Satin Finishing and file advice.

izafireman

izafireman

Well-Known Member
Having little success with finding a way to cut down the time on my knives when satin finishing and generally cleaning up the flats.

The steel I use is Elmax mainly laser cut and hardened to 60-61 HRC. I then normally remove the oven scale and take any surface flaws out on a glass platen and ceramic belts keeping the blanks as cool as I can. After this I use 'scurfs' made of stitched mops with a glue agent then Lea Satene stick compounds, not sure if you get them in the States as UK based.

The scurfs are in 80, 120, 180, 240 , 320 and 320 on a soft loose fold mop for the final machine aided stage. From then on it is hand sanding with good grade wet and dry. https://www.moleroda.com/product/lea-satene-compounds-satin-finishing/

My issues are two fold. Firstly there must be a better way of achieving a satin finish than using my method as time consuming and the scurfs only last so long before I have to remake them, a messy process. I have contacted abrasive supplier but they either don't understand my needs or don't get back to me, I was told to try flap wheels but just turned out a costly mistake.

I have seen convoluted wheels and unitised wheels , does anyone use these and if so what grades to take a blank up to a good satin finish or is there another method?

My other issue is I have tendentious in my right arm so wish to keep hand sanding down to a minimum

Anyone any ideas of how I can achieve a good satin finish please?

Finally I need to buy more files, what are the best makes to buy please?

Thanks
 
If you aren't getting every single scratch out from the previous grit when you change belts, then no amount of hand sanding or buffing is going to help. When the blade leaves the belt at 220 for example, there should not be any vestiges of previous grits. The truth will become apparent when you hand sand at 320grit. It should take all of 15 minutes to remove any scratches at all from the belt grinder. If it is taking longer than that, then they are not 220grit scratches.
 
My method is to grind my blades up to 400 grit. I then hand sand with 220 grit lengthwise on the blade to remove any irregularities from grinder mistakes and such. Then back to the grinder a 400 grit, 600 grit, and 1000 grit. I then finish with hand sanding at 600 grit for a final finish. I find that that first stage of hand sanding at 220 grit is what makes all the difference in my finishes and, believe it or not, actually reduces the time I spend hand sanding significantly. There's something magical about that 220 grit.
 
BrandantR said:
My method is to grind my blades up to 400 grit. I then hand sand with 220 grit lengthwise on the blade to remove any irregularities from grinder mistakes and such. Then back to the grinder a 400 grit, 600 grit, and 1000 grit. I then finish with hand sanding at 600 grit for a final finish. I find that that first stage of hand sanding at 220 grit is what makes all the difference in my finishes and, believe it or not, actually reduces the time I spend hand sanding significantly. There's something magical about that 220 grit.
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That's something I will try as I would have used a higher grit so looks like I should go lower.

Thanks
 
If you aren't getting every single scratch out from the previous grit when you change belts, then no amount of hand sanding or buffing is going to help. When the blade leaves the belt at 220 for example, there should not be any vestiges of previous grits. The truth will become apparent when you hand sand at 320grit. It should take all of 15 minutes to remove any scratches at all from the belt grinder. If it is taking longer than that, then they are not 220grit scratches.
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^^^ TRUE!!^^^ I would also add that learning to identify the visual difference between the various grit scratches is a big key.
Elmax? Whew! That's a major handicap to finishing in itself, and even worse in the hardened state.

We all come at things through the lens of our own experiences..... but in the case of grinding/sanding/finishing as it applies to knifemaking, I've found that it sometimes requires modifying the way an individual thinks. We see a scratch, and instinct tells us to work on that scratch/area to remove it. Try looking at it this way..... a scratch is something that has depth, and at the bottom of that depth is what I call "the lowest common denominator". What's that suppose to mean? It means that if you concentrate on the scratch(es), you will get rid of it, but in the process, you create a "divot"/low area. What you should be thinking/doing, is removing all the area surrounding the scratch, until it is brought down to the level where the scratch is eliminated, and the entire area is smooth/level.

Very often when we search for a way to speed things up, it ends up being counter productive. Most of the time the fastest way to produce a knife.... is SLOWLY. ;)
 
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EdCaffreyMS said:
^^^ TRUE!!^^^ I would also add that learning to identify the visual difference between the various grit scratches is a big key.
Elmax? Whew! That's a major handicap to finishing in itself, and even worse in the hardened state.

