Dupli Color and blushing

[atomicholiday]

Quick question about Dupli Color perfect match.  I just reshot my 70 1/2 Camaro and the finish came out smooth but blushed pretty badly.

I’ve done some research here and elsewhere online, and know that humidity is the issue.  In this particular case I don’t think it’s the outside atmosphere but a different cause I’ll explain in a minute.

My question is, can I continue adding coats as usual, or do I have to sand or strip the paint?  It’s smooth, without excessive orange peel.  Just looks milky.  What are my next steps?

 

 

So here’s the root cause (and I won’t do this again).  I’ve sprayed this exact color before without issue, but this is a brand new can.  Don’t think that’s the problem.  Outside it’s sunny, 85 degrees, and humidity is only 48 percent.  I’ve sprayed this stuff in higher humidity without issue.

Here’s where I believe it all went wrong.  Watching a video from a well respected model builder, he recommended washing your model, and then drying it with a hairdryer (low heat) and painting immediately, to avoid dust collecting on it.  I don’t believe his advice is wrong.  He’s won many awards.  But I do wonder if there might not be more to it.  I followed this advice, drying the model until no visible moisture could be seen anywhere.  My theory is that there must have still been some moisture (microscopic particles) on the surface.

[moparfarmer]

If you've got blushing and some not so shiney spots a polish job usually fix that problem.

 

[StevenGuthmiller]

Blushing is not a problem at all with Duplicolor paints.

It happens quite often.

you don’t need to do anything to correct it in order to shoot more coats.

You don’t even have to do anything to it in order to clear coat.

The clear coat will eliminate the problem.

If you’re not using a clear coat, and you still have some blushing after your final color coat, just polish it a little as Wayne suggested.

 

 

 

Steve

[Rick L]

As a general rule, don’t spray rattle cans if the dew point is within 20 degrees of the ambient temperature. If you’re mixing paint you can add retarder.

[Ace-Garageguy]

2 hours ago, StevenGuthmiller said:

Blushing is not a problem at all with Duplicolor paints.

It happens quite often.

you don’t need to do anything to correct it in order to shoot more coats.

You don’t even have to do anything to it in order to clear coat.

The clear coat will eliminate the problem.

If you’re not using a clear coat, and you still have some blushing after your final color coat, just polish it a little as Wayne suggested.

Exactly.

[Muncie]

2 hours ago, atomicholiday said:

Here’s where I believe it all went wrong.  Watching a video from a well respected model builder, he recommended washing your model, and then drying it with a hairdryer (low heat) and painting immediately, to avoid dust collecting on it.  I don’t believe his advice is wrong.  He’s won many awards.  But I do wonder if there might not be more to it.  I followed this advice, drying the model until no visible moisture could be seen anywhere.  My theory is that there must have still been some moisture (microscopic particles) on the surface.

Thinking out loud... it may have been dry, However, the temperature of the water you used, or the temperature of the blow dryer may have changed the temperature of the model - there may have been too much difference between the model and temperature of the air or the temperature of the paint.   It may take more time letting things sit between washing and painting to let everything get to the same temperature.

[atomicholiday]

2 hours ago, StevenGuthmiller said:

Blushing is not a problem at all with Duplicolor paints.

It happens quite often.

you don’t need to do anything to correct it in order to shoot more coats.

You don’t even have to do anything to it in order to clear coat.

The clear coat will eliminate the problem.

If you’re not using a clear coat, and you still have some blushing after your final color coat, just polish it a little as Wayne suggested.

 

 

 

Steve

Awesome.   That's what I was really hoping to hear.   

39 minutes ago, Muncie said:

Thinking out loud... it may have been dry, However, the temperature of the water you used, or the temperature of the blow dryer may have changed the temperature of the model - there may have been too much difference between the model and temperature of the air or the temperature of the paint.   It may take more time letting things sit between washing and painting to let everything get to the same temperature.

You may be right.   I used low heat, but it still warmer air than outside atmosphere.   It would have had about 10-15 minutes to cool while the paint was warming up,  but who knows. 

Thanks all for your quick replies. 

[StevenGuthmiller]

Duplicolor “Perfect Match” touch-up paints are extremely fast drying, which can ultimately trap a little moisture, which is the cause of blushing, and I’ve had this phenomenon happen virtually every time I’ve used it, regardless of the conditions at the time of spraying.

It’s just kind of the nature of the beast.

I’ve learned to ignore it because it’s absolutely nothing to worry about, and it will have no affect on the finished job whatsoever.

 

 

 

Steve

Edited July 12, 2023 by StevenGuthmiller

[Bills72sj]

It has been awhile since I used Duplicolor. When I got blushing. I just recoated it later or simply clearcoated over it.

[atomicholiday]

I’ve shot Dupli Color three times before but this is the first time I’ve seen blushing.

