Corrosion testing

REK Knives

REK Knives

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Knifemaker / Craftsman / Service Provider
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So after getting a couple of the top contenders (as a benchmark) from this testing, I decided to do my own testing in a variety of conditions and ways. This will be ongoing testing over the coming months/years.

I'm using some sample blades in 1095 steel that were sandblasted and degreased for maximum possible corrosion.

i-wWj55K6-X4.jpg


The first 4 I'll be comparing are Hornady One Shot, WD40 specialist corrosion inhibitor, coconut oil (said to be the main ingredient in frog lube), and a control.

After the oil application I wiped off all the excess with a dry paper towel. There is an interesting difference between the wd40 and one shot which I'll discuss later.

Here are the 4 blades with the three lubed up - same order as in Pic above.

i-Br2Ln8Z-X4.jpg


I will be leaving outdoors and spraying once a day with a saltwater solution (4000 ppm salt content in water).

First application has been started at about 2pm today. Updates will be coming soon!

i-MHvFW9M-X4.jpg
 
This is interesting... LCTI (WD40 Specialist Long Term Corrosion Inhibitor) is more of a spray on grease almost - you literally can't get it on thinner than this without wiping some off lol

i-MVMKct2-X2.jpg


And here's the One Shot... it basically dries almost instantly leaving a MUCH less greasy feeling part

i-H6JJQXN-X2.jpg


But with both I still wiped off any and all excess for this test - the same I would on a normal knife blade :)
 
Have you seen anybody test Fomblin/Krytox? Offhand I would have guessed it would be the top contender, but maybe too expensive for these applications.
 
ToddS said:
Have you seen anybody test Fomblin/Krytox? Offhand I would have guessed it would be the top contender, but maybe too expensive for these applications.
Click to expand...

No I'm not familiar with those but I'll check them out... I do have a specific rust inhibitor oil I'll link to later that I'm gonna test out. It stinks to high heaven though lol

3fifty7 said:
Man o man, there are some great worm holes to go down on this !

Add to the test:
Weapon Shield
Frog Lube
CLP
Tuff Cloth
Eezox

Can we do pivot lube resistance and wear next ?!?!?!
Click to expand...

Patience young grasshoppah... :) Yeah I have eezox and weapon shield on hand.
 
Josh, have you considered trying mineral oil on one? I appreciate the fact that it’s one of the only truly food safe (IMO) options relative to what’s been listed, aside from the coconut oil, which obviously doesn’t cut it, according to some very straightforward pertinent experiment I just read about ;)
 
Fullflat said:
Josh, have you considered trying mineral oil on one? I appreciate the fact that it’s one of the only truly food safe (IMO) options relative to what’s been listed, aside from the coconut oil, which obviously doesn’t cut it, according to some very straightforward pertinent experiment I just read about ;)
Click to expand...
I'll give it a shot!
 
ToddS said:
Have you seen anybody test Fomblin/Krytox? Offhand I would have guessed it would be the top contender, but maybe too expensive for these applications.
Click to expand...
do you have any specific recommendations from either company on what you suspect would work best?

Just got off the phone with an engineer from Krytox about the XP-1A5 series oil. You were right this stuff is expensive!!! (about $300 for a pint) but it checks all the right boxes for me
  • food safe
  • high corrosion resistance
  • true water displacing (will sink to bottom of water)
The only thing is that it's on the thicker side so we'll see. He said they don't normally send samples but he has some contacts to where the thinks he can work it out so I can try some out. Excited about that, thanks for the recommendation Todd!

Regarding Krytox (who, interestingly enough had one of their first major sales for the first apollo space shuttle) vs Fomblin... I'll see if I can get this right lol, it was quite in depth. He was saying they both use PFPE (perfluoropolyether) but they use a different chain. Krytox uses a K fluid which is a branched and shielded molecule which apparently gives it better high temperature stability and more corrosion protection. Most of Fomblin's oil is made from a linear chain which has better cold temp stability and it lacks the proprietary corrosion inhibitor in it that Krytox develops and puts in their oils.