We all come at things through the lens of our own experiences..... but in the case of grinding/sanding/finishing as it applies to knifemaking, I've found that it sometimes requires modifying the way an individual thinks. We see a scratch, and instinct tells us to work on that scratch/area to remove it. Try looking at it this way..... a scratch is something that has depth, and at the bottom of that depth is what I call "the lowest common denominator". What's that suppose to mean? It means that if you concentrate on the scratch(es), you will get rid of it, but in the process, you create a "divot"/low area. What you should be thinking/doing, is removing all the area surrounding the scratch, until it is brought down to the level where the scratch is eliminated, and the entire area is smooth/level.

Very often when we search for a way to speed up thing up, it ends up being counter productive. Most of the time the fastest way to produce a knife.... is SLOWLY. ;)
Click to expand...

I agree about Elmax being a tough steel , haven't made things easy for myself )) and wise words about haste.
 
In my opinion, hand sanding, no matter how you do it, is an investment in your product. I was very anti-hand sanding until ED talked me into doing it and now I feel like the knife is not finished unless I have hand sanded it. I offer machine finishes to customers who do not care about the quality of a well done hand sanding for a lesser price because I have to put less effort into the blade. I really have not met anyone who has told me "There is nothing I like better than the effort it takes to hand sand a knife". So, I guess none of us really like it...
 
Agree that hand sanding is the way to go. But the telltale problem here is the huge amount of time and effort the poster is spending.

We’ve all been there- 3 hours or more into hand sanding a blade when it should take 45 minutes to an hour for a 600grit satin finish. That’s what it takes me on a big chef’s knife. In my early days I’d spend several hours on a basic little 4 inch blade hunting knife. The reason it took so long was because I was hand sanding out grinding mistakes and coarse scratches.

John Doyle boiled it down: this is a grinding issue. We’ve all been there and learned this the hard way.
 
Well said , I think that grinding is the key to prep for hand sanding. I know I have done a lot of hand sanding at times because I didnt do a good job getting the scratches out on the grinder
 
Exactly. In the early days I began hand sanding at 220, and occasionally needed to drop back to 120. That’s a dead giveaway.

I now begin hand sanding at 320 after finishing on the grinder at 220. It takes about 15 minutes to have a perfect 320 finish, and that’s on a big knife.

The turning point for me was recognizing 5 minutes into hand sanding that I needed to go back to the grinder. Once I began demanding a perfect belt finish at 120, 220 became all about reducing time hand sanding instead of actual grinding. The knife needs to be done at 120. Nothing left to remove or fix. It should be perfect. Any time on the grinder after that is about surface conditioning.

You have to be hard on yourself to get it right on the grinder. It’s always a temptation to call it good. But the reality is that 5 minutes on the grinder will take you an hour hand sanding.
 
Well I ground a blade this afternoon and took longer than on the belts as advised, stopping at 400 and then dropped down to 320 by hand and a lot better results. So getting there..

Cheers to all.
 
it is extremely difficult to know when you’ve removed all of the scratches from the previous belt. What helps me is to grind at a 30 to 45 degree angle when i think i’m there. This shows me what i’ve missed. same method that people recommend for hand sanding.
 
One Armed said:
Everyone is going on about sanding, and how it should only take X-amount minutes, otherwise your grinding is no good, yadda, yadda... but no one is talking about steel choice. Hand sanding a blade made from the simple carbons & forging steels vs a blade made with high alloy CPMs is night & day difference! That 15-45 minutes with say 1084 will in fact turn into HOURS with M4, or the super high Vanadium 20cv I use!
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I think most of us realize that not all steels are the same. Obviously some steels have much greater wear resistance than others.

However, its pretty sound general advice to make sure your grinding is nice and flat and consistent before you start hand sanding, regardless of the steel you're using.

The OP stated that the steel was elmax. I haven't personally used it. Have you? Looking at the specs, there isn't a huge red flag indicating that it would be terribly difficult to hand finish.
 
Chris Railey said:
In my opinion, hand sanding, no matter how you do it, is an investment in your product. I was very anti-hand sanding until ED talked me into doing it and now I feel like the knife is not finished unless I have hand sanded it. I offer machine finishes to customers who do not care about the quality of a well done hand sanding for a lesser price because I have to put less effort into the blade. I really have not met anyone who has told me "There is nothing I like better than the effort it takes to hand sand a knife". So, I guess none of us really like it...
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Hand sanding is my favorite part of knife making. It is very relaxing.
 
