Cutting tests - which materials?

[lowviz]

You highlight one of the challenges of attempting comparative testing, and that is the testing conditions themselves. There are so many variables it is impossible to truly represent real conditions. ...//...

You kind of NEED water if you are going to rate/describe a tool's cutting ability to divers. Try cutting both polypropylene and nylon topside and underwater. If you want to "sell" this to divers, you may wish to do some testing in a pool. You don't need to be on scuba, just cut the line in water.

You mention free floating and when a line can be tensioned. My thoughts would be that effectively this translates to the diver having to hold the line to cut it, or the line being either properly under tension (both ends fixed), or fixed at one end so it is easier to pull on it. Another scenario is that the line is wrapped round the divers limb/s or equipment. In this case, the wrapping provides resistance for the cut.

Line can be really annoying underwater, especially old encrusted stuff. Wet line that is nearly weightless underwater does not act like dry line either.

To allow me to do some form of testing I decided that I would keep things simple and cut in the dry (so I can keep track of all cuts and make notes easily) and to cut lines that are untethered and must be hand held, and lines which are tethered at one end so I can pull against something. This will have to do for now. ...

That's fine for topside. Line gets funny underwater. I had it wrapped around some back mounted gear where I couldn't tension it in either direction. Paramedic shears worked well. Doing everything dry doesn't sound like a big sell for divers, IMHO.

...//... Not quite sure the purpose of this post as there is no need for a disclaimer in this thread which is only discussing materials I intend to use for testing. Rather than just ignore it though.... ...//...
I am not affiliated with any manufacturer, nor paid by any for my testing, however I am supplied with samples for testing FOC which are not returned (or sold). ...//...

Perfect. That is exactly what I was looking for. I always look at the tester's motives first. You test cutting tools. No problem.

You could have just as easily been someone trying to introduce a new cutting tool via a rigged test. Now we know.

 

[Bison Ravi]

Would be really interested in a review of the new line cutter from dive gear express, with ceramic blades. (can't rust).

 

[TacticalReviews]

You kind of NEED water if you are going to rate/describe a tool's cutting ability to divers. Try cutting both polypropylene and nylon topside and underwater. If you want to "sell" this to divers, you may wish to do some testing in a pool. You don't need to be on scuba, just cut the line in water.
Line can be really annoying underwater, especially old encrusted stuff. Wet line that is nearly weightless underwater does not act like dry line either.
That's fine for topside. Line gets funny underwater. I had it wrapped around some back mounted gear where I couldn't tension it in either direction. Paramedic shears worked well. Doing everything dry doesn't sound like a big sell for divers, IMHO.

A constant dilemma is how far to take the testing. I do the reviewing on top of a day job, so have to set some limits.

I take on board the difference in cutting underwater and will do my best to incorporate this in some way. What will be interesting to know is if the best dry cutter is also the best wet cutter. At least with the dry cutting information there will be some form of comparison. I might need to present detailed dry cutting results and comment on wet cutting results (as I won't be making notes).

Shears are really the best for lines as you don't need any tension at all. This is not in question. (As well as always EDCing a knife, I also EDC scissors)

 

[TacticalReviews]

Would be really interested in a review of the new line cutter from dive gear express, with ceramic blades. (can't rust).

I would be interested to see how that performs as I've already looked into ceramic cutters and blades to use in cutters that come with steel ones. I was told by the manufacturers that the ceramic blades are ground to a wide bevel angle so don't seem to be as sharp as thinner steel blades. They refused to be involved as they didn't think the ceramic blades would compare well despite zero corrosion issues. The ones I was looking at were not aimed at diving so if this has been specifically designed perhaps it ill work well.

 

[TacticalReviews]

Finally after a great deal of other work on a group review of 12 dive knives I was able to carry out the cutting tests this weekend. Very interesting results, and what a difference wet cutting makes. For complete authenticity I also carried out the cutting tests in sea water.

Now I just have to work out the best way to present 100+ results.

Thanks to everyone who provided input here, it was incredibly useful.