Full Tang Clan, I have a Gatco and I have a friend who has the Lansky. They seem to be very similar. They do leave marks on the blade, but with a piece of paper towel between the clamp and the blade it seems to stop this from happening. Be sure not to over tighten the clamp.
I find both only good for reprofiling the edge on well used knives or bad factory QC, I then take it to the Sharpmaker to put that hair popping edge on them. Personally if I had known the difference at the time I would have purchased an Edge Pro. Although more expensive, I think I would have been better off in the long run.
There are advantages/disadvantages on both sides.
The Gatco clamp gives you "really" the indicated angles, it is larger and therefore less sensitive to blade width and thickness to "keep" these angles. On the other hand, it is asymetrically built, i.e. the angles on both sides of the blade are "very slighly" different, which should shouldn't bother at all (if you clamp the blade always the same way!). The hones are much broader and longer, giving you a nice speed advantage in sharpening, except for strongly recurved blades.
The Lansky clamp's angles are NOT as given,
unless your blade happens to have "ugly" dimensions. The clamp is very small, making it very sensitive to blade dimensions and clamping to duplicate a once set angle (well: you might resharpen, once in a while?).
On the other hand the clamp is symetrical. i.e. both sides of the blade will show exactly the same angle (IF you clamp it symetrically). The hones are quite small, which is a clear disadvantige, it takes more time to reach the same result. The ever loosening screws of the guide rods are a nuisance in my eyes.
Both systems do work, give perfect results (for small knives!) when handled correctly, but my (personal) nod goes to Gatco.
Do not use them on blades longer than 4" or so, you'd have to do it "in sessions".
I've got a Lansky and it works quite well. I, with zero sharpening experience or skill, can put a shaving edge on a very dull knife. It also works well for rebevelling - I would hate to have to rebevel a knife on a sharpmaker (I haven't tried it, it just looks like it would take years).
The instructions recommend that you put masking tape on the back of the blade where it comes in contact with the clamp so the blade doesn't get scratched. I put tape on the clamp instead - don't have to redo it for each knife, and don't have to clean the tape off.
I haven't used a Gatco so I can't comment on those, but I would recommend a Lansky.
Jason aka medusaoblongata
"I have often laughed at the weaklings who call themselves kind because they have no claws"
I'm in the same boat as sigsauer and Mykl. I have a GATCO and use it for reprofiling. When I have a really big blade, I use a small c clamp instead of the clamp provided to hold the blade. The key to using these types of sharpeners is patience. Don't try to horse it. Take your time and they will do a great job. But someday I will probably pony up for an Edge Pro, although lately I've been doing more and more reprofiling on my Grizzly knife grinder. It was only $100 more than an edgepro and can do wonders. I have a buffing wheel attached that is great for convex blades and I love to sharpen my hatchets and axes on a slack belt. Gives a great convex grind that is razor sharp but robust.
I get some pleasure from finding a relentlessly peaceful use for a combative looking knife.
The clamp is made of Aluminum, so it shouldn't scratch steel. But, if the blade has a polished finish it might. A bit of paper towel between the clamp and the blade, as Mr. Sigsauer suggested, removes that risk.
I got the delux set that includes a hone that is supposed to be able to sharpen serrated edges, but I can't seem to get that part to work very well. It's doubtlessly just me.
I also bought the "Ultra Fine Hone" and replaced the "Extra Corse" hone with that since I don't let my knives get so bad as to need that Extra Corse (I did have to dig it out a few months ago when a friend of mine dropped by with six M16 Bayonets that ye bought at some surplus place. He said I could have one if I'd sharpen all six. Well, I didn't really want one, they're ugly, but I did it as a favor to him. It took a couple of hours, but when I was done, they'd all shave the hair off your arm.) I ended up using mine as a kitchen knife, though it rusts if you as much as look at it sideways.
Anyway, I like my Gatco. Skip the serration hone, but get the Ultra fine hone.
I have both the lansky and the original version from Loray. They both work great, but the clamps WILL scratch the back of the blade. My main complaint with these small clamp type sharpeners is the way they tend to not sharpen the curved area up by the tip. As soon as I can afford it, I am getting the Edge Pro system.
Beware the blades grind. I' ve no real experience with the Gatco but the Lanskys clamp will not hold angles consistently nor the blade itself securely if there is no flat surface to clamp on to. Meaning flat grinds and vey high hollow grinds will be problems.
I have found that it serves me best when trying to bring a very dull blade back to life with the diamond hones. Or to start a reprofiling process if needed. But not for "normal" touch ups/ sharpening.
Signnnnn... Spyderco: where are those diamond speed sleeves???
I have GATCO EdgeMate Pro Deluxe version and it works well for me. I agree with ZUT&ZUT with one addition: the clamp may work pretty clumsy on dagger-style blades with no flat surface between main grind and false edge.
No problem if even a small amount of flat surface presents like for ex. on BM Ares or CRKT Mirage.
[Both of the long term tests on the skarb - a clamp system- felt that this was the best of the clamp systems available. BladeMagazine found that the clamp left no marks on the blade. Check www.skarb.com for more info.