John4890 Posted February 21, 2012 Share Posted February 21, 2012 When I make a knife I usually just hammer the metal until I get the shape I want and then put an edge on with a grinder. I have two problems with my knives. They are not that sharp and there are pock marks all along the blade. A few days ago I had a thought. I thought that maybe I could just flatten the metal and get a rough shape and then use my grinder to really take some metal away and give it a nice finish with some emery cloth. For the longest time I was against grinding for reasons that now seem silly to me. So, my real question is how much do you depend on grinding to get a professional quality knife like this?http://www.google.com/imgres?q=railroad+spike+knife&um=1&hl=en&sa=N&biw=1366&bih=681&tbm=isch&tbnid=7_NXIhteEeuzZM:&imgrefurl=http://www.bladeforums.com/forums/showthread.php/798124-Two-Forged-Twisted-Railroad-Spike-Knives-SOLD!&docid=4vV-sFE8oyRvXM&imgurl=http://i644.photobucket.com/albums/uu161/PrometheanBlade/Spike%252520Knives/Spike%252520number%2525201/IMG_5598.jpg&w=640&h=480&ei=uBlET9LRIuTv0gHLvajdBw&zoom=1&iact=hc&vpx=875&vpy=150&dur=12&hovh=194&hovw=259&tx=75&ty=106&sig=103323268583190958241&page=4&tbnh=149&tbnw=210&start=58&ndsp=20&ved=0CM0CEK0DMD0 I also figure that since a grinding wheel is circular my knife would be fairly thin which would mean a better edge. Let me know what you think. Thanks! Quote Link to comment Share on other sites More sharing options...
Rich Hale Posted February 21, 2012 Share Posted February 21, 2012 Keep in mind that there are a few things that leave wot you call pock marks in a blade: One is actual loss of steel from heating the blade and scaling. The other is related to that: If scale falls onto the anvil or is not removed from the blade and you hit the blade it leaves a dent in the steel. the other usually leaves larger dents and that is hammer marks, they are most of the time related to the shape of the face on your hammer or whether you are using it correctly. If you take a piece of scrap wood the same thickness as the blade and hit it like you do the blade steel yoiu can see the marks youi leave..but you have to do this many times and kind of get an average to see. A stone wheel on a grinder is not right for blades.You need to learn by using files and abrasives or get a correect belt grinder fo knives. you can make real nice knives without any grinder. but you will need to research heat treat and annealing to be able to do that. After that you llneed to spend time on basic forging and working hot steel. WE all had to start somewhere and yoiu are on the right track, maybe you moved alittle farther into the raft so far,,slow down and back up will pay off a lot later on. If yoiu want to learn more it is all on this site.Including a bp 0235 whih shows how to mirror polish a blade and wot it takes. If you need more specific help post a few pics and maybe one of us can move you a long. Have fun! Quote Link to comment Share on other sites More sharing options...
MattBower Posted February 21, 2012 Share Posted February 21, 2012 You're on the right track, but a bench grinder is not the thing for what you want to do. Familiarize yourself with draw-filing and sanding blocks. And get used to your back and shoulders being sore. (At least sanding always makes my back and shoulders sore.) A belt grinder is the professional way to do a great deal of the work you're talking about. I know of a few people who can make as-forged blades that, in my opinion, look great (although it's a different look from what most of us are used to). I am not one of those people. Quote Link to comment Share on other sites More sharing options...
Backwoods Blacksmith Posted February 22, 2012 Share Posted February 22, 2012 I finish forging the blade with a flatter and the pack the edge. This is how I get the forged blade as smooth as I can before grinding. I use the belt grinder to semi finish and then draw file and use sanding blocks to finish. In the old days I did use a big 12 in bench grinder to rough but still had to draw file to get flat. Quote Link to comment Share on other sites More sharing options...
Hayden H Posted February 22, 2012 Share Posted February 22, 2012 As a beginning knife maker I've done it both ways. I've ground blades on 1 by 30 harbor freight sander, hand filed (pain to do but it make you understand angles and width), and forged. I'd much rather forge a blade to rough shape and grind it down to its final shape. Then hand file from a peice of bar stock. The trick to polishing a blade if its ground (this is what works for me) is get 220 grit metal sand paper and hand sand the blade length-wise until all the scratches form grinding are out then get on the buffer with white craftsman brand polish (It aint the best but its what I have and what I'll use until I run out) to a shine. It takes a while to sand the blade the way it needs to be, but I like shiny objects so its worth it. And be safe using the buffer, flying sharp-pointy objects at 1750 rpms isn't fun to dodge Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted February 22, 2012 Share Posted February 22, 2012 Bench grinder is not the way to go! Even an angle grinder will do a better job starting a blade. Draw filing and then block sanding can do a professional finish (with maybe a touch of buffing at the very end) (note that scale is an abrasive and wears out your files *FASTER* so remove the scale with vinegar, HCl or a grinder before going to the files.) The belt grinder----not a 1by...is the pro tool and it's very hard to go back to hand work after learning the belt grinder---though when I'm out of practice I will still rough in with the belt grinder and then finish off by hand Quote Link to comment Share on other sites More sharing options...
