Rustoleum 2x Gloss clear over 2x satin. Has anyone done this?

It will work great. One of the cool things about satin and flat finishes is they generally have a higher percentage of solids in the formulation, so you can build a finish faster by using flat/matte/satin instead of gloss.

This is especially true for clear coats. I often shoot 6-8 coats of satin clear, and only one or two topcoats of gloss clear.

 

Mixing finishes, e.g., spray finish over Tru Oil, can sometimes cause a crinkled finish or one that remains gummy. Tread carefully when doing this.

It always is worth the time to do a small test piece on scrap wood to make sure two dissimilar finishes will play nice with each other.

Generally, if you use only finishes of the same brand/formula from the same maker (i.e., the satin and gloss you have), you're good to go.

 

Just one thing to consider....the gloss is going to be "more clear" than the underlying satin coats which have flattening agents in them. If your intended end game is gloss, the best practice would be to stick with gloss for all your coats. In fact, many times, folks will use gloss for all initial coats even when the intended end result is satin, only switching to the "flatter" finish for the last coat or two. That preserves the clarity. It probably matters less for something that has solid color coats but potentially could be "visible", even if minimal, for a clear finish that exposes the wood underneath. Subjective for sure, but worth thinking about.

 

Follow the re-paint times on the can. Make sure each coat is dry or that crinkle that Peegoo talked about will happen. I've used both satin and gloss under clear gloss. The key is to follow the re-coat times and do no more than 3 passes in a day. If you flood any area it will take a long time to dry. Do not over sand the body 220-320 max. I had some adhesion issues sanding 320-400 before spraying. Good luck.

 

Yeah, it depends on the type of volatile solvents and the solids formula for the specific finish. Some have solvents that flash off really fast and recoat schedule is compressed. Some, like Valspar's version of cellulose acetate aerosol, let you recoat any time you like--so long as the previous layer has tacked up.

Valspar is one of my favorites because Behlen's, Reranch, and Stew-Mac lacquer can creep or run if you get just a wee bit too much coverage. The Valspar stays put. It's available in clear and several colors, and you can get it at Hopeless Despot and Lowe's. And it's not $12 a can. This stuff:


That is NOT my hand. I swear!

 

Chunkocaster, Deft and Watco also sell really good aerosol lacquers. Another very good, very common one is Rustoleum lacquer...check locally for this stuff:

I've had great results with all of the brands I've mentioned here.

 

An important consideration is the type of finish (interior or exterior type) you choose.

It's intuitive to assume exterior grades of finish are much tougher that interior types, because they have to withstand the elements, right? Precisely--which means exterior finishes have to remain a bit softer to account for expansion and contraction of substrates as surfaces get really hot and really cold throughout the seasons. A hard, abrasion-resistant finish can crack or craze as it expands and contracts.

Interior-grade finishes are substantially harder and more durable. This durability is a good thing for guitar finishes.

 

As mentioned above - while it DOES get used as a guitar "paint" (it's not a fine-finish like lacquer, polyesters and other long-term, durable finishing systems) and may look great initially, it will have only a fraction of the durability of a properly-applied lacquer system.

You not only sacrifice abrasion resistance and film toughness. Enamels have very poor solvent resistance (many cleaners, polishers and fretboard "oils" and "conditioners" will damage or discolor the film); they yellow and/or fade more rapidly (sometimes when subjected to darkness and not UV light!), also yellowing when exposed to ammoniated cleaners; and can be subject to "blocking" - where a coated surface sticks to another coating, guitar stand, case fabric, etc.

Not a coating I recommend for guitars under any circumstances.

 

Looks really nice and we aren't really trying to emulate a factory finish. So What if it ages - some folk pay good money for that! I've seen the Rustoleum products in the hardware store here.
Why not try car paints? They are all compatible - here's mine in Ford Bermuda Blue over grey primer - more of a semi gloss polished up with T-cut. The guitar is a sort of short scale travel guitar based on a Supro style with a 23 inch scale and solid sides length made out of cheapest ply with a sapele neck.