How low does humidity need to be for Lexan paint to properly adhere?

[Robbbbbb66]

I have Taimya PS-5 paint and I’m wondering at what percent humidity is to much?

Everything is probably preped and the body already has a can of TRX black on it already but is still mostly clear.


I have searched the forum and have not came up with a definite answer.

TIA

 

[LicketySplit]

I have Taimya PS-5 paint and I’m wondering at what percent humidity is to much?

Everything is probably preped and the body already has a can of TRX black on it already but is still mostly clear.


I have searched the forum and have not came up with a definite answer.

TIA

I don’t have an exact answer for you but the last body I painted came out fine and I live in Miami.

 

[LibertyMKiii]

I have painted on some high humidity days right after the rain and it turns out fine.
Ideally probably under 70%, but the majority of the time it will still be ok.

 

[Robbbbbb66]

I don’t have an exact answer for you but the last body I painted came out fine and I live in Miami.

Thanks.

I have painted on some high humidity days right after the rain and it turns out fine.
Ideally probably under 70%, but the majority of the time it will still be ok.

Okay, I think I can find time below 70%.

Thanks.

 

[Mikeeeeeeeeeeeeeeeal]

Curious if this is simply a drying time conundrum or will extreme levels of humidity cause other adverse effects.

 

[Cheez]

Apply in a well ventilated area and use a heat gun or hair dryer. DO NOT use to high of heat! Drying time should 15-30 minutes. When in doubt wait it out.

 

[Robbbbbb66]

Apply in a well ventilated area and use a heat gun or hair dryer. DO NOT use to high of heat! Drying time should 15-30 minutes. When in doubt wait it out.

Okay, I’m doing everything except the hair dryer part.

 

[Diem Turner]

Technically you want humidity below 50% but, from my experience, temperature is the more important factor. Cold really affects curing of the paint (which shouldn't be a problem this time of year). What you can do to help mitigate if you're in the Amazon basin or something similar is to use a blow dryer or a space heater between coats.

 

[Robbbbbb66]

Technically you want humidity below 50% but, from my experience, temperature is the more important factor. Cold really affects curing of the paint (which shouldn't be a problem this time of year). What you can do to help mitigate if you're in the Amazon basin or something similar is to use a blow dryer or a space heater between coats.

Temp is going to be 70f~, do I still need to use the hair dryer at these temps ?


Also, when and how long do you hair dryer for ?

TIA

 

[Diem Turner]

Temp is going to be 70f~, do I still need to use the hair dryer at these temps ?


Also, when and how long do you hair dryer for ?

TIA

Tamiya paints dry really fast. When I say fast I mean like five minutes. You probably shouldn't even need it to be honest. Unless your humidity is 90%+, then maybe hit it for 2-3 minutes between coats. I take it you washed the inside thoroughly and given it a quick hit with a Scotchbrite pad or something similar? That helps the most with adhesion. I typically do one light dusting coat and then hit it with a covering coat and then hold it up to the sun to see where it's still a little thin.

 

[FJC_GUY]

Technically you want humidity below 50% but, from my experience, temperature is the more important factor. Cold really affects curing of the paint (which shouldn't be a problem this time of year). What you can do to help mitigate if you're in the Amazon basin or something similar is to use a blow dryer or a space heater between coats.

Temperature is definitely a major component of adhesion with paints and adhesives in general. Anything not specified for low temperature use will usually start losing adhesion if applied below about 60° of material surface temp.

 

[Robbbbbb66]

Tamiya paints dry really fast. When I say fast I mean like five minutes. You probably shouldn't even need it to be honest. Unless your humidity is 90%+, then maybe hit it for 2-3 minutes between coats. I take it you washed the inside thoroughly and given it a quick hit with a Scotchbrite pad or something similar? That helps the most with adhesion. I typically do one light dusting coat and then hit it with a covering coat and then hold it up to the sun to see where it's still a little thin.

