VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

  #1  
Old 11-04-2017, 09:56 AM
maniago's Avatar
maniago maniago is offline
 
Join Date: Aug 2014
Location: Bowie MD
Posts: 886
Default Inside the cowl paint

What are you guys using for primer/paint for the inside of the fiberglass cowl and cowl atch strips?? Logic dictates that it has to be some kind of high temp paint, but the James instructions just say epoxy, so I'm torn. I really have no idea how hot it'll get under the cowl - I'm also running a plenum.

I still have a bunch of Akzo 463-12-8 and I love the stuff, but its not high temp. In fact I cant get a data sheet that says what its temp tolerance is. I bought some rattle can high temp engine paint, but its enamel and I vaguely rem that enamel cant take flexing.

Thoughts?
__________________
Mani
Busby MustangII (FoldingWing) Pending DAR.
Don't be a hater; I'm a cousin with thin wings!
N251Y (res)
Reply With Quote
  #2  
Old 11-04-2017, 10:00 AM
Mike S's Avatar
Mike S Mike S is offline
Senior Curmudgeon
 
Join Date: Sep 2005
Location: Dayton Airpark, NV A34
Posts: 15,420
Default What I did...

Thin epoxy brushed on to fill, Vans reflective stick on foil over that.
__________________
Mike Starkey
VAF 909

Rv-10, N210LM.

Flying as of 12/4/2010

Phase 1 done, 2/4/2011

Sold after 240+ wonderful hours of flight.

"Flying the airplane is more important than radioing your plight to a person on the ground incapable of understanding or doing anything about it."
Reply With Quote
  #3  
Old 11-04-2017, 10:47 AM
BillL BillL is offline
 
Join Date: Sep 2007
Location: Central IL
Posts: 5,516
Default

I just did this - used epoxy primer to stick to the resin and urethane 2k top coat (white). Areas with hot parts near are getting vans reflective material and some 1/16" fiberfrax under the foil where the really hot parts are within 2". That cowl won't take a lot of heat and don't expect it to get that hot. Tg of the resin considered.

I can not say how well it works, but followed DanH's technique and he says his works well.

So one thing, definitely use the neat epoxy and squeegee it on to fill any and all pin holes and seal the weave. What ever you use won't look very good if you don't. If you want it really smooth, then finish (squeegee)with some micro, but it will take a lot of sanding to look smooth.

I know Will James was experimenting with some fine weave for the inside to facilitate a smooth surface. I got an early model with no core material and raw weave was easily visible. Maybe yours will be easier
__________________
Bill

RV-7
Lord Kelvin:
“I often say that when you can measure what you are speaking about,
and express it in numbers, you know something about it; but when you
cannot measure it, when you cannot express it in numbers, your knowledge
is of a meager and unsatisfactory kind.”
Reply With Quote
  #4  
Old 11-04-2017, 10:53 AM
Stoo Stoo is offline
 
Join Date: May 2006
Location: LL10, Naperville, IL.
Posts: 68
Default

I used West Systems epoxy with white pigment (Aircraft Spruce). I did not thin the epoxy but used a heat gun to warm the cowl a bit as I applied it.
Stewart Willoughby, 6 wiring/panel.
Reply With Quote
  #5  
Old 11-04-2017, 11:00 AM
maniago's Avatar
maniago maniago is offline
 
Join Date: Aug 2014
Location: Bowie MD
Posts: 886
Default

Quote:
Originally Posted by BillL View Post
I just did this - used epoxy primer to stick to the resin and urethane 2k top coat (white). Areas with hot parts near are getting vans reflective material and some 1/16" fiberfrax under the foil where the really hot parts are within 2". That cowl won't take a lot of heat and don't expect it to get that hot. Tg of the resin considered.

I can not say how well it works, but followed DanH's technique and he says his works well.

So one thing, definitely use the neat epoxy and squeegee it on to fill any and all pin holes and seal the weave. What ever you use won't look very good if you don't. If you want it really smooth, then finish (squeegee)with some micro, but it will take a lot of sanding to look smooth.

I know Will James was experimenting with some fine weave for the inside to facilitate a smooth surface. I got an early model with no core material and raw weave was easily visible. Maybe yours will be easier
My cowl is only a few months old, I have the core material. Not worried at all about the inside being smooth - is there something I dont know here? (my cowl outside is as smooth as glass - no pin holes etc, not sure if that was what you were referring to - its smooth enough to go straight to primer).

