Removal and Prevention of Salt Water Corrosion on Accessories

[toddr]

OK, I have a few dive accessories that hit the salt water for the first time. I've noticed specifically on one of my XS Scuba Mini Fog Cutters what appears to be little rust spots. They appear to be just on the surface and between the blades. I also noticed this same thing on another accessory ring. I had the same thing happen last year to a Z-Knife, but I didn't think anything about it. It stayed in it's case and it was a few years old anyways. I didn't have any trouble with my Ti knife.

Here are my questions.

1) What is the best way to remove this without machines? Would just a wet sanding or fine sandpaper work? Should I be concerned about messing with the finish?

2) Other than putting a small coat of O-ring grease, any other descent methods to prevent this?

Just looking for thoughts on this.

 

[Akimbo]

Bull Frog - The Complete RUST & Corrosion Protection System | Cortec Corporation

Boeshield T-9® | Corrosion Protection and Waterproof Lubrication

Lanocote Anti-Corrosion Grease

 

[Goodtime Adventures]

Normally just soaking in hot water for a while will remove salt water build up from accessories. That, and making sure you rinse thoroughly with fresh water after each use to prevent it! Once removed, you can also apply some grease/anti corrosion lubricant to prevent future problems. Good luck

 

[joewr]

Hi,

All ferrous metals (those containing Iron) are subject to saltwater corrosion. Even the most stable of stainless steels will eventually secumb. Without getting into the details of the chemistry, suffice it to say that the "villain" in all this is the chloride ion in seawater...and its tendency to behave like hydrochloric acid. Couple that with the dissolved oxygen and you have a potent corrosive environment.

Since your Ti knife is not made of a ferrous metal, it will resist corrosion forever--on a human time scale.

So, getting back to your ferrous knives and removing the corrosion. You can give that traditional material called Naval Jelly a try. It works most of the time. You can use some fine steel wool, if needed, but hopefully it will not be. Now the bad news: once corrosion has occurred, it is easier for it to re-occur. That is because the pitting associated with the original corrosion provides a wonderful entry point for the new corrosion to get "seeded". That is one of the reasons why using an abrasive is to be avoided if possible--it just creates surfaces that are ripe for corrosion.

Probably the best and cheapest way to protect your gear is by spreading on a thin coating of vaseline after cleaning your gear. If you go to the trouble of cleaning it by wiping off the vaseline after every dive day, rinsing with fresh water, drying it with a soft towel, and re-applying the vaseline, you will probably keep corrosion under control. If you want to use more expensive materials such as silicon grease, etc., that is fine. However, they probably won't work any better than vaseline.

Note that I suggested drying with a towel. Air drying might work okay, but the presence of any residual chloride coupled with air (oxygen) and moisture will just lead to more corrosion.

I hope this helps....

joewr

 

[ams511]

So, getting back to your ferrous knives and removing the corrosion. You can give that traditional material called Naval Jelly a try. It works most of the time. You can use some fine steel wool, if needed, but hopefully it will not be.

Probably the best and cheapest way to protect your gear is by spreading on a thin coating of vaseline after cleaning your gear. If you go to the trouble of cleaning it by wiping off the vaseline after every dive day, rinsing with fresh water, drying it with a soft towel, and re-applying the vaseline, you will probably keep corrosion under control. If you want to use more expensive materials such as silicon grease, etc., that is fine. However, they probably won't work any better than vaseline.

I would avoid using Naval Jelly. I did this once when I first started diving and it turned my shiny knife grey. I would also avoid steel wool because if it gets stuck on the surface it will rust. You are better off using emory paper. I would also avoid using petroleum jelly as it can degrade neoprene if you get any on it.

My recommendation would be to try some diluted vinegar first to remove the rust. That is what DIYers use to clean metal regulator parts. For prevention a coat of wetsuit zipper wax may help or silicon grease. If you have pure carnauba wax that would work too but do not use petroleum based waxes.

Also I would clean the knife and the sheath separately as soon as possible in the rinse tank or fresh water hose. Then towel off the knife and store it away from the sheath until you can do a proper soak of both items.

 

[joewr]

I would avoid using Naval Jelly. I did this once when I first started diving and it turned my shiny knife grey. I would also avoid steel wool because if it gets stuck on the surface it will rust. You are better off using emory paper. I would also avoid using petroleum jelly as it can degrade neoprene if you get any on it.

