I have another gelcoat that's designed for spraying, but this one didn't work well - see the picture below. Instead of consistent flow of aerosol, it's spilling chunks. I tried both FN6 and FN7 nozzle. I also tried to increase the pressure from 5 bars up to 8 bars with the same result. Do you think it's not intended for use with this gelcoat gun?

It worked with FN6!

As said probably too small nozzle.  Your flow rate and pressure seems perfectly reasonable for gelcoat spraying.


Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

I would suggest trying one of the bigger nozzles, initially, as the FN3 feels a very small one to be using for gelcoat

I tend to use the FN6 for gelcoat and use the FN4 for spraying pattern coat primer which has been thinned down quite a bit with acetone.

If this doesn't fix things, I'd then look at the cup set-up to make sure that everything is sealing correctly

Hi, I am using the gelcoat gun for the first time. I am trying it with a white low viscosity polyester gelcoat designed for spraying. The gelcoat manufacturer recommends 2-3mm spray nozzle at a 5-bar pressure, so I am using FN3 (2.4mm) nozzle. The cup is half full and you can see on the video that there are small drops falling from the nozzle when not spraying which I think is OK. However, when I pull the trigger, very little gelcoat is flowing, just the first drop. I tried to increase the pressure up to 8 bars and it's all the same - no gelcoat is flowing, just the air at a high pressure. The compressor is 256 l/min (9 cfm), 10 bar. Do you have any idea what's wrong?