Bach-RCU

I am lying up fuselage - this is the 2nd lay-up in these molds.
4 layers of Partall #2 and PVA.
During rolling and stipling on the cloth the PVA starts to lift at few places, especially at the flange, where it has completely peeled off on few places.
Should I take everything out and clean the molds ?
Or, do you think that it is going to separate ?

Please help quick !!!
Thank you

Petr

Bach-RCU

Never mind,

I took it out ..
Cleaned those few places by denat. alcohol. It went fine. Just wondering what caused the PVA to stick so lightly to the base.
One thing, that might caused it was, that I let the last layer of Partal wax dry only about 3.5 hours. Could that be it ?
I also instead of spraying the PVA by Airbrush , brushed it on by fine foam brush.


Petr

FLYBOY

My Feedback: (11)

I am guessing you had the PVA too thick? I have had it lift if I get too much on. I would do 1, maybe 2 coats of pva then wax, but I am not an expert. Others might have a better idea.

Ron S

My Feedback: (2)

I usually put pva on with a foam brush, and I've never seen it pull off the surface before - that's strange...

ace2002

dont use pva on a mold that has been broke in,wax on 5- 10 times is all that is needed, your part will release fine
Mike
Advanced Composite Engineering
(707) 762-6542
Mike

Ollie

I'm not quite sure where you are between cycles of use. However, before starting a new part layup you should thoroughly wash the PVA from the mold, rewax it four times or more, polishing between wax applications and reapply fresh PVA. If the parts are easily removed from the mold, you can gradually decrease the wax applications between cleaning and reuse as the wax layers become well established and more or less permanent. At the first sign of difficulty removing a part from the mold, go back to four layers of wax and polish after washing off the PVA.