# Sanders?



## Janger (Aug 23, 2019)

I have a little 4x36" belt bench sander with the circular disc. It has a little motor - it works fine for what it is. It's slow and I can stall it pretty easily. It would be nice if it was more powerful. It was $40 used I think... Similar to: https://www.kmstools.com/king-canada-4-x-36-belt-6-disc-sander-117779
I want to take mill scale off in a hurry, handle burrs, and shape parts. The usual. I also find trying to sand the inside of corners there is not enough clearance to get in there.

You can get this new combination at Busy bee for $399, 1HP motor (Chinese), 6" x 49" belt and the disc. Similar to what I have but bigger.
https://www.busybeetools.com/products/belt-and-disc-sander-6-x-9-craftex-cx.html

Similar is this from King Canada 1HP for $469
https://www.kmstools.com/king-canada-6-x-48-belt-disc-sander-5767

There is this King Industrial at KMS 3" x 79" belt  2HP 220V 10Amp. $950 A metal working product not wood repurposed. Looks good. not a very wide belt.
https://www.kmstools.com/king-industrial-3-x-79-metal-belt-sander-141967

@CalgaryPT Peter I believe has a kalamazoo maybe similar to this one 20" disc sander. Very fancy. $3K USD
https://www.trick-tools.com/Kalamazoo-20-inch-Disc-Grinder-DS20-10370

Anybody have any thoughts? is variable speed useful? what about the clearance problem into corners? are zirconium belts a problem to source? I've never found the round disc useful and it tends to rattle so I took it off. Why do you want a belt vs a disc?


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## CalgaryPT (Aug 23, 2019)

I do have the Kalamazoo you mention, but also have an Ellis ( http://www.ellissaw.com/ellis-6000-belt-grinder/ ). Both are very useful and have their specific purposes. I use both about the same amount, but I think the disc is better suited for squaring off and for square tubing, which meets my needs for fabrication. For smaller stuff and machining guys, I think the belt is the way to go; more flexible to your needs.

The reason why the rattle occurs on the disc machines I think John is that these machines are designed for wood. The platten has little mass and the pressure from feeding metal deforms it causing the rattle (my 2 cents of engineering theory). The Kalamazoo platten must weigh 40 lbs and takes 30 mins to stop after power is cut. It doesn't rattle. But it is way overkill for small stuff.

Having said this I had a Crappy Tire wood disc sander for years and years and used it only for metal. Still worked like a dream when I sold it. It was cast and the platten was bulky for a wood machine.

I see little value in variable speed. Maybe the knife makers do, but I never have.

Zirconia belts/discs are the way to go if you can afford them. Not hard to source anymore.

You're free to try my machines if you want John.


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## Dabbler (Aug 23, 2019)

I buy my zirc belts off amazon.ca from Red Label  Abrasives.  

Your little sander will be better at material removal (in metal) if you go to a much coarser belt.

I have a 35 yr old busy bee 6 X 48.  It works well.  A disc or belt sander is so simple that a BB is a viable option.  Go for 2X72 if you intend on buying one and want the best for metal working -  more versatile and easy belt availability.

I also have a 1 X 30 with fine grit for polish and sharpening tungsten.


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## historicalarms (Aug 24, 2019)

Like you I have the 4 x 36 belt with a round plate as well but same as you again I very seldom use the plate....however the belt part is probably the most used machine in the shop, everything that comes out of the lathe or mill usually gets a "burr removal" slight touch to the belt.

    again as you I find the 4" belt a bit of a pain on some weird shaped pieces so also have a 1" wide belt machine that the rollers are somewhat smaller dia., allowing tighter inside curve work. 

     for 99% of the 4" belt work I just use the hardware available 400 grit belts but a buddy of mine located some 1100 grit belts somewhere in Calgary and gave me a few that if you want to get real nasty edges on a knife or similar object  there your huckleberry. Even the wore out 400 grit belts will work for tuning HSS cutting bits but damn those 1100 grits are smooth.


