Sell me bench polishing things

[cheb]

I've an 8" SIP bench grinder with bespoke profiled grinding wheels. I've also a couple of 6" bench grinder with good wheels so the plan is to turn the 8" grinder into a polisher. What bits do I need to do this and what compounds etc do I need. I'll be polishing aluminium, steel and stainless.

 

[jinjahbiscuit]

You need a right hand and a left hand threaded adapter, one for each end of the bench grinder shaft assuming you'll put a mop on both ends.
Go to thepolishingshop.co.uk and you can purchase full kits either "general purpose" for a variety of metals or dedicated kits for a particular type of metal you want to polish. Everything you need in one place!

 

[cheb]

Thanks, I'll look at that later.

 

[brightspark]

some of these the correct bore for your grinder doubtful if you will get them threaded to fit your grinder but there held with grub screws http://www.google.co.uk/shopping/pr...MImu6O8bag4wIVE5zVCh2gIAk8EAQYAiABEgJrZ_D_BwE

 

[frank horton]

dont waste ur time inless ur polishing watch faces.....u'll keep stopping it....and it'll overheat........
just aint enough horse power......
tried over the years to do it on the cheap......got fed up and made this outta scrap.....2x greasable flange bearings...30mm shaft ??.....3hp motor......will run all day.....belt gaurd now made.....moveable but stable....extra ballast if needed....

 

[Wallace]

Noo Noo! Nice build, something I have wanted to do for years but I make do with an old 8” bench grinder, time and a few techniques as I don’t do enough polishing these days.

 

[the black box]

As said above thepolishingshop. Have all you need. On a small polisher you won’t be doing larger stuff but they are good for small/intricate bits keep the mop size down around a 6” mop on an 8” grinder to run up the surface speeds. Let me know what you are polishing and I can tell you what you’ll need

Always have your wits about you always have an emergency stop fitted on any machine no matter the size

I have been a commercial polisher for nearly 10yrs and have had my fair share of accidents luckily no this serious (I’m usually on a 3hp direct drive machine) but I know people who have plate/pins in their arms from a polisher. Oh and always wear a decent dust mask. I didn’t when I first started and ended up with asthma.

I keep meaning to write a guide to polishing for here would there be much interest?

 

[Wallace]

I would be interested, always willing to learn the correct professional way to do a job!

 

[magnet]

That's a cracking set up there Frank good bit of inspiration might fit a guard or two when i build one though ........Cheers

 

[cheb]

As said above thepolishingshop. Have all you need. On a small polisher you won’t be doing larger stuff but they are good for small/intricate bits keep the mop size down around a 6” mop on an 8” grinder to run up the surface speeds. Let me know what you are polishing and I can tell you what you’ll need

Always have your wits about you always have an emergency stop fitted on any machine no matter the size

I have been a commercial polisher for nearly 10yrs and have had my fair share of accidents luckily no this serious (I’m usually on a 3hp direct drive machine) but I know people who have plate/pins in their arms from a polisher. Oh and always wear a decent dust mask. I didn’t when I first started and ended up with asthma.

I keep meaning to write a guide to polishing for here would there be much interest?

I'm not sure, but most likely it'll be getting the worst of the marks off Japanese motorcycle aluminium and old steel tools. A less aggressive version of a wire brush or grinder if that's not too stupid a thing to want.

There's a bewildering range of polishing mops. At worst I've learned they're not called wheels.

 

[jinjahbiscuit]

@the black box, as with wallace, always willing to learn new stuff (or correct bad habits).

 

[cheb]

FH, you're no doubt right but I don't think I'll ever need to polish that much to worry about speed. It's much more likely that my impatience and lack of attention to details will put me off first.

 

[slim_boy_fat]

FH, you're no doubt right but I don't think I'll ever need to polish that much to worry about speed. It's much more likely that my impatience and lack of attention to details will put me off first.

If you're not careful, even a 250W bench grinder can 'grab' a part and inflict sore bits - don't even ask how I came by that nugget!
It's also a messy business again- don't ask.....

 

[cheb]

I've no illusions as to who would win in a fight between me and a machine tool.

I'm thinking of having a non latching foot pedal connected to a NVR switch. I won't have to remember where the on/off switch is as I'm thrown across the workshop whilst being mangled cartoon stylee.

Mess, that's why I built another shed.

 

[the black box]

I'm not sure, but most likely it'll be getting the worst of the marks off Japanese motorcycle aluminium and old steel tools. A less aggressive version of a wire brush or grinder if that's not too stupid a thing to want.

There's a bewildering range of polishing mops. At worst I've learned they're not called wheels.

So your old tools depending on finish desired a standard sisal mop and a bit of menzerna 523lbz would remove most stuff and give a fairly Matt finish. You could also use a satin lap mop if you just want a similar finish to a wire brush but less aggressive no compound needed just a bit of scotch bright in a wheel format

Ali I do tonnes of castings all are varying quality, some come up ace others like above come up ok but have lots of porosity in the casting.

First step is to abrasive up to around 400g I wouldn’t recommend a coarse abrasive (I usually go 240, 400 rarely 180g) as you can easily mishape a part or put waves in it. You need to remove any marks, pitting and to create an even finish something like below this step is the most important in all polishing if after finishing the part doesn’t look nice then you haven’t finished

You can use spindle mounted flap wheels in die grinders, taper bore flap wheels on your bench grinder (not sure on speed you have) or simple wet and dry (I usually wet and dry to flat completely)

Next up

1st stage polish I run a close stich (actually a colour version which is harder but that’s not needed for you) with a bit of menzerna 439t compound this is nice and greasy so no need to use tonnes. Watch your heat here on smaller castings and if you see small black dots stop and go and buff up or part will be scrap. Main aim is an even shine with removing the abrasive marks.

