Today's Message Index:
----------------------
1. 05:58 AM - Re: deburring the canopy edges (Dave Mader)
2. 05:58 AM - Re: deburring the canopy edges (Doug Gray)
3. 07:10 PM - Re: deburring the canopy edges (Paul Besing)
4. 09:13 PM - spar (Wheeler North)
5. 10:04 PM - Fw: Fw: Fly-in Fish Fry (smoothweasel@juno.com)
6. 11:47 PM - Chemicals and canopies (Hal / Carol Kempthorne)
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 |
|
| Subject: | deburring the canopy edges |
--> RV-List message posted by: "Dave Mader" <davemader@bresnan.net>
One very easy way to to finish the edges of the plexi (after hours of using
different, finer
grades of sandpaper) is to get a small, approx. 4" diameter buffing wheel
that you can
chuck in your drill. Add buffing compound, turn fairly slow, & follow the
edges.....
works great.
Dave Mader
2nd 6
-----Original Message-----
From: owner-rv-list-server@matronics.com
[mailto:owner-rv-list-server@matronics.com]On Behalf Of RV8ter@aol.com
Subject: RV-List: deburring the canopy edges
--> RV-List message posted by: RV8ter@aol.com
How often should one debur and smooth the canopy edges and tools/techniques
are folks using?
Touch up edges after each and every cut before each trial fit or only after
the last or nearly last cut/fit?
Is the issue that it could crack just handling it or sitting on its own
weight if laid on the unfinished edges?
thx,
lucky
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 |
|
| Subject: | Re: deburring the canopy edges |
--> RV-List message posted by: Doug Gray <dgra1233@bigpond.net.au>
Here is a post from 5 years ago. It was a keeper then and I repost for
the benefit of this discussion.
Do not archive ... because it is already there!
Doug Gray
RV-6 fuselage
Dear list,
Motivated by my recent bad experience with my canopy and vinylester
resin I have done some research into plastics. These are some of the
things I have learned.
1. Plexiglass is a trade name for one version of acrylic plastic. Our
canopies are acrylic, whether they are "plexiglass" per se I am not sure.
2. Acrylic plastics are long chain polymers. You can reduce them to
short chain polymers and monomers by "cracking" them with heat and a
solvent. In this sense "cracking" has the same connotation as "cracking"
in a petrochemical refinery.
3. The crack resistance (in a mechanical sense) of acrylics depends on
their being long polymers. When you reduce them to short polymers they
will then lose their crack stopping properties and allow cracks to
propagate from any tiny surface imperfection.
4. Both vinylester and polyester resins may or may not contain solvents
that will depolymerize acrylics. The composition of either is quite
variable and dependent on the local manufacturer. This explains why some
people have got away with both polyester and vinylester resins on occasion.
5. The more aromatic (lighter fraction in general) the solvent the worse
it hates plexiglass. If you have to clean plexi it is best to use heavy
(non-aromatic) hydrocarbon fractions. The safest are kerosene or mineral
turpentine. There is a fraction called X95 which is slightly lighter and
still safe. This is the chief component of WD40 and most other
penetrating water displacement agents. Anything based around the benzene
ring (benzine, toluine etc) is bad, bad, bad.
6. In Australia the manufacturer DOES add a small quantity (less than
.5%) of silicone to WD40. In Austalia this means it does not have to be
mentioned on the label. I cannot speak to the US formulation. This is
bad for paint.
7. High heat of its own is enough to depolymerise acrylics. Thus "flame
finishing" gives a lovely look but is a bad idea as it leaves a non
crack-resistant edge.
8. Edges should be sanded after cutting in a longitudinal fashion. Any
surface imperfections are less likely to propagate cracks. This is the
natural tendency when finishing a long edge anyway. Holes can be
finished with a cone shaped grinding stone. This again leaves any
scratches aligned with the surface rather than at 90 degrees.
9. It is good to work on warm plexiglass. It is bad to make it locally
very hot. Van's recommendation of several partial thickness passes with
the cutoff wheel is good practice.
10. There will be a tendency for the plexi to "learn" a new shape with
the passage of many temperature cycles. This means it is bad to store it
under stress because it will slowly deform to the stresses. On the other
hand it means if you install the canopy with some local stresses and get
away with it (no cracks) the likely hood of cracks will go down with the
passage of time.