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## Tom O (Aug 24, 2019)

Has anybody tried citric acid baths for removing scale?


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## Brian H (Aug 25, 2019)

I had a o at making my own 2 x 72 belt grinder. Works very well and fit well into my budget! I just couldn't justify the cost of the commercial units out there. I like the variety and cost of belts available.
I'm still making various tooling and accessories to go along with it


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## CalgaryPT (Aug 25, 2019)

What a beautifully clean shop. Nice job on the grinder.


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## Brian H (Aug 25, 2019)

CalgaryPT said:


> What a beautifully clean shop. Nice job on the grinder.



Thanks. Keeping it that clean is always a chore, it always seems there are several projects on the go and there inevitably in the way of each other. I usually do a good clean up every month or so (usually takes all weekend too...LOL)


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## CalgaryPT (Aug 25, 2019)

Well you win an award from me. Sorry to say that isn't worth much. But congrats. It's beautiful.


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## Chicken lights (Aug 25, 2019)

Would you guys build or buy a tool rest/table for your sanders? 
If you guys vote for building one....I’ll take volunteers to step up...


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## Janger (Aug 25, 2019)

Tom O said:


> Has anybody tried citric acid baths for removing scale?


I’d like to know more about that...


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## Janger (Aug 25, 2019)

Brian H said:


> I had a o at making my own 2 x 72 belt grinder. Works very well and fit well into my budget! I just couldn't justify the cost of the commercial units out there. I like the variety and cost of belts available.
> I'm still making various tooling and accessories to go along with it



Nice build Brian H. ! Questions...

Are those skate board wheels?
Did you crown any of the wheels?
How do you adjust tracking? Did you have trouble with that?
Is that a 1750 rpm motor? Is the speed ok?
What kind of plate do you have behind the sand to press against? It's hard to see. Steel?
Would you mind posting a few more pictures ?
I really like this sander after going to look a bunch of them at KMS tools:
There is this King Industrial at KMS 3" x 79" belt 2HP 220V 10Amp. $950 A metal working product not wood repurposed. Looks good. not a very wide belt.​https://www.kmstools.com/king-industrial-3-x-79-metal-belt-sander-141967​​Making something could be a good project... hmmm. What are the unexpected difficulties to anticipate?


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## PeterT (Aug 25, 2019)

I don't quite get the KMS. 
- (red arrow) has a round wheel by the work plate making an odd profile... as opposed to most sanders like BtianH's where the belts runs in front of a backing plate & thus makes a natural 90-deg to whatever thickness of work is presented to it. What am I missing here?
- (green arrow) does this open up or somehow swivel around to expose the straight section of belt? I don't see any provisions to mount a platten.


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## CalgaryPT (Aug 25, 2019)

PeterT said:


> I don't quite get the KMS.
> - (red arrow) has a round wheel by the work plate making an odd profile... as opposed to most sanders like BtianH's where the belts runs in front of a backing plate & thus makes a natural 90-deg to whatever thickness of work is presented to it. What am I missing here?
> - (green arrow) does this open up or somehow swivel around to expose the straight section of belt? I don't see any provisions to mount a platten.



My Ellis is the same. The small radius at front is almost insignificant for up to 1/8" stock. The green arrow door does open, and you use it to get 90 degrees as needed or for wider stock. The material rest should fold away (or be removable), giving you access to the bottom radius on the belt—super handy for fabricators that want to develop or smooth a curve on stock such as tubing. It's used a lot by custom motorcycle and car makers, as well as artists/metal sculptors like Kevin Caron.


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## PeterT (Aug 25, 2019)

aha, thanks for the under the hood shots Peter


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## Brian H (Aug 25, 2019)

Janger said:


> Nice build Brian H. ! Questions...
> 
> Are those skate board wheels?
> Did you crown any of the wheels?
> ...



