Clear coat in cold and humid environments

[Paradox916]

I was at the pain store the other day and was reading the cans I didn’t know this but apparently lacquer is more tolerant of low temps and high humidity; up to 80% humidity vs 60% for clear coat. and lower temp down to the 50s (F). For some reason I have this idea in my head that yellowing would be an issue but I don’t know that for a fact. Anyone have an experience with using lacquer?

 

[benny_profane]

I was at the pain store the other day

The main issue that you're dealing with with lacquer / shellac is the chemical base. Typically, these differ from other clear coats (e.g., spray paint varnishes, polycrylic) in that they are solvent or oil based. It's true that finished such as polyurethane can yellow over time. The bigger concern is interaction with the substrate. If you're putting a solvent-based finish over a waterslide decal, for example, you will most likely melt the decal. You could also run into issues of cracking or bad adhesion. Check the SDS and other product information for details about interaction with other finishes and products.

 

[Paradox916]

Didn’t even think about it melting the decal..... that would suck.

 

[benny_profane]

Have you ever given polycrylic a shot? It's not nearly as hard as a solvent- or oil-based clear coat, but you can apply it with a foam brush indoors without nasty de-gassing.

 

[Big Monk]

Have you ever given polycrylic a shot? It's not nearly as hard as a solvent- or oil-based clear coat, but you can apply it with a foam brush indoors without nasty de-gassing.

Have you guys tried the Minwax spray polyurethane?

That stuff is a dream. Obviously more expensive but I've used it on a number of projects now and it is very nice to work with.

 

[flemming]

Have you ever given polycrylic a shot? It's not nearly as hard as a solvent- or oil-based clear coat, but you can apply it with a foam brush indoors without nasty de-gassing.

I used this on my first few pedals. Several coats certainly makes a nice durable finish, but I hated dealing with drips and brush strokes. They all look fine, but if I look at them closely it tickles my anal retentiveness.

 

[Big Monk]

I used this on my first few pedals. Several coats certainly makes a nice durable finish, but I hated dealing with drips and brush strokes. They all look fine, but if I look at them closely it tickles my anal retentiveness.

You’d love the spray poly then. Very fine most spray with no drips or brush strokes. I imagine someone could get 5-6 pedals out of each can.

 

[benny_profane]

There are two types of polyurethane: water- and oil-based. Take a look at the SDS and materials interaction info to see which would work for your application. Polycrylic can definitely be tough to work with. There's a learning curve, but working quickly and in thin coats, you can get great results and avoid cloudiness/drips.

 

[Paradox916]

So for anyone That is interested
Clear coat: temp range 55-75F and humidity below 60%
Polyurethane down to 50F and 75% humidity... Next can I get I will have to try the poly...

 

[cooder]

Here's a clear coat that's specifically designed for cold and humid conditions, apparently...

Sorry, I couldn't resist...

 

[jjjimi84]

I have just started using krylon triple thick glaze over oil based paint and it works really well.

Stinks to high hell but gives off a nice shine