Problem: Krylon Triple Thick Clear Coat

[burningman]

I'm new to clear coating and just began using Krylon Triple Thick Clear Coat over decals and labels.
I sanded after one coat using a 600 wetsand. The finish is looking slightly patchy and very dull.

Will using a successive coats bring back the lustre or just make worse the dullness with a shine over it?
thanks.

[Mark Hammer]

The "triple thick" stuff is not likely oriented towards this particular application, so I wouldn't expect it to hold up well.

Imagine you're icing a cake, and you apply an extra thick layer of icing on top for "extra flavour".  Now leave the cake out uncovered on the counter overnight.  Will the outside surface of the icing get hard?  Yes.  Will it be hard all the way through, down to the cake?  No.  The icing underneath will still be soft.

Same thing with clearcoat intended to be "extra thick".

[burningman]

Thanks Mark. I've avoided clear coat for a long while because of this issue. I heard good things about the "triple thick" and thought I would try. Hopefully the finish won't be that pitiful once I'm done with it.

[Mark Hammer]

It's not quite the same thing, but I recently refinished our bedroom hardwood floor with Varathane.  Some years back, I refinished the main floorin the manner I had been led to believe was standard.  I rented a floor sander, and bought one of those applicators contractors use that looks like a curling broom, and applied the Varathane standing up.  It came out thick, and besides having bubbles in too many places, is easily subject to chipping and shows up scratches far too easily.  When I redid the upstairs, I decided to hand-apply successive thin coats (with the grain), rather than use what amounted to a mop to pile the stuff on.  Not what I'd do if I was a contractor who needed to do all the floors of a 7-bedroom home in one afternoon, but each layer dried rock hard, the feel is wonderful on your feet, and it looks sumptuous.

That digression aside, even though the final goal may be to have a glassy coat, you may have better luck in your circumstances by applying successive coats that each get to dry/cure completely, rather than applying one thicker coat that never really cures.  If it was just paint, you could stick that in a toaster over and expedite the drying, but when decals are involved, the requisite degree of care and temperature control needed to produce efficient curing of a thicker coat without damaging/degrading/discolouring the decals, may be hard to achieve.  Better to take your time and build up coats.

[burningman]

I think I'll take your advice about applying thinner coats of clear. Thanks Mark

[wavley]

I had good results with triple thick but I dried it in the box that my wife uses to burn silkscreens.  I think that multiple coats of thinner clear coat is the easier way to go because the triple thick stuff tends to sag, I didn't have any trouble with cloudiness or anything but I see how it could happen.

[modsquad]

Many thin coats is the way to apply any clear coat on any surface...wood, aluminum, etc.   Appying a thick coat does not cure properly and leaves imperfections in the coat that weaken it.   Ask Mark 

Think of how carbon fiber or kevlar is used.   For impenetrability they use multiple layers that then make a strong barrier.   Thin coats allow the clear to cure and harden completely with little or no imperfections.  But you have to be patient.   Can't tell you how I know that.

[m-theory]

One of few subjects around here that I can speak with a bit of authority on, based upon a previous life in which I was a paint specialist!

In reality, there aren't any clearcoats that are tested and approved for use over decals and labels, and in fact, if you want to get technical, it's highly unlikely that any of us are truly following manufacturer's guidelines on application techniques and materials useage to the tee.  Much more likely, we do the best we can with what we're working with.  

I personally haven't seen any spray bomb clearcoat that's worth spraying.  They're all messy, smelly, die back (dull) terribly after dry, NEED to be buffed for any respectable gloss to appear, and don't hold up for beans.  

The only thing I've found that even comes close to automotive clearcoats, in terms of gloss, adhesion, durability, etc., is envirotex, which is a two-part, epoxy clearcoat that you mix up 1:1 and pour on.  It's in the varnish section of your local hardware store, and one coat equals 50 coats of varnish.  As long as you're careful about aggressively blowing off (hair dryer works well) excess material, you end up with a very level, extremely glossy, extremely durable finish that literally looks wet, without any buffing whatsoever.  Other than avoiding excess mil thickness (excessive film thickness tends to cause yellowing, puddling, heavy sags, and even delamination in some cases), the caveat of concern is that you keep it completely free of flying dust, bugs, and other foreign objects for close to 12 hours.  During this period, it remains tacky, and anything that lands on it will be there forever.  

I use a disposable cake pan with plastic cover, set my pieces on disposable plastic cups, lay the material on and carefully blow away excess, then cover it immediately and walk away, only coming back to check up on it a couple times over the next 30-45 min.  During that time, you can still apply material and get it to flow out.  After that, it becomes too gooey for it to flow out properly, so any mistake corrections or early dust particle removal has to be done within 30-45 minutes.  When you're satisfied that it's as close to perfect as you can get it, cover it, walk away, and forget about it for at least 12 hours.  There's nothing that can be done after 45 minutes that will do anything but screw it up, so if it's not right at that point, resolve yourself to letting it cure out, sanding it down with 600g wet sandpaper, and re-applying it.  

When it's dry enough to handle (about 16 hours or so), you can use a small jeweler's screwdriver and/or razor blade to CAREFULLY scrape away the clear from joining surfaces and screw holes, and use a strong knife blade to clean out all drilled holes.  The clear cures hard as a rock in about 72 hours, depending on how thick you laid it out.  It's not QUITE as bullet proof as modern automotive clears, but it's plenty durable enough for pedals, it looks fantastic, it's simple to use, it's economical, it's non-toxic and fumeless, and it absolutely blows away any spray bomb clear out there, in every possible way.  Oh, and yes, it will work over decals and labels, although you might have to watch for lifting decals during the first 30 minutes or so.  

[m-theory]

A few examples of envirotexed pedals.

[Mark Hammer]

Zachary Vex had a post here, easily 6-8 years ago, where he outlined the steps in finishing the gorgeous pedals featuring Jason Myrold's handiwork.  When viewed in nice lighting, the clearcoat finish on those older pedals (not the less costly Vexter ones) with the graphics is pretty striking.  There were a LOT of steps.

[wavley]

My wife uses envirotex in her art all the time, that stuff is great, I'll have to go steal some from her!

[m-theory]

Zachary Vex had a post here, easily 6-8 years ago, where he outlined the steps in finishing the gorgeous pedals featuring Jason Myrold's handiwork.  When viewed in nice lighting, the clearcoat finish on those older pedals (not the less costly Vexter ones) with the graphics is pretty striking.  There were a LOT of steps.

One of my paint customers did custom artwork on bikes and cars that was frequently featured in magazines.  Most people would be floored at how many steps is required in that sort of work.  I once read an article describing how hockey goalie facemasks were painted, and it said that it wasn't uncommon to have over 100 hours wrapped up in a single mask.  Adhesion and surface prep issues aside, the topcoat artwork itself can be incredibly time consuming, and can require dozens of layers/steps.  It's really a fascinating art form.