Re: COZY: Final thoughts from the Peel Ply side of the force


Bulent Aliev
 

Michael,
I'm taking the risk of attracting the wrath of many people here. 
I built my whole airplane without using a single square inch of PP. I did wet layups pouring the epoxy on and spreading it around fast (High heat and humidity) with plastic squeegee. Than laying over the whole thing sheet of 4 mil plastic from Home Depot. Stretch it lightly by hand and than with larger squeegee start chasing the extra epoxy and air bubbles from the center out. Once you squeeze air and epoxy out, it can not get back in. If I see dry spot, just drive some epoxy to this spot. Amazing how much stuff comes out. After a while of working out all unnecessary epoxy and bubbles, the layup starts looking transparent. Left it to cure with plastic on. One big benefit for us here in hot and humid FL is that the layups were cured in absence of air (no amine blush). Did the spar caps like that, and they looked like solid glass with no air bubbles. We did all that with Todd Silver in his backyard cabana / building shop :).
Later I had to sand off the shine with 80 gritt, and 40 gritt for bonding areas. But you have to sand anyway even using PP.
My CZ is 5" wider, 2" taller inside and the fuselage is 1/2" Lastafoam. With Electric NG, wheel pants, upholstery, two batteries, all up it came at 1193 pounds. We did the W&B in 2005 with Steve Wright.
Again: that's what I did. Does not mean you should do it. Just sharing my experiences.

Happy Federal Holidays to All! :)

 
Bulent "Buly" Aliev
CZ MK-IV N484BD
X50 Edgewater, FL

On Wed, Dec 23, 2015 at 9:58 AM, Michael Garmon <michaelagarmon@...> wrote:
Buly,
Do you remember how much extra epoxy you used on the heavy wing? I am curious since 10 lbs represents around 3/4 of a gallon of MGS mixed with the correct ratio of hardner. If all of the 10 lbs  due to epoxy, that seems like alot extra.
Thanks 

Michael Garmon 
Sent from Samsung tablet


-------- Original message --------
From: Buly <bulent.enginegear@...>
Date:12/23/2015 7:33 AM (GMT-06:00)
To: steve harmon <sharmon32@...>
Cc: Bill Allen <billallensworld@...>, Canard Aviators <canard-aviators@...>, Cozy Builders <cozy_builders@...>
Subject: Re: COZY: Final thoughts from the Peel Ply side of the force

I had the chance to weigh two wings in the same  stage of finish. One built not using any PP and one PP'd everything.
The wing without using PP (just 4mil plastic) was 10 pounds lighter?

 
Bulent "Buly" Aliev
CZ MK-IV N484BD
X50 Edgewater, FL

On Wed, Dec 23, 2015 at 8:24 AM, steve harmon <sharmon32@...> wrote:
When I was building the cozy I did a couple of experiments with peel ply on the elevators. The one with peel ply weighed a little bit more. If you want a super light air frame to much pp.  will add some weight of course it depends on the builder.
Steve build on



> On Dec 23, 2015, at 2:13 AM, Bill Allen <billallensworld@...> wrote:
>
> Some final peel ply thoughts (how composite-geek is that for a festive thought)
>
> I agree with all that has been posted about peel-ply and always use it, and it was used extensively in the construction of my LongEz.
>
> So why did RAF come out against it in a CP,  publishing a "do not peel ply entire parts, only use it where you will  be making another layup later on".  I recall there were some reservations against it due to a) difficulty of inspection for air blisters  b) possible dry patches   c) extra weight of a PPd component  (I don't have my CP file with me today)
>
> I (and my mentor, Al Coha) took the opposite view; ie; the layup was done, wetted and inspected before it got its PP skin, which gave another sequence of bushing, hairdryering (cold climate) smoothing and trimming. All mitigating in favour of a better part.
>
> However, having just watched Mike Arnolds' excellent series of DVDs on YouTube, I cant recall him having PPd anything.
>
> So I'm just wondering, what is the current perceived wisdom on PP on whole parts (not just for bonding areas later on, or anti-spike precaution)  amongst those who do it for a living, like Scaled, -  and why RAF came out against it in writing.
>
>
>
> Bill Allen
> LongEz160 N99BA FD51
> VA N2CR FD51
> CZ4 G-BYLZ EGBJ
> LeDiesel EGBJ
>
> PS: While writing this, my wife asked me what it was about. As I started to outline the situation, I saw her glaze over.  I now understand how a priest feels trying to explain transubstantiation .


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