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Consistency in the finish grind. Photo heavy.


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Ok ill be mindful in the future and try to get it a bit thinner -- and wont post HT grind with anything coarsererer than an 80 and see if that speeds me up a bit. (my last 2 blades i even attempted a palm sander with an 80 grit to get out scratches .... to achieve mild success... i think... the pads fill up way too fast even with lube

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Haha, I actually sold a rifle to buy my grinder, so I totally feel your pain   So, I checked out around to see if I could find out where I had read that A45 belts were equivalent to 400 grit. A few

I love the Trizact Gator belts. I usually go to hand sanding at 220 right off the A45, and if I did my grinding properly it doesn't take long to get to 400 or 600.

In the quest for less hand finishing and more consistent finish grinds. Based on a conversation on another forum. I decided to do a study of grinds with the same weight belt with the same dimensions.

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OK, this whole difference in grit size standards thing blew the top of my head. I can't believe I didn't know this before now.

 

As it turns out, I needed to get into this topic today for polishing some fiber optic ends at work. I managed to find this chart which is the most complete cross reference I have seen yet between CAMI FEPA, A-grits and Micron sizes:

 

http://www.seabean.com/polish/GritScales.htm

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OK, this whole difference in grit size standards thing blew the top of my head. I can't believe I didn't know this before now.

 

As it turns out, I needed to get into this topic today for polishing some fiber optic ends at work. I managed to find this chart which is the most complete cross reference I have seen yet between CAMI FEPA, A-grits and Micron sizes:

 

http://www.seabean.com/polish/GritScales.htm

 

Now that is a comprehensive chart. Thanks Brian!!

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OK, this whole difference in grit size standards thing blew the top of my head. I can't believe I didn't know this before now.

 

As it turns out, I needed to get into this topic today for polishing some fiber optic ends at work. I managed to find this chart which is the most complete cross reference I have seen yet between CAMI FEPA, A-grits and Micron sizes:

 

http://www.seabean.com/polish/GritScales.htm

Ok, so how do we read this in comparrison to something like the Trizac gator

?

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Ok, so how do we read this in comparrison to something like the Trizac gator

?

 

There is the finishing scale column that has the A measurements in it, and since the Trizact belts are done in that measurement, I would assume a direct correlation. I am sure that it doesn't take into account the belt backing and the structure of the grit...

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Matt Parkinson put me onto these wheels, Bader sells a hub and cloth contact wheels which give you a soft back for your belt grinder that will blend and polish wonderfully. Combined with my 3hp VFD setup, I can put it at barely a crawl and still not stall it out too. This is a #70 density fabric wheel, and cloth backed grinding belts hug it perfectly.

 

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So what will it do to a flat?

Pretty much just hugs it like using a soft leather back behind hand sanding. I've not had it long enough to play with it much yet, but using it vertically it helped blend away any little waves in my flats so that they were un-noticeable when holding it in bright light.

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  • 4 months later...

Wow - excellent stuff and thanks to all, especially JJ.

 

I am a big fan of Rhynowet. I jump to hand sanding after 400 grit j-flex, and go to 220 grit. I have compared 220 and 400 Rhynowet with 3M, and it is AMAZING how much time I saved with Rhynowet.

 

I just use diluted Windex to lubricate it, and I don't always even bother.

 

I have some Trizacs and I used to use them when I was making things with ricassos. Btw- all my ricassos tapered, and Ed Caffrey has a vid where he discusses the fact that he things they should taper in two directions just like blades. I don't know how his ideas have or have not filtered into ABS judging, though.

 

I am always interested in ways to keep very long, flat surfaces, well... flat. I do a lot of drawfiling of tempered steel on swords for this reason. Yes, I use special files for this (new-old-stock Nicholsons have proven the best, from back when they had more than 100 pts of carbon).

 

But... if a softer contact wheel would help to blend then it may be worth looking into. The problem is that almost every sword design I make has a ridge somewhere on the blade, so a wheel for blending is a bad idea.

 

Here is a helpful tip (for me it works, anyway) - one of the best ways I have found to get different softnesses of sanding blocks is to simply wrap more paper around the block. One sheet, with nothing but brass, steel, or hard wood acts one way, wrap it up to several times and each wrap changes how it acts. I use this especially for smoothing and polishing the edge on swords. It can imitate the shape given by Waterstones if you use a bit of a rolling motion while you sand.

 

For me, on swords (which get a TON of TLC), 220 grit is still doing some of the fine shaping, and follows SMOOTH CUT 10" files (Grobet Mill files so they are single cut). 10" has slightly larger distance between teeth, and it pins less than the 6" do. Pinning is evidence of Satan!

 

For the ridge of a sword, I just use one sheet on brass or steel backing, and make certain it is pulled tight. I usually refine the ridge with a 10" smooth cut file before the 220 grit paper.

 

Anyway, since there is so much great info here, I thought I would put some of my techniques specific to making truly convex sword bevels, and polishing them once they are made. I hope that is ok.

 

JJ, you have a lot of great ideas, and I love your attitude. Give it hell, my friend.

 

I wish I could freakin' draw (I know that you are thinking, "it's easy." I think the same thing about multivariate statistics... everyone has a knack for something). Mine is NOT drawing.

 

Great information, and great spirit of collaboration.

 

take care all...

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Thanks Kevin.
What I saw at ashokan from Greg Cimms was that all of his blades were machine finished prior to hand finishing on a rotary platen.
So they were all slightly but nicely convex.
He didn't loose ridgelines though they may be a little softer they are actually more historically acurate I think.
A rotary platen is $500 but for smoothing those long runs on a sword or making really clean kitchen ware I think its a great tool to look into.

It will also make sanding easier because as you point out, you can go to a soft backer.
My backers go from steel to corean to leather backed wood and even to foam.
I don't use the foam much but the leather backed wood is the finish backer and I use it on every grit.

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  • 2 months later...

Wes if you can get the full assortment from A300 to the A30 and see what they do.

I just did another blade and it is great.

34 minutes to do one side at 800 on a 9" blade.

never stop learning, I've had million miler truck drivers tell me the day they think they know it all they will hang up the keys....

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