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I don't really understand buffing
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=21732		 Page 1 of 1
Author:  David R White [ Tue Mar 31, 2009 8:20 pm ]
Post subject:  I don't really understand buffing
...there I've said it and I feel better already.

I know the pros use a proper buffing set up. I know some non-pros like myself use other things, a drill press or hand held drill, a ROS with pads, an automotive type random orbit polisher.

My current approach is to use the surbuf pads on a ROS with menzerna compounds. This after an epoxy pore fill and eithe shellac or KTM9. My finishes are not bad, definitely glossy but they could be improved. They suffer from occasional dead spots (I assume sanding through), levelling imperfections, swirl marks (if you really scrutinise it) and perhaps they don't have the "depth" that a great finish has.

I know at one level buffing is really just like sanding, you work your way up in grits removing coarser scratches to get a flatter shinier surface - but I think I'm missing something, what is it? What would be the benefit of running a proper buffing set up? Can great results be achieved without a buffer if you have the skills and patience?
Author:  Rod True [ Tue Mar 31, 2009 8:39 pm ]
Post subject:  Re: I don't really understand buffing
A little bit of heat is produced by power buff (this is my understanding anyway) and it sort of allows the finish to flow out better thus just producing a more brilliant shine.

I could certainly be talking out my arse of course, but this is my understanding. Maybe it has to do with more pressure or a larger surface area or speed or.

OK, I'll join you David. I don't really understand it either :)
Author:  Fred Tellier [ Tue Mar 31, 2009 9:03 pm ]
Post subject:  Re: I don't really understand buffing
I don't understand it either but it sure works. Like David I hand polished my 1st 3 guitars and got a quite good finish I but it was so much work. I bought some buffing wheels from Caswell, a cheap arbor at Woodcraft and menzerna fine and extra fine compound and buffed my 4th build the other night and it sure is easy. I had it already wet sanded with, 600, 1200 and 2400 then buffed with fine then extra fine. From 2400 sanding to a polished guitar it was only about 1 hour, but it will be even faster the next time as I was learning as a buffed. I sure was nervous as I could imagine all kinds of bad things that could happen, but it is quite easy.

Fred
Author:  David R White [ Tue Mar 31, 2009 9:16 pm ]
Post subject:  Re: I don't really understand buffing
Okay Fred, so it was less work and it was faster. What about the quality of the finished product? Is it somehow magically better, and if so what about it?
Author:  DannyV [ Tue Mar 31, 2009 9:22 pm ]
Post subject:  Re: I don't really understand buffing
Fred said it. It fast and easy. The youtube link you posted at Lerivee was great. You can get yourself set up pretty inexpensively also.

Danny
Author:  Kent Chasson [ Wed Apr 01, 2009 12:32 am ]
Post subject:  Re: I don't really understand buffing
David R White wrote:
I know at one level buffing is really just like sanding, you work your way up in grits removing coarser scratches to get a flatter shinier surface - but I think I'm missing something, what is it? What would be the benefit of running a proper buffing set up? Can great results be achieved without a buffer if you have the skills and patience?


That's it right there. You can get the same results using micro-mesh and taking it up to 12000 but it will take you longer.

Like anything, there's a learning curve and the right wheel at the right speed with the right compound is essential. I assume there's plenty in the archives about details.

It's also a great way to give a finished guitar a quick death ..... catch an edge and it can rip it out of your hands and smash it on the floor, especially a neck. Ever see a "demo" body cut in half to show you the bracing? I bet 90% of those were fine before the buffer.

The only thing I hate worse than buffers are the alternatives.
Author:  Kevin Gallagher [ Wed Apr 01, 2009 4:43 am ]
Post subject:  Re: I don't really understand buffing
Heat is the enemy when it comes to buffing, That's precisely why it's of paramount importance
to keep the surface being buffed moving to avoid heat building up. The finish should not be sanded
level or buffed until it is dry and cured.