Anyway, it will be interesting to check out if he can manage to get me a sample.
 
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razor-edge-knives said:
do you have any specific recommendations from either company on what you suspect would work best?
Click to expand...
I've not observed any difference between Fomblin and Krytox. I use the grease for o-rings and it spreads quite well, usually put a dot on the fingertip of a glove and work it in. The version I use is for high vacuum, but there are a variety of formulations, some specifically for anti-corrosion, eg, Fomblin AR 555 or Krytox XP2A7

http://www.motionusa.com.s3-website-us-east-1.amazonaws.com/dupont/Crossover_Card.pdf

Looks like GPL227 is available on Amazon in affordable quantities.
 
The other stuff I already have here is E-Tec 501 which I'm gonna be comparing shortly...

_________________________________________________

Here is an update on the parts... We've been getting a lot of rain lately so the salt solution couldn't really dry. I wanted to speed up the oxidation process so I brought them inside to dry... there were no signs of corrosion on the LCTI or One Shot blades prior to doing this but check them out now!

So this is 2 days and 2 salt sprays and some rain

i-sznMnrz-X4.jpg

i-x6v6M6G-X4.jpg
 
Last edited:
ToddS said:
I've not observed any difference between Fomblin and Krytox. I use the grease for o-rings and it spreads quite well, usually put a dot on the fingertip of a glove and work it in. The version I use is for high vacuum, but there are a variety of formulations, some specifically for anti-corrosion, eg, Fomblin AR 555 or Krytox XP2A7

http://www.motionusa.com.s3-website-us-east-1.amazonaws.com/dupont/Crossover_Card.pdf

Looks like GPL227 is available on Amazon in affordable quantities.
Click to expand...

Looks like that's a grease though... I'm wanting an oil for pivots and to spread on blades. In reference to the engineer I spoke w/ above, he may see about development of small bottles of this stuff for the knife market which would be pretty sweet.
 
Ok I decided to start over again w/ 4 new products. I will re-run the one shot and LCTI against the top contenders here probably. This time I'm going to keep inside (to control variables) and spray twice daily w/ salt solution then allow to air dry. Unfortunately the E-tec is expired in 2018 so I don't expect it to be a top performer but I'll try anyway.

i-x7sDP3Z-X4.jpg


Here are the same blades after being sandblasted... there was some pitting on the far right one from all the rust but I at least removed it

i-2XPH5Rx-X4.jpg
 
3fifty7 said:
Man o man, there are some great worm holes to go down on this !

Add to the test:
Weapon Shield
Frog Lube
CLP
Tuff Cloth
Eezox

Can we do pivot lube resistance and wear next ?!?!?!
Click to expand...

I use CLP on my guns and never had any rust on them. So I coated a stipped SR 101 blade in it twice in 1 week. Applying a heavy coating then allowing it to sit for 3 hours or more than wiping the excess off. Oddly the knife began the rust the first day I got rained on (it's my EDC). I cleaned the knife with steel wool and then soap,
went back to mineral oil and haven't had any rust come back.
 
954Ink said:
I use CLP on my guns and never had any rust on them. So I coated a stipped SR 101 blade in it twice in 1 week. Applying a heavy coating then allowing it to sit for 3 hours or more than wiping the excess off. Oddly the knife began the rust the first day I got rained on (it's my EDC). I cleaned the knife with steel wool and then soap,
went back to mineral oil and haven't had any rust come back.
Click to expand...

Wow, that is interesting!! So when you applied the mineral oil do you wipe the excess off as well?
 
954Ink said:
I use CLP on my guns and never had any rust on them. So I coated a stipped SR 101 blade in it twice in 1 week. Applying a heavy coating then allowing it to sit for 3 hours or more than wiping the excess off. Oddly the knife began the rust the first day I got rained on (it's my EDC). I cleaned the knife with steel wool and then soap,
went back to mineral oil and haven't had any rust come back.
Click to expand...
Same here. I’m probably about 50 miles N of you, and have been disappointed by some corrosion inhibitors, but always pleased with the mineral oil’s protection :)
 
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