Ironic: My Exile speaker screws are rusty...

[ian ashton]

I just thought it was funny that the speakers marketed for marine use come with black screws that aren't stainless, lol. Not a big deal, but just a heads up to others that are installing, use different screws.

In other news, a few months and 30 or so hours in I still ABSOLUTELY LOVE my Exile speakers! Everyone that has heard them so far has been blown away (literally, and figuratively!)

As you were...

[jmvotto]

Ian. you can get black coated ss screws at lowes, i bought some for my heater vents.

you got any pics of those installed.?

[rdlangston13]

yeah, the black screws that came with my exiles turned to a nasty orange color in a hurry. i swapped them all out for stainless last week. the grilles still have some orange residue in the screws holes tho. couldn't get it all out

[mmandley]

What black screws are you referring to? Mine are all SS or chrome in color. The speakers for the cabin are black but no issues with color change.

[rdlangston13]

What black screws are you referring to? Mine are all SS or chrome in color. The speakers for the cabin are black but no issues with color change.

the black screws that came with the cabin speakers. they ALL rusted, every single one. some where more severe than others.

[mmandley]

No i understand the black screws in the cabin speakers, i was meaning more so the post Ian made, i thought he might have been talking tower speakers.

I wonder why yours are rusting, i didnt think you were that close to salt water or brackish water.

[ian ashton]

Yea, talking about the cabin speakers. I'm not close to salt or brackish water, lol.

[ian ashton]

Ian. you can get black coated ss screws at lowes, i bought some for my heater vents.

you got any pics of those installed.?

I'll dig some up and post 'em.

[rdlangston13]

im not not that close to salt water either, maybe 100 miles.

[philwsailz]

If you are going to the local home improvement store to get stainless, get the un-painted ones. Stainless gets its "stainless" property from a thin later of oxide on the metal's surface. This layer is maintained in an environment where it is exposed to oxygen. If you put it in an environment where the oxygen can be depleted, especially where it is connected to another dissimilar metal, you will form rust, even in stainless. A painted stainless screw in the marine environment will face exactly the condition in which it might go ahead and rust on ya.

In a marine environment we also have to watch for a phenomenon called crevice corrosion, where stainless fasteners are slowly eaten away by rust in a low or no oxygen environment. This can happen even in fresh water, not only brackish or salt; I have even been party to a stainless fastener that failed due to crevice corrosion. The fastener was part of one of my old sailboat's standing rigging. Luckily it didn't fail under sail and I was able to remedy the low oxygen situation and replace the fastener without incident. If you keep the surface of good stainless exposed to oxygen, it will not rust or corrode.

When purchasing stainless, know there are several grades. You can buy stainless that is still magnetic. 304 stainless has some chrome it it but not enough to keep from being picked up by a magnet. 304 stainless can and will rust, just like steel, but it does so more commonly where it is touching another surface, like a fiberglass boat hull. If you have ever seen some slight orange around a piece of stainless on an older boat, you can be fairly certain it is 304. 316L is a grade of stainless that is considered marine grade, and it is non-magnetic. It is the spec stainless for higher end boats and boat accessories where exposure to brackish or salt environments is expected.

I have found that the un-painted non-magnetic stainless fasteners at the local home improvement store have enough chrome to be used for non-critical applications where ultimate strength is not a safety factor. The painted ones may work, for a while or for a long time, but know that they may eventually rust. I believe you have a better chance of preventing rust by going with the unpainted ones, but again, pass them by a magnet and make sure you can't pick them up with a magnet before buying them. I am not sure if they are 316L, and I am not sure it is worth trying to find out, but if they are non-magnetic, they are at least better than the potentially rusty 304.


FYI

Phil
Kicker

[ian ashton]

The magnetic-ness has an impact on how rusty they get?

[philwsailz]

The magnetic-ness has an impact on how rusty they get?

No, it is indicative of the presence of enough carbon steel in the alloy to rust. Only an indicator, not a cause

Phil
Kicker