Author Topic: Polishing stuff?  (Read 743 times)

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Offline CopperCone

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Polishing stuff?
« on: July 13, 2018, 06:25:12 am »
So if you look at tables for commonly sold products intended for polishing cars or wood, you get something like this

http://i.imgur.com/tYhgNX3.jpg

How many steps do you think is reasonable on such a scale?

For instance with metal lapping you would probably use only 2 or 3 grades of abrasive, but its typically hard diamond/carbide.

Does it even make sense for something soft like paint? I figure like 2 steps ? 3 if your crazy?


For instance with a surface grind finish I see people start to lap with something like 20 micron then go down to 3 micorn.
« Last Edit: July 13, 2018, 06:29:05 am by CopperCone »
 

Offline metrologist

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Re: Polishing stuff?
« Reply #1 on: July 13, 2018, 06:46:10 am »
oxtoolco has some recent videos on lapping - optical flat grade lapping. Of course, it sometimes comes up in casual ways, but he has a few dedicated vids.

I talked to an undertaker about polishing coffins...

Me: How do you know when it's done?
Undertaker: I don't know, I just keep polishing until they take it away.

(that was actually used as a response to middle management...)

Oh, that was fun...

Management said to a writer about his too lengthy manual - Can't you just take out some of the words?
Writer: Scoff, nobody ever told Mozart to take out some notes!
Management: Actually, yes. The Emperor Joseph II said about The Marriage of Figaro - "...too many notes, Mozart"
« Last Edit: July 13, 2018, 06:51:34 am by metrologist »
 

Online sokoloff

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Re: Polishing stuff?
« Reply #2 on: July 13, 2018, 07:04:47 am »
It's all a matter of how much of a hobby you want to make it.
When I was really into detailing one of my cars, I used the 3M line and would typically clay, then 9, 5 [3000], 3, 2 [3000], and 0 with a random orbital and a bunch of pads/mitts.

Now with kids, a family, a bigger job, and other things to spend my time on, I try to drive through rainstorms every now and again.
 
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Offline CopperCone

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Re: Polishing stuff?
« Reply #3 on: July 13, 2018, 07:54:34 am »
Hmm that is more then I thought, I figured you would have a big product line because you want to be able to start with the minimum paint removal incase the paint layer is thin.

You actually saw a benefit going through so many steps? I understand that the final layer must be the correct grit/mesh size, but I am suprized something like plastic needs so many sub steps. I am not even confident I need to do all that different sand paper work when I work on wood. I guess I need to try it. Just happened to buy em all so I use em all because they were cheap.

Also, did you keep dedicated pads for different polishes? Or just give em a good wash?

I actually use a clay bar if I am quickly doing wood work out doors with polyurathane. It still picks stuff up after you use a tarry cloth carefully between sending. I would typically do up to like 220 or 320 for wood, give it another coat, then go wet sending 400, 800, 1000, 1500/2000... with claybar in between.

I want to expore the world of polish though. Ceramic coatings are very interesting too. I kind of wonder how it would adhere to bare metal without all the paint under neath. I figure since its fairly hard the paint might deflect under it and cause it to chip. I don't really care so much about asthetics as rust.. it would be nice to have metal that you can touch without oil getting everywhere.
« Last Edit: July 13, 2018, 08:04:56 am by CopperCone »
 

Offline CopperCone

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Re: Polishing stuff?
« Reply #4 on: July 13, 2018, 08:03:12 am »
Also do you know what kind of grit sizes those coatings have in them if you compare it to using wet sand paper?
 

Offline thm_w

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Re: Polishing stuff?
« Reply #5 on: July 13, 2018, 08:07:27 am »
oxtoolco has some recent videos on lapping - optical flat grade lapping. Of course, it sometimes comes up in casual ways, but he has a few dedicated vids.

Timecode 24:45
https://youtu.be/_EypdnIydCg?t=1489

Also
 

Offline eKretz

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Re: Polishing stuff?
« Reply #6 on: July 13, 2018, 08:49:10 am »
You need separate pads for each grit.  If you try to just wash the pads, they will never come fully clean and the coarser grit particles that are stuck in the pad will ruin your finer finish.
 

Offline CopperCone

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Re: Polishing stuff?
« Reply #7 on: July 13, 2018, 11:56:13 am »
Will a washing machine do it?
 

Offline eKretz

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Re: Polishing stuff?
« Reply #8 on: July 14, 2018, 02:34:35 pm »
No. The abrasives are sharp edged and tiny. They embed in the cloth and will not come out no matter what you do. If you really don't care about getting optical clarity super high polish it might not matter to you,  but I would never use multiple grits on one pad. Normally you bring up a polish on something like a car's finish with wet sanding first, then use 2 or 3 polishing pastes, so you don't really need that many pads. I keep mine in separate zip-lock bags so they don't get cross-contaminated.
« Last Edit: July 14, 2018, 02:37:08 pm by eKretz »
 

Offline CopperCone

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Re: Polishing stuff?
« Reply #9 on: July 15, 2018, 02:48:57 am »
My main beef with this is the storage space requirement. To have all the little different disks in the different sizes I want to use all the different polishing compounds would take up quite a bit of space. Keeping my dremel bits stored (and I don't even have most of them) requires like 2 big plastic organizers.

I already have like three tool box drawers filled with different grinding wheels, sanding disks, cutting wheels, brushing wheels, manual brushes.. a bunch of 6 inch disks would take up another tool box if I add all the different buffing wheel, rogues, polishes, waxes, compounds, applicators, tarry cloths, etc.

To be efficient it seems like you would need 2 giant wall closets and a dedicated table with disposable liners for a decent 'surface finish station'

Then double that for a painting station.

