MIMF

In some of the old Polyurethane finishes there was a Flattening agent added to there regular gloss finishes whereby you could achieve a semi gloss or flat finish. Does anyone have any experience with Water based Lacquer in this regard. I've been trying to do this by sanding, but I can still see sanding marks in the finish.

There are water based and low voc LEED compliant lacquers and conversion varnishes available from ML Campbell and sherwin Williams in dull sheens. We've used them for cabinets, not guitars but I'm sure they'd work. For jobs in the past we've purchased separate flattening agents for use in solvent based lacquers. Since we're just starting to switch over in our shop I can't speak to the availability of such things for water based, but the manufacturer or distributor that you bought yours from should be able to help.

Most of the popular water based lacquer companies have a flat or semi--gloss version. However, I always use the gloss version. I noticed that if I sand the finish up to 2000 Mirka Abralon pad (on a random orbit sander), the finish is a very uniform and flat. From this stage, you can just leave it, or with just a little bit of buffing, it turns gloss. You could stop at a 1000 Mirka Abralon pad for an even flatter finish. I usually go to 4000 for less buffing on the wheel. Hope this helps you out.

Thanks for the response guy's. Chris, which random orbit sander do you use ? I'm building Archtops & I don't know whats best to use. my 5 & 6" round or 5' square don't seem appropriate so I've always done it by hand.

I've got a pneumatic ROS sander that has 2" and 3" diameter hook and loop pads. Works good on flattops. When I use it on archtops I add an interface pad which easily conforms to the arching. All this stuff is readily avialable from online auto polishing suppliers.

I have a very inexpensive 5 inch Black & Decker ros, and a very old Porter Cable 1/4 sheet finish sander. Just got a 5 inch Mirca Ceros, but i have not used it yet.

Barry, The only RO Sanders w/ 2 or 3" dics I've seen (on line) have a pistol grip did that take some time to get use to Vs. the palm grip ?

Robert

For what I call a silky finish I go through my usual finishing process using the same lacquer I normally use but at the last stage rather than buffing to a gloss I use 0000 stainless steel wool and a product called Wool wax.

It's not a wax but a type of soap in a thick gel used by antique restoration shops to clean and polish old finishes. The wool wax lubricates the steel wool and creates a very smooth consistent silky finish.

I use it on all of my guitar necks because it gives a much softer feel to the hand than a gloss finish.

Joel

Joel, This is a good thing to know. I wasn't familiar with Wool Wax.
Why do you use Stainless steel wool in stead of a softer wool like copper or aluminum ?

Robert

I have never thought of copper wool or aluminum. I will have to try them.

Joel

I've tried brass wool & it's far less aggressive than steel.

When I want a less-than-high-gloss finish I add silica powder to my usual finish. I've used it successfully in lacquer, varnish, and shellac. It is a powder so there are no compatibility issues that I know of with any finish. The trick is to have no imperfections on the surface before the final coats, and to be able to spray a virtually perfect coat with no dust because the final coats cannot be sanded or buffed and maintain the semigloss effect. I can use more or less silica to control the amount of gloss. Scrubbing the surface with grit, steel, bronze, brass, aluminum or whatever does not give me the same look.

I've heard about this technique, but with my little home made spray booth I'm always getting small particles of dust. I don't think I could pull it off.

"Scrubbing the surface with grit, steel, bronze, brass, aluminum or whatever does not give me the same look"
I'm sure thats why Joel called it his Silky finish.

Do you color sand before the last coat ?

Thanks for the help - I'll get some silica & try it out