Yes, they are skateboard wheels (amazon purchase)
I crowned the tensioner wheel. I used a hydraulic piston for tensioing the pulley making belt changes quick and easy
Yes it is a 1750 rpm motor with a 6" drive pulley.It is made from a piece of 7" 4140 shaft so there is a bit of weight so it acts like a flywheel.
I have a piece of 1/2" plate for a platten that has been ground flat and smooth.
I will take some close up pictures and download them for you.
I looked at several designs and integrated what I liked from all the different models I looked at


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## Brian H (Aug 26, 2019)

Janger said:


> Nice build Brian H. ! Questions...
> 
> Are those skate board wheels?
> Did you crown any of the wheels?
> ...



Janger,
I did my best to get pictures to answer your questions. Let me know if you want a pic of anything specific


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## Chicken lights (Aug 26, 2019)

Brian H said:


> Janger,
> I did my best to get pictures to answer your questions. Let me know if you want a pic of anything specific


Very nice work!


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## Janger (Aug 27, 2019)

Very Cool project Brian. Inspiring.


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## John Conroy (Aug 28, 2019)

Nice job Brian! My belt sander speed is too slow to remove serious amount of metal as it is designed for wood so I may decide to build one like yous some day. How thick is the frame plate everything is fastened to?




I'm thinking of getting rid of the disc sander part and playing with pulley ratios to get more speed. I dont know how many feet per minute would be safe so some trial and error may be required, or possibly a variable speed motor so it could be used for wood and metal.


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## Janger (Aug 28, 2019)

Good to see what you have John Conroy.

Brian what rpm is that motor and what horse power? Do you want variable speed? Please post a picture of the metal flywheel pulley. Thanks!


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## kevin.decelles (Aug 28, 2019)

Oooooo, I see a project forming. Very cool. I think I have everything but the skateboard wheels


Sent from my iPhone using Tapatalk


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## Janger (Sep 1, 2019)

https://www.kmstools.com/king-industrial-3-x-79-metal-belt-sander-141967 

Thoughts and questions on this style sander.

The drive train is just two 7.25" wheels with rubber tire treads. They have some to buy on amazon for about $50 each with the rubber tread. https://www.amazon.ca/Yibuy-Serrate...Y8VSH9QYN35&psc=1&refRID=SPQ8J99BJY8VSH9QYN35 

On those sanders tension is from a two prong Y shaped axle holder inside the housing with an adjustment screw. It has a quick release so changing belts is simple. Tracking is a simple mechanism on the axle. The black adjust bar in the base lets you tilt the whole thing up/down. John C. pointed out the SFM of the machine is 6900 SFM which is really fast for a metal sander - probably too fast. Both the BB and the King are very similar units - must be the same people making both. 

I like the fold out section on the top to get access to a large sanding surface. I'm imagining using it to rip the mill scale off larger flat bar so it's ready to machine. Flap discs on angle grinders do a quick job but they make such a mess and send grit everywhere in the shop. This flat sanding surface is similar to the Ellis machine @CalgaryPT has. Peter do you use your Ellis to rip off the mill scale or flatten large surfaces? Would a knife maker style 2x72 be as effective for cleaning up scale? What I'd really like is a tool simmilar to a two sider wood planer for metal. I know they have these things for industry but they're super expensive. Shove the metal in and it comes out cleaned up on both sides. 

The tilt feature I'm not so sure about. It seems you would need to tilt it down to use it more knife maker style and then you're hunched over. Tilting it up means the belt is going up instead of down.??


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## Chicken lights (Sep 1, 2019)

Why couldn’t you use an automotive style belt tensioner...to, well, tension the sanding belt? 

Any that I’m used to seeing are spring loaded and require one tool, usually a ratchet, to release the tension so the belt can be changed 

And unless the actual bearing is bad you could steal a used one from a wrecking yard, likely for next to nothing.


