Cowling Materials

[BillyBob]

I believe this to be an RV-6 question. Apparently there are two types of cowling materials that have been used, the older "white" gel coated polyester? cowling and the newer (possibly RV-7) green fiberglas cowling. Aside from the obvious different of the molded air scoop on the fiberglas cowling; can anyone explain other differences due to the materials, weight, resin, working, patching materials, etc.

Thanks in advance.

 

[praterdj]

I?m not 100% sure but I believe the green is the polyester and the white is an epoxy based material. I know I?ve heard that you don?t want to use polyester resin on an Epoxy part.

 

[painless]

Actually, the newer S-type cowls, AKA the green ones, are pre-preg Epoxy. The older White Gel-coated ones are polyester.

The older polyester cowls are heavier than the s-type and are more prone to distortion.

The S-type cowl's downside is that they are full of pinholes that the builder is responsible for filling in. That translates into time consuming. But that aside, the S-type cowl has proven easier to install and get to fit.


Regards,

 

[Mel]

The other disadvantage of the newer cowling is that because of the pin holes, the cowling must be finished on the inside. Otherwise the pinholes will allow oil to get into the honeycomb material and destroy the integegrity.
Mel...DAR

 

[painless]

Yep. Forgot to mention that one Mel.

Regards,

 

[houndsfour]

cowling material

I have the polyester cowl with the add on air scoop. Question, what should I use to repair the cracks that have appeared at the cowling / scoop joint?
I have been using epoxy and micro baloons as a filler. This repair lasts about 4 or 5 hrs. and starts to crack again. Any ideas?
Rich
Rv-6 / N721ET