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Polishing tutorial


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Ok, there have been a lot of paint and polishing questions asked recently, so I thought I'd do a brief description of the polishing process, first here is a list of what I use for polishing.

Stew mac Polishing compounds #1, 2, 3, and 4 (coarse, medium, fine, extra fine)

Micro cut sandpaper 2000 grit (unless my spray job sucked then I start with 1200, 1500, and then 2000)

Stew mac foam buffing pad and electric drill (soon I will have a nice big buffing wheel in the new shop though) x4 One for each compound

Water

Ivory hand soap

Patience.

Elbow grease.

Ok, This will be assumed that you have a nice clear coated body (see The painting tutorial I did for painting and applying clear)

Difference being from that painting tutorial that I usually put on about 10 coats of clear on a guitar body before final polishing is done.

So, once the paint is good and cured, we go to step one.

Step one: Sanding

First thing you need to do, is sand out all imperfections or built up edges, if you sprayed well and the paint flowed out nice this won't take very long. It generally takes me about 1 and a half hours to sand out a body starting with 2000 grit. You'll want to do this with some water with ivory hand soap mixed in. Yes use Ivory, it is the only soap on the market that is 99% oil free. (you want oil free in case you should sand to deep or discover you need to spray another coat of clear for some reason)

Sanding always in one direction (I always sand lengthways on the body) use a semi hard block and level the entire body. If you have dust spots or really large built up edges use a hard block to knock them down, then go to a semi hard block (I really like the foam block you get with micromesh)

I start with the top of the guitar as this is usually the most difficult to sand because of all the cavities. Unless there is a dust speck or something on the very edge, don't sand the edges, the clear is always the thinnest there and it doesn't take long to cut through an edge. Then do the back, and then the sides, the worst part is in the horns, this is also where the clear always seems to stay the roughest so it takes a bit longer than the rest. When you do the perimiter, I sand with the body all the way around, never across the sides, just always along them.

Sand until the entire guitar (except the edges) is an overall dull flat sheen, if you see shiny spots, keep sanding, these will become awful looking marks once it's all shiny again.

Step 2: Coarse cutting (if you have sprayed with laquer, you can skip this step as laquer is far softer than the Poly's I spray)

Apply the cutting compound all over the top of the guitar with a rag. Mount your drill with the foam pad on it on your work bench (I used to hold the drill and secure the body, but that was stupid, this is so much easier) I run about 1500rpm. Using a good amount of pressure, cut the entire top. The compound will fly everywhere, so use old clothes, a shop coat, and safety glasses, a particle mask is a good idea too. I personally start with the lower half of the top and work through the cavities and stuff. You'll notice alot of shine come back with even the coarse. Keep wiping it clean and applying compound until you can't see the 2000 scratches anymore. BE CAREFUL AROUND EDGES!!!!!!! NEVER let the wheel come into the edge, I always polish so that the rotating wheel is going OFF the edge, there are 2 reasons for this.

1: If you are letting the wheel come into the edge, there is way more pressure and cutting through the paint is far more likely.

2: If it grabs a corner, you run the risk of the body being taken from your hands and zinged across the room (have had a couple close calls but never actually lost a body yet :D )

Oh, during all the cutting stages, you'll want to also wear rubber gloves, this crap will be messy, and the rubber gloves also helps you to hold onto the rather greasy compound.

Now do the back the same way. Then the sides, but be very careful on the sides, you don't want to burn through an edge. Inside the horns is very difficult, you can do these by hand if you want, but the foam pads will reach all the way in, even on the deep scoops of an ibanez body, but watch out for the plastic backer on the pad, it will cut into your clear in a big hurry.

Step three: Medium compound

Basically repeat step two with the Medium, just make sure to use a NEW pad and clean all the coarse compound off before you start with the medium.

The guitar will really start to shine now, keep wiping the body and checking for any deep scratches that are left over and get rid of them. At this point you will also start to notice that if you didn't sand everything flat all the marks are starting to show badly again. You might want to resand at this stage before you get to far into it. At this stage, when you wipe the body clean, use a soft cotten pad, not paper towel as it will put in scratches.

Step four: Fine compound

Same thing again with fine now. I use a little more pressure with the fine though (again use a NEW pad). Now this thing is starting to glow, with the fine compound I also hit all the edges now, but still be careful, just the foam pad alone will cut through an edge if you use to much pressure or leave it there to long.

Again, wipe it all down and look it over, it should look pretty close to factory finish now.

Step five: Extra fine (swirl remover)

This step is basically the same except I use 2000RPM and light pressure, you are now just buffing the body, not cutting, you dont' want to put heat marks or rub marks into the clear at this point. Again use a new pad and just do small area's at a time with the swirl remover, a little bit of this stuff goes a LOOOOOOONNNNNNNGGGGGG way, and it flings all over everything. Once you've gone over the entire guitar with this, wipe it all down once more and check everything, make sure it's perfect, if you have to go back, go back.

Step six: Finishing

Wipe it all down with a flannel cloth, and if you want, put some wax on it, I use meguire's automotive wax and then clean it all down with some Dunlop guitar polish once I'm done waxing (I wax by hand) then when you assemble, be sure to always set the body on flannel cloth. If you scratch it and it's your guitar, it's a piss off, if you scratch it and it's a customer guitar, it's a nightmare!

Hope this has been helpful to everyone, next time I polish out a body I will take pics of the process and add them to this thread.

