shellac blushing

[swarfrat]

I was so thrilled by the lack of rain today and finding my 4oz spray gun that I forgot to check the humidity. 93%

Blushing so bad that I'm blushing for not checking.

The worst of it is on the black. Another shot of black and more shellac and that should be ok. but I have some blushing on the top too.

Can i remelt this without going all the way down?

 

[Peegoo]

Hang the guitar in a warm place (not in direct sunlight) for a few days. Sometimes the blushing goes away on its own.

If it doesn't, it means moisture is encapsulated in the finish. Shooting new over old will not guarantee the blush will come out. If that were my project, I'd wipe with DNA until the blush is gone, and then re-shoot.

 

[swarfrat]

I might try shooting DNA on the next 50% day we get. I suppose I might could shoot DNA and bring it inside still wet

 

[Peegoo]

I might try shooting DNA on the next 50% day we get. I suppose I might could shoot DNA amd bring it inside still wet

It may be hard to control drips because it's water-thin.

 

[ChicknPickn]

Yeah, as Peegoo said, shellac is so easily wiped away with alcohol that it's the most sensible approach to this kind of problem. That's what I'd do.

 

[swarfrat]

Apparently blush reducer is available but its just remelting the finish. Going to try DNA first

 

[Lou Tencodpees]

I wonder how it would work wiping on a super low cut version of your shellac, where the alcohol can cut through but still keep doing the shellac thing.

Just thinking out loud.

 

[swarfrat]

this is more promising than i had hoped

 

[swarfrat]

Wow. I just sprayed it with 91% isopropyl from a disposable squirt bottle indoors and wow. That was some ugly blushing too! I just hit it again to be sure and will check it tomorrow in sunlight.

Of course I used this to justify a small quiet airbrush compressor just to have some inside the house air for random projects. I bought it planning to use my Iwata airbrush to mist DNA on it, but the heavy mist from a 97c squirt bottle didn't seem to leave an ugly surface.

 

[Silverface]

Can i remelt this without going all the way down?

FWIW blush remover/solvents should never be sprayed AT the surface, but fogged lightly at 18-24" above and sprayed *parallel to* the surface so it floats down onto it. Spraying directly at a blushed surface usually creates runs or waves, complicating the problem.

 

[swarfrat]

So the squirt bottle actually did an ok job removing the blushing. the finish didn't really run, but is a little wavy/matte. I think because the squirt bottle puts out a pretty coarse mist compared to the airbrush. I guess that compressor will come in handy on monday when it gets here.

I don't want to spray shellac inside, but I am curious to see if i can float this matte out with a finer alcohol mist and some patience. I think i can get it flat enough to keep spraying shellac without having to sand back, though I might indeed cut back to a 1lb cut.

I also need to figure out how to lock my guitarbeque spit in place while the sides dry. It will generally stay put with the back up, but it really wants to float face up pretty bad. Sides up... forget about it

 

[Peegoo]

Of course I used this to justify a small quiet airbrush compressor just to have some inside the house air for random projects.

Cheap airbrush kits these days are *amazing* compared to what was cheap about 30 years ago. The best compressors are the type with the motor attached to a little tank. The tank makes the air behave in the same manner as a filter capacitor in an amp: it acts as a reservoir and smooths the ripple (pulse of the compressor, in this case). A smoother airflow gives you far greater control of application.

 

[swarfrat]

yeah, that's what I got coming. i made sure to get a tank. i waffled a bit on a 1/3hp 1.3cfm vs the rest of the 1/5 hp 0.8cfm boxes but in the end i decided a 47db compressor i xan use in the house was more new capability than something 10db louder thàt still wasn't as much as my garage small compressor. But it all started looking at drying.

 

[swarfrat]

Actually this one:

 

[Beebe]

I sprayed shellac cut with 190 Proof Everclear indoors for a while. First with Preval spray units then with a compressor.

Note, the Preval units do contain a chemical propellant that may not be safe indoors... Follow manufacturer safety instructions.

I used those pop up spray booths that are like tents and quite affordable.

My basement was covered in over-spray dust. It cleans up pretty easily with a Swiffer duster, but finds it's way into everything.

Now I've got a spray booth built off of the garage with a spot cooler, radiative space heater, dehumidifier, and exhaust fan ducted in... Much better.

If I get blushing, it usually goes away on its own in a few minutes of flashing off in a dry space, or I mist it with alcohol from the spray gun to help it along.

I think that by putting a light coat down over a wet coat, you run the risk of the light coat hardening over the wet one and trapping the solvent. This could cause it to never fully harden, or you'll get little dots in the finish where the solvent bubbled up through.

The only time I intentionally put a light coat down over a wet one is when spraying an orientation coat with metallics. The wet coat should be immediately before the dryer coat, and wet enough to melt the light coat when it lands... at least that's how I try to approach it.

The humidity can get pretty high indoors here in Atlanta when not running the HVAC. Fortunately we have a separate unit for the basement. I would sometimes alternate the heat and AC to keep the temp and humidity under control.

Now I keep a hygrometer handy to avoid issues.

 

[swarfrat]

190 proof has been illegal in this state for 10 years now... I doubt there's much stock. Highest we can buy is 150, which is more water than i want to lay down intentionally.

Klean Strip doesn't actually list the ethanol/methanol percentage. I do wonder about the bittering agents, but at least it doesn't have purple dye.

 

[swarfrat]

A lot of worry about nothing. Once again I blew through while sanding. The new compressor is quiet and i was able to reshoot the edges with brown/black inside. It was 60F/47% today so i shot 5-6 coats as it was drying really fast.

I like where it is i think. its no matte and not gloss. I'll let it sit overnight and check for drips. I may just call it good at that point