jdelgadoc1300
New Member
Dear all,
Beforehand, thank you everyone for your amazing contributions, I've reading the forum for a while and I've learned a lot from you guys.
Today I came to you with a professional question. First of all, I do expect not to violate any forum rules, because the product I'm asking is not from SPI.
I am a Coatings Engineer for an Automotive Tier 1 manufacturer. I'm in charge of two coating processes, one of them involving a Clear Hardcoat which is cured with UV energy, which is applied to a transparent polycarbonate part (so clear on clear), with a paint robot and automatic spray gun.
On my current parts I'm not getting a good surface finishing. Reading from this forum I can relate this condition to high solids, resulting in urethane wave effect.
My original mix is with 60% solids, I added IPA to the mix and got to 44% solids. This improved the finishing but it is still not okay.
Controlling temperature and humidity in the room at 25°C and 50% r.H., 1 minute ambient flash-off, then 2 minutes hot flash-off (compliant to coating datasheet).
I've changed my air cap from HVLP to Conventional, and right now using 4 bar for atomization air and 1.5 bar for shape air, dosing at 98 cc/min. This also improved but slightly.
For this kind of coating and process I can't do any cutting, buffing, re-working.
So do you have any ideas on how to improve the waviness on the surface for the end result?
Thank you in advance!
Beforehand, thank you everyone for your amazing contributions, I've reading the forum for a while and I've learned a lot from you guys.
Today I came to you with a professional question. First of all, I do expect not to violate any forum rules, because the product I'm asking is not from SPI.
I am a Coatings Engineer for an Automotive Tier 1 manufacturer. I'm in charge of two coating processes, one of them involving a Clear Hardcoat which is cured with UV energy, which is applied to a transparent polycarbonate part (so clear on clear), with a paint robot and automatic spray gun.
On my current parts I'm not getting a good surface finishing. Reading from this forum I can relate this condition to high solids, resulting in urethane wave effect.
My original mix is with 60% solids, I added IPA to the mix and got to 44% solids. This improved the finishing but it is still not okay.
Controlling temperature and humidity in the room at 25°C and 50% r.H., 1 minute ambient flash-off, then 2 minutes hot flash-off (compliant to coating datasheet).
I've changed my air cap from HVLP to Conventional, and right now using 4 bar for atomization air and 1.5 bar for shape air, dosing at 98 cc/min. This also improved but slightly.
For this kind of coating and process I can't do any cutting, buffing, re-working.
So do you have any ideas on how to improve the waviness on the surface for the end result?
Thank you in advance!