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## PeterT (Sep 1, 2019)

Some of the knife belt sanders have accessories to grind down stock with the belt in lay down (horizontal) mode. But I think its kind of designed for blade guys on their typical stock who don't have mills.  The stock retention & overall procedure look a bit iffy to me. There are also hand held belt sanders the autobody guys use but they are expensive, heavy when electric or air gobblers when pneumatic.
https://reederproducts.com/shop?ols...-grinder-c0db55d6-ad2d-44ce-a61f-980d82d3c2b2

https://www.google.com/search?q=pne...0LDkAhXeGTQIHTEkDYwQ_AUIESgB&biw=1920&bih=937

Grinding is a very power consuming & heat generating mode of material removal. The typical flap or disc sander mode for removing scale & crap is messy as you say but OTOH better to keep that stuff outside your shop full of precision machines if you are just prepping stock for milling. The neighbors may not like the noise or the red oxide dust cloud, modern life in the community I suppose.


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## PeterT (Sep 1, 2019)

Here is another (blade application) vid of above that gives some visual context to material removal rate.


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## Tom O (Sep 3, 2019)

I found this interesting.


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## TheLocalDrunk (Sep 3, 2019)

Brian H said:


> I had a o at making my own 2 x 72 belt grinder. Works very well and fit well into my budget! I just couldn't justify the cost of the commercial units out there. I like the variety and cost of belts available.
> I'm still making various tooling and accessories to go along with it


I really like that!
Might have to "borrow" that design.
If you were to make a second one.... what would you change?


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## Janger (Sep 3, 2019)

Very interesting and informative videos! I’m quite interested in the mill scale removal question. Some guy has a demo of using muriatic acid - that’s strong stuff very fast. However somebody in the comments said vinegar works but is slower... well I have pickling vinegar 7%. I threw in some scrap and nuked it for 3 minutes. Two hours later look what happened. 

It’s coming off all right with some wiping. I nuked it again as hot chemicals generally work better and I’ll leave it for a few more hours.


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## Tom O (Sep 3, 2019)

This is the one at protospace using the caster wheels.


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## PeterT (Sep 3, 2019)

The belt grinder performance video is interesting but there are a couple of apples & orange issues in there that could lead you to the wrong conclusion. You can't compare a wood sander to a metal sander regardless of belt width because the intended use materials dictate different SFPM values. Excessive speeds even with very coarse grit can cut inefficiently even to the point of burning wood whereas most ferrous alloys can tolerate & benefit by higher speeds. Its like comparing wood & metal band saws, except now the opposite applies - wood favors higher speeds because the tooth can make an efficient chip & remove it whereas metal has higher much strength & therefore limits to reduced SFPM for best efficiency.

Comparing HP alone is dangerous because its a function of rpm & torque. If you put a 1 HP 30Krpm spindle motor on, it would spin like crazy... until you touched the belt, then it would stall & fall off the efficiency curve. If you put a 1 HP 2Krpm motor on, it would never stall because it has so much torque, but you would never remove  much material no matter how hard you pressed it in because SFPM is too slow.


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## PeterT (Sep 3, 2019)

There are a whole bunch belt sander ideas & projects packaged in this home-made-tools link
https://www.homemadetools.net/category/belt-sanders-and-grinders


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## Brian H (Sep 4, 2019)

TheLocalDrunk said:


> I really like that!
> Might have to "borrow" that design.
> If you were to make a second one.... what would you change?


Actually, this is my second one. The first one I made was very crude an didn't have the ease of tracking and hydraulic cylinder for easy belt changes. I'm very happy with this design. I haven't come across anything I'd do differently


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## Brian H (Sep 4, 2019)

PeterT said:


> The belt grinder performance video is interesting but there are a couple of apples & orange issues in there that could lead you to the wrong conclusion. You can't compare a wood sander to a metal sander regardless of belt width because the intended use materials dictate different SFPM values. Excessive speeds even with very coarse grit can cut inefficiently even to the point of burning wood whereas most ferrous alloys can tolerate & benefit by higher speeds. Its like comparing wood & metal band saws, except now the opposite applies - wood favors higher speeds because the tooth can make an efficient chip & remove it whereas metal has higher much strength & therefore limits to reduced SFPM for best efficiency.
> 
> Comparing HP alone is dangerous because its a function of rpm & torque. If you put a 1 HP 30Krpm spindle motor on, it would spin like crazy... until you touched the belt, then it would stall & fall off the efficiency curve. If you put a 1 HP 2Krpm motor on, it would never stall because it has so much torque, but you would never remove  much material no matter how hard you pressed it in because SFPM is too slow.


