Hap40 corrosion testing

[Surfingringo]

Well, some folks have been asking me about how corrosion resistant hap40 is and I haven't really had an answer. I have been using my Delica and Stretch as edc knives and haven't had them in corrosive environments so my experience with the steel has been pretty much like everyone elses. In the interest of getting some more information on the steel though, I decided to take my Stretch out in the kayak today.

After six hours sitting in the gunnel bathing in saltwater there was a significant amount of corrosion on the exposed hap40. By the time I got to the house there was even some minor pitting that would not fully come out with flitz. Before doing this testing my feeling was that this steel was slightly less corrosion resistant than m4 and this test confirmed that for me. I love the steel nonetheless and it has not shown ANY corrosion issues in my normal daily use, even here in the tropics, but it will definitely start to break down if you leave it exposed to highly corrosive environments.

I did a quick little video review while out on the water but unbeknownst to me, my camera fogged up so you can't really see any of the corrosion that I am talking about. I didn't bother taking pics either since I thought I had it on video. What I had was probably 12-15 small but prominent orange rust spots on each side. Like I said, by the time I got to the house it was significantly worse. No real surprises...I knew it was going to rust, I just wanted to see how quickly.

https://youtu.be/J4GO-PYUO64

[can't freehand]

what was it like around the folding pivot?

my zdp-189 corrodes in that area just by staying in the pocket (sweat at work). That's the main reason why I hate non-stainless steels in folders, you have to disassemble to prevent the washers from being ruined by corrosion, but doing so voids the warranty, not to mention the hassle of having to disassemble every time salt/soap/blood gets in that part.

[Surfingringo]

what was it like around the folding pivot?

my zdp-189 corrodes in that area just by staying in the pocket (sweat at work). That's the main reason why I hate non-stainless steels in folders, you have to disassemble to prevent the washers from being ruined by corrosion, but doing so voids the warranty, not to mention the hassle of having to disassemble every time salt/soap/blood gets in that part.

No issues there because the hap40 is not exposed there. Is your zdp-189 laminated? I know some folks prefer solid blades but this is one of the distinct advantages of the laminated blades.

[ejames13]

Thanks for the review/test! Sometimes I feel like my non-stainless blades will corrode into oblivion if I don't constantly wipe them down. Good to know HAP40 can withstand even saltwater exposure without being badly damaged.

[bearfacedkiller]

Awesome Lance! I have used my HAP Delica on a ton of fruit and put it in my pocket all covered in fruit juice many times and while it is developing a patina it hasn't rusted at all. It has developed a patina faster than either of my M4 blades though so I would agree that it seems a little less stainless than M4. I have had it out on the ice for a day of icefishing and it was used to gut a few Mackinaws and it didn't stain at all. While obviously not stainless it has been corrosion resistant enough for my semi arid environment.

Good stuff, thanks for taking the time to share that. :)

Nice to see you learning to love the Stretch.

[Surfingringo]

Awesome Lance! I have used my HAP Delica on a ton of fruit and put it in my pocket all covered in fruit juice many times and while it is developing a patina it hasn't rusted at all. It has developed a patina faster than either of my M4 blades though so I would agree that it seems a little less stainless than M4. I have had it out on the ice for a day of icefishing and it was used to gut a few Mackinaws and it didn't stain at all. While obviously not stainless it has been corrosion resistant enough for my semi arid environment.

Good stuff, thanks for taking the time to share that. :)

Nice to see you learning to love the Stretch.

Yeah Darby, the kayak on saltwater is a very corrosive environment. I know that most of these steels will never be used in those kinds of conditions and they really shouldn't be when there are so many better options. It's an easy way to compare the properties of steels though because you can learn a lot in a very short amount of time.

Like you said, I have cut all manner of stuff with my Delica and haven't given any special attention to maintaining it. Until today it still hadn't even developed too much of a patina.

I a 1-10 corrosion resistance scale (of non stainless steels) might look something like this?

Cruwear- 8
M4 - 6
Hap40- 4-5
Superblue- 1-2

I don't actually own any cruwear so I placed it there based on what others have said.

[Tdog]

Thanks Lance, as usual pics/video add to the thread. My Caly 3.5 (laminated) also rusted quickly around the saltwater. Rust formed on exposed zdp edge, along the lamination line, and on the jimping in hours. I washed, flitzed, and lubed heavily around the pivot area. The knife cleaned up nicely. I won't purposely carry it around saltwater again. Stainless or H1 is better suited. Good to know how the Hap40 reacted. Been crappie/speck fishing for me lately....pulling some nice slabs. Can't wait to get back to St. Augustine or the Keys. Take care.

[bearfacedkiller]

I a 1-10 corrosion resistance scale (of non stainless steels) might look something like this?

Cruwear- 8
M4 - 6
Hap40- 4-5
Superblue- 1-2

I don't actually own any cruwear so I placed it there based on what others have said.

That sounds about right to me.

After seeing no staining on my Cruwear Military after a ton of use around the yard and a ton of food prep over the course of a year I just had to see how stainless it was. I opened it and put it tip down in a glass of room temperature white vinegar (filled just enough to submerge the blade but not the handle) for three hours. I cleaned it really good with isopropyl and then hot water first to remove any oils. It discolored ever so slightly but not enough that I can ever get it to appear in a picture and I can only really see it in certain lighting. I did the same thing with a Kershaw in D2 and it turned a dark grey in three hours. I do not actually like forced patinas but the glass of vinegar is my homemade scientific test. Cruwear is very stainless. I used my Cruwear Manix to clear a bunch of weeds around the yard and left it covered in goo for a couple of weeks by accident and it had brown spots all over it and it took a bit of toothpaste and elbow grease to get it cleaned up. I have left a VG10 knife covered in goo from weeding before and got pitting so I must have some nasty weeds in my garden.

[elena86]

Lance, I dare to say that for your fishing tasks, the slight belly cutting edge of an Endura is more usefull since it doesn't have that trailing point.But, of course, you'll have to do your magic on the blade shape before that( remove the hump and make it pointy as you do to your Pac Salts).Now I'm more confident and thanks to you and Darby I am going to use my Hap40 Delica for my daily cutting and peeling fruits when it comes to that.

[can't freehand]

No issues there because the hap40 is not exposed there. Is your zdp-189 laminated? I know some folks prefer solid blades but this is one of the distinct advantages of the laminated blades.

Solid

good to know the laminate works so well