Currently the body has a a couple coats of TRX black but is still mostly translucent, should I hit it with a scortchbrite pad again?

When the body was clear I scotch pad it and washed the body with soapy water a let dry for an hour.


TIA

 

[Diem Turner]

Currently the body has a a couple coats of TRX black but is still mostly translucent, should I hit it with a scortchbrite pad again?

When the body was clear I scotch pad it and washed the body with soapy water a let dry for an hour.


TIA

Nah, sounds like you're good to go brother

 

[Robbbbbb66]

Nah, sounds like you're good to go brother

Cool, I will paint it in a hour or so and tell y’all how it went.

Thanks.

 

[RedondoBeachRC]

I agree I live near the beach and have painted a bunch of bodies. Most of my issues came from cold weather.

You should be good.

You don’t need to use a heat gun or hot air dryer but it does help a bit. I do very light passes over it after each coat and then let it sit for 5-10mins to air dry.

Since you already have some light black coats on you should be good with doing some light, medium coats. Aim to get it light tight in 3-4 coats.

 

[21STalion]

Typically paint is designed to be shot at 70/70

That's 70f & 70% rh

If it's not designed for this standard then it should be labelled to what it's formulated for.

I would not use a hair dryer or heat gun, not that you can't, but why would you? We use heat in a body shop because we want to get the next customer in faster, not because it improves quality. Although there is less opportunities for dirt nibs to make it into the paint. Again, not a problem for a DIYer

Too low of a humidity will cause a dryer rougher finish. Too high may never cure, but should eventually.

I went to college for refinishing technology in a previous lifetime.

 

[slick2500]

Typically paint is designed to be shot at 70/70

That's 70f & 70% rh

If it's not designed for this standard then it should be labelled to what it's formulated for.

I would not use a hair dryer or heat gun, not that you can't, but why would you? We use heat in a body shop because we want to get the next customer in faster, not because it improves quality. Although there is less opportunities for dirt nibs to make it into the paint. Again, not a problem for a DIYer

Too low of a humidity will cause a dryer rougher finish. Too high may never cure, but should eventually.

I went to college for refinishing technology in a previous lifetime.

This explains why my body is so rough inside. It's really dry here like normally maybe 30-40%.

 

[FJC_GUY]

Typically paint is designed to be shot at 70/70

That's 70f & 70% rh

If it's not designed for this standard then it should be labelled to what it's formulated for.

I would not use a hair dryer or heat gun, not that you can't, but why would you? We use heat in a body shop because we want to get the next customer in faster, not because it improves quality. Although there is less opportunities for dirt nibs to make it into the paint. Again, not a problem for a DIYer

Too low of a humidity will cause a dryer rougher finish. Too high may never cure, but should eventually.

I went to college for refinishing technology in a previous lifetime.

If I remember right low humidity causes the rough finish because the paint is very close to dry already when it hits the surface?

I spent a couple of years working at a paint store, also in a previous lifetime, so I remember bits and pieces.

I also may be confusing the 60° number with the 3M adhesives used in automotive. The VHB sticks to a warm surface forever but will peal right back off a cool surface.

Agree that a hairdryer is only for quicker coating and won't improve quality unless you are working in a place where you need a surface skin quick to avoid contaminants floating in.

 

[21STalion]

This explains why my body is so rough inside. It's really dry here like normally maybe 30-40%.

So how they counteract this in the body shop, and since they mix their own paints, they can mix in a slower or faster acting hardener.

This is also why I like airbrushing instead of the spray bomb (among other reasons) I mix my own paints. I'm not using PS paint and its not peeling either. I can mix my paint however I want to get it just the way I want it.

Here is some random video, first that popped up explaining the different hardener speeds.

 

[Mikeeeeeeeeeeeeeeeal]

This explains why my body is so rough inside. It's really dry here like normally maybe 30-40%.

??????? Shoooooooot, get on my level bruh:

17% is actually up, I think it's normally around 10%