need advice from you painting pros

[rutabaga bob]

First the question, then some background: is there a way to remove/reduce the orange peel look to a clear coat?  Have started simple (!) painting on raco box covers...sanded off the galvanizing, cleaned with denatured alcohol or acetone, sprayed a few layers of rustoleum auto primer, and baked.  Then I sanded down the primer with 1500 grit paper and recleaned, then sprayed with rustoleum satin finish red and baked.  Sanded that like the primer, cleaned, and sprayed rustoleum crystal clear, trying my best to do thin coats, and baked.  I then wet-sanded the clear, cleaned, and sprayed more light coats, and baked.  Looked awful.  I thought it might be the satin red, so I sanded down to metal and started over, just using primer and clear.  Looks awful.  I read one post in an old thread where the poster had no trouble with his paint jobs, he just baked the box before spraying.  Anyway, I've got a bogus looking cover plate, and I really don't want to sand it down to metal again, if I don't have to.  Please advise...I'm not looking for 'show-car' quality, but I'd like to beat this problem.

[Philippe]

Orange peel can occur when a new coat of (paint, lacquer etc.) hits a pre-existing coat/layer of paint or lacquer. The 'hot' finish (due to various evaporative hardeners like acetone et al) cooks into the existing paint/lacquer & actually melts it a bit.

Nozzle diameter/opening plays a major role which is why many/most autobody pros would never even consider painting a car's finish with a spray can...unless one is going for a potentially half-assed appearance.

The smaller the nozzle opening, the smaller the orange peel...which is desirable as there is less finish sanding required & reduced chances of a 'sand-through'.

Unfortunately most consumer grade spray can nozzles shoot larger diameter spray particles...the plastic nozzles are cheap & easier to clean/de-clog than the smaller (and more expensive) brass ones used with air compressors & paint guns.

If you ever decide to tackle a nitrocellulose finish on your guitar, all of this will become even more apparent...spray cans work but they can be more labor intensive in terms of sanding & getting a smooth, mirror-like finish at the end.

[rutabaga bob]

Would backing farther away and trying to just mist the clear on help any?

[Quackzed]

yeah, misting will help... try a few light non-covering mist coats, let dry 1 hour, a few more very light mist coats let dry overnight, then 1 semi light covering coat... then leave it to fully cure and do aother light wet coat if you need it...
doing mist coats first and letting em dry will create more surface area for the 'wet' coat to spread over and keep it from running or orange peeling...
i usually get orange peeling when i spray over a built up/not fully dry surface or put on a too heavy coat, the mist coat should help to give a bit more reoom before orange peel...

[rutabaga bob]

Okay, Gil...when this stuff is fully dry, I'll sand it level and do the misty approach - or should I just start over?

[Quackzed]

so long as its really dry, sanding flat should be fine...

[m-theory]

In a previous life, I was an auto refinish specialist, so I think I can provide some insight.  I'll try to keep this brief, but want to try to point out the basis for my theory on this. 

First, I don't think that what you're seeing is actually orange peel.  Orange peel is generally caused by insufficient finish flow.  This can be caused from a number of things, including improper spray tip/nozzzle, pressure, and reducer selection, as well as ambient humidity and temperature at spray time.  Beyond that, some products just tend to lend themselves to spray out more orange peeled than others.  A typical example would be a spot/panel clearcoat, which is designed for production, not glamour, and thus the focus is on cure time, not flow. 

My guess is that what you're seeing is actually lifting/wrinkling of the substrate, caused by the clear coat, which is probably lacquer-based, attacking those underlying films and re-wetting them.  Bear in mind that there is no such thing as "cure" in non-catalyzed products.  "Curing" is what happens when a hardener catalyst bonds with paint resins to cause a molecular change as the finish dries.  When fully cured, the end product is basically a very hard plastic that's impervious to solvent penetration and highly resistant to environmental and chemical damage.  What we're spraying out of a can is ALWAYS re-wettable, because there is no hardener involved.  This means that, 100 years from now, you could take a lacquer solvent-soaked rag and rub the paint right off.  It will never "cure."

Making matters more challenging in this particular case, you're using Rustoleum, which is comprised of alkyd, or synthetic enamel resins.  There are two related characteristics to this resin.  One is that it's very easy to get a gorgeous, glass-like finish with it.  It lays down and flows out beautifully.  The reason for this is the second characteristic, and the one that causes concerns for us, in spraying pedals.  It dries VERY slowly, from the inside out. 

