humidity and nitro finishing: what if humidity climbs 2 hours after spraying

[sethmeister]

Was hoping to get another coat of sonic blue on my warmoth strat body this evening.

I know you want to spray nitro in 50% humidity or dryer.  It is now and will be about 40% or so this evening but by 7pm it will be in the 50% range and will keep going up throughout the night into the high 80%.  Temp is currently 87F and will drop intp the low 60's overnight.

Is it safe to spray at 5pm assuming by 7pm the paint will have dried enough that the incoming humidity will not affect things? 

Or does humidity cause issues even 2+ hours after spraying?

I can always just wait another day but you know how it is...  :blob7:

Thanks!

 

[Rick]

Not sure with nitro but with house paints when you get at least 2 hours of dry time below 85 percent humidity your good.   The main thing is the rh at time of application.

 

[sethmeister]

Going to uncharacteristically err on the side of caution and wait til tomorrow.

 

[wildbill]

Good idea, bloom sucks. Higher temp and higher RH combine like algorithmically or something. Nitro out gasses for a long time or at least wants to. I always wait if in any doubt. Did I mention that bloom sucks?

 

[sethmeister]

I did a little more research and I think perhaps the issue is not so much the humidity but the dewpoint.  That is to say the difference between the temperature and the humidity.

For instance yesterday it was 60 something percent humidity but the temp was 90 degrees.  I sprayed and had no problems at all.  This is good because with summer in NH there are not going to be very many days with humidity below 50%.

 

[swarfrat]

Dewpoint is basically another way of expressing humidity. But the easiest way to lower the humidity is raise the temperature.

A dehumidifier is basically an air conditioner (which forces the water to condense) which dumps it waste heat back into the same room it came from.

 

[Rick]

In upstate NY the humidity is usually at its lowest about 3 hours before sunset.

 

[TBurst Std]

Dewpoint is basically another way of expressing humidity. But the easiest way to lower the humidity is raise the temperature.

A dehumidifier is basically an air conditioner (which forces the water to condense) which dumps it waste heat back into the same room it came from.

Winner winner chicken dinner

Humidity is merely a ratio of temp vs dew point.
It’s all relative.

 

[sethmeister]

So it seems safe to conclude that as long as the value of humidity percentage is significantly less than the value of temperature in degrees I am safe to spray lacquer.

How much less I don't know but at 60% and 85 degrees things appear to work fine.

I do know I took a meterology course in college and hated it  :tard: