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I'm looking at trying some satin finish acoustic bodies (pre-cat lacquer). There are 4 options for sheen; semi-gloss (60), satin (40), matte (20) or flat (10). Can anyone tell me which one they would recommend I try first? I'm guessing satin or matte would be what I'm looking for. If anyone can tell me the different advantages or disadvantages to the different sheens that would also be helpful.

Thanks

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Josh House

Canadian Luthier Supply
http://www.canadianluthiersupply.com
https://www.facebook.com/canadianluthiersupply?ref=hl
House Guitars - Custom Built Acoustic Instruments.
http://www.houseguitars.com

The lower the sheen the softer the coating due to the flattening paste added. Though a a catalyzed product will be tougher than an air dry.You gave no frame of reference as to what you are looking for in the look of the final finish but most of the non gloss finishes on manufacturers instruments are either Matte or flat.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

We use a lot of precats for furniture. 40-60 are easily the most popular, just enough sheen that it doesn't polish up immediately where it is handled, yet flat enough that you're not inclined to think it was meant to be high gloss. Also note that the slower the reducer the more gloss you will retain.

Tim

I guess I would say I'm looking for something similar to a manufacturer satin finish. Like what you would see on a Lowden for example.

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Josh House

Canadian Luthier Supply
http://www.canadianluthiersupply.com
https://www.facebook.com/canadianluthiersupply?ref=hl
House Guitars - Custom Built Acoustic Instruments.
http://www.houseguitars.com

Lowden's finish is pretty flat, probably closer to 20 sheen.

Tim

Is it advisable for a person to use standard satin lacquer or does it need to be something designated for guitars as seems to be the case for high gloss?

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Doug

Don't let fear or common sense stop you from trying to build something

At our shop we use a satin that I think comes it at around 30, but our most popular sheen is a 20 matte by far. I tend to guide people who are getting any figured wood to at least the satin though. I personally have very little use for 60 sheen, semi-gloss. The one thing is it gives you a shiny finish without having to cut and buff, butt every time I look at it, I wish I was cutting and buffing it...

Sounds like I'm probably looking for something in the 20 range (matte). The guitars I will use this finish on are not going to be figured woods, mainly mahogany and walnut.

I'm looking at Mohawks DuraCoat pre-cat http://www.mohawk-finishing.com/catalog_browse.asp?ictNbr=571

I'll echo Doug's questions, am I ok to use a this finish on instruments seeing as it is not formulated specifically for instruments? I use the Mohawk classic instrument lacquer for my gloss stuff, and figured I'd stick with the Mohawk brand. In another thread I posted a while back people were recommending pre-cat lacquer for satin finishes and this stuff from Mohawk looks like it would do the trick. I know other builders who use standard lacquers on their instruments and it seems to work fine. If someone has experience with the DuraCoat or can tell me why I might not want to use it please let me know.

Thanks

_________________
Josh House

Canadian Luthier Supply
http://www.canadianluthiersupply.com
https://www.facebook.com/canadianluthiersupply?ref=hl
House Guitars - Custom Built Acoustic Instruments.
http://www.houseguitars.com

Josh, we used duracoat in our shop for a short time. Perhaps forty or fifty gallons. It is softer than what we use now, Becker Acroma. Also if you do use 20 sheen it will polish up a bit where it is handled. It will also mark up pretty easily, fingernails and the like. I'd test on a scrap first. Also the flattening agent falls out of suspension quickly. Stir well and often. Also strain well.

Tim

Hey Josh

Yes you are on the right track 20 ' is what you are looking for. I spray a 25' for a satin finish, it will get you that satin look from the factory instruments.

You shouldn't be to concerned about flexibility issues, the main concern is to keep the film build under the max usually 5 mill or so with the cat products.

Let me know if I can help

Joel

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http://Michaudmade.com

Yeah I'd echo Tim's statement about stirring often. The more flattening agent you have, the faster it'll settle out. That means if you spray out of a cup that's been sitting for any length of time you'll get a very flat section followed by shine, and you may as well throw the remainder in the cup out, because you'll be dealing with unknown quantities at that point.

Thanks for the tips and suggestions.

What I'm gathering from some of the responses is that I want something with a sheen in the 20 range, but that if I go with the pre-cat than I may end up with a finish that is softer than what I want. I'm looking for durability that is at least as good as the gloss nitro I use on my other stuff.

So I'm looking through my catalogue and reading about post-cat lacquers and conversion varnish. I've done a lot of experimenting with different finishes over the years, but have so far stayed away from the 2 part finishes. I moved into a new shop late last year which has a large spray booth and so I'm wondering if I should be taking a look at 2 part finishes. I'm looking to achieve a durable satin finish that takes less work than the gloss to apply, and preferable dries in less time than the 2-3 weeks for the gloss nitro. Experimenting with finishes takes a lot of time (and money), so if I can eliminate some of these options I'm looking at before testing them that would be good.

