So your bluing looks good and it wears well but how does it stand up to corrosion? That is after all the reason we blue our guns. So I did a corrosion comparison. I mixed a cup of tap water with one tsp of non-iodized table salt to act as the corrosive medium. Why that ratio??? Saline solution and our tears are equal to ½ tsp of salt to a cup of water. I was looking for something a bit more corrosive to speed things up. I need a container to hold the metal samples and the salt water. When your wife is searching the web for instructions on how to replace a leaky kitchen faucet you can steal away with a 9 x 13 baking pan unnoticed to put your metal samples in. I will return it when Im done.
Not wanting the pan to influence the evaluation (and because I don’t like getting yelled at) I laid down 2 layers of freezer paper and then a paper towel. I sprayed down the paper towel with the salt water to saturate it.
Next I sprayed barricade rust inhibitor on a paper towel and wiped only the 400 grit side of the samples and laid them on the wet paper towel because I wanted to test the corrosion resistance of Barricade since we all wipe our guns down with oil or some protective film. Nobody reblues a gun and leaves it unprotected. That being said, the polished side of the steel went without any protection to see if any of the raw blues performed better against corrosion than the other blues. The controls were protected as the image below describes.
As you can see, each blued sample, on the polished side (thanks to taping off at certain times) will have a blued area, an abraded area and an unblued area. Then the samples were covered with another sheet of paper towel and again saturated with the salt water solution.
Lastly another layer of freezer paper was used to depress the paper towel against the samples to make sure contact was made and the entire pan was then covered with plastic wrap to keep it from drying out so as to maintain a humid environment. The plan is to let the samples rest for 24 hours or until my wife notices her pan is missing.
Meanwhile, my wife is making great progress with the sink ………………..
After 24 hours of the samples sitting in a salty/humid environment, they were uncovered and examined.
Initial observations of the polished side show that F and A had the least amount of corrosion. Note that control G was not blued nor protected by Barricade and it faired the best of all. This is because a polished surface always stands up the best to corrosion. I learned that a long time ago as a custom knife maker. Highly polished knives are less apt to corrode than rough finished knives.
The samples were then wiped dry and buffed with steel wool to remove the corrosion and compromised bluing. Since still photos don’t do it justice I shot a video to show the appearance of the metal samples. You can see where the bluing was completely removed. (more reason to use a rust prevention solution on your guns)
https://www.youtube.com/watch?v=kk2vL7spEzA
Then I flipped the samples over to observe the 400 grit side that was blued and protected with Barricade. Despite the Barricade some samples still corroded but only slightly. Samples F and A had the least visible corrosion.
Another view
Here is a video of the 400 grit side after being steel wool buffed.
https://www.youtube.com/watch?v=iO_zIvz4hB8
I replaced the freezer paper and paper towel in the pan with new versions and again wetted it with the same salty solution. This time I coated all blued samples (both sides) with Barricade and again laid them on the paper towel since its pretty clear what happens to unprotected metal.
And again I covered them with another paper towel that was saturated with salted solution. By now you have probably observed that the cake pan did not stand up well to this environment. I have not shown the pan to my wife yet. My wife likes her jewelry, while it may seem out of date she still wears a mood ring. When she is happy, it turns blue. When she is angry it leaves red marks on my forehead. I will delay showing her the pan for now.
The plan is to leave the samples in this humid environment for another 72 hours. This will give me some time to run to the store to buy a replacement cake pan. This kills two birds with one stone since Mother’s Day is coming up and a new cake pan wrapped up with a boxed cake mix makes a perfect gift for any mother. I won’t make the mistake of buying her a leaf rake and weed trimmer line like last year. I think she liked them although she mumbled something that sounded like “shoulder pads for a snake”
Fast forward 72 hours and this Is what the samples looked like after removing the top layer of paper towel. This is the 400 grit side with a heavy application of Barricade. Samples A and F look the least corroded.
Clearly no bluing (which etches and compromises the metals surface) performed the best while unpolished, unblued and with no barricade (Lower left sample) performed the worst based on the picture below. This suggests that if you highly polished your gun and didn’t blue it at all, it would stand up the best to corrosion (but would be shiny as all get-out)
Again, still photos make it hard for you to see what I see so here is a video of the polished side.
https://www.youtube.com/watch?v=_ycMIBtaOI0
The final comparison was going to be cost but because none of these products will break the bank since they can be purchased in such small sizes I don’t know if price is a motivator or a reason to buy one product over another. Are you looking for the best bluing product for your firearms or are you buying based on price???? The prices ranged from $8 to $13, Again, not enough to make a purchase on price point alone and since any one of these bottles of blue will last the average sportsman a lifetime of touchups, price really isn’t that much of a driving factor.
It should be noted that many of the blues cost more for shipping than the product itself and paying for shipping is not a value added expense. Having purchased Dicropan many times through the mail I can tell you that caustic and hazardous shipments can really inflate shipping costs. The last time I bought Dicropan from Brownells the product cost was $12 and the shipping was $15. Those extra $15 didn’t make the gun any bluer or protected from the environment. If you do not live in the lower 48, you may not be able to get all of these products via the mail. But since I touched on the price factor, the lowest cost for shipping via an online order was F.
With all the evaluations complete, my notes indicate that I should probably be switching my standard, go-to blue. (that was after all the reason for spending the time and money and straining my relationship with my bride on this evaluation) I want to provide myself and those I do restorations for with the best cold bluing I can get my hands on and based on color, uniformity, abrasion resistance, and corrosion resistance, I need to stock up on “F” Nu-Blu. You however are free to buy which ever blue you like. I am not trying to tell you what to do.
Lastly, as it relates to rust inhibitors, Your gun cost you plenty. You want it to look and perform well for many years. Protect the metal. Remember this. Oil is a lubricant. Its not a rust preventative. Oil is also hard on wood and gun finishes. Get a product that is labeled as a rust preventative or inhibitor and put it on the metal only. In the future I plan to secure a variety of rust inhibitors to do an evaluation much like this one.
I want to thank this pan for giving its life in the service of gun owners everywhere. Although I wonder if there might be is a cake pan restoration thread in all of this? I could strip the finish and blue the whole pan. My wife would be the envy of the church cake ladies with such a tricked out piece of cookware. Sounds like a great birthday present.
So there you have it. Not all blues are the same or created equal. Use this info as you see fit.