One Armed said:
Everyone is going on about sanding, and how it should only take X-amount minutes, otherwise your grinding is no good, yadda, yadda... but no one is talking about steel choice. Hand sanding a blade made from the simple carbons & forging steels vs a blade made with high alloy CPMs is night & day difference! That 15-45 minutes with say 1084 will in fact turn into HOURS with M4, or the super high Vanadium 20cv I use! Don’t believe it? Try it! Tried it, and still insist it’s the same? Someone’s lying! So...NO, it’s not always a question of grinding.

And for any that would say, “that’s why I don’t use those steels”... To me, that is simply a compromise. Compromising the best steels for ease of machining.
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I only work in stainless. That 45 minutes is CPM154 amd AEBL.

That 45 minutes used to be 3-1/2 hours when I wasn’t grinding very well.

If a material is difficult to hand sand, the grinder is the ONLY solution to the problems stated. There is no magic either in steels, abrasives, or processes. The worse you grind the more you sand. It really is that simple.

If you are spending 3 hours hand sanding there is a problem, and it isn’t the steel. If you think it is, change steels and prove it to yourself.
 
To the OP

Try Rhinowet Red Line paper and Mobil 1 synthetic for your hand sanding. This combination is the closest thing to magic I’ve come across in knife making.
 
Well, well, well, what a interesting debate.
I hate hand sanding but at the early stages of becoming a famous UK
knifesmith lol lol, I read that if you do not get your finish with what you are using do NOT think you will get it if you go to a smoother paper.

My UK 4 x 36 dealer only sells 120 grit and coarser belts.
I have some ceramic 40 grit, brilliant.

I have not progressed to freehand grinding yet, early days, I have made a jig the same as the young lad Greg on youtube, it is ok but my knew 4 x 36 needs some alignment help when erect.
These cheapo machines are a starter unit IMHO..

Anyway, I have farmers, gamekeepers and general rough arse types as friends who only want a rugged sharp knife and not bothered about high micro finishes but I would still prefer to be able to produce it when needed.

I thought, before reading this that I was the only one who had sanding terror. lol

The knife I am on now will be raffled at a shoot near Christmas for a
'c' charity so I better pull my socks up.

I love this site and knife making

Thank you a zillion times
 
Thanks for all your replies.

A few things I read, tried and learnt from this thread.

Firstly it was noted that hardened Elmax is a tough steel to hand sand but at the end of the day Elmax is designed to be tough and used in industrial moulds and blades, some of which are designed for cutting steel. I also found out that some Elmax that is shipped to the states is a slightly different composition than the European version due to the preferences of end users. I am led to believe that the US version is for want of a better word 'dirtier' so that it is easier to machine for the applications it is used for. What the composition of Elmax from your knife suppliers is I do not know.

My original thread was leaning more towards using machine techniques for doing the bulk of the work on the steel but as there were lots of good information about hand sanding I decided to go with that.

I had ground a blade out up to 400 grit and wasn't happy with it (see my post regarding plunge line) so opted to see if I could rescue this blade.

The first thing I did was to alleviate the error I had between my platen and table which had caused the plunge issue. I then took the blade back to the belt but tried my first real attempt at free hand flat grinding, obviously a tad easier as I had already got a good surface/angle from when I had used a jig. I was expecting it to be difficult but if I am honest I found it easier than using a jig and also way more controllable, my only issue was that using Gator belts on a glass platen was annoying as it created a high pitched noise....not sure if this is the case with Gator on glass platens? So I will definitely be trying more freehand grinding once I get my new steel cut.

So the blade was looking salvageable so I then tried the hand sanding as advised. Normally I would not drop the grit to 220 as the thought horrified me but as I only had 240 lowest I thought I would try. Bit of a revelation to say the least as that grit was far more responsive and took marks out a lot easier, nothing like the nasty scratch pattern I had imagined there would be. Still tough on hardened Elmax but far easier than the method I was using before, so all in all a good result as I have certainly learnt from this.

Thanks to all who have replied.

P
 
I’m very happy to read this. It sounds like you hit several milestones.

Freehand grinding sounds much more difficult than it really is. Make yourself a cheap file guide to clamp on the blade and voila- you can run the guide right up to the belt on each side and get matching plunges. That little swoop at the top will still require all of the things you just discovered (squareness, belt tracking, etc).

Gator belts do whine on a glass platen. As the top and bottom corners eventually wear down from the belt running over them that noise will lessen.
 
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