Sanders?

[Hruul]

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

 

[Tom Kitta]

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.

 

[John Conroy]

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

 

[Dabbler]

@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.

 

[Tom Kitta]

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.

 

[Dabbler]

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.

 

[Bofobo]

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

 

[Janger]

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.

 

[Hruul]

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.

 

[Janger]

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.

 

[Tom Kitta]

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

 

[PeterT]

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).

 

[Hruul]

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.

 

[Bofobo]

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

 

[historicalarms]

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.