Enclosure Finish

[Joaquín V]

Hi! im new here, nice to meet you folks

I got a question maybe you can help me with this.

I am working on a design. My idea is something similar to what zvex does with some designs, where they sand the cabinet and then partially paint a design like for example some fuzz factory (in my case UV printing). My question is if after sanding and doing the uv printing, should I apply something else to the cabinet to protect both the printing and the case, or is it not necessary?

thaaaanks

 

[HamishR]

Can you apply a UV print to a bare enclosure? What I have done on the enclosures I have had UV printed by Tayda is get them to do a clear matt powdercoat then the UV print over that. It doesn't seem to need another clear coat over that. The clear matt powdercoat is a really nice finish to the touch and looks great.

 

[Alan W]

By definition, the UV in UV printing means that there is a curing process that makes the finish durable, so the UV printed surfaces don‘t need any additional protection. But @HamishR brings up an important concern, adhesion.

Aluminum is tricky to get paint to adhere to. After washing it down with solvents, in my shop we always etch primed as a first coat. I’m pretty sure you can get etching primers in spray cans, but not positive. This was for lacquer or enamel spray painting. Aluminum takes powder coating well. I’m not sure about UV printing on bare aluminum, so the suggestion for a base clear coat is a good one. I’d ask whoever is doing the UV printing for you—they should have the experience to know if adhesion on bare aluminum is doable.

 

[HamishR]

Which brings up another question - what exactly are the enclosures made of? I'm not sure they're just aluminium. Isn't there a fair amount of zinc in there?

 

[Feral Feline]

I used an automotive-grade spray can clear adhesion-promoter as a primer for a candy-tangerine colour (pic below seen in couple of my other posts on the forum):

The bottom on the left was an opaque flat-grey primer, the drilled face on the right was painted after using the clear adhesion-promoter — same paint, different sub-surface prep.

You can see the face of the pedal (R) is much more vibrant, and that's due to the bare-metal under the paint offering some additional reflection.
Alas, I don't have a pic of the enclosure with just the adhesion-promoter — basically it looked like the raw metal, maybe with a bit of sheen to it.


A word about clear-coating raw aluminium... I worked for a bike manufacturer that liked the look of polished aluminum, but the company still wanted some protection so somebody that doesn't know any better said to clear-coat the frames. They looked great — on the showroom floor. A few rides in and the clear-coat was scratched and after just a few months of rippin' the trails the MTB frames, the clear-coat was peeling off and looking dull. I'm sure they would've continued to look great if adhesion-promoter had been used between the polished alloy and the clear-coat. Mind, that's a while ago and the adhesion-promoter I used on the pedal may not have been yet developed yet for the bike-frames way back when.


So, I don't know how well a UV-print would stick to the adhesion-promoter, but I would definitely recommend using it instead of trying to get a UV-print on raw bare aluminium.

 

[Bricksnbeatles]

Which brings up another question - what exactly are the enclosures made of? I'm not sure they're just aluminium. Isn't there a fair amount of zinc in there?

I don’t think so. Zinc is almost 3x heavier than aluminum, and the average enclosure is pretty much in line with what I’ve experienced with cast aluminum. Even small amount of additives can have big impacts on the properties of a metal— I’m no metallurgist, but i could see them having like 5% zinc by volume in the alloy to improve strength, but it’s definitely not a ton if there’s any

 

[HamishR]

The matt clear powdercoat Tayda uses has been holding up better than a lot of other powdercoat finishes I've tried! The enclosures are not polished; they're just regular cast finish. To me it's the equivalent in pedals of the plain brown paper bag. I think it looks better than leaving the pedals unfinished.

 

[Markus Kersius]

I've had a Scott McKeon fuzz with Hendrix inspired monterey strat graphics on it.
The rest of the pedal is bare unpolished aluminium finished with some kind of clear coat.
That clear coat bubbled and then started flaking randomly on the corners, top and bottom.
Same as the ATB bikes Feral Feline wrote about.