What happens when heat is generated by buffing is the finish expands with the temperature
increase. Then, when it cools, it shrinks or contracts and that beautiful flat glossy surface can show
some texture again.

With lacquer, if you heat it under the buffing wheel to a temperature that allows it to flow at
all, the finish will likely be picked up and can peel off like skin in the warm areas.

Speed of the buffing wheel is an important thing to pay attention to. You should be able to sink
your hand into the edge of your spinning buff and get an idea of what kind of heat is generated
under different pressures. I used to run my wheels much faster than I now do. I have a friend who
is a buffer at Tiffany & Co. He's polished and buffed trophies for Superbowls, PGA tournaments
and the U.S. Open among others and really knows his wheels, compounds and techniques.

He was in my shop one day years ago and hit the switch on my buffing rig, let get up to full
speed and just sank his hand deep into the fabric of the wheel on one side. He immediately
said, "Turn that to about half that speed and you'll be a happy guy when you buff a finish." It's
also important to change the direction in which the buff's rotation contacts the surface often.
Every time I charge the wheel with compound, I work perpendicular to the last pass over a
surface. I always finish up with a small random orbital buffer and a very fin liquid compound.

The surface must remain as cool as possible throughout the entire process.

...and Kent hit a very important point above too. Always work with the buffing wheel pulling
from the center of your surface toward and/or off an edge. Never try to buff an edge with the
wheel turning into it. The guitar will seem to disappear and all you'll hear is crash and smash.

Then you'll have one of those cool demo body halves that people can look at to see the
bracing inside and the nice clean work that you do in there.


Regards,
Kevin Gallagher/Omega Guitars
Author:  Arnt Rian [ Wed Apr 01, 2009 6:21 am ]
Post subject:  Re: I don't really understand buffing
Quote:
Kevin Gallagher Always work with the buffing wheel pulling
from the center of your surface toward and/or off an edge. Never try to buff an edge with the
wheel turning into it. The guitar will seem to disappear and all you'll hear is crash and smash.


I've never had that happen, but I've been close on a couple of occasions. It is quite sobering, to say the least. What I do as a small measure of insurance is to put a thick padded carpet mattress thingy on the floor under the buffer. Hopefully it can cushion the impact should ‘things happen’. My buffer is powered by a smallish motor that will stall if I really lean my work into the buffing wheels, it also helps to avoid overheating.

Image
Author:  joe white [ Wed Apr 01, 2009 10:27 am ]
Post subject:  Re: I don't really understand buffing
Nothing much to add except Arnt, you need some goggles and a respirator. Those wheels are shedding cloth and compound in micro sized particles and in the eyes and lungs they go! eek

As for the heat, that is a real killer and one thing that helps is to limit the amount of buffing wheel area. Depending on the number of plys, I only run one to two wheels on any given shaft to create about one inch of buffing surface. More wheels do buff faster but increase heat as well and that leads to raising/exposing grain. Some actually like this look but I want a glassy even finish.
Author:  David R White [ Wed Apr 01, 2009 12:02 pm ]
Post subject:  Re: I don't really understand buffing
Well I'm surprised. From what you're all saying the advantage to a real buffing system is speed. One could really achieve similar results with sanders, drills or buy hand, but it would be more work. It sounds like the improvements I'm after need to come by developing more skills with application and levelling.
Author:  Kevin Gallagher [ Wed Apr 01, 2009 12:48 pm ]
Post subject:  Re: I don't really understand buffing
Dave,
Speed and time are, of coarse, two very important benefits of using a buffing system that
incorporates a shaft and wheels. The simple fact that the two wheels can be charged with
different compounds of progressively finer grits saves time as well.

The fact that the wheels keep the buffing surface moving over the surface at a consistent
rate and in a consistent direction creates an easily controlled environment for working the
finish to a gloss without breaking through the topcoats into the sealer or through everything
down to the wood creating dull or bare spots.

