WILL TRAPPED SOLVENTS GO AWAY

JC Daniel

Promoted Users
I sprayed 3 coats of Universal today on a trunk lid and waited exactly 30 minutes between each coat, I just came out of the shop and notice a small area about 3 inches wide by 10 inches long that has a milky look so I am guessing it is trapped solvents. Will this go away or do I need to redo the trunk lid?
 
I treat flash times as minimums. They are usually given for 70 degrees degree temperatures but there are variables. Are you using fast, medium or slow activator? Any reducer added and the speed of the reducer?
Generally, you can look across a panel and see if it is still flashing. Not just by wet looking spots but by a wavy look to the air above the panel. A secondary test is to touch some clear that is on the masking tape and see if it sticks to your glove.

The one time my clear developed a hazy look to it was when I covered it too soon with plastic. It didn't go away until I did a cut and buff on it.
 
I used Universal clear, Slow activator with no reducer. I probably did'nt give enough flash time even at 30 minutes because it was not that warm in the shop.
 
No I do not have a non contact thermometer. I have had the trunk lid in the sun for 5 hours now and the cloudy look is still in place.
 
Try sanding that area and some of the surrounding with 1000g. If is only been a couple of days and it's cool, maybe that will help with the entrapment. Just grasping at straws for possible fixes. Good luck!
 
@JC Daniel , I'm not sure what the problem was, but not knowing your surface temps is a pretty big handicap. Non-contact thermometers can be had very cheaply these days. We simply would not run our shop without one. It's very important to know your surface temps to choose activators and reducers at spray time. When curing, it's good to know what the temps are later on so that they don't fall below minimums. If you have an infrared lamp or even put something in the sun, it's helpful to know how hot things are getting to get consistent, predictable results.
 
Does sound like trapped moisture, which likely won't go away without deep sanding. I was using the matte clear on wood entrance doors & ended up with a few that showed up spots next day or later after many problem free jobs done in all sorts of temp & moisture conditions. Some of my issues seemed to be with the flatners, but had to switch to a water base clear since the wood could have been a moisture source. In my case , I had to sand all clear in bad spots & out to end of wood part to not show rings in clear. No fun.
I didn't have quality moisture removal in air compressor system either.
 
I had no idea of the non contact thermometer, I am going to invest in one now. I am going to put the trunk lid in the sun again today and if the problem is still there I will sand Monday and get back to business.
 
yep, usually wont go away. its almost always moisture. always be aware of the weather when your spraying. its those rainy cool days that will get you. the clear will blush then your done. you can usually get away with it on base to a point but unfortunately not clear.
 
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