Reducing PPG Concept Urethane

I shot my first batch of PPG concept today, and it shot slower (and had more orange peel) than I expected. When I was shooting the primer, I accidentally over reduced it - and discovered that it sprayed much better. Smoother finish and faster spray.

I mixed the PPG per the instructions: 4 paint, 2 reducer, 1 hardener. I'm wondering if "over reducing" will make it spray better.

And also what are the risks of using too much reducer. I know it may run, but is there anything other than runs that I should be watching for?


Thanks,

John

On Saturday, January 23, 2016 at 6:42:21 PM UTC-5, wrote:
I shot my first batch of PPG concept today, and it shot slower (and had more orange peel) than I expected. When I was shooting the primer, I accidentally over reduced it - and discovered that it sprayed much better. Smoother finish and faster spray.

I mixed the PPG per the instructions: 4 paint, 2 reducer, 1 hardener. I'm wondering if "over reducing" will make it spray better.

And also what are the risks of using too much reducer. I know it may run, but is there anything other than runs that I should be watching for?


Thanks,

John

I mix 8 to 5 to 2. This is 25% more reducer. Flows better. Better flow for me means less likelihood of going too heavy and making runs.
Good luck
UH

Thanks! Do you make any adjustments for cold weather?

Do you make any adjustments for cool weather?

Heat the paint........old painters trick. Works on gelcoat and rattle-cans too. If ambient temp is below 70f, I set the gallon of paint in a pot of boiling water (crack the lid). The guys at Prestec tell me their product should not be thinned. I'll be spraying gelcoat next week and max temp is 50'ish. Even with spray booth heated to 70, that doesn't last long with the exit fan on and remember the sudden release of pressure (at the nozzle) cools the product even more. BTW, this is what causes little water droplets to be sprayed onto your paint (if you don't have an adequate dryer)....... I'll be heating Prestec next week and will report back.
JJ

On Saturday, January 23, 2016 at 8:46:48 PM UTC-5, wrote:
Thanks! Do you make any adjustments for cold weather?

No.
Using slower reducer also helps flow out at the expense of recoat time. Even in cool(70 or less) shop I use medium temp reducer to get better flow out. It adds a few minutes between coats but makes it easier to get a bit better result.
For acrylic urethane I use a turbine HVLP system which gives a big pattern and has no water in the air. I can't make myself use my $400 gun for polyester topcoat so I do get a few fish eyes in that.
FWIW
UH

Keep paint products in heated office/house for 24 hours before shooting. Add reducer/thinner until happy with viscosity. Adjust gun meticulously. Keep gun clean or use $40 guns and replace often. Spray multiple coats rather than one thick one with California Curtains "runs". Adjust air pressure to your liking. You want good atomization. Use water traps (that's plural). Good lighting in work area.

Manufactures recommendations are just that. My mentor laughed when I first showed him the instructions. Yea right was his response.

Good luck.

Lane

I know nothing of refinishing work, but just curious why people would use gelcoat when you can use urethane paint. I just paid an extra $4,500 for the urethane option on a new glider. They tell me I will never have to refinish, (except for spar cap shrinkage).

On Sunday, January 24, 2016 at 6:52:42 AM UTC-8, wrote:
Heat the paint........old painters trick. Works on gelcoat and rattle-cans too. If ambient temp is below 70f, I set the gallon of paint in a pot of boiling water (crack the lid). The guys at Prestec tell me their product should not be thinned. I'll be spraying gelcoat next week and max temp is 50'ish. Even with spray booth heated to 70, that doesn't last long with the exit fan on and remember the sudden release of pressure (at the nozzle) cools the product even more. BTW, this is what causes little water droplets to be sprayed onto your paint (if you don't have an adequate dryer)....... I'll be heating Prestec next week and will report back.
JJ

JJ

I sprayed my Cirrus with Prestec last winter. UH gave me valuable advice. In the end I thinned it down like Urethane. Sprayed very nice with minor polishing out required. It was a pleasant experience. Now removing the old gel coat was not pleasant. But you've been to that rodeo many times!

Lane

For that classic look. And the ease of future repairs.

Lane