So, after several experiments here’s what I’ve found.
Preparing your enclosure
Obviously it’s better to paint your enclosure after it’s been drilled, so do that first. next you’ll want to use 1500 grit (wet or dry) to get the enclosure ready for the primer. I always use a wee bit of water It stops aluminium dust getting kicked up into the air PLUS I’ve found that bare enclosures have a wax like reaction to water. The water starts to bead up. After a gentle sanding you’ll find that this no longer happens, that’s the sweet spot. I love the look and texture of unfinished enclosures, and I try to maintain that in my pedals. Feel free to sand your enclosure with ever finer grits (start much lower than 1500, early hundreds should suffice, and finish between 1500 and 2000) if you want a shinier finish.
Next you’ll need to give the bare enclosure a good clean with warm soapy water, rinse well, and give your workbench a clean too.
Primer is hugely important, and it’s a step i didn’t fully appreciate or understand early on. I use this,
and it works a treat. The posca paint adheres to it really well, and applying a second coat or wee touch ups is much, much easier. The paint won’t flake or rub off.
You only need a few coats (I usually do 3 or 4 depending on spraying conditions and how well the enclosures react). If you spray too much or not evenly enough you’ll get dull grey patches where the spray has pooled. When the enclosure is starting to look a ‘healthy’ kind of dull, you’ve done enough. Be sure to pay attention to the sides of the enclosure too.
Hand painting the enclosures
I’ve only used the posca paint markers so far, but I find them easy to use, I love the colour selection and the results are spot on. I recently bought some Winsor and Newton acrylics and brushes. I’ll post findings when I try them.
Krylon as colour protection
I’ve applied the Duplicolor clear coat directly to the artwork, and found that whilst the clear coat was nice and strong, it sometimes hasn’t preserved the colours as well as i’d hoped, especially for blocks of colour, and even more so for black. See below.
It’s not a huge problem and it has a charm of its own, but I generally prefer adding this extra step to add a touch more quality.
Final clear coat
For the final clear coat, I still haven’t decided which of the Duplicolor sprays I prefer.
The Acrylic Enamel clearcoat comes in matte and gloss, both have worked well. The Gloss Clear with ceramic seems to produce a thicker more consistent finish, which looks like it will be tougher, but it sometimes seems to add an almost imperceptible yellowish hue to the enclosure. This doesn’t seem to affect the colour of the paints much, but does give the bare metal a (very) faint almost golden look. I can’t find any pictures to show this, like I say it’s very slight. I am concerned that this yellowing might get worse with exposure to sunlight, but at this point it’s impossible to say.
So, put simply my current method for preparing, painting and finishing enclosures is…
- After drilling, use 1500 grit wet or dry paper to gently sand down the enclosure.
- Give the enclosure a thorough clean with warm soapy water
- Dry thoroughly, and wipe clean with paper towels
- Stick the enclosure in a spray box
- Apply Duplicolor adhesion promoter primer in 3 or more coats, first two coats light, third and fourth (etc.) a little more comprehensive, wait three minutes between coats. If you spray too much or not evenly enough you’ll get dull grey patches. When the enclosure is starting to look a ‘healthy’ kind of dull, you’ve done enough
- Leave enclosure to dry for a couple of days.
- Do the artwork with posca pens, leave for a day.
- Apply a couple of coats of matte Krylon to maintain the integrity of the colours. Leave it to dry in a warm, dry place, covered for a week.
- Apply Duplicolor clear coat (matte/gloss/ceramic) in 5 or 6 coats, first two coats thin, slowly applying slightly thicker coats as you go. Each coat ten minutes apart. Don’t exceed 1 hour total spray time.
- Place box of pedals in a warm dry place out of direct sunlight. on radiator if possible and leave to dry for a full week.
Don’t forget to give all the sprays a good shake before use (at least 2 mins), and a smaller shake in between coats. Remember to read the instructions on the can carefully.
Primer – one can is good for roughly 5 – 7 enclosures, possibly more.
Krylon – one can is good for 5 – 7 enclosures, depending on how many sweeps you want to give.
Duplicolor clear coat – one can is good for 2 or possibly 3 enclosures depending on conditions and size of enclosure.