Keep the suggestions coming!

_________________
Josh House

Canadian Luthier Supply
http://www.canadianluthiersupply.com
https://www.facebook.com/canadianluthiersupply?ref=hl
House Guitars - Custom Built Acoustic Instruments.
http://www.houseguitars.com

Josh,
I have used flattening agents as well as semi-gloss and flat finishes on furniture as well as when I worked in body shops and my problem with anything that has a flattening agent in them is most seem to mark up (and get glossy) with handling and scratching with things like fingernails or picks or anything that isn't sharp.

I have finished a few guitars in semi-gloss and I find just using gloss lacquer sanded with anywhere from 800 to 2000 grit wet or dry sandpaper will give me a finish that doesn't mark up nearly as much as using a flattening agent. The trick to getting a uniform finish is to sand only with the grain and use either oil or water as a lubricant. Also lightly sanding the sandpaper with itself will take the initial sharp grit off the paper so new paper will not bite as much. If that makes any sense, new paper will give you a different "gloss" level than used paper.

The other way is to use 00, 000 or 0000 steel wool but I hate using the stuff so I like sandpaper better. Steel wool will get into everything and can end up inside a guitar where you will play heck getting it out. It will also rust if you don't get it all... And you do NOT want it around a magnetic pickup.

You may want to play around with some test pieces to see what you like best.

Cheers,
Bob

No matter what I end up trying for finish I will certainly be doing lots of test pieces.

_________________
Josh House

Canadian Luthier Supply
http://www.canadianluthiersupply.com
https://www.facebook.com/canadianluthiersupply?ref=hl
House Guitars - Custom Built Acoustic Instruments.
http://www.houseguitars.com

Post cat will be harder, but you will have to do the chemistry. Conversion varnishes can be finicky about mix ratios.. For the most durability in a satin finish I will usually seal and then run a few coats of gloss, level sand and run two flow coats of satin. You must also respect the mill barrier with these finishes, dry builds over 5 mils will cause problems usually down the road. Also be aware of shelf life on these products as it is shorter than most, usually one year once the can is opened. As to "Instrument finish" It's a marketing game as far as I am concerned. A 12" wide Red Oak panel in a 5 piece door can expand/contract over 1/4" from RH changes seasonally. Any cabinet or wood finish that can keep pace with that is surely flexible enough to use ona guitar.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Good tips Brian. I'll probably avoid the post-cat finishes, or at least hold off expirumenting till I have more time. The extra hardness and quicker dry time of post-cat does appeal to me. Shelf life is not a big concern as I build enough instrument to go through finish pretty quick.

I'm thinking your method of 2 coats of satin over some gloss may be the first thing I try. How do you rub out your satin finish? Like Bob I figured I would just sand it to a certain point and then stop.

_________________
Josh House

Canadian Luthier Supply
http://www.canadianluthiersupply.com
https://www.facebook.com/canadianluthiersupply?ref=hl
House Guitars - Custom Built Acoustic Instruments.
http://www.houseguitars.com

Hi Josh,

I didn't want to get into this until you asked because it is a learning curve and pricey but to imitate that Lowden finish durably I would use ICA's polyurethane. It comes in a 10 sheen called "Dead Flat" and looks identical to the Lowden finish. The durability of this stuff is unreal and the matte finish will not polish out from handling for years and years and years. Any gun can spray it and it's pretty straightforward and uncomplicated for a high tech finish, but it is expensive. I checked my stock but don't have either the 10 or 20 sheen to put together a sample for you. ICA's North American headquarters is in Ontario, I would call them, explain what you're doing and see if they are responsive to some sort of sample setup. I've never asked them but it seems a shame to make such a large investment to test for guitar work. I assure you though you will not be disappointed with the result, it's a scary stunning product.

Tim

Josh,
Satin finishes do not get rubbed out. That is the beauty of spraying a non glossy finish what ever level of sheen you choose. You spray it on and your are done.

The finish I was talking about is not like that and it has a different look to it also. It is difficult to explain but to me it is much richer than using a flattening agent because if you look really close you can see the fine scratches.

This is my GIbson LG-0 that has the sides and back done in the way I explain. You can see it is different than just a flat finish. I happen to like this kind of finish because if it did get any scratches in it I can easily just lightly sand them out and the finish is back to "like new"

BTW, The neck has been oiled so that is not what I am talking about. This picture was taken in front of a window and on a normal glossy finish you would see the reflections.

But this finish does require work after you spray it where all the others you are discussing don't. They are just spray and forget.

Bob