US)     Profile for Swellmonster  Send Email to Swellmonster     
Right on Biggie!
And its cheap! Like me! ;)
logan posted 02-07-2003 01:57 PM ET (US)     Profile for logan  Send Email to logan     
I have used a product called CLR (Calcium lime rust) with succsess. sold in house cleaning area of stores.


myotherboatisawhaler posted 02-11-2003 07:32 PM ET (US)     Profile for myotherboatisawhaler  Send Email to myotherboatisawhaler     
try on/off it is an acid based marine cleaner sold at west marine. good stuff! mitchell
kingfish posted 02-12-2003 09:44 AM ET (US)     Profile for kingfish  Send Email to kingfish     
Muriatic acid and On-Off (Marikate), while they will remove rust stains on gelcoat, are both *very* caustic, and are overkill for simple rust stains.

For those folks that are interested in removing rust stains but not having to wear rubber gloves and repirators, and not worrying about the galvanize on their trailers, oxalic acid and/or various products with ocalic acid in them like Barkeepers Friend and many of the other products mentioned above are simpler and safer to use. Save the big guns for the big problems.

Another product that I always have around and always works well is Starbrite Rust Remover. You can find it at most Marinas and in most of the marine products catalogs. I think the active ingredient is oxalic acid, but I'm not sure.


jaccoserv posted 02-14-2003 01:54 PM ET (US)     Profile for jaccoserv  Send Email to jaccoserv     
I'm with myotherboat....

On/Off is the way to go. The stuff is amazing, just pour a little on and the rust washes away, you won't need gloves or a respirator as long as you're careful. This stuff is also great for getting any stains off your scrubbling necessary!!!
If you're coverning a big area, such as the waterline all the way around your boat, you might want to invest in one of those 2-gallon pesticide sprayers(the kind with the hose, that you pump...about $10)

kingfish posted 02-14-2003 02:40 PM ET (US)     Profile for kingfish  Send Email to kingfish     
On/Off is phenominal stuff - I've raved about it in these forums more than once - but it is overkill for just a rust stain on gelcoat, which is what this thread is about.

On/Off is a combination of muriatic, phosphoric and oxalic acids, and what it will do like almost no other is remove scumlines and the like when the boat has been left in the water in stagnant or other environments heavy with marine growth or chemical elements like tannin.

Those of you who have used it and understand its caustic nature certainly can do what you want with no reason to listen to me; but those who haven't, and who only have some minor rust stains should know that there are far less caustic and dangerous ways to clean up rust stains that are every bit as effective. And if you let On/Off come into contact with your skin, you damn well *better* wear rubber gloves (or you will be sorry), and you better cover your galvanized trailer with plastic or it will powder your galvanize.

Chap posted 02-14-2003 02:52 PM ET (US)     Profile for Chap  Send Email to Chap     
I agree King.
You've heard of not doing something else into the wind, it's the same with on/off.

I was cleaning the cedar water foam stains off a hull with the stuff in a cheap tupperware container when the plasic began to melt and smoke. Strong stuff; my friend's dog ran and hid in the canoe shed until we were done.

edfish posted 02-24-2003 01:55 AM ET (US)     Profile for edfish  Send Email to edfish     
I am surprised that noone has mentioned using phosphoric acid. It is one of the two parts of teak cleaner. If you can find the (now) undiluted form of it, it is probably called OsPho, or Rust Loc. Get a garden sprayer and use it full strength. I fish commercial crab on my '72 21' Outrage for crab and the traps always bleed all over the boat. At the end of the season I take the phosphoric acid and spray it on the boat after I wash it and wait for a few minutes and it is all gone!. Some of the very heavy spots may take a second spray. The stuff also takes the funky brown off the hull that slowly appears over the season above the water line. If you have a lot of galvanized on the boat you may want to coat it with a coat of Vaseline and then do the job. The Best of the day to everyone. ED
Bigshot posted 02-24-2003 10:12 AM ET (US)     Profile for Bigshot  Send Email to Bigshot does muriatic acid and Mary Kate's On/Off which are readily available. muriatic is the cheapest at like $3/gal.

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.