I keep the contact area between the wheel and the surface being worked to a minimum by
running only a single buff on either end of the shaft. With the surface of a guitar having lots
of curves and variations in their flatness, a random orbital sander equipped with a pad and
buff, can cause pressure to be unexpectedly or unintentionally in one area more than another
causing the finish to be much thinner there or to be buffed through.

One rule that I always observe is that i never do final buffing while anyone else is even in
my shop. First, the extremely fine particulates that seem to fill the air are not the best thing
for anyone....including the buffer operator....to breathe in. Second, conversation is one of the
least suspected distractions that can cause a lapse in judgement and result in damage to the
guitar being buffed. A split second of lost concentration and things can go dangerously
wrong.

Trying to achieve what is possible in minutes with a powered buffer with shaft and wheels
using Micro Mesh would take, literally days of long hours of hand work while progressively
working your way through the grits up to 12000 in that set. I use Micro Mesh often while doing
repairs and touching up finish, but would never consider using it as my primary method of
creating a gloss finish. You'd better have your schedule open and your elbow grease close at
hand if you're ever going to think about going the Micro Mesh route and I would venture to
say that the results will never really be as consistent or as good as are possible with a buffing
wheel.

I've never seen a finish done with hand held sanders and buffers that approaches or equals
the quality of a finish achieved by using a buffing wheel system and the compounds used in
it. I've some that are passable, but none that are as nice. It's far more than just time and work
that are being gained through the use of the buffing wheels mounted on a shaft. The level of
quality that is possible is much higher as well.

Whatever method you choose, always apply it carefully and with the constant awareness
that the finish is only a matter of a few thousandths of an inch thick and can be broken through
in a matter of seconds if pressure is concentrated in one area more than others, not only with
sanding gear and methods, but in the buffing stage as well . Always moving, always patient
and always avoiding heat buildup are three simple things to keep in mind while buffing a finish
to a high gloss.

Regards,
Kevin Gallagher/Omega Guitars
Author:  Fred Tellier [ Wed Apr 01, 2009 9:42 pm ]
Post subject:  Re: I don't really understand buffing
Quote:
Okay Fred, so it was less work and it was faster. What about the quality of the finished product? Is it somehow magically better, and if so what about it?


Hi David

A night and day difference, the shine jumps out and grabs you, my skill will get better and I think I can improve on it some more. I probably spent around $150 Canadian for the compound, buffs and arbor, I had a old 1/4 hp 1750 RPM motor so only needed a pulley and belt to hook it all up. When I add up the cost of liquid polishes I used on the 1st 3 guitars it was way more than the menerza compounds and I only used about 1/4 inch of the length of each compound stick, it looks like there is enough for at least 10 or more guitars.

My hand polished finishes were always commented on as excellent by anyone who played my guitars, I can't wait to show the new one. I have posted some photos of it on photobucket. I just finished stringing it up yesterday afternoon and have played it quite a bit, and it got a good workout at my local guitar shop.

Photos of the guitar at http://s190.photobucket.com/albums/z228/fetellier/2009%20Guitar%20builds/

Fred

Fred
Author:  npalen [ Wed Apr 01, 2009 10:00 pm ]
Post subject:  Re: I don't really understand buffing
Nice looking work on the bracing also, Fred!
Author:  David R White [ Thu Apr 02, 2009 3:48 pm ]
Post subject:  Re: I don't really understand buffing
Thanks for all the comments.

It's good to know that if I ever start thinking I don't need a new tool, I have friends who will convince me I do!
Author:  Fred Tellier [ Thu Apr 02, 2009 4:35 pm ]
Post subject:  Re: I don't really understand buffing
Quote:
t's good to know that if I ever start thinking I don't need a new tool, I have friends who will convince me I do!


I think that you can never have enough tools, and the bigger, noisier, and more expensive the better. Actually I am like you David I have to convince myself that I need each tool and then wonder how I survived without it.

Fred
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