Spraying Polybrush

[BajaCat]

This is the first time I've painted an airplane (or much of anything else). I'm in the process of applying the two specified spray coats of Polybrush using a HVLP setup. Can anyone tell me how to tell when I have applied the right amount of Polybrush? The instructions I have, including the Poly Fiber Aircraft Coatings manual, seem pretty vague. I can still see the weave of the fabric after two coats, and the color isn't completely uniform on the wing, which suggest to me that I should apply another coat, but I don't want to apply too much either.

Thanks,

Jim

[Av8r_Sed]

You're just supposed seal the weave but not fill it with the Polybrush. It will have darker and lighter pink areas depending on how much bled through to the back of the fabric.

Don't try to completely fill the weave with the Polyspray either, unless you want a really heavy airplane.

[jtpitkin06]

Trying to fill the fabric completely with Polybrush will add lots of weight and several hundreds of dollars.


To really understand a fabric coated airplane, go to your local airport and look at some factory painted fabric covered airplanes. One of the best jobs you will see is Legend Cub. Their fabric finish is superb. The detail in pinking tapes and how they finish corners is first rate. But the finish is still semi-gloss. The covering is fabric and definitely looks like it.



Fabric covered airplanes have a semi-gloss finish. Fabric does not have a high sheen or a super glossy look. The fabric weave is visible.
When spraying on your Polybrush coats you normally just seal the fabric. The combination of a brushed on first coat forced into the weave and two sprayed coats on top usually do the job. Because Poly Brush is translucent you will still have a somewhat blotchy appearance and the surface should be fairly smooth without brush ridges. The fabric will be sealed but you will still be able to see the weave. Remember, at this point, you still have six coats of paint to go… three Polyspray; and, three Polytone or, three of the “Thanes”. Those additional six coats will fill in a lot of the fabric weave.


In the hot summer months, be sure to use retarder reducer so the paints will not dry before they hit the fabric. If your coating feels like fine sandpaper, you need retarder.


John