Buying buffing setup

[demonx]

I've got a rough idea of the Mirotone products and assure you I would not be putting anything as course as 600 or 800 anywhere near it (the clear coat).

In your first build coats, I'd suggest laying a sealer first. Mirotone do make one that I've used in the past and if you're keen to stay with that brand I suggest clear sealer (PU5545) (Hardner - 5747) as your first few build coats. Spray at least three in the one session leaving 10 minutes between the first and second (assuming youre not in a temp controlled booth), then 20 minutes between your second and third. Let that sit for a few days and rub it back with 320 or similar if you think it'll need building again. If not then you can hit it with something in the range of 400-600 before you spray your final clear.

Spray two or three coats of clear using the same time frame as suggested above. Let it sit for several days. I usually like to leave things for a week befgore I sand them. As perry suggested, your final clears shouldnt need anything courser than 2000. A friend of mine is a veteran acoustic luthier and uses mirotone. I think he starts at 1500, 2000, 2500 and then 3000. He only hand polishes with 3M finess it and a polishing rag. Nothing electric.

I personally believe that once you're into the clear coat theres no need to go heaps of different grades unless your spray technique needs improving, I start at 2000 wet to level it, then wet rub it (as if buffing) with a 3000 pad, followed by the buffer. There are no swirl marks. No fine scratches and a nice shine.

So my guess is your main problem was the sanding stage, not the buffing.

[demonx]

I should add that I'm no longer using the Mirotone sealer, I've switched to west systems epoxy and I'm using 2k automotive clear, but my advice will work for the Mirotone products, as I have used and experimented with them and my process works with them with good results, I just like the finished look of the products I'm using now better, however they're also much more expensive.

[Phil Mailloux]

I usually just buildup with clear coating, never used sanding sealers or other fillers. At this point I'm starting to consider using something else and just a few coats of clear over it. How's the West System? Epoxy is usually a bitch to sand down, not sure I want to go down this way, until what grade do you sand the epoxy to? does the clear coat product you use melt into the epoxy sanding scratches well?

Then again, I might just try to use the 2000 grade wet as you mention on final coat and sand flat between the coats at something a lot less aggressive than the P400 I was using. Lastly, when you guys talk about the 2000 grit sanding paper, which one do you use, is that the stewmac micro-finishing paper?

[Allen]

Go into any local automotive paint supply store and pick up some P2000 wet and dry paper. Various brands out there and they are pretty much similar in quality. Comes in smaller (about 1/3rd the size) sheets than say P400. It's pretty expensive, but you don't need reams of it.

[demonx]

I usually just buildup with clear coating, never used sanding sealers or other fillers.

This is what I did for years until I decided the sinkback was simply unacceptable if I wanted a professional finish.

How's the West System? Epoxy is usually a bitch to sand down, not sure I want to go down this way, until what grade do you sand the epoxy to?

It's a real pain in the butt, but it's the best method I've trial/errored so far.

Does the clear coat product you use melt into the epoxy sanding scratches well?

The first lot of epoxy I usually knock back with a random orbital and 120 grit - UNLESS - it looks like I wont have to second coat it, the second lot of epoxy I'll sand with 320 then 600. The clear coat fill all those scratches and they'll never be seen.

Then again, I might just try to use the 2000 grade wet as you mention on final coat and sand flat between the coats at something a lot less aggressive than the P400 I was using. Lastly, when you guys talk about the 2000 grit sanding paper, which one do you use, is that the stewmac micro-finishing paper?

As Allen said above, just go to a Automotive paint store and buy a packet of 2000 git there. I only use about one sheet, sometimes two to do a whole guitar. I tear it into halfs (its already half a sheet in the packet) and use them as I need them. So a packet of 3M 2000 (around $50ish) will last you for years. I've never bothered with the Stewmac micromesh and all the other crqap they sell. Your local automotive store will have everything you need. The 3000 grit I use does not come as paper, its a pad to go on a buffer, but I've never used it that way, only by hand. It also came from a Auto paint store.

[Mark G]

Hello there all,

Following everyones advice I sprung for a 3 inch pistol buff yesterday. I paid $180 for it at a tool shop in Smithfield. I did see some cheaper on ebay but was uncertain of their quaility. I've given it a bit of a go on a lapsteel that's just finished. I used some repo doctor compound that I've used for ages but will be sourcing some 3M product ASAP to see the buff really do it's job. I am very impressed so far. I've spent about half an hour and it looks great- no sign of the fine circles and scratch marks I've come to despise. I love the weight of the tool and how in control it feels compared to my drill and lambswool pad. Thanks for the tips. will post some pics when it's properly polished.