scjohnson243 Posted February 18, 2013 Share Posted February 18, 2013 So I have a 4" belt grinder I have inherited - I just tried it this evening with 50 "grit" paper on it to knock out some knicks of a knife blank I had forged earlier, and it takes FOREVER to grind away some metal - I can see using it for finishing the knife and cleaning it up, but to help "Shape" the blade what are you folks using?? It will be awesome for the wood on the handles, but I need to find something to help my bad forging :) and advice would be lovely. :) Thanks folks! Quote Link to comment Share on other sites More sharing options...
Rich Hale Posted February 18, 2013 Share Posted February 18, 2013 "i listed everything on grinding blades years ago in bp 0235,,,may help you a bit! Quote Link to comment Share on other sites More sharing options...
scjohnson243 Posted February 18, 2013 Author Share Posted February 18, 2013 Thanks Rich - I just read it, it appears all you use are belt sanders? I assume you are much better at forging than I am, so your not having to grind away a lot of metal, like I do! :) Thank you Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted February 18, 2013 Share Posted February 18, 2013 40 grit blaze belts can take off 1/4 in a single pass on my Bader B-3 its only 1.5 HP, of course if I used aluminum oxide it may take all day to do the same. Quote Link to comment Share on other sites More sharing options...
Justin Carnecchia Posted February 19, 2013 Share Posted February 19, 2013 2" by 72" is pretty much the standard for grinding knives. If nothing else because there is the largest selection of belts. These grinders are not cheap though, $1000+ range. My advice is once you've decided your serious enough to spend that much start saving. Till then make do with what you have. I would recommend you resist the temptation to buy marginal grinders, that you will replace down the road. Personally I have a KMG by Beaumont Metal Works, I have the basic platen set up with a 2hp motor. I will add the small diameter wheels in the near future, and at some point will add a variable speed motor. If I could do it again I would have gotten a variable speed set up to start. Steve is right, good belts in the proper grit make a big difference. I like the Norton Blaze in 50g but they are around $10 a piece, personally the time they save and the added life of the belt is worth it for me. Look around and see what kind of belts you can find for your 4". I worked for a while with a 3" by 18" belt sander held in a vise, it was just slower. If you start taking this seriously then start thinking about a better grinder. Quote Link to comment Share on other sites More sharing options...
Dodge Posted February 19, 2013 Share Posted February 19, 2013 Be aware that there is a difference between belt "grinder" and belt "sander". Mostly has to do with power. A grinder has the power grind steel as well as wood, plastic and knuckles. A sander usually is only good for wood plastic and knuckles. Quote Link to comment Share on other sites More sharing options...
metalmangeler Posted February 19, 2013 Share Posted February 19, 2013 Maybe I should not add this as you were not looking for this, but imporoving forging skills should be a top priority this will not cost near as much as the grinder. Things to think about are brush that scale off rather than forging it into the steel, also keep it from building up on the anvil and getting pounded into the blade from there. Use a flatter as needed and it should help reduce those hammer marks. Make sure your hammer faces are properly dressed. After you get the grinder of your dreams the forging skills will save you $$$$$$$$$ in belts and time. Quote Link to comment Share on other sites More sharing options...
basher Posted February 19, 2013 Share Posted February 19, 2013 If you are looking to make knives then a Belt grinder is the number one tool to have. They have the ability to turn a forged or unforged lump of metal into a finely finished knife. In most situations if you are forging a blade it is good practice to remove decarb to bring you back to good steel and this means removing at least 20 thou from each side of the blade (at least) . and grinding is much much quicker than forging unless you have massive distal tapers going on (for example long swords). The rule of thumb is that you need 1hp per inch of belt width to grind metal , more is better. Much as I love the forging.... It is the reality that blademaking is as much about grinding ,as it is forging, and often more so. Quote Link to comment Share on other sites More sharing options...
scjohnson243 Posted February 19, 2013 Author Share Posted February 19, 2013 Thanks all, this answers quite a bit more than what I was using, I was using a sander, i guess.. I put on 50grit (The coarest(is that a word?)) belts I could find over at home depot and I can see it would finish m knife very well, but for any type of "Shaping" its just not cutting it. (heh heh) Forging skills very much need work, and I'm doing the best I can on that, I have a meeting this weekend, and just got a class scheduled for a few weeks, so I hope that will help with some guidance also. I have a few more belt grinders at home, some have 1" or 2" belts, I need to see what type I have, my father spends a lot of time at garage sales and he has been buying up all the ones he sees... They are probably not expensive nice ones, but maybe I lucked across a good one. Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted March 13, 2013 Share Posted March 13, 2013 few if any box store will carry real metal belts. only good for wood. see my prior post about aluminum oxide... Quote Link to comment Share on other sites More sharing options...
liamh Posted March 13, 2013 Share Posted March 13, 2013 Maybe I should not add this as you were not looking for this, but imporoving forging skills should be a top priority this will not cost near as much as the grinder. Things to think about are brush that scale off rather than forging it into the steel, also keep it from building up on the anvil and getting pounded into the blade from there. Use a flatter as needed and it should help reduce those hammer marks. Make sure your hammer faces are properly dressed. After you get the grinder of your dreams the forging skills will save you $$$$$$$$$ in belts and time. Yes! I thought i was the only one to use a flatter on knives consistantly :P Quote Link to comment Share on other sites More sharing options...
Christopher M Posted March 25, 2013 Share Posted March 25, 2013 I use a 36 grit AO belt on my 4x36 bench top belt sander to refine the shape Quote Link to comment Share on other sites More sharing options...
Rich Hale Posted March 25, 2013 Share Posted March 25, 2013 Christopher a lot of folks use AO belts and some of them for a long time...however if they change up to better belts they never go back...For rough work I like the blaze belts by Norton. A belt sander does not have to power it takes to use one of the better belts, When you can remove a lot of metal efficiently it takes more power. Quote Link to comment Share on other sites More sharing options...
Robert Yates Posted March 25, 2013 Share Posted March 25, 2013 I am Building this one . http://www.metalwebnews.com/manuals/knife-grinder.pdf Sam Quote Link to comment Share on other sites More sharing options...
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