Softening a glassy polyurethane finish

MatthewK

Member
Messages
152
Hi all - I posted this on another forum and got a very wide mixture of responses to it. Because of that, I'd like to start out by saying that this is NOT A RELIC JOB, neither was it my intention to create an old-looking instrument, and the instrument does NOT LOOK BEAT-UP OR ARTICIFICALLY AGED. I simply like the look of wood and wanted the finish to look more like wood and less like wood encased in plastic.
No doubt many of you guys have tried similar things, just thought I would post my experience in softening the finish on a 97 Sheraton with 0000 steel wool followed by a carnauba wax polish. Make sure you don't use a mechanical sander - it's more work by hand but you avoid those tell-tale squiggly lines in the finish.
I've tried to photograph the difference - the original finish was a thick glassy clear coat:
4247995914_260f7cc1fa_o.jpg

After a plastic scouring pad (BAD idea) and 0000 steel wool (GOOD idea) the finish was dull:
4247227333_dee930c54f_o.jpg

Wax on, wax off:
4247227335_ccf60e6c24_o.jpg

The final finish is much harder to photograph. You'd never mistake it for a vintage instrument but it has a soft patina instead of a hard shine. The scratch marks apparent in these photos are not visible in real life - the camera is focusing more closely than the human eye can:
4247995926_825c39fe41_o.jpg

4247995920_e1a83b8d8c_o.jpg

There are a few actual scratches there, and that's because the guitar is 12 years old and has been played. The end result - just to repeat myself - is anything but a relic job:
4036164093_9aed5be1da_o.jpg

The holes are from the stop tail I removed - will use a plug cutter to make some wooden buttons to fill them - one of these days.
 
Messages
2,528
Looks good to me. To be honest though, I don't believe your camera is focusing any closer than my eyes can. I have pretty good vision up close though + I'm young.
 

MatthewK

Member
Messages
152
If you like it, what does it matter what we think?

Not sure what you're getting at there. I posted this because I would like to have had an idea of how this would work, before I started. I thought it might be useful to others considering similar finish treatments.

And yes, I do like it. And Bradd - if you can focus so that a 2 inch area fills your field of view, you have good eyes indeed. However, I agree, I reckon you could probably see about that much detail if you focused intently on the surface from a few inches away.
 

mnjordan

Member
Messages
1,368
Great job man. I'm seriously considering doing this to my Sheraton. I love the axe, but the thick poly finish is lame.

Would you suggest just the 0000 wool?
 

MatthewK

Member
Messages
152
Thanks for the positive comment! I wet-sanded with 800 grit wet-and-dry paper by hand first - otherwise I would have gone through a ton of steel wool. The nylon scouring pad was a really bad idea, it must have grit embedded in it because it put some nasty scratches into the finish - hence the sand paper.
I'd also recommend removing all the hardware, if you can stand it - makes an even finish much easier to achieve. I combined it with a re-wiring job and changing the tailpiece. At the very least you need to tape up the pickups so they don't fill with steel wool fragments.
 

MatthewK

Member
Messages
152
By the way, the "wax" picture above is just the wax wiped onto the dulled surface, before any polishing.
 

Ahess86

Member
Messages
330
Looks good to me. I wonder what it will look like after your forearm rests on the the guitar for a couple of hours.
 

MatthewK

Member
Messages
152
I did this a couple of months ago, it looks the same now. The finish is fully polished, it's just that the surface is no longer mirror flat, so it avoids the glassiness.
 

johnh

Member
Messages
5,140
I know that photos are tricky things, but do you have a before and after phot of the whole guitar from the front?
 

Nick Sorenson

Rocketfire Guitars
Silver Supporting Member
Messages
1,098
I'd bet that finish is pretty thick. I'd doubt that you could take enough off with the scour pad and steel wool (in a reasonable amount of time that most people would be patient enough to spend in this process) to get through the finish.

But it looks good. I like it better.

I don't know Epiphone's (maybe Samick??? not sure) process for finishing. But my guess is a clear sealer (usually very thick on the import guitars I've seen), color (dyed poly), and then clear.

I agree with the person who mentioned 800 grit. That won't put super deep scratches in but it will put some in of course since it's sandpaper. That's a good starting place for sanding a clear coat. You could start at 400 or 600 if you're careful. If you wanted you could still remove the scratches I'm sure without worrying about cutting through to color. How careful you'd have to be just depends how thick the clear coat was and what is left. My guess is you could go 800 until it looks uniform, 1000, 1200, then buff by hand using a medium buffing compound for a car such as Meguires. Most of the sandpaper in 400-2000 or even 15000 grit ranges will be wet sand paper. This prevents clogging. But it will also get your guitar wet if you're not careful.