What is "neat epoxy"? Not heard that term before.

I like the idea of reflective and even fibrax in the obvious hot spots.....
__________________
Mani
Busby MustangII (FoldingWing) Pending DAR.
Don't be a hater; I'm a cousin with thin wings!
N251Y (res)
Reply With Quote
  #6  
Old 11-04-2017, 11:50 AM
BillL BillL is offline
 
Join Date: Sep 2007
Location: Central IL
Posts: 5,516
Default

Quote:
Originally Posted by maniago View Post
My cowl is only a few months old, I have the core material. Not worried at all about the inside being smooth - is there something I dont know here? (my cowl outside is as smooth as glass - no pin holes etc, not sure if that was what you were referring to - its smooth enough to go straight to primer).

What is "neat epoxy"? Not heard that term before.

I like the idea of reflective and even fibrax in the obvious hot spots.....
If your interior is smooth, and no pinholes, HURRAY!!! You are way ahead. Maybe all you want is a scuff, prime, top coat. I am wishing I had swapped with Will for a new one when he offered

Neat epoxy, no additives or dilution. I sounds like you won't need this.

The fiberfrax will go directly on the spots to be protected, and covered with the self adhering Vans reflective material. Other areas I am just using the reflective material direct to the paint.
__________________
Bill

RV-7
Lord Kelvin:
“I often say that when you can measure what you are speaking about,
and express it in numbers, you know something about it; but when you
cannot measure it, when you cannot express it in numbers, your knowledge
is of a meager and unsatisfactory kind.”
Reply With Quote
  #7  
Old 11-04-2017, 11:51 AM
erich weaver's Avatar
erich weaver erich weaver is offline
 
Join Date: Aug 2006
Location: santa barbara, CA
Posts: 1,682
Default

Neat epoxy, meaning unthinined. Vans says to thin with some acetone to help fill pin holes, but if you work it around well with a squeegee it will fill without thinning and avoid potential weakening of the fiberglass from the acetone

E
Reply With Quote
  #8  
Old 11-04-2017, 12:43 PM
maniago's Avatar
maniago maniago is offline
 
Join Date: Aug 2014
Location: Bowie MD
Posts: 886
Default

Ok thanks guys. Neat as in scotch neat. Not heard it allied to epoxy, but I get it now.

For sure you should have traded yours Bill. My top side cowl is smooth enough to see my face in it (not a pretty sight, but you get the idea!) The inside is a bit like an absorbent dish cloth in texture. Smooth in that way and also shiny, but not smooth enough for reflections. Both are devoid of pin holes - very much better than any fiberglass part with gelcoat Ive ever seen.

I'll scuff and prime with Akzo then and relieve Vans of some of that a reflective foil. Does it have a proper name and number, or just search Vans for reflective foil?
__________________
Mani
Busby MustangII (FoldingWing) Pending DAR.
Don't be a hater; I'm a cousin with thin wings!
N251Y (res)
Reply With Quote
  #9  
Old 11-04-2017, 04:44 PM
BillL BillL is offline
 
Join Date: Sep 2007
Location: Central IL
Posts: 5,516
Default

heat shield, cowl
__________________
Bill

RV-7
Lord Kelvin:
“I often say that when you can measure what you are speaking about,
and express it in numbers, you know something about it; but when you
cannot measure it, when you cannot express it in numbers, your knowledge
is of a meager and unsatisfactory kind.”
Reply With Quote
  #10  
Old 11-04-2017, 05:07 PM
bruceh's Avatar
bruceh bruceh is offline
 
Join Date: Mar 2008
Location: Ramona, CA
Posts: 2,370
Default

Three coats of white tinted epoxy (West Systems) with a tiny bit of acetone to thin looks like this after being rolled/brushed on.
Nice hard shell coating. Good visibility of any drips/leaks. Easy to wipe clean with some soapy solution.
This is before laying down the reflective aluminum and heat shielding from Van's.



More photos here.
__________________
Bruce Hill
RV-9A N5771H flown over 800 hours!
http://www.overthehills.com/RV-9A-Project
APRS Tracking for KJ6YRP and New Flying Blog
2020 VAF donator
EAA Tech Counselor, Build assistance - canopy/tanks/fiberglass/electrical/repairs
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 01:44 AM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.