My recommendation would be to try some diluted vinegar first to remove the rust. That is what DIYers use to clean metal regulator parts. For prevention a coat of wetsuit zipper wax may help or silicon grease. If you have pure carnauba wax that would work too but do not use petroleum based waxes.

Also I would clean the knife and the sheath separately as soon as possible in the rinse tank or fresh water hose. Then towel off the knife and store it away from the sheath until you can do a proper soak of both items.

Hi,

Time for some chemistry????

Most chemical rust removal agents are acids; Naval Jelly contains phosphoric acid; vinegar contains acetic acid; oxalic acid contains, well, oxalic acid. All require cleansing with fresh water after use.

Vaseline, a by-product of lubricating oil manufacture, will, indeed, degrade some of the adhesives used on wetsuit seams. However, a thin coat used on your sheathed dive knife will not come in contact with those seams. Now, if you want to smear some on those seams, well....

Any abrasive such as steel wool or emery (Emory is a university in GA, inter alia.) paper will leave scratches on metal surfaces. The residue from those scratches will be fine particles of the metal that was abraded. Thus, steel wool will cause no more problems than emery paper. And the villain(s) are the scratches left by whatever abrasive you use.

Remember that the enemy is salt water + oxygen. So, the sooner you protect the surface of your steel knife, the better. If you do it from the very first day you have your knife, it might look nice forever.

One, final word on vaseline: the folks who worried about the effect of vaseline on neoprene were triathlon athletes who were looking for a way to ease getting in and out of wetsuits. Smearing gobs of vaseline on your body prior to donning a wetsuit is a very different phenomenon than putting a thin coat on the blade of a stainless steel knife which will be completely sheathed. But if vaseline usage will cause you to lose sleep--or lead you to forcing your pet chimp to smoke whilst wearing glasses--by all means, use silicon grease.

joewr

 

[TSandM]

You've gotten some good advice on what to do once the corrosion has occurred. But I just wanted to add that you can prevent a great deal of it by making sure gear is rinsed thoroughly in fresh water immediately after use, and dries as quickly as possible. The chemical reactions that produce the corrosion occur far faster in an aqueous environment.

 

[ams511]

Hi,

Time for some chemistry????

Most chemical rust removal agents are acids; Naval Jelly contains phosphoric acid; vinegar contains acetic acid; oxalic acid contains, well, oxalic acid. All require cleansing with fresh water after use.

Vaseline, a by-product of lubricating oil manufacture, will, indeed, degrade some of the adhesives used on wetsuit seams. However, a thin coat used on your sheathed dive knife will not come in contact with those seams. Now, if you want to smear some on those seams, well....

Any abrasive such as steel wool or emery (Emory is a university in GA, inter alia.) paper will leave scratches on metal surfaces. The residue from those scratches will be fine particles of the metal that was abraded. Thus, steel wool will cause no more problems than emery paper. And the villain(s) are the scratches left by whatever abrasive you use.

Remember that the enemy is salt water + oxygen. So, the sooner you protect the surface of your steel knife, the better. If you do it from the very first day you have your knife, it might look nice forever.

One, final word on vaseline: the folks who worried about the effect of vaseline on neoprene were triathlon athletes who were looking for a way to ease getting in and out of wetsuits. Smearing gobs of vaseline on your body prior to donning a wetsuit is a very different phenomenon than putting a thin coat on the blade of a stainless steel knife which will be completely sheathed. But if vaseline usage will cause you to lose sleep--or lead you to forcing your pet chimp to smoke whilst wearing glasses--by all means, use silicon grease.

joewr

As usual Joe you cannot stick to the point.

First, I am telling the OP from first hand experience to avoid naval jelly, it will discolor the knife. At least it did mine.

Second, I do know that vinegar is acid but it is also not as strong as naval jelly, especially when diluted. So for minor corrosion it would be smart to start with the weakest acid possible.

Third, call any wetsuit manufacturer and ask them if they recommend petroleum products for use with their wetsuits. One of the first things that you should have learned in OW when talking about equipment is that petroleum-based products have no place in diving. Silicon grease is cheap and every diver should have it on hand to lubricate the o-rings in their dive lights, camera cases, etc. Yes, the knife is sheathed but it could accidentally come in contact with the wetsuit.

