KR> Re: Sanding Vinyl Ester Layup

[Charles Brown]

From: "rdrace...@aol.com" 
To: kr...@mylist.net
Sent: Tue, November 23, 2010 8:05:49 PM
Subject: Re: KR> Re: Sanding Vinyl Ester Layup

What is PVA?


In a message dated 11/23/2010 8:04:39 P.M. Pacific Standard Time,  
l...@vandyke5.com writes:

Sorry  PVA.  I hate this iPhone sometimes

Sent from my iPhone

On  Nov 23, 2010, at 8:57 PM, Lee Van Dyke   wrote:

> If you know that you will have to sand V/E you can spray  pcs on the
> area that you layed up, it will help form a "crust" if you  will.  Then
> sand easy peasy lemon  squeezie

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KR> Outboard wing tanks

[David Goodman]

Steve wrote:

How close to the rear of the forward spar should the back of the tank be?

Steve,

I have aluminum tanks in my outer wings.  They run almost to the tips.
Inboard they are 14 inches aft toward the rear spar and outboard they are
nine inches deep.  My tanks are almost right up against the forward spar,
with the 1/4" space between spar and tank side being filled with expanding
foam.  This helps keep the tank in position and prevents chaffing of the
two.

Baffles for long tanks are a must.  I have two in each tank.  Without them
you are at great risk in uncoordinated flight of your plane becoming
unbalanced and difficult to control.

As far as CG, my plane does not move more than one third of an inch between
full tanks and empty ones.  I usually do not have to make more than one or
two small trim changes on a long cross country flight due to shifting CG.
If you make your tanks so they go all the way to the aft spar this probably
is not the case, but that is opinion.

Have a joyous Thanksgiving. 

IHS,

Dave "Zipper" Goodman
Vertical Avionics, Inc.
www.verticalavionics.com

KR> Outboard wing tanks

[Mark Langford]

Steve Phillabaum wrote:

>> I am building my wing tanks from Fiberglass. (Final Choice).  But as far 
>> as size goes.  Because I have the forward spar that is 8 inches tall I 
>> plan to make my tanks. 6 inches tall at the spar, 10" wide, 5" deep at 
>> the rear (for the root end).  36" long. 4 inches tall, by 10" wide by 3" 
>> deep (for the tip end).  This will give me approximately 7.00 gallons 
>> each.  Also will give me about 1" of foam between tank and wing skin.<<

What you're describing is almost exactly what I built for my outer wing 
tank, except mine was 8 gallons, and extended 40" starting at about 8" from 
the stub (root) end of the outer wing.  It'll work fine...go for it...

Mark Langford
n5...@hiwaay.net
website www.n56ml.com

KR> Outboard wing tanks

[Larry Flesner]

At 07:34 AM 11/24/2010, you wrote:

>The question I propose is;  How close to the rear of the forward 
>spar should the back of the tank be?
>Steve Phillabaum
+++

All my fuel is in the outboard wing panels only, 12.5 gallon each 
side.  They start at the root and extend to the 36 inch rib at the 
end of the wing.  They extend just 10 inches behind the forward 
spar.  That puts them so close to the C.G. that my C.G. changes just 
one inch from full to empty tanks.   If you are only looking for 6 or 
7 gallon per side you could make them even narrower and longer and 
keep them right on the C.G.  Install some good baffles to avoid slosh 
and you won't even know they are out there.

Off net for the next three days.  Have a good holiday...

Larry Flesner

KR> Outboard wing tanks

[phillabaum...@aol.com]

The question I propose is;  How close to the rear of the forward spar should 
the back of the tank be?

I am building my wing tanks from Fiberglass. (Final Choice).  But as far as 
size goes.  Because I have the forward spar that is 8 inches tall I plan to 
make my tanks. 6 inches tall at the spar, 10" wide, 5" deep at the rear (for 
the root end).  36" long. 4 inches tall, by 10" wide by 3" deep (for the tip 
end).  This will give me approximately 7.00 gallons each.  Also will give me 
about 1" of foam between tank and wing skin.
Will the 10" wide (front to back) be a problem with weight and balance? or 
should I make them longer but yet narrower?  I still want to stay just above 
the 6 gallon volume.  I hope to start working on them this Saturday while I am 
forced to be at work just to watch workers on site.
P.S. I am building them per one of the Tony Bingelis' methods. 

Steve Phillabaum
KR2Swide
Shorter, Alabama
334-740-0066

KR> Re: Sanding Vinyl Ester Layup

[smwood]

What is PVA?

In a message dated 11/23/2010 8:04:39 P.M. Pacific Standard Time,
l...@vandyke5.com writes:

Sorry  PVA.  I hate this iPhone sometimes

On  Nov 23, 2010, at 8:57 PM, Lee Van Dyke   wrote:

> If you know that you will have to sand V/E you can spray  pcs on the
> area that you layed up, it will help form a "crust" if you  will.  Then
> sand easy peasy lemon  squeezie
++

PVA is Poly Vinyl Alcohol.  It is sometimes used as a mold release agent so 
that molded parts won't stick to the mold surface.  The PVA is water 
soluable and will easily wash off the part.  The PVA will absorb some of the 
wax film that would otherwise form on the surface of the part during the 
curing of the wet layup.  Resin manufacturers put the wax in the resin (both 
Epoxy and Vinyl Ester) to keep the curing resin from absorbing moisture from 
the air.  The absorbed moisture would interfere with the curing process.
Another easy method to get the surface wax film off the cured part is to 
wipe with MEK (Methal Ethyl Ketone).  Don't use Acetone; it is too 
aggresive, evaporates too fast and will leave it's own residue.  Then you 
have to wipe the Acetone residue off with MEK.  Have plenty of ventilation 
AND do wear protective gloves when handling all of these toxic chemicals.

Sid Wood
Tri-gear KR-2 N6242
Mechanicsville, MD, USA
smw...@md.metrocast.net

KR> Sanding Vinyl Ester Layup - Or 'What is PVA'

[Mark Langford]

Get PVA at http://www.aircraftspruce.com/search/search.php  .  I also 
searched Wicks' site because I KNOW they have it, but after about a minute 
of search through everything from tailwheels to foam, I gave up and found it 
instantly at AS  Basically it's used as mold release agent.  Wax the mold 
with mold release wax, then spray a very light dusty coat of PVA (if you put 
it on wet it'll just bead up on the waxed surface), and then once that dry 
coat dries, you can put on a wetter coat or two to form the film.  Then 
layup your cowling or whatever, let it cure, and the PVA will pop apart (or 
will dissolve if exposed to water).  Never heard of using it for sanding 
purposes, but if Lee says it works, it probably does...

Mark Langford
n5...@hiwaay.net
website www.n56ml.com 

KR> Sanding Vinyl Ester Layup - Or 'What is PVA'

[Dan Heath]

PVA (Polyvinyl Alcohol)

See N64KR at http://KRBuilder.org - Then click on the pics 
See you at the 2011 - KR Gathering in Mt. Vernon, Il - MVN
There is a time for building and it never seems to end.
Daniel R. Heath - Lexington, SC

KR> Re: Sanding Vinyl Ester Layup

[Peter Drake]

Polyvinyl acrylate That is white wood glue.

Peter Drake UK

rdrace...@aol.com>
Re: Sanding Vinyl Ester Layup 


What is PVA?




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