I never finish any projects because finishing finishes me

[EBK]

Came back from a long weekend away from my house to see this had happened to my clear coat on one of my multi-year builds:

Looks like window frost, which might have been cool if it went at all with the rest of the design.  Uggh! 

[italianguy63]

Weird!

[bluebunny]

It's Jon Patton's "Snow Day" overdrive, right?   

[amptramp]

You have to use chemically compatible finishes.  It's like lacquer and enamel - you can paint enamel over lacquer but not lacquer over enamel or you will get wrinkling or surface blemishes.  You can't just pick any clear coat to go over any paint.  You also have to keep temperature and humidity within limits.  It's humid where I am so no painting of any kind can go on now.

[EBK]

The finish looked fine for several weeks. Carefully baked it on.  Always too humid to paint here (except for Winter, when it is dry but too cold).  I baked it in my toaster oven.  This was sitting on a shelf next to other pedals prepared in the same way (but a long time ago), and the other pedals are fine.
This is Krylon Crystal Clear over powder coating, which I've done successfully before.

[davent]

I like the look.

Would it disappear under  thin layers of more of the same clearcoat?
dave

[EBK]

Would it disappear under  thin layers of more of the same clearcoat?
dave

That's what I'll try first.  Reminds me of car windshield repair.

[Ben N]

Clone of a Frostwave pedal, right? (And in a 1590A, yet!)

[Ice-9]

I'm wondering why you are putting a clear coat over a powder coating ? What type of powder coating is it that you have, for example you can have polyester or epoxy. It might make a difference what type of powder coating is used when you are applying a clear coat.

Also applying a clear cost over a gloss finish might cause some separation as there is less key for the clear coat to hold on to.

[EBK]

I'm wondering why you are putting a clear coat over a powder coating ?

To protect the decal I laid on top of the enclosure.

What type of powder coating is it that you have, for example you can have polyester or epoxy. It might make a difference what type of powder coating is used when you are applying a clear coat.

The box is a Hammond brand (their off the shelf cobalt blue 1590B), so the type of powder coating is knowable, but I don't know it (haven't asked or researched hard enough).

Also applying a clear cost over a gloss finish might cause some separation as there is less key for the clear coat to hold on to.

Fair enough, but would that create the window frost pattern I'm seeing? Asked another way, what physically happened to create those isolated snowflake cracks?

[pinkjimiphoton]

90% of the time when that happens its cuz the topcoat didn't bite into the color coat... but in this case, looks like atmospheric moisture got in. finger oils could do it too.

you MAY be able to get away with it by re-clearing it. the solvents in the new coat will dissolve and re-flow the earlier coats.

wet sanding with 600 grit with warm water with a drop or two of dish soap can help.

another issue might be that you didn't scuff it up before clearcoating. clearcoats, whether poly, enamel, or laquer, need to stick to the stuff they're painted on. if ya don't scuff it up slightly before application, it won't stick and can lift like that.

my money is on too much humidity. there's a bunch of ways this can happen.

google "blush eraser".... behlens makes it in aerosols fairly cheap, i use it if i get blush when painting <in new england, it never is stable weather wise> or crazing like that.

speaking of which, crazing can happen too if it gets knocked hard while the paint is curing. i had a guitar neck i was clearcoating fall off a hook once, and ALL the laquer ended up looking like a shattered mirror. almost cool enough to keep, but not quite.

good luck man!

[Mark Hammer]

I'm wondering why you are putting a clear coat over a powder coating ?

I put clear coat over powder-coat because my rub-on lettering is starting to dry out after 20 years (10 for the white lettering), and I need something for the letters to initially grip, before I spray clear coat over them.

[EBK]

I'm thinking some 600 grit wet sanding may be the best solution to salvage this project.

The enclosure is customized with a JB Welded standoff and significant modification to the interior of the lid.  I'd hate to start over, and I'd hate to lose the powder coat.  Also hoping not to sand into the decal because it is a white decal reverse printed to match the cobalt blue (but, if I do, I'll probably be able to peel up the decal, I suppose).

Will be a delicate operation.  Will probably add another year to this multi-year project.   

[pinkjimiphoton]

I'm wondering why you are putting a clear coat over a powder coating ?

I put clear coat over powder-coat because my rub-on lettering is starting to dry out after 20 years (10 for the white lettering), and I need something for the letters to initially grip, before I spray clear coat over them.

always remember, ya gotta scuff it if you want the clear coat to adhere. putting down a clearcoat before the decal is cool, but SCUFF IT before adding the decal. then when you clear over it, it will adhere and seal the decals/letters better.

when wet sanding, use 400-600 grit paper, and use warm water with a drop or two of dish soap...helps lube the sanding process, and helps keep it clean, too... when done sanding, rinse with plain tap water and let it dry.

[bean]

Do a light partial sand through the color back to bare enclosure. It will be relic. Trust me - it looks cool! Go the extra mile and bury it in the ground for a few weeks for some natural patina.

[EBK]

always remember, ya gotta scuff it if you want the clear coat to adhere.

Let me add another tidbit to this wisdom:
Just because you get away with it once, doesn't mean you'll get away with it a second time. 

Allow me to present my suspiciously shiny and pristine enclosure that I rediscovered after a procedure that started as wet sanding, but very quickly changed to something very akin to scraping ice off of a windshield:

The decal was lost in the process, of course.

[pinkjimiphoton]

that sucks bro, sorry! didn't mean to mislead you. looking at the original pic, i think your topcoat may have been incompatible. i've had similar happen before too, with guitars... a lot of work to fix!

if ya get a sunburst you're happy with, it never fails, as soon as ya start to clearcoat, some shit will happen

[EBK]

that sucks bro, sorry! didn't mean to mislead you.

You didn't mislead me! You pointed directly to the problem, which gave me the idea to scrape away the clear coat!  You're the mid-story hero here (actually, you share the spotlight with Mick, who also pointed to the problem)! 

My additional observation relates to my Uber Tuber build, where I did the exact same thing without any adhesion problems.  Got lucky, I believe.

[pinkjimiphoton]

luck definitely comes into play sometimes, bro. glad ya got it sorted out!

[EBK]

Do a light partial sand through the color back to bare enclosure. It will be relic. Trust me - it looks cool! Go the extra mile and bury it in the ground for a few weeks for some natural patina.

Can we throw this in the Please Steal My Idea Thread?
I'd absolutely love to see someone actually bury a pedal and dig it up later.