If you bake these, you may very well be exacerbating the problem, because the hot outside air will cause the film surface to skin over and trap solvents underneath.  Even though it may very well seem fully dry to the touch when it cools, it's entirely possible that what lies underneath is quite susceptible to attack from fresh solvents.  Generally, this will cause a wrinkly appearance.  Sometimes, it's not as severe as a full-out wrinkle, but is definitely severely orange peeled.  Case in point, hammertone finishes, which are designed to intentionally create massive orange peel in this manner. 

I'd say that you're probably seeing this on your box, and not traditional orange peel.  A clearcoat sprayed over a substrate that's been sanded completely smooth, and a surface area so small as a pedal box, really shouldn't cause orange peel severe enough to look "awful."  Look closely at the surface, and see if you can determine what exactly it is you're looking at.  If it truly is just orange peel in the clearcoat, you can sand it smooth and buff it shiny.  If it's deeper than that, it's the previously described scenario...wrinkling/lifting, caused by the harsh solvent in the clearcoat attacking the substrate.  I'm leaning heavily towards the latter, not only because of the products you're using and the fact that you baked it, but also that you sanded before applying the clearcoat.  Especially if the clearcoat is lacquer-based, what you did in sanding was to open up the top layer and expose the softer, vulnerable layer underneath, and lacquer is a very harsh solvent that has no trouble at all re-wetting an already-soft substrate.

If that's the case, you really need to completely strip the entire thing and start over.  This time, don't bake it.  Follow the recoat times on the back of the cans.  You should be good leaving it to air dry overnight.  If you wait longer than the recommended recoat time, you'll have to wait until it fully dries, which is probably 7-10 days.

[joegagan]

m-theory, that is a great post.

one key term you used , that i do not hear mentioned often is 'flows out".  the key to gloss without tons of sanding and buffing is a nice wet coat that gels to itself and flows. the flood of shiny metal coated products we see from china is not because they wet sand and buff, but because they have dialed in the flow rate/ nozzle size/pattern/ hardeners/paint properties etc etc to make it come out of the paint process already shiny.

[rutabaga bob]

Who'd-a thought some simple spraying would be such a pain!  Thanks to you all for the replies.  The clear is also enamel.
I am posting some pix to hopefully let you see the stuff.  Near as I can tell, it is just a clear coat issue. 

[m-theory]

I wouldn't say that looks "awful."  That's very minor orange peel that should be very easy to remove, although it doesn't look to me as though you have enough mil thickness to cut and buff, without reaching the color coat.  If it were mine, I'd very carefully go over it with 1500g wet paper, recoat it with one very fine mist coat of clear followed by another 2-3 wet coats,  let it dry thoroughly, carefully wet sand it again, buff it, and call it done.  It looks like it's going to be beautiful when you're done.  Go very easy on the wet sanding right now, because it looks like it's got barely over 2 mils of clear as it is, and that's the minimum you want AFTER cut/buff. 

I like your graphics, btw.  I'm a complete clod with a pen or marker in my hand, so I'm a bit envious of your skills!  I can make a pretty finish, but I can't do graphics for squat. 

[rutabaga bob]

The photos don't do it proper (in)justice!  Now, the can says 'apply 2 or more light coats a few minutes apart', so should all the spraying be done in one sitting, then let it sit for a week before wet sanding/buffing?  Also, should I use auto polishing compound for the buffing? (dupont #7 or similar).  Thanks!  Larry

[m-theory]

Sorry...I forgot to check back on this in a timely manner! 

Yes, you want to do all of the spraying in one session.  Otherwise, you've got to let it sit for the entire time that the can indicates, which is usually 7-10 days.  Remember that you're going to be sanding and buffing off a couple of mils, and you want to have 2 mils when you're done, so apply accordingly.  The one and only time I used a lacquer clear, I had nearly a dozen coats on it before I started sanding/buffing. 

And yes, for polishing, use a typical automotive compound...not too aggressive, though.  If you've got the Dupont stuff lying around, that would probably work fine, although I'm not aware of where it sits in the "grit" world.  I used a 3m swirl mark remover when I did mine.  Whatever you use for compound, rub it by hand.  If you put a buffer to it, you'll almost certainly burn through the clear in places, especially the edges.