11. UV will gradually depolymerise the acrylic. Over a long period of
time it becomes more brittle. Protecting your canopy from UV is a good
idea. I hope the above is helpful to someone, it is garnered from a
variety of sources but I think is all correct. I welcome any further input.
Cheers, Leo Davies
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: deburring the canopy edges |
--> RV-List message posted by: "Paul Besing" <azpilot@extremezone.com>
Avery sells a "Plexiglass Edge Scraper" that works excellent.
Paul Besing
RV-6A Sold
RV-10 Soon
http://www.lacodeworks.com/besing
Kitlog Pro Builder's Log Software
http://www.kitlog.com
----- Original Message -----
From: "David Burton" <dburton@nwlink.com>
Subject: Re: RV-List: deburring the canopy edges
> --> RV-List message posted by: "David Burton" <dburton@nwlink.com>
>
> >Only use rubbing alcohol to remove the duct tape
> > sticky,
>
> Actually, only use Stoddard solvent or Kerosene... Alcohol is one of the
> worst things to put on acrylic. Sorry.
>
> Here are a couple of good links:
>
> http://www.lpaero.com/accessories.html
> http://www.wingsandwheels.com/page37.htm
>
>
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 |
|
--> RV-List message posted by: Wheeler North <wnorth@sdccd.cc.ca.us>
I can't speak for the box type spars completely, but the 84 bolt specials
used in the 3s 4s and 6s need to have the spars very close to exact. If not
the pounding in method works, but the necessary rigging to follow is a real
pain, and will never be completely right.
RE alcohol, you chemists may correct me, but straight C2H6O is Ethyl alcohol
whereas methyl alcohol is CH4O. The ethyal should not have problems but good
luck buying it without the mixer. The methyal alcohol is as such to make it
not safely drinkable(and therefore untaxable), but some times they use a
little benzene to accomplish the same. The benzene is way bad for acrylics.
Not worth finding out the hard way.
Another product that is very bad are the DEET based bug sprays, be cautious
with these when air camping and at airshows. I had some of this wipe out a
set of ninety dollar eyeglass lenses, and was happy it wasn't my canopy. It
took about three hours to craze them completely, after cleaning them off
right after a little over spray got on them.
W
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 |
|
| Subject: | Fw: Fw: Fly-in Fish Fry |
--> RV-List message posted by: smoothweasel@juno.com
I received the following message from Crystal Lee.
Subject: Re: Fly-in
> Gerald,
> The food is bought and the hanger swept, I guess we go rain or shine.
Please come help us eat!
> Crystal Lee
If you choose to land at the Macon airport, transportation will be
provided
to the Lee's. If you want to check out the runway go ahead and fly out
there
and call Dwight - he will be monitoring 122.75.
If you drive down, please go by the Macon airport on the way (directions
are
below) to look for any stranded souls who need a ride. If worse comes to
worse and you land at Macon and don't have a ride, call Dwight's Father
Levi
Lee at 726-5560.
I attached the following directions from an earlier message:
We are located at:
GPS: N 33 08.511' W 088 24.485'
1950 ft. grass N/S runway
Caution: Power pole on the S/W corner of the runway
If driving:
Travel Hwy 45 to Prairie Point Rd. Turn East on Prairie Point Rd, pass
Macon Airport and of about 8.5 mi. to Greenbriar Rd. Turn South onto
Greenbriar, look for black catfish mailbox. Turn right at the mailbox
and
drive between the ponds to the house.
Questions? Contact us at:
Dwight Lee (662) 726-9709 e-mail: bubbalee69@juno.com
Levi Lee (662) 726-5560
Yall come on down if ya can.
Weasel -4
Message 6
| 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: | Chemicals and canopies |
--> RV-List message posted by: Hal / Carol Kempthorne <kempthornes@earthlink.net>
At 09:09 PM 5/14/2004, you wrote:
>--> RV-List message posted by: Wheeler North <wnorth@sdccd.cc.ca.us>
>
>Another product that is very bad are the DEET based bug sprays, be cautious
>with these when air camping and at airshows. I had some of this wipe out a
>set of ninety dollar eyeglass lenses, and was happy it wasn't my canopy. It
>took about three hours to craze them completely, after cleaning them off
>right after a little over spray got on them.
I should ask my optician wife but I think eyeglasses are made of
polycarbonate which is what Lexan is. Maybe.
I do hear every so often that someone has tried some kind of stuff and
found it to work good as tho they had never heard of delayed reactions.
hal
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! --
|