If you have any questions please feel free to ask B)

Jeremy

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my thanks too. I do hope Brain adds/moves these to a more permanent location on the main site - it's easier to refer to.

:D

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  • 4 months later...

good plan on the polishing. thanks!

reply to

fidgec94 Posted on Nov 19 2003, 08:49 AM

  Anyone know roughly how thick an aerosol will apply a coat of polyurethane? Ive used up two cans and was wondering what sort of thickness ive built up. How does this thickness compare with a coats applied by an airbrush or spray gun? 

i dont think it matters how much PU u put on, just go till your happy with the glossy-ness, and feel/look. 2 cans seems quite a bit, so ill wager theres enough on there to do!!

mike

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  • 1 month later...

is there any alternative to the stewmac polishing compounds? I'm a little tight on income right now and cant afford the stuff along with the shipping. Anything that i could find at a local hardware or auto store?

Help is greatly appreciated!

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Nate,

I've yet to even use a polishing compound...I prefer to do it all by hand. I start with a 600 Grit wetsanding paper, and from there go 800, 1000, 1200, 1500, then 2000. This takes a lot longer, but yields excellent results. I still finish with 3M "Finesse It" machine polish. Check Reranch, they have the proper finishing papers if you don't want to use compounds.

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  • 2 months later...
  • 6 months later...

Hi,

im currently in the final stages of my clear coat. need some advise.

do i sand the clear every time i add a coat? or do i sand it after a several coats, like what i read from stew mac?

also how much sanding is needed? just to make it flat? I sanded through a couple of times.

After the clear coats, i plan to wet sand from 800 to 1500, cant get my hands on the 2000 grade. will it make alot of difference?

also i read that brasso can be used. do they yield the same results? or its better to use a swirl remover?

im after that gloss finish, but dont plan to buff it, lack of eqpt. any other gd alternative?

currently, my plan is to finish the wet sand from 800 - 1500, then use a white cotton cloth (reraunch said red is not needed) to rub it in circular motion. Then i will use Finesse It by 3M.

Any other products i can use other than the Finesse It?

Sorry for the long post.

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If you get a run or dust in the clear, sand that spot down until its gone. But when your done with your last coat of clear, start with 600 wet until 2000, but in your case 1500. Start with 600, and stop once all the paint appears dull and flat. Then sand with 800 until the scratches from the previous grit is gone. And keep doing that. Then when you reach 1500, you can buy 3M Fine Cut Rubbing Compound. You can rub that in with a cotton cloth. When your done with the fine cut rubbing compound, get 3M Finesse It II. Rub that in and your paint will look like glass!

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Question: What is the best way to remove the coarser (prior generation) polishing compound before going to the next-finer grit? Wipe it down with water? Naptha? Dry wipe?

I think my prior finishing jobs, which were ...OK... may have suffered from not completely 100% removing the old compund first (like, maybe only 99%...).

Any thoughts?

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I typically sand down to 2000, then go with fine cut, then swirl remover. My problem has been that most of the finish looks pretty mirror-like, but I can still see isolated scratches. I am thinking that this is because there are still a few bits of 2000-grit floating around during the fine-cut, and then a few fine-cut bits still floating around during the swirl remover.

I've got loads of experience with polishing small minerals, and this is the effect that you get when you don't completely clean off the previous grit. With minerals you can clean them in an ultrasonic bath between grits, but not guitars...

...so what's the best way to get rid of that last 1% of grit that might still be floating around?

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It might be that you missed like an 800 grit, or an 1000 grit scratch. Either that or when your polishing it, if you put it on like a flannel jacket or blanket there might be something a little rough on it, causing scratches. But after your sand with 2000, then polish with fine cut, there shouldnt be any 2000 scratches. Its got to be a scratch or a previous grit you didnt sand out.

What polish do you use?

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It might be that you missed like an 800 grit, or an 1000 grit scratch. Either that or when your polishing it, if you put it on like a flannel jacket or blanket there might be something a little rough on it, causing scratches.

Yeah, could be.

After the 2000 wet, I go with 3M Perfect-It II Fine Cut, then finish with Meguiar's #9 Swirl Remover 2.0.

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If you are using laquers you can get away with sanding with coarser than 2000 and then just using compounds. If you are using 2 part paints, like urethanes, you don't want to start with anything coarser than 2000, if you need more than 2000 sand it with 600 and spray another coat.

Even after only 2000, you will probably still want to use a coarse cutting compound first and go up to the x-fine.

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Ok, that might be my problem. I've been using Minwax fast-dry polyurethane (from rattle cans, on top of sanding sealer knocked flat with 600), and knowing that the application rate from cans is a bit lower than air guns, I tend to apply semi-thick coats (if I wait 15-20 minutes between coats, they melt together well). I always get a bit of orange peel once its fully dry, and so I tend to start with 600 or 1000 grit and go up from there.

Sounds like the thing to do is start with 2000 and just be patient. Thanks Jeremy.

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if I wait 15-20 minutes between coats, they melt together well.

"Melt" isn't really what poly's do.

What you are really doing is spraying tac coats and they shouldn't be too thick.

You have the right time-frame between coats, but you should start with a thin coat, wait, thin coat, wait and thick coat. Let dry for about 36 hours and do it all over again.

With rattle-cans, you should wait until after your second go-around before starting to knock down high spots.

I would suggest starting with 1000 before round 3 and work your way finer between rounds.

5 rounds should do it for a thick application and then you should be near you final destination of 2000.

After that, buffing will be next.

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