I did some aluminum table now, i have to decontaminate the entire area after every step too..

I want a a wet clean room floor so it self cleans and I can just hose it down

Do you need to keep those applicators and stuff in a humidity controlled enviroment? Like microfibers and stuff.. at least theoretically? And how can you tell when to replace them?

Also do the compounds chemically break down the polishing wheels and stuff? Can you store em dirty?
« Last Edit: July 15, 2018, 02:58:59 am by CopperCone »
 

Offline eKretz

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Re: Polishing stuff?
« Reply #10 on: July 17, 2018, 05:53:08 am »
Are you doing automotive finishing or Dremel polishing of tiny stuff? I'm a little confused.  Anyway,  for automotive polishing needs,  I have a vari-speed buffer in its own tool bag in a cabinet.  The pads used for it are dedicated for just that purpose and kept separately in ziplock bags - one for each pad. I think there are 3 or 4, and they fit in the bag with the buffer. I use the pad and then put it back in the bag. There are also several different types of pad - there's foam, microfiber and fluffy, in order of aggressiveness.  I usually just use the fluffy pads and rake them good before and after use,  they can be used until they fall apart, probably for years if you aren't using them every day.

As far as all the different pads and compounds,  yes they can take up quite a bit of space. Not much can be done about that. You won't get quality work if you don't take the time to do it right.
 

Offline T3sl4co1l

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Re: Polishing stuff?
« Reply #11 on: July 17, 2018, 12:02:10 pm »
Steps?  About a factor of 2-3 in grit size per step.  So, say, 100 grit, then 220, 600, 2000, etc.

A larger factor means slower material removal.  If you go right from 150 to 600 grit, you'll spend a lot longer grinding on an almost-completely-smooth surface to get rid of the few remaining scratches from the 150.  And if you don't remove those scratches before going to the next step, they're not going away, they're going to be there forever.  Because the removal rate at 2000 grit is even slower still.

You could do finer steps, like 100, 150, 220, 330..., but now you're spending not all that much time grinding, and a lot more time inbetween, cleaning the surfaces, and you need to stock all these grits, and use them in the right order...

Tim
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Offline CopperCone

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Re: Polishing stuff?
« Reply #12 on: July 29, 2018, 04:41:54 am »
I was wondering where the barrier between being practical and neurotic is.

I made a aluminum table stand out of dirty ass aluminum and cleaned using 220 (oscillator), 400, 800, 1000, 2000 (buzzer) and maquires ultimate compound (rotary polisher, milwakee), then aluminum polishing compound. the finish is kind of hazy but its mirror like, I can see the pavers reflect off of it in the sun with high fidelity, then coated it with car wax. It's not super great but for outdoors use where water tends to accumulate and splash stuff on it, it is acceptable.

I am watching truck restoration videos on youtube and they get much better results. I do kind of like the finish at 2000 grit with the buzzer, it is not reflective but very interesting looking.

For clear plastic maquires ultimate compound polishes it up, but it looks like I need another step.

I think I just need a finer compound or something.
« Last Edit: July 29, 2018, 05:01:53 am by CopperCone »
 

Online sokoloff

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Re: Polishing stuff?
« Reply #13 on: July 29, 2018, 04:47:25 am »
For clear plastic, you can’t skip 1000 straight to 2000. Need at least a 1600 step in between. You also want to do it wet and flush the debris away. The higher grit numbers are fast to do in general.

I do headlights with 600, 800, 1200, 1600, 2000, and 2500. Then finish with a UV blocking clear coat.
 

Offline CopperCone

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Re: Polishing stuff?
« Reply #14 on: July 29, 2018, 05:02:56 am »
for headlights I used the kit a few years back, they got hazy again.. but I found that just using maquires with the rotary polisher made them look great, it does need some kind of UV coat though, but since it takes about 2 minutes to clean it up, i don't know if I will bother. battery tools are great.

I would like to clean up my PCB etch tank too, which is made of clear whatever welds with acetone, but it looks like it would require some kind of special tool since its narrow inside.

Before I had alot of decent tools I restored a scratched up VOM face to very good finish by just using sand paper, tooth paste and finally doing a vapor polish. It did distort a tiny bit though, probably a consequence of vapor polishing stuff that was rough... but it would be more then acceptable to vapor polish the sides of my etchant tank. Looks great when its wet.
« Last Edit: July 29, 2018, 05:06:16 am by CopperCone »
 

Offline CopperCone

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Re: Polishing stuff?
« Reply #15 on: July 29, 2018, 05:07:52 am »
ain't polishing relaxing? im so happy you can get garbage looking decent again

head lights are kind of shit though. I wish cars came with glass you can put over em to extend their life.
« Last Edit: July 29, 2018, 05:10:12 am by CopperCone »
 

Offline LeonR

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Re: Polishing stuff?
« Reply #16 on: July 29, 2018, 01:47:15 pm »
You can "polish" those too, using toothpaste. There are some videos at youtube on that.
 

Offline CatalinaWOW

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Re: Polishing stuff?
« Reply #17 on: August 14, 2018, 05:45:23 am »
I believe that these multi-level sequences are intended to be the fastest way to get to the final finish.  At each step you need to remove material to level with the deepest scratches from the prior step.   You can get there with very fine grits, but it takes a long time.

That said, it is more of a rough guess because it depends on the details of the material and the technique of the person doing the sanding.  Feel free to experiment.  But when you do, note both the final finish and the time it took to get there.  If you get done quickly you will probably find artifacts from deeper gouges and scratches.  If you don't have these artifacts you are likely to note that your arms are very tired and it took a long time to do the job.
 


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