Matte finishes

[John]

Has anybody got experience spraying matte finishes from a gun. I'm looking for a manufacturing perspective.

[Russell Vance]

Hello John,

We have matte nitrocellulose as a preferred finish on our custom guitars, vancecustomguitars.com - we mix our own matte ratios using a dry matting agent but have also used premix commercial matte finishes from our lacquer supplier.  

We changed over to in-house mixing to give more flexibility in the range of matte finish from "satin" to full 'matte" thereby saving us a lot of money in held lacquer stock or having to buy in small amounts for individual finishes.   The matte agent also settles over time and requires reconstitution for older stock which is a lengthy shake and strain process.  Much easier to make it up on the spot in the quantity required.  

The matting agent needs to be appropriate to the finish system being used (according to our lacquer manufacturer who was also a bit hesitant to provide the stuff for whatever reason) and mixing it it properly and completely is essential to avoid the white spotting that can occurs otherwize.

We strain it using ultra fine mesh filters (90-125 micron) after initially mixing the dry agent into a combination of thinners and a minimum amount of lacquer - this gets the wetting process going and incorporates the components.  This mix gets added to a standard lacquer/thinners mix and well stirred and shaken before straining.

Shoot a test batch to check for complete incorporation of the components and viscosity.   We use the standard guns - Iwata Supernova WS-400s with 1.4 nozzle @ 40 PSI  with dual Norgren water vapor filters, opened up a bit to spray the matte finish coat.

The matte finish is shot onto a standard gloss schedule and the finish is generally scrubbed flat with up to 1200 grit wet and dry and given a light finish coat before having the final matte coats (1 or 2) applied.

The matte nitro finishes shine up with use and give a good "used " look with use.

Is this the sort of info you seek?

Rusty.

[Ned Knepp]

I really gotta stop going to your site but when I hit the lottery...

[Russell Vance]

Thanks for the compliment Ned, but if the AUD keeps falling like it is against the US$  I'll be able to give you one and still make a profit.

[John]

Thank you Rusty, it is the info I was looking for.

 The car guys do a  matte clear coat over a gloss color coat. Any thoughts on that? 

[Russell Vance]

Hi John,

It's a good look, the Lambo finish is just the bomb.  

How it's done is up to the propriety guys - some Auto finishes go on in sequence "sticky" so they attache to each other before the catalyst sets everything hard, as do acrylic metallics etc.  Some of the airbrushing and clearcoating schedules on the Custom Car shows on TV appear dodgy to me, but they may have a secret.   How the matte coat is applied to a clear coat depends on the system they are using.  Clear coats are typically a very hard tough coat designed so stuff doesn't stick to it or scratch it once it's gone off.

For Nitrocellulose finishes its just too easy as everything sticks to everything regardless and the old lacquer reconstitutes - which is why I like the stuff so much.

R.