TheSamba.com :: View topic - Anybody shooting Nason single stage? Solvent pop problem.

Fri Aug 10, 2012 8:44 am

I shot the interior of my 63 rag last night. Everything looked great but when I checked on it this morning, I noticed a lot of solvent pop. The product guide recommends 5-10 minutes for flash time. I shoot heavy so I left 15 minutes. I'm using medium reducer and it was 80* F in the garage.

Anybody offer any advice or possible solutions? Am I OK to leave longer flash times?

Fri Aug 10, 2012 4:27 pm

Heavy is heavy..flash time doesn't apply to the mil thickness of the coat...much like applying many coats of clear...it isn't so much the layer but how much product is put down before and how it it can breath....5 drop coats breath better than two heavy coats...also air flow has soooooo much to do with it...to much I'd dye back and possible solvent pop as it " glazes" over before it can breath and to little makes it dry on itself so fast there is solvent left...so it pushes out causing little fish eye looking appeal.

Sand it...and clear over it if you dare or reshoot it with another coat of nano or another acrylic urethane

Hope this helps

Fri Aug 10, 2012 4:41 pm

schell '59 wrote: ...also air flow has soooooo much to do with it...to much I'd dye back and possible solvent pop as it " glazes" over before it can breath and to little makes it dry on itself so fast there is solvent left

Can you explain this part a little more?

My supply shop suggested a slower reducer since I'm in a garage and can't control the temp. I'm just on the edge of Nason's medium and slow reducer. The cut off between the two is 85*.

Fri Aug 10, 2012 7:54 pm

Envious wrote: schell '59 wrote: ...also air flow has soooooo much to do with it...to much I'd dye back and possible solvent pop as it " glazes" over before it can breath and to little makes it dry on itself so fast there is solvent left

Can you explain this part a little more?

My supply shop suggested a slower reducer since I'm in a garage and can't control the temp. I'm just on the edge of Nason's medium and slow reducer. The cut off between the two is 85*.

i'll try to explain....

what schell is saying is too much product (especially with single stage) it won't off gas correctly. you know the heat waves coming off the pavement on a hot day? picture the ground as your paint, and the heat waves as the gasses coming off the surface

if you pork on the paint too heavy, the top most 'layer' if you will traps all the gas. the result of this is the bubbles. the bubbles are because the paint is looking for a way to 'vent' itself. what happens is the paint kind of softens/re activates the primer because it simply can't breathe, hence the term 'solvent pop'....it is no different than taking a rag wet with lacquer thinner and leaving it on a hood, anything under the rag lifts up

when schell says glazing over, think of it this way....if you take a steak and toss it on the grill for 1 minute a side, it looks done, but the center is raw...same with paint. if it is not allowed to slowly build color, the top looks done, but the center is still wet.

having air flow over/around fresh paint allows the air to help pull some of the stuff to the surface. reducers...i like a mid temp, but if you are shooting the the heat of day, a hi temp may be a bit better. all the reducer does (for the sake of arguement) is allows the paint to flow...

between your slow reducer and your public admission to heavy coats= solvent pop

if you use low temp on a hot day, the stuff will dry mid air and look like shit if you use a hi temp on a cold day, it will take forever to dry.

what you should have done is several light coats with the correct flash times between coats. remember, the guys that wrote the tech sheet make more money than all of us put together. you have pissed off the God of Paint, and he has banished you to hell for trying to cheat. it happens to the best of us

Sat Aug 11, 2012 6:12 am

THAT was a freakin' excellent explanation!
God of Paint... hilarious but true. :)

A slower hardener might help too, but as said, heavy is too heavy unless you're really experienced and spraying on the edge.
Be careful with slow reducer, spray it too heavy and you'll need eavestrough to catch the runoff.

If the tech sheet calls for 5-10 minutes flash time, remember that time needs to be REALLY extended inside a car where there is very little air flow to help the flash-off.
A trick that may help is to run a finger lightly along a painted area that is inconspicuos (sp?) and if the paint "pulls" slightly as your finger moves along it, it should be ready for another coat.

Mike

Sat Aug 11, 2012 10:39 am

forgot to mention the finger trick...good catch. i like to try and wait till the paint will hold a finger print, then flow out a bit so your finger print isn't there anymore. if you do it and it is stringy when you pull back, it is still too wet.

if you use rubber gloves, touch the paint with a glove on, and when the paint will hold it and snap the glove back, you should be good to go. it will be sticky enough to hold the next coat and dry enough to help prevent pops/runs

Sat Aug 11, 2012 6:41 pm

Thanks for all of the great advice. I'm striving for a very high level of quality and this little set back really pissed me off. Hundreds of hours of prep down the toilet because I wasn't patient in between coats. Live and learn I guess.

Do you think I'll be able to see the bubbles as I sand to know how far to go or should I be safe and sand all of the color off, back to primer/sealer?

Mon Aug 13, 2012 6:41 pm

you may see pock marks (little craters) if you don't hog it down far enough