Poly Brush: brush or spray?

[ceslaw]

Poly Brush: Brush or Spray

Cubcrafters sprays but the Polyfiber manual brushes: ‘that’s why its called Poly Brush.’ On the first plane it was sprayed and it worked just fine. I like to make test panels to experiment with colors, spray gun settings and the like. As an experiment a coat of Poly Brush was applied using a foam brush. To my surprise it dried smooth with no brush strokes and even color. Admittedly it was a
thin coat, but it got me thinking.

IMG_3004.jpg

IMG_3005.jpg

At the factory time is money so spraying obviously saves a lot of time and money. But a lot of Poly Brush that could go on the plane ends up as over spray and gets sucked out of the paint booth. So why not brush on the first coat or two and then perhaps do a final coat with the spray gun? That would get more of each gallon on the plane and, perhaps, fill the fabric pores a bit better.

Has anyone had success brushing on the Poly Brush?

[Daveembry]

here’s some stuff I wrote about it and one of my videos. The factory sprays a small section and then uses a 4” foam brush immediatley for the 1st coat. Then 1 more final coat that is sprayed.

https://forum.cubcrafters.com/showthread.php/3266-Building-the-EX3-Tips-amp-Hints?p=21942&viewfull=1#post21942

wing polybrush part 1 https://youtu.be/XCXM-kz7Zng

Fuselage part 1 https://youtu.be/kve1yTEcHag

part 2 https://youtu.be/FLYdaRwm5ww

part 3 https://youtu.be/utLaMt5bpg0

part 4 https://youtu.be/wE13TZUuiu0

Poly Brush: Brush or Spray

Cubcrafters sprays but the Polyfiber manual brushes: ‘that’s why its called Poly Brush.’ On the first plane it was sprayed and it worked just fine. I like to make test panels to experiment with colors, spray gun settings and the like. As an experiment a coat of Poly Brush was applied using a foam brush. To my surprise it dried smooth with no brush strokes and even color. Admittedly it was a
thin coat, but it got me thinking.

IMG_3004.jpg

IMG_3005.jpg

At the factory time is money so spraying obviously saves a lot of time and money. But a lot of Poly Brush that could go on the plane ends up as over spray and gets sucked out of the paint booth. So why not brush on the first coat or two and then perhaps do a final coat with the spray gun? That would get more of each gallon on the plane and, perhaps, fill the fabric pores a bit better.

Has anyone had success brushing on the Poly Brush?

[ceslaw]

Thanks Dave. I always enjoy revisiting your detailed posts.

Perhaps I will use a foam brush on the bottom surface of the elevators followed by a second coat sprayed. This may be the best way to test my suggestion of foam brushing the first coat of Poly Brush, spraying the second. No one will notice if the plan goes awry on the bottom of the elevators.

The last plane I built was indeed done the way mentioned: spray an area, foam brush, spray another area, foam brush, etc. Seemed a bit cumbersome.

Always looking for alternate ways to skin a cat, to coin a phrase. Perhaps I will report the results down the road. (Sorry. Its a cliche sort of day).

[Daveembry]

Yes, it’s a pretty good workout spraying….brushing very quickly…..then moving on. Gets your arms in shape. 😂

I like the idea of the air pressure blowing the poly brush down into the fibers. The purpose of the poly brush of course is to fill the fabric……so spraying it and then brushing just seems to do a really good job of that. You just spray it on “liberally”….. I hate that word too! 😜

Thanks Dave. I always enjoy revisiting your detailed posts.

Perhaps I will use a foam brush on the bottom surface of the elevators followed by a second coat sprayed. This may be the best way to test my suggestion of foam brushing the first coat of Poly Brush, spraying the second. No one will notice if the plan goes awry on the bottom of the elevators.

The last plane I built was indeed done the way mentioned: spray an area, foam brush, spray another area, foam brush, etc. Seemed a bit cumbersome.

Always looking for alternate ways to skin a cat, to coin a phrase. Perhaps I will report the results down the road. (Sorry. Its a cliche sort of day).

[Dan L]

I’ve used both methods; brushing only and spraying followed by brushing with a foam brush and my opinion is the second method results in a smoother finish. But it is also easy using this method to not get complete penetration into the weave. There should be some backside drips. If you see these drips then you know there is good saturation.