Finally a paint problem I can ignore!?

[Rocking Rodney Rat]

13 hours ago, Rick L said:

As a general rule, don’t spray rattle cans if the dew point is within 20 degrees of the ambient temperature. If you’re mixing paint you can add retarder.

The dew point is almost ALWAYS within 20 degrees of the temperature here! That's (one of many reasons) why my paint jobs suck....  -RRR

[SCRWDRVR]

I use Dupli-color a lot, I've found it doesn't like humidity, perfect match and the clear. I try not to use it unless the humidity is below 50% around 40% is Ideal. I paint in my basement with an indoor spray booth vented and I have a humidity gauge down there so I know when it's good for painting. You can also use a small heater to blow hot air on it to get the blush out of it when spraying, just be careful about how hot. Blushing can be polished out in most cases but I prefer to try to stop from having it.

[Chariots of Fire]

I've had that happen to me a number of times.  I just let it set up good and then polish it out.  Doesn't ever seem to be a permanent problem.  Sometimes it happens and sometimes it doesn't. 

[StevenGuthmiller]

1 hour ago, Chariots of Fire said:

Sometimes it happens and sometimes it doesn't. 

Exactly.

 

I've had it happen when I'm spraying Duplicolor in the winter time when it's 20 below zero outside with no humidity to speak of.

It just happens.

But it's a complete nothing burger.

 

 

 

 

Steve

[atomicholiday]

1 hour ago, StevenGuthmiller said:

Exactly.

 

I've had it happen when I'm spraying Duplicolor in the winter time when it's 20 below zero outside with no humidity to speak of.

It just happens.

But it's a complete nothing burger.

 

 

 

 

Steve

Steve, you spray outside when it’s that cold?  I’ve always waited until it was at least 60 degrees when shooting color.  Even with warming up the paint.
Has it ever been a problem for you?  That would really open up my season.  Currently I’m spending the summer focusing on shooting bodies and the other seasons doing things like clean up and assembly.

[StevenGuthmiller]

23 minutes ago, atomicholiday said:

Steve, you spray outside when it’s that cold?  I’ve always waited until it was at least 60 degrees when shooting color.  Even with warming up the paint.
Has it ever been a problem for you?  That would really open up my season.  Currently I’m spending the summer focusing on shooting bodies and the other seasons doing things like clean up and assembly.

No.

I spray inside.

But in the winter time in my part of the country, the air is normally extremely dry, whether you're inside or out.

I don't have a humidifier, so it's basically just as dry in the house as it is outside.

 

 

 

 

Steve

[ewetwo]

I don't know anything about paint blushing. What is it?

[StevenGuthmiller]

28 minutes ago, ewetwo said:

I don't know anything about paint blushing. What is it?

It's when a hotter lacquer paint, which dries very fast, traps a small amount of moisture in the paint, giving it a patchy, foggy look.

Ultimately, the fogging is generally on the surface of the paint, so light polishing or clear coating will eliminate it.

 

 

 

Steve

[atomicholiday]

It looks like this.

This is GM torch red.  It should look just like the cap on the paint can.

 

[Chariots of Fire]

Another experience with Duplicolor is that the more coats you put on, the brighter the color gets.  Not saying it should be put on heavy but 3-4 coats is probably a good number.  Duplicolor is a very fine spray that allows it to be done that way.  Polish out the foggiest after the last coat.  You should get super results.   Never try polishing it out between coats or you will have a real mess on your hands.  The paint will draw and bead up and Duplicolor is a hard paint to strip.

[StevenGuthmiller]

1 hour ago, atomicholiday said:

It looks like this.

This is GM torch red.  It should look just like the cap on the paint can.

 

Yup.

That's it.

 

 

 

Steve

[ewetwo]

Oh. I haven't experienced that yet but I'm sure I will. LOL

[bbowser]

Is there a similar situation with enamel?  I've had issues with blushing and additional coats don't help.

[StevenGuthmiller]

9 minutes ago, bbowser said:

Is there a similar situation with enamel?  I've had issues with blushing and additional coats don't help.

I’ve not heard of this happening with enamel.

Enamel dries slow enough that any trapped moisture can gas out along with the solvents.

I suspect that your problem might have been something else.

 

 

 

Steve

[bobss396]

I believe it has something to do with the recent formulation of the bigger cans. I have used the older small cans I have had around... no blush even at low temperatures.

I did a '62 Ford back in the spring with one of their red pearls. I shot it outside in about 50-degrees, low humidity. Instant blush as soon as I came inside. I let it dry and scuffed it up, wet sanded with a DM 2400 cloth to break down most of the blush. I gave it another coat, in my warm laundry room... again... blush. 

I let that dry for a day and color sanded it from 1500 to around 3600 grit DM cloths. I followed that up with clear lacquer, SEM 1K HS clear, P/N 40903. That was the answer.