I agree. When I do use my sander for knife scales I have to be very careful not to burn the wood. Key seems to be good sharp belts and keeping them clean.
Mine runs approx 3600 sfpm


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## CalgaryPT (Sep 4, 2019)

Janger said:


> https://www.kmstools.com/king-industrial-3-x-79-metal-belt-sander-141967
> 
> Peter do you use your Ellis to rip off the mill scale or flatten large surfaces? Would a knife maker style 2x72 be as effective for cleaning up scale?


I only use it for squaring surfaces. I did know of an artist that used your pickling vinegar trick but used a heated tank with a hose to a spray gun for large sheet products.


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## Janger (Sep 5, 2019)

Janger said:


> Very interesting and informative videos! I’m quite interested in the mill scale removal question. Some guy has a demo of using muriatic acid - that’s strong stuff very fast. However somebody in the comments said vinegar works but is slower... well I have pickling vinegar 7%. I threw in some scrap and nuked it for 3 minutes. Two hours later look what happened.
> 
> It’s coming off all right with some wiping. I nuked it again as hot chemicals generally work better and I’ll leave it for a few more hours.



After 24 hours the bright bits of metal are turning dull. But they clean up easily. On the right is after 30s on the sander. Middle is just steel wool. Left is raw stock with mill scale for comparison. The middle is kind of a uniform grey kind of cast iron looking. I think it would take paint well.


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## John Conroy (Sep 9, 2019)

I added a 1" X 30" belt sander to the same stand as my large one. After replacing the supplied belt with a 240 grit one this is my go to sander for small stuff. Seems to be well built and very smooth with the higher quality belt. I cobbled together a platform for it from some sheet metal, thin angle steel and 1/4" round rod.


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## Janger (Feb 24, 2020)




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## Dabbler (Feb 24, 2020)

so if you *like* mechanical means, this video (a bit salesy)  gives 2 alternatives of the 4:


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## CalgaryPT (Feb 24, 2020)

Dabbler said:


> so if you *like* mechanical means, this video (a bit salesy)  gives 2 alternatives of the 4:


That was a great vid. Super informative. Too bad those brushes can be over 300 dollars.


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## Hruul (Feb 25, 2020)

I like some of the comments from that video.  Especially if you have the time, use vinegar.


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## Tom Kitta (Feb 25, 2020)

I finally fixed my 6 by 48 with 12" combo by scrapping the burned out 1.5hp motor and replacing it with 2hp in the cabinet. I have this https://federatedtool.com/king-kc-7...5tM6Jb3LS-40w5AhNXei9SXBD4Y3UNXcaAmBIEALw_wcB except mine is green and labeled "general". 

1.5hp motor was way too weak and without proper protection it burned out. Even my 2hp feels a bit anemic. I think these things should have 3hp motors. 

On the other hand it works great for sharpening large drill bits - finish is more uniform vs. large grinder. It is also a champ with small burrs etc. For larger stuff grinders still rule as they can remove metal at much faster rate.


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## John Conroy (Feb 25, 2020)

For quick removal of mill scale I have found these stripping discs do a good job.

https://www.ebay.ca/itm/4inch-Black...oval-Fit-For-Angle-Grinder-5Pcs-/383342813603


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## Dabbler (Feb 25, 2020)

@Tom Kitta If you replace it with a 4 pole motor (1725 RPM) you get 3X the torque, which is what you are concerned about.  3000 RPM motors have 1/3 the effective torque under load.  The belt speed is far less critical than is commonly believed.

BTW the KMS version for the same thing has a 3HP motor on it, so you are right.


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## Tom Kitta (Feb 25, 2020)

I use a 2 pole motor but I also use belt to slow it down by half - I have a single belt transmitting power from the engine to a pulley on the shaft where old motor was. 