Justin Carnecchia Posted February 22, 2012 Share Posted February 22, 2012 Yeah quite a bit of grinding, (Sanding). I use the grinder for profiling, setting final bevels, polishing up to 200g and sharpening. From 200g on the grinder I go to 2500g by hand. While there is nothing wrong with the neo-tribal forge finished knives, for a professional looking knife you are going to have to do some sanding. Before I got my KMG belt grinder I used a 3" by 18" belt sander held upside down in a vise. It all depend on what you are looking to do. I suggest checking out the American Bladesmith Society site and forum, there you will see some of the best of forged knives. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted February 22, 2012 Share Posted February 22, 2012 And to bring a bit of history to it---An old Sheffield saying: "If a good blade you would win you must forge thick and grind thin!" Quote Link to comment Share on other sites More sharing options...
John4890 Posted February 23, 2012 Author Share Posted February 23, 2012 Thanks for the replies everybody. I definitely have some experimenting to do! Quote Link to comment Share on other sites More sharing options...
Don A Posted February 23, 2012 Share Posted February 23, 2012 Angle grinder with flat sanding discs in varying grits can do some good, clean work. But like everything else, it takes a lot of practice to get the touch. I heard a man say once concerning building wooden bows "what you can ruin in 10 minutes with a hand tool you can ruin in 10 seconds with a power tool". This applies to blades as well. Draw filing is good to learn. It teaches blade geometry and patience all at the same time. Quote Link to comment Share on other sites More sharing options...
Frosty Posted February 23, 2012 Share Posted February 23, 2012 A couple points. Grinding then filing is bad for your files as the abrasive grit gets imbeded in the steel and dulls files. Another hand technique that is surprisingly fast, and precise with practice is a scraper, Sen. These are basically a plane, maybe more like a shave, intended for steel work. A technique for using a wheel that makes my knees shake is to open a gap in the tool rest and address the wheel by holding the blade vertically between the rest and the wheel and grind it longitudinally. Do NOT do this, certainly NOT on anything like a recommendation from me, I don't. The very thought of a knife blade getting away from me doing this brings to mind being castrated, gutted or pithed by a flying blade. I mention the above technique only because I've seen it in a book and on a college TV ad and do NOT want someone trying it thinking it's in any way safe. Just because something can be done doesn't mean it should be done. Frosty The LuckyMod comment: The proper way for this is to remove the blade rest, Or use a pro machine that has a contact wheel installed. Quote Link to comment Share on other sites More sharing options...
MattBower Posted February 24, 2012 Share Posted February 24, 2012 Well now Jerry, which is worse for files: taking a freshly forged blade, grinding off the scale, then filing, or taking a freshly forged blade and filing off the scale? :) Of course I know all about vinegar and the other chemical methods of removing scale, but there are times when waiting for the chemicals to do the job just isn't in the cards. Personally, I grind then file. (Sometimes I use a wire wheel to remove the scale, which is probably the best non-chemical solution as far as the files are concerned.) Quote Link to comment Share on other sites More sharing options...
rockstar.esq Posted September 4, 2012 Share Posted September 4, 2012 Matt, I agree- perhaps the intent is to clean the ground blade before filing? It's hard to imagine a file will last forever cutting metal. You can dull a carbide bit after cutting enough soft steel. Quote Link to comment Share on other sites More sharing options...
bigfootnampa Posted September 5, 2012 Share Posted September 5, 2012 Well I must say that with my new grinder (2" X 72") I'd have to be quite a masochist to do much hand filing for basic shaping purposes. I first turned it on and sharpened all the knives in the house in about 40 minutes... the thing is that despite my near obsession and considerable skill, at keeping my blades sharp, none of the blades I sharpened that day had EVER been quite so sharp before! It is an awesome tool for sharpening alone and the $1,000 investment that had at first seemed a bit of a splurge now looks like an incredibly wise investment!! I have had cheaper sanders before but this is a real knife grinder and with a digitally controlled 2 HP motor and I got some quality industrial belts for it... and the DIFFERENCE is absolutely STARTLING!! I've done a lot of work with my flap wheel grinders and many other thrifty shortcuts... but I now realize how badly I was handicapping myself! Not saying that everyone has to have one of these grinders... but if you are doing lots of work with makeshift equipment... your life could be much BETTER! Quote Link to comment Share on other sites More sharing options...
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