Today's Message Index:
----------------------
1. 03:15 AM - Kevlar (Pilots4ETW@wmconnect.com)
2. 06:03 AM - Re: Kevlar (Jim Markle)
3. 09:23 AM - Re: Some aerodynamic stuff (walt evans)
4. 02:50 PM - Re: Kevlar (gbowen@ptialaska.net)
5. 09:11 PM - Re: Kevlar (Rcaprd@aol.com)
Message 1
INDEX | Back to Main INDEX |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
I'm thinking of putting a couple layers of Kevlar on the fuselage tank I'm
building to offer more safety over a simple fiberglass tank. I read in the Wicks
catalog that Kevlar is 2.5 times stronger than E glass, and 10 times stronger
than aluminum on a specific tensile strength basis.
The problem is I don't want to invest in a pair of $60 scissors that will
probably be used one time. Does anybody have any experience in cutting Kevlar
with a regular pair of scissors or is there an alternative to the $60 version?
Roy
Message 2
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
I have experience cutting Kevlar and the scissors are an absolute must.
But don't buy any. I have a pair sitting here collecting dust and would be glad
to loan them to you.
Send me an SASE (and promise that you'll return them!) and you're welcome to borrow
them.
If you decide to buy some for yourself, don't buy the $60 ones....get the $26 ones from ACP (http://www.acp-composites.com/acp-ta.htm)
Jim Markle
Plano, TX
214.505.6101
----- Original Message -----
From: Pilots4ETW@wmconnect.com
To: pietenpol-list@matronics.com
Sent: Friday, March 11, 2005 5:14 AM
Subject: Pietenpol-List: Kevlar
I'm thinking of putting a couple layers of Kevlar on the fuselage tank I'm building
to offer more safety over a simple fiberglass tank. I read in the Wicks
catalog that Kevlar is 2.5 times stronger than E glass, and 10 times stronger
than aluminum on a specific tensile strength basis.
The problem is I don't want to invest in a pair of $60 scissors that will probably
be used one time. Does anybody have any experience in cutting Kevlar with
a regular pair of scissors or is there an alternative to the $60 version?
Roy
Message 3
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: Some aerodynamic stuff |
Corky,
My take on the down thrust of the engine is since the plane wing normally flies
with some positive incidence, the engine/prop is flying with zero incidence.
walt evans
NX140DL
----- Original Message -----
From: Isablcorky@aol.com
To: pietenpol-list@matronics.com
Sent: Thursday, March 10, 2005 7:57 PM
Subject: Pietenpol-List: Some aerodynamic stuff
Pieters,
As I build my engine mount jig some little questions have popped into this ole
brain. I remember from a long time ago, maybe flight school or somewhere, that
the downthrust angle on the engine is to force a more direct blast on the lower
surface of the wing.(High, single wing).
Now as I plan to extend the mount a full 2 inches forward of the plans and lengthen
the cabanes another 2 inches over the plans.
It would seem to me that it would be necessary to drop the engine incidence to
compensate for these changes.
Now those of you in the know please advise. I'm laying out the jig for a 4 degree
downthrust measured from the firewall and a wing incidence of 1 degree 30'.
Sure would appreciate some help on this one. I promise to leave the list alone
for the future.
Corky in La nursing Isabelle with a strep throat
Message 4
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
--> Pietenpol-List message posted by: "gbowen@ptialaska.net" <gbowen@ptialaska.net>
I've worked a fair amount in the composites industry with Kevlar, so here's
my two cents worth. 1) Don't think Kevlar is gonna give you what you're
looking for in terms of accident damage to your tank over glass, especially
using only a couple plies over the glass core, 2) if you impact something,
that pokes a hole in your gas tank, you're gonna have a leak whether it's
covered with Kevlar or not, the resin system will shatter and leak at the
damage spot, 3) Kevlar is very hard to work with for two reasons, a: it
cuts very difficult therefore needing the special cutting tools, so you
gotta shell out the $60+ bucks, b: it has a lot more filaments per tow
bundle than glass so it consumes more resin per square foot to wet these
bundles out. 3) Kevlar has a tendency to separate from the glass plies.
The composites shop folks at Lufthansa used to get new 737/747 engine
cowlings from their supplier in the US that had a Kevlar inter-ply to
prevent jet engine vanes from shooting thru the cowling into the fuselage.
I watched them remove the Kevlar ply, just like peel ply, and toss it away,
because subsequent repairs to the cowling wouldn't stick. Kevlar has a
couple nice advantages, a) stronger than fiberglass or carbon, b) lighter
than either one.
Gordon Bowen
Original Message:
-----------------
From: Pilots4ETW@wmconnect.com
Subject: Pietenpol-List: Kevlar
I'm thinking of putting a couple layers of Kevlar on the fuselage tank I'm
building to offer more safety over a simple fiberglass tank. I read in the
Wicks
catalog that Kevlar is 2.5 times stronger than E glass, and 10 times
stronger
than aluminum on a specific tensile strength basis.
The problem is I don't want to invest in a pair of $60 scissors that will
probably be used one time. Does anybody have any experience in cutting
Kevlar
with a regular pair of scissors or is there an alternative to the $60
version?
Roy
Message 5
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
In a message dated 3/11/2005 5:15:56 AM Central Standard Time,
Pilots4ETW@wmconnect.com writes:
I'm thinking of putting a couple layers of Kevlar on the fuselage tank I'm
building to offer more safety over a simple fiberglass tank. I read in the Wicks
catalog that Kevlar is 2.5 times stronger than E glass, and 10 times stronger
than aluminum on a specific tensile strength basis.
The problem is I don't want to invest in a pair of $60 scissors that will
probably be used one time. Does anybody have any experience in cutting Kevlar
with a regular pair of scissors or is there an alternative to the $60 version?
Roy & Sterling,
I agree with Gordon. I don't think the effort to use Kevlar in with the
lay-ups of Fiberglass is worth it. Kevlar is the most abrasion resistant
material of all the composite materials...that's why it's used in bullet proof
vests. It is a LOT more expensive, hard to cut, difficult to wet out. You're
trying to build 'Crashworthyness' into your plane...much better to build
'Airworthyness' into it. There are two types of Fiberglass: E-glass is used where
electrical resistance is the requirement, and S-glass is used when strength is
the requirement. Of all the composite materials, Carbon Fiber is the
strongest in compression, but offers poorest in abrasion resistance, therefore
each
type of material has it's place in a given design, in addition to the type of
resin.
I used Omni-direction Kevlar on the leading edge (about 1/2" wide), for
'tipping material', on the 3 props that I've built, because of it's abrasion
resistance. Then wrapped the entire blade with one layer of the light weight
fiberglass, all the way to the root. I used Polyester Resin (auto body stuff)
on the props. Epoxy Resin, such as the 'West System', is the preferred type of
resin for fuel, oil, and chemical resistant applications.
Chuck G.
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|