I think it looks 100% better than it did! I share your sentiment on those finishes. Very nice.
 

Keyser Soze

Member
Messages
1,472
Mirka makes a product called Mirlon.

http://www.mirka-usa.com/mirlon.html

They are abrasive pads but they are quite different from the usual stuff you'll find at Home Depot (these can be found at places like Woodcraft.) The pads are thinner, much more flexible, and softer (they will actually pull apart like floss.) But the grit is much sharper and, unlike the cheaper stuff, these will get the job done without leaving a visible scratch pattern.

There is a three pack available that contains 360 grit, 1500 grit and 2500 grit. The 360 grit is super aggressive so save it for something else (maybe stripping the back of a neck.) Start with the 1500 grit followed by the 2500 grit and it will do a great job of knocking a gloss back to satin suitable for waxing or polishing.

Like the product description says, this stuff may be fine, but it cuts aggressive so light even pressure is your friend. Even though it is a pad I still use a foam backer block.
 

dspellman

Member
Messages
8,304
If you like it, that's what counts.

I'd personally never bother; my guitars develop real patina.
You want to be careful doing this with new guitars; some of them are UV-cured polyester and are actually pretty thin (thinner than nitro), but due to their self-leveling properties, attain a gloss look more easily than even thicker coats of some other materials. You may find your self "patina-ing" right through to bare wood if you're not careful.
 

MatthewK

Member
Messages
152
Good point, in fact the binding had a kind of yellowish tint over it which disappeared pretty quickly if I even touched it with the steel wool. The finish on the wood was (and is) pretty thick, although I watched it like a hawk to see if it was lightening up anywhere prior to breaking through.
In general I prefer my instruments to have real patina as well, I only had the steel wool to smooth the back of a neck which used to catch my hand. In this case I felt like the finish ruined the feel of an otherwise superbly made instrument. I wish I could say it sounded more "alive" or whatever, but I changed the tailpiece at the same time, so that had far more affect on the acoustic tone than any coating.
And yes it's a Samick made instrument, from 1997. I will try to get a more realistic shot of the new finish; it still has a substantial shine to it, just less glassy.
 

Funkwire

Senior Member
Messages
728
Hey Matthew--I chimed in on your thread in the 'other' forum. :)

I did a similar technique to my Xaviere. Here's a before pic:

100_0153-1.jpg


And an after:

100_0815.jpg


I changed the tuners, pickups, switch, and caps at the same time, so I just stripped everything off the guitar. I'm really happy with the result. Like you, my intent wasn't to make it look reliced or aged. I think it looks better without that glassy poly finish.

By the way, that Sheraton is gorgeous. Does the Frequensator tailpiece make a difference in the sound?
 

tjmicsak

Member
Messages
5,764
These both are great as far as my tastes go. I think too much shine looks like cheesy poly plastic anyway and the flat look is amazing!
 

MatthewK

Member
Messages
152
Hey Matthew--I chimed in on your thread in the 'other' forum. :)
I did a similar technique to my Xaviere.
That's kind of full circle, then, because seeing your job made me think seriously about fixing the finish on mine! Thank you for that.
By the way, that Sheraton is gorgeous. Does the Frequensator tailpiece make a difference in the sound?
Thanks again, I think I have got it right now. I will freely admit the tailpiece was for cosmetic reasons, but it has changed the sound as well, since every string now resonates behind the bridge. Acoustically it's about 50% louder, and amplified there is a "thickening" of the tone like a tiny smidgin of 12 string fullness - of course the strings behind the bridge are not in tune, but they do add a kind of "presence" to the notes. I have a Fender Jaguar which does the same thing, but the Frequensator is much louder, probably because this is semi-hollow.
When I give it some hefty overdriven gain the difference is very noticeable - chords and notes sound pretty normal, but the way it breaks up is very different, sounds kind of chaotic which I like. If I mute using my left hand and just attack the strings it gives me this crazy sounding bark which is pretty cool. So - slightly fuller tone when playing clean, much more chaos and noise when driven hard. Pickups are stock but may not be for longer.
Oh - and I expected it to be a bit looser in the strings, but it's not.
 



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