Stainless steel components

[baz]

I've noticed over past 2 years of owning our R25 that various components that presumably are made from stainless steel are going rusty. How come? Just what quality of Marine grade stainless steel does Ranger Tugs use for their boats ?

Taken from wikipedia... http://en.wikipedia.org/wiki/Marine_grade_stainless

Marine grade stainless is a stainless steel preferred for use in marine environments[1] to avoid pitting corrosion. The AISI number grade is 316 and refers to the chromium content.
The salinity contained with the oceans acts as a catalyst to the rusting process, therefore a higher quality stainless steel is used on marine vessels.
While the steel is not completely rust-proof, the alloy is more resistant than household stainless steels, and hence more expensive. Fire trucks manufactured in the United States are made with Marine Grade stainless steel.

 

[Bruce Moore]

How often do you wash and wipe down your railings? And how often do you polish them? We've found washing routinely, i.e. after boating and incurring spray, and polishing periodically, i.e. once per season with spot polishing as needed, has prevented any significant rust.

Bruce

 

[abcandjrc]

All steels contain iron and based on the alloy are, as a sage once told me, "Stain-Less" or "Stain-More". Generally what is seen as rust is the oxidation of iron molecules which are on the surface. Even a small amount can result in streaks which make the situation look much worse.

To remove the stains, use a cleanser which contains oxalic acid. Barkeeper's Friend@ is one brand which worked well for us. For really heavy staining and even layers of rust, make a paste of the cleanser and allow several minutes for it to work before rinsing.

Like already posted, washing down after exposure to salt water is a good preventive. We tried BoeShield T-9@, and while it did work, it is quite soft and will wipe off where you or lines and gear make contact with it. We finally found that we got the most relief by appling a good automotive paste wax to the stainless.

 

[commander bill]

My understanding is that most marine S/S components obtained on the market are usually made from 304 stainless. This includes things such as railing and cleats. Some items such as anchor windlass are made from 316 grade S/S. I have noted that screws are usually 304 while some bolts can be 316. 316 is more corrosion resistant (and much more expensive$$$$) than 304. I am not sure if bulk material such as rails are available in 316.

 

[baz]

My understanding is that most marine S/S components obtained on the market are usually made from 304 stainless. This includes things such as railing and cleats. Some items such as anchor windlass are made from 316 grade S/S. I have noted that screws are usually 304 while some bolts can be 316. 316 is more corrosion resistant (and much more expensive$$$$) than 304. I am not sure if bulk material such as rails are available in 316.

Well that was an interesting tidbit of info. I say this as the bolts that hold the radar in place are rusting quite badly whereas the anchor windlass is in pristine condition without me having to do any cleaning of it.

My wash down of the boat after a trip out is typically done the day after as when we dock we are all tired and want to get going and the Captain is given no time to do the wash down... :shock: I wonder if this is significant and can lead to unwanted rusting etc. ?

 

[knotflying]

Try NEVR-DUL it comes in a blue can. I get it at my local hardware store. It is a cotton type material saturated with something that works great. It takes all that oxidation off fairly easy.

 

[RProffer]

Here is a little tip I started using years ago. Any of the stainless (or chrome) that starts to rust, I clean with 0000 steel wool, and then I paint it with clear lacquer paint. I never have to touch it again.

 

[baz]

Well, today I got hold of a very soft wire brush shaped liked a tooth brush and applied some chrome remover liquid on the brush and was able to clear all that brown looking stuff off bolt heads and the gel coat at the base of many of the bolted down plates etc. It worked like a champion and there's little of the brown stuff to be seen anywhere on my boat now. 😀

I even was able to get the radar holding bolt heads to look as if they were fresh from the factory... nice. 😀

Thanks for all the advice given here -- much appreciated.