Go Back   Cruiser Log World Cruising & Sailing Forums > Cruising Forums > Living Aboard
Cruiser Wiki

Join Cruiser Log Today

Thread Tools Search this Thread Display Modes
Old 12-17-2009, 02:15 PM   #1
JeanneP's Avatar
Join Date: Jul 2004
Posts: 2,098

Another of my "hot buttons".

If rust stain remover is safe for fabrics it is usually hydrofluoric acid (also used for etching glass) or occasionally oxalic acid (also used for bleaching wood). They are dangerous because they will not burn your skin, but will migrate through the skin into the tissues and attack the nerves in the body. It is very difficult to treat if this happens, and you will know by the incredible pain, but often with no redness or irritation showing on the skin.

I strongly suggest using rubber gloves with any acid. I am very afraid of hydrofluoric acid (household "Rust Stain Remover", often in a brown bottle in the cleaning section of the store), and somewhat so with oxalic acid. I like oxalic acid for its general stain removing qualities, though, and keep a container of the crystals on the boat. But, because these do not burn when they touch your skin, it's easy to believe that it is safe enough to use without rubber gloves. It isn't.

I first read of the danger of hydrofluoric acid in DISCOVER Magazine. Here's a link to the article: An Invisible Fire

Hydrochloric acid (also called Muriatic acid), and phosphoric acid, also remove rust and rust stains. They can burn the skin, are highly reactive and have a greater propensity for splashing up and into one's eyes.

The bottom line, of course, is to be cautious with any acid, and don't allow yourself to be lulled into not taking appropriate precautions.


In 1986 we went cruising for a few years. After 20 years and 50+ countries and several oceans, we are STILL "cruising for a few years".

MV WATERMELON (New) | Cruiser's Dictionary, free ebook

= Cruiser's Dictionary, North America,
JeanneP is offline   Reply With Quote
Old 12-17-2009, 04:05 PM   #2
redbopeep's Avatar
Join Date: Jun 2007
Home Port: Washington DC
Vessel Name: SV Mahdee
Posts: 3,188

ouch! Thanks for the info. I use hydrofluoric acid based materials to prep metal before painting and oxalic acid to bleach wood after stripping and before re-varnishing if there are water stains. While I use gloves, I didn't know about this info that your skin won't warn you with pain! My oh my.

Thanks again for the information.

"Do or do not. There is no try." - Yoda

What we're doing - The sailing life aboard and the Schooner Chandlery.

redbopeep is offline   Reply With Quote
Old 12-17-2009, 05:32 PM   #3
atavist's Avatar
Join Date: Jan 2007
Vessel Name: Persevate
Posts: 548
Send a message via Yahoo to atavist

Good to know... my normal rust stain remover is oxalic acid, I usually use a respirator when using it but have never bothered with gloves... I'll start using them too.

My not normal use stain remover, On and Off, (I just label it "ACID") is Hydrocloric acid, phosphoric acid, and oxalic combined... the bottle actually reads "May cause sudden death" ... I hardly ever use it but when I do I wear longsleeves, a respirator, goggles (not just safety glasses) and gloves... I used it on the deck once and it melted the nonskid on contact... scary stuff.
“The world turns aside to let any man pass who knows where he is going.” (Epictetus 55 - 135 AD)

"To see new things, and live day to day, is better than wine or poppy, and fitter for a man." (Theseus)
atavist is offline   Reply With Quote
Old 02-02-2012, 09:52 PM   #4
Join Date: Jan 2012
Home Port: La Paz Baja
Vessel Name: Fei Tzu
Posts: 7

As a biochemist I am often amazed that toxic and nasty means are utilized to achieve what can be done with little risk and cheaply using common and easily obtained materials.

Sodium or potassium Metabisulfite works, citric acid works, other fruit acids work......

Just go out to the store and buy a container of Rust Out or CLR in a pinch.

Metabisulfite also works on removing red wine stains, mercury etc.

bajaron is offline   Reply With Quote
Old 02-03-2012, 07:11 PM   #5
Moderator/Wiki Sysop
Istioploos's Avatar
Join Date: Apr 2008
Home Port: Samos
Vessel Name: S/Y Thetis
Posts: 556

Will try potassium metabisulfite next time. Thank you for the tip.

The World Cruising and Sailing Wiki

Help to build this free, online world Cruising Guide

Built by cruisers, for cruisers.

=Mediterranean,Black Sea,North Atlantic,Caribbean
I've Contributed to the Cruisers Wiki: Mediterranean, Black Sea, Atlantic
Istioploos is offline   Reply With Quote
Old 12-01-2012, 09:24 PM   #6
Join Date: Feb 2010
Home Port: the boat
Vessel Name: Skipping Stone
Posts: 79

Phosphoric acid, normally sold as Ospho is by far the safest and best rust cleaner. All commercial ships, including those huge white cruise ships use it for removing the unsightly rust streaks. They use rollers on long handles, perhaps you have seen them, thinking they were painting.
I've always used it bare handed, though it can sting a bit f you have an open sore. The commercial concentration is 5%, if I remember right, be it in a quart bottle or a 55 gallon drum.
Brush it on, wait a while, and wipe it off w/ a rag (Ospho has a green coloring agent that will remain) and polish if you wish. For very difficult rust stains, just keep applying and in time the rust streaks will go away. Won't hurt fiberglass or paint, but plays hell with bare teak, by the way. Great in the engine room, parts that get hot or not, and a first step cleaner for repainting rusty metal, like engines. Do not use on zinc coated metal. Safe for rust stains on most fabrics, too.
As an aside, you drink it every time you have a Coke!

"Any a**hole can make a boat go; it takes a sailor to stop one"
Spike Africa, aboard the Schooner Wanderer, Sausalito, Ca. 1964
capta is offline   Reply With Quote

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Worst Stain Ever! atavist General Cruising Forum 15 12-18-2009 01:26 PM
Best Varnish Remover? SilentOption Repairs & Maintenance 10 01-04-2009 04:38 AM
Rust Problems... Kuapaa General Cruising Forum 17 07-27-2007 01:24 AM

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

RV & Travel Trailer Communities

Our RV & Travel Trailer sites encompasses virtually all types of Recreational Vehicles, from brand-specific to general RV communities.

» More about our RV Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

All times are GMT. The time now is 07:07 AM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.0