Fourth, emery cloth, garnet paper, micro mesh, etc are made out of minerals not metal like steel wool. They will scratch the knives the same as steel wool. However steel wool can leave particles of steel in the scratches which then rust and the knife will look even worse. I made this mistake cleaning a cheap aluminum wok with steel wool and then had rust on the bottom. You do not have the same problem with mineral papers as the materials are non-ferrous and don't rust.

 

[joewr]

As usual Joe you cannot stick to the point.

First, I am telling the OP from first hand experience to avoid naval jelly, it will discolor the knife. At least it did mine.

Second, I do know that vinegar is acid but it is also not as strong as naval jelly, especially when diluted. So for minor corrosion it would be smart to start with the weakest acid possible.

Third, call any wetsuit manufacturer and ask them if they recommend petroleum products for use with their wetsuits. One of the first things that you should have learned in OW when talking about equipment is that petroleum-based products have no place in diving. Silicon grease is cheap and every diver should have it on hand to lubricate the o-rings in their dive lights, camera cases, etc. Yes, the knife is sheathed but it could accidentally come in contact with the wetsuit.

Fourth, emery cloth, garnet paper, micro mesh, etc are made out of minerals not metal like steel wool. They will scratch the knives the same as steel wool. However steel wool can leave particles of steel in the scratches which then rust and the knife will look even worse. I made this mistake cleaning a cheap aluminum wok with steel wool and then had rust on the bottom. You do not have the same problem with mineral papers as the materials are non-ferrous and don't rust.

Hi,

You're right. I'm wrong.

In spite of all my efforts on your behalf, your grammar remains atrocious, though. It's lucky you never had Miss Conde for your 9th grade English class; you might never had made it out of junior high school. The proper sentence form is: "As usual, Joe, you cannot stick to the point." Note the commas.

Oh, yes, vinegar is not an acid. But it does contain acetic acid.

joewr

---------- Post added November 10th, 2013 at 07:59 PM ----------

As usual Joe you cannot stick to the point.

First, I am telling the OP from first hand experience to avoid naval jelly, it will discolor the knife. At least it did mine.

Second, I do know that vinegar is acid but it is also not as strong as naval jelly, especially when diluted. So for minor corrosion it would be smart to start with the weakest acid possible.

Third, call any wetsuit manufacturer and ask them if they recommend petroleum products for use with their wetsuits. One of the first things that you should have learned in OW when talking about equipment is that petroleum-based products have no place in diving. Silicon grease is cheap and every diver should have it on hand to lubricate the o-rings in their dive lights, camera cases, etc. Yes, the knife is sheathed but it could accidentally come in contact with the wetsuit.

Fourth, emery cloth, garnet paper, micro mesh, etc are made out of minerals not metal like steel wool. They will scratch the knives the same as steel wool. However steel wool can leave particles of steel in the scratches which then rust and the knife will look even worse. I made this mistake cleaning a cheap aluminum wok with steel wool and then had rust on the bottom. You do not have the same problem with mineral papers as the materials are non-ferrous and don't rust.

Hi,

A few chemistry comments.

Have you ever asked the question, "What caused the discoloration when I used naval jelly?" Answer that question and you will know what you did wrong. If you knew the answer to that question, you would also know how to solve the problem. And I already gave you the clue.

Secondly, if you want to "start with the weakest acid possible", why not use either club soda (carbonic acid) or grapefruit juice (citric acid)? If you understood the concept of pKa, you would understand this question.

Thirdly, if you do use any abrasive--steel wool or not--you need to clean the surface carefully to eliminate small particles. However, if you coat the knife with grease--silicon or ____, you will prevent salt water from contacting the metal--whether on the knife or the residual particles.

Fourthly, the amount of vaseline on a knife is so minuscule that it would be impossible for it to effect seams on a wet suit. However, I did note that if you were going to lose sleep over this, just use silicon grease. Of course, if you were sloppy and just piled the grease on the knife, smeared it on the sheath, and wiped your vaseline-laden hands on your wet suit, you would probably have a problem. I give the members of this site more credit than that. But, maybe, you do not.

That's it: no more. I won't even bother to assist you in mastering English grammar anymore.

joewr