Main problem in making it faster is the 12" combo wheel which would then go very fast - there is argument against making these combo machines and sticking to just belt - which is what is indeed seen in machines designed just for metal.


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## Dabbler (Feb 25, 2020)

there is significant power loss in using a V belt and pulley... also a power loss.  So the motor has less torque than you need and about 20% power loss through the belt.  I have several 6X48 belt grinders.  The 3./4 one is belt drive and you can tell.  the 1HP one is direct drive and has a lot of power.


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## Bofobo (Feb 27, 2020)

Chicken lights said:


> Why couldn’t you use an automotive style belt tensioner...to, well, tension the sanding belt?
> 
> Any that I’m used to seeing are spring loaded and require one tool, usually a ratchet, to release the tension so the belt can be changed
> 
> And unless the actual bearing is bad you could steal a used one from a wrecking yard, likely for next to nothing.


I would guess that the belt likely would rip under the force of the serpentine belt tensioner, I need to use a breaker bar to remove my gm belt, where as every available belt sander comes with a knob, spring  or low pressure pneumatic ram for that purpose, good idea if you could weaken the spring coil first


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## Janger (Apr 5, 2020)

I've been trying soaking in vinegar again. Sanding it off makes such a mess - fine black grit coating everything. Here are some samples showing before and after. The cleaner parts were in the vinegar for 48 hours and I also rubbed them down after 24 hours with some steel wool. The 1x1 looks worse but it was in there for much less time. Here is the rusty gronk bucket with the vinegar in it.


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## Hruul (Apr 6, 2020)

Hello Janger, Are you using normal vinegar or the 10% cleaning type?  I saw that Home hardware has the cleaning version on sale this week in my area.


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## Janger (Apr 6, 2020)

I'm using pickling vinegar which is 7%. I'd like to try 10%. Hruul if you give it a go I'd like to hear your impressions.


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## Tom Kitta (Apr 6, 2020)

Anyone tried citric acid? Can get it at grocery store or online - powder may be cheaper then even vinegar.


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## PeterT (Apr 6, 2020)

Citric acid recommendation comes up often as the go-to cleaner for silver solder prep.  But these are generally machined parts with pretty good surfaces to begin with. They are looking for clean prep prior to fluxing. 

Mill scale can be all kinds of crud from the rollers, die, lubrication system and be say 1-10 thou deep. And corrosion is different again. I guess I'm suggesting don't expect miracles from mild acids on rough stock. Some people keep a set of tools or inserts to get through this layer before machining the actual part. Probably a surface grinder would be the most effective but I know that's what you're trying to avoid. I've used some ~80 coarse grit 'blue' paper on my palm sander & it actually worked pretty decent. If you have the kind with the dust bag & the discs have those suction holes, might be worth a try. Some people dont like to mix woodworking equipment with metal like this if you get any hot chips in with the wood sawdust (= kindling).


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## Hruul (Apr 6, 2020)

Janger said:


> I'm using pickling vinegar which is 7%. I'd like to try 10%. Hruul if you give it a go I'd like to hear your impressions.


Hello Janger, if I ever get around to doing this I will let you know how it works.  I have never tried to descale with vinegar before.


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## Bofobo (Apr 6, 2020)

I recently tried it for the first time, and when I could wipe away the scale of rust and expose the printed  sizing on the socket I pulled out some rusty tin snips from my scrap bin and they are now fully functional. Washed with soap, water and a soft cloth then oiled and good as new


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## historicalarms (Apr 7, 2020)

I'm certainly going to give this a go when the weather turns here. I have tool boxes of tools that sat out on various heavy construction & farm implements for years and we lived between two natural sour gas plants thru most of those years so the tarnish/rust is thorough. Be nice to bring back some of the old man's tools to the condition they were when he used them...extensively...some probably have skin particles from his knuckles & the back of his hands LOL. He was very aggressive in every thing he did and every wrench was a "knuckle-buster" when he had it in his hands.


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