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edge finishing after heat treat


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So when I heat treat a knife I leave the edge about as thick as a dime, I was wondering how you get that dime thick edge down to a final edge without putting a secondary bevel on?

If this is in another thread can you please point me towards it.

Thanks

-Thomas

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If your finishing it by hand it would come down to strips of sand paper wraped around a piece of 1 inch flat stock or a file. Set it up on a filing jig and go to town.

Edited by Jeremy Blohm
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Start around 120 grit and work your way to a finer like 400 grit and so on until you get your desired adge and polish.

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1 hour ago, Thomas Kadatz said:

I was wondering how you get that dime thick edge down to a final edge without putting a secondary bevel on?

You go back to the grinder. Depending on how thin I want the final edge to be before I put the secondary bevel on, and how thick I left the edge for heat treat, I might even go back down to 50 grit.

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If you are talking about a convex edge then usually using the slack belt portion of the grinder (off the platen) with a worn 120 grit or fresh 200 . Put a piece of duct tape on the sides of the blade above the edge to protect it and hold the side of the blade almost touching the belt till the belt just wraps around the edge. It helps if you have a multiple speed setup so you can use the slowest speed.

BBG (before belt grinder) I would use a file to set a series of micro-bevels towards the final edge and the use circular strokes on the coarse side, followed by the fine side, of a gray Norton synthetic stone.

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I am assuming you're doing this without a belt grinder, in which case Vern's suggestion is good.  And yes, the big Norton synthetic "India" stones are decent for final grind and rough polish.  I know nothing about water stones other than that they are expensive, but they do work well.

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I have a little 1x30 belt sander but the tracking is messed up and it is a pain to use. so I am not using a grinder at the moment. Water stones are expensive but I think I will start getting them one by one, maybe from Lee Valley.

Thanks for the video Joshua I will have to check out some more of yours.

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You can adjust the tensioner assembly on your 1x30 to make the belts run true. Here's a tutorial I put together for getting those little guys running right... https://sbg-sword-forum.forums.net/thread/46064/harbor-freight-belt-sander-maintenance

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It is a master craft sander and half of the tracking wheel is actually worn down so there is a substantial step down that half of the belt has to run on, so I would need a replacement wheel and I am not sure if they make replacements.

I might just save up for a 2x72

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I see. I use my 2x72 for the bulk of the work, but I go to the 1x30 for the finesse work and final sharpening. You can get a new 1x30 from Harbor Freight for about $40 and some change with all the 20% coupons they mail out.

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If you don't have the belt grinder, try a scraper and/or draw filing to work the bevels and edge down.

Edited by Joshua States
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19 hours ago, Thomas Kadatz said:

Thanks everyone, I guess its back to the sand paper for me.:mellow:

are the Norton stones good for a first set?

A large Norton stone is a good thing to have around. They are relatively cheap, consistent and do a pretty good job up to the point of a really fine edge. The steel isn't all that picky until you get to the really fine level. I don't see spending a lot of money for a stone for the rougher work if the steel doesn't know the difference.

Dad taught me to use them and the file trick to rejuvinate/salvage abused axes and hatchets. I had to figure out on my own that if you start with a new Norton it is better to use water as a lube on the stone as opposed to oil. Oil tends to gum up and is harder to clean off.

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5 hours ago, Vern Wimmer said:

A large Norton stone is a good thing to have around. They are relatively cheap, consistent and do a pretty good job up to the point of a really fine edge. The steel isn't all that picky until you get to the really fine level. I don't see spending a lot of money for a stone for the rougher work if the steel doesn't know the difference.

Dad taught me to use them and the file trick to rejuvinate/salvage abused axes and hatchets. I had to figure out on my own that if you start with a new Norton it is better to use water as a lube on the stone as opposed to oil. Oil tends to gum up and is harder to clean off.

I use CRC brakleen but any brake cleaner should do and it keeps my stones clean. I have the scary sharp sharpening system after I put the initial secondary bevel on with a worn 240 grit belt.then an have four different grades of stone although I generally only use 3 of them.

The brakleen keeps the stone clear of debris but I use 50/50 canola oil and kerosene for lubricant.

I have donr a lot of knives on this system and really like the repeatability of angle on both sides as the stones are changed and being in thier own holders it s as simple as putting one down after giving it a spray with brakleen, and picking up the next.

http://www.scarysharp.co.nz/

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