Next

A g quality mop with a bit of menzerna p164 blue just to remove the marks from the close stich.

Next/last

WDR (white double raised) otherwise known as a swansdown compound up to you here I run p175 but that’s a very expensive compound and a bit ott for the majority of work this produces a finish that a micro fibre will scratch! I’d recommend a bit of p126 pink compound. This is that final stage last marks removal here

Afterwards a bit of autoglym paint sealant to protect the finish and job done

Let me know if you need any links etc I use menzerna products as they are economical and give amazing results but if you want animal product free than they have a guide what products to get instead.

If I get 5 I’ll get a proper guide covering different materials, strokes etc maybe even a video!! where’s best to put this just write a standard post up?

if anyone’s in Somerset and wants tuition/help send me a pm and you can visit the workshop.

 

[Country Joe]

Nice guide there, very handy!
Thanks for putting in the time.
But I was still wondering......

Does all that apply to both steel and ali?

As you can tell, I know very little about this but have given it a go before, using various tools - after ruining a couple of bench grinders in the past.

Before I did any more, I decided I was going to get a motor form this guy, down your way - and make something along the lines of some that I’ve seen on here.

Didn’t ever (or yet, anyway) get round to it, though - but this thread might just jerk me into action, though!

With this in mind, I was wondering which of these two motors runs at the right speed? - (i.e. would you use 1400 or 2800rpm?)

https://www.ebay.co.uk/itm/Compress...272950?hash=item419831c5b6:g:CV8AAOxyUrZS86MQ

https://www.ebay.co.uk/itm/Electric...00-rpm-3-HP-/271904454684?hash=item3f4ec4b81c

Also, why is the slower one 4-pole and the quicker one 2-pole?

Can I only use the 2-pole (The quick one) as I’ll only have 2 wires (aside from earth) to use - or is this irrelevant in this respect, and refers to something inside the motor, that wouldn’t concern me, as it’s supposed to be single phase?

It feels as if I’m probably missing something obvious, here!
Bet you wish you'd never posted all that, now!

All the Best,
CJ

 

[the black box]

Nice guide there, very handy!
Thanks for putting in the time.
But I was still wondering......

Does all that apply to both steel and ali?

As you can tell, I know very little about this but have given it a go before, using various tools - after ruining a couple of bench grinders in the past.

Before I did any more, I decided I was going to get a motor form this guy, down your way - and make something along the lines of some that I’ve seen on here.

Didn’t ever (or yet, anyway) get round to it, though - but this thread might just jerk me into action, though!

With this in mind, I was wondering which of these two motors runs at the right speed? - (i.e. would you use 1400 or 2800rpm?)

https://www.ebay.co.uk/itm/Compress...272950?hash=item419831c5b6:g:CV8AAOxyUrZS86MQ

https://www.ebay.co.uk/itm/Electric...00-rpm-3-HP-/271904454684?hash=item3f4ec4b81c

Also, why is the slower one 4-pole and the quicker one 2-pole?

Can I only use the 2-pole (The quick one) as I’ll only have 2 wires (aside from earth) to use - or is this irrelevant in this respect, and refers to something inside the motor, that wouldn’t concern me, as it’s supposed to be single phase?

It feels as if I’m probably missing something obvious, here!
Bet you wish you'd never posted all that, now!

All the Best,
CJ

I can’t comment electronically (as far as I know pole related to windings/field) but I know on speeds. My current beast is a 2800rpm cannings I’ve also used a 1400rpm polisher both are great

The 2800 is better for abrasives I’m mostly doing piece rate work on stainless and Ali i can do as much as a 10hr day on 200 pieces. So speed is very important

The 1400 would be better for intricate stuff and is more user friendly, less likely to snag personally I’d choose this for the home user you’ll be able to do plastics and wood as well.

The above is mostly for Ali, brass, copper you can also use on steel but we can go a bit more aggressive than this I’ll write a better post once I have some time and a few more pictures of each stage.

Polishing is something that isn’t taught anywhere and is a bit of a dying trade so much can be automated and the labour costs are big part and it’s a job no one wants to do!!

 

[the black box]

To add I have a stainless job in to do so will get some pictures along the way of each stage.

 

[Country Joe]

To add I have a stainless job in to do so will get some pictures along the way of each stage.

That's good of you - I realise (unless I was uniquely messy!) that a polishing environment must be one of the last places you'd want to use a camera!

And it looks like the 1400rpm it is, then. I do remember thinking that both the bench grinders were a bit quick (while they lasted!), anyway.

After that point, I occasionally used a kit from thepolishingshop.co.uk for use with a die-grinder, as it had way more oomph than the dead grinders, and has variable speed, but was a bit of a pig to mount safely enough to use on small hand-held items - which had originally been the plan.

I'm pretty sure I saw motors that had a shaft on either side back then, as opposed to just the one-sided units I can see on there now, too - but I am getting on a bit, so might only have imagined this part!

Also, apologies to @cheb for the hi-jack!

All the Best,
CJ

 

[the black box]

No problem I’ll be starting a new guide thread in next few days will take me a while to get it all together