Fiberglass Fin Building

Fiberglass Fin Building

Post by Al Gloe » Sun, 05 Oct 2003 21:59:05



Ok, I was trying to learn something the hard way, that is figure it out. In
particular, how do you properly use fiberglass to reinforce/fillet a fin
mount?

Wha I have achieved so far:

1) On overpowering headache from the smell of the resin - Ok proper
ventilation will help that.

2) A gooey sticky mess. Here is where I could use some pointers.

Is it better to mix the resin, apply it to the airframe, and press the dry
composite into the root or use a paper mache technique where you dip the
composite in the resin and lay it down wet?

If there is any reference material available, I'd appreciate it if anyone
who can point me in the right direction.

Thanx

 
 
 

Fiberglass Fin Building

Post by Tim Summer » Sun, 05 Oct 2003 22:22:06


Quote:
> 1) On overpowering headache from the smell of the resin - Ok proper
> ventilation will help that.

Get rid of that stuff (polyester resin) for starters and pick up some US
Composites or West Systems Epoxy. The Epoxy systems have almost no odor to
them.

http://www.uscomposites.com/epoxy.html

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Fiberglass Fin Building

Post by tai f » Sun, 05 Oct 2003 22:12:49


I had always wet the surface first then apply dry cloth to the surface, less
mess that way. then if its not enough resin then you can add some more with
a brush...
 
 
 

Fiberglass Fin Building

Post by Kevin Trojanowsk » Sun, 05 Oct 2003 22:50:59


Quote:

> 1) On overpowering headache from the smell of the resin - Ok proper
> ventilation will help that.

As Tim indicated, it sounds like you're using the wrong resins.  A
respirator is a better idea than ventilation, anyway.

Quote:
> 2) A gooey sticky mess. Here is where I could use some pointers.

> Is it better to mix the resin, apply it to the airframe, and press the dry
> composite into the root or use a paper mache technique where you dip the
> composite in the resin and lay it down wet?

I've done both, but for reinforcing fillets, I prefer to run the strip
of cloth through the resin then use gloved fingers to squeegee all the
excess off, and lay it down in place.  Nitrile gloves are great for
this, as they allow you to get "hands on".

If it's a joint down inside a body tube, a dowel can be used to position
the strip.  Lay the strip lengthwise down the end of the dowel, and
allow it to fold in half.  Then roll the strip off of the dowel and into
the fillet.  Takes some practice, but it's doable and works well.

-Kevin

 
 
 

Fiberglass Fin Building

Post by David Weinshenke » Sun, 05 Oct 2003 22:58:44


Quote:

> Ok, I was trying to learn something the hard way, that is figure it out. In
> particular, how do you properly use fiberglass to reinforce/fillet a fin
> mount?

> Wha I have achieved so far:

> 1) On overpowering headache from the smell of the resin - Ok proper
> ventilation will help that.

Were you using polyester resin or epoxy?

Quote:
> 2) A gooey sticky mess. Here is where I could use some pointers.

> Is it better to mix the resin, apply it to the airframe, and press the dry
> composite into the root or use a paper mache technique where you dip the
> composite in the resin and lay it down wet?

> If there is any reference material available, I'd appreciate it if anyone
> who can point me in the right direction.

What sort of fiberglass were you using?

-dave w

 
 
 

Fiberglass Fin Building

Post by Bob Kapl » Sun, 05 Oct 2003 23:14:11


Quote:

> Ok, I was trying to learn something the hard way, that is figure it out. In
> particular, how do you properly use fiberglass to reinforce/fillet a fin
> mount?

> Wha I have achieved so far:

> 1) On overpowering headache from the smell of the resin - Ok proper
> ventilation will help that.

> 2) A gooey sticky mess. Here is where I could use some pointers.

On both of these points, it sounds like you used polyester instead of epoxy.
Polyester stinks, has a short shelf life, and is a PITA to work with.
Usually just a few drops of catalyst to a large amount of resin. If that's
what you got, trash it now.

Go with something like System 3, West, Raka, etc instead. In fact, buy or
download the System 3 book for answers to most of your questions.

        Bob Kaplow      NAR # 18L       TRA # "Impeach the TRA BoD"
                >>> To reply, remove the TRABoD! <<<
Kaplow Klips & Baffle:      http://nira-rocketry.org/LeadingEdge/Phantom4000.pdf
    www.encompasserve.org/~kaplow_r/    www.nira-rocketry.org    www.nar.org

 Save Model Rocketry from the HSA!   http://www.space-rockets.com/congress.html

 
 
 

Fiberglass Fin Building

Post by Gary » Sun, 05 Oct 2003 23:19:40


Quote:

> Ok, I was trying to learn something the hard way, that is figure it out. In
> particular, how do you properly use fiberglass to reinforce/fillet a fin
> mount?

> Wha I have achieved so far:

> 1) On overpowering headache from the smell of the resin - Ok proper
> ventilation will help that.

> 2) A gooey sticky mess. Here is where I could use some pointers.

> Is it better to mix the resin, apply it to the airframe, and press the dry
> composite into the root or use a paper mache technique where you dip the
> composite in the resin and lay it down wet?

> If there is any reference material available, I'd appreciate it if anyone
> who can point me in the right direction.

> Thanx

I think you have two separate questions here; filleting and reinforcing.

ROL InfoCentral has some tips on glassing:

http://www.FoundCollection.com/

A Google search with "rocket fins fiberglass" should turn up a few
informative links.

For reinforcing, I use thin epoxy (or *** thinned epoxy) on well
sanded tubes with the fins mounted. I cut out a piece of cloth to go
from fin tip, across the body tube, and to the tip of the adjacent fin
with the weave crossing the fin roots in an "X" pattern. Allow some
overlap on all fin edges. I wet the surfaces with a thin layer of epoxy,
lay the cloth from one fin tip to the other, and fill-in dry spots or
dab off wet spots. If you use thin (long setup time) epoxy, let it soak
in a few minutes before applying the cloth. After the epoxy dries, I
trim and sand the overlap. I use foam brushes for glassing. Work your
way from one point to another in laying the cloth, don't lay the entire
piece down at once. "Tugging" or pulling the cloth once it is down may
pull it up and away from the fin/tube joints. You want intimate contact
between the glass and rocket.

I don't have trouble with epoxy fillets cause I don't try to make them
perfect. ;) I use twenty or sixty minute epoxy, dab it along the joint
with a stick and let it "mold itself" into a fillet shape. I use
FillnFinish after the epoxy dries to make up for my chad application.

I accidentally stepped on a LMR cluster bird with TTW glassed fins
(don't ask). The only parts to survive were the fins.

--
Gary Bolles
NAR 82636

summum jus, summa injuria est

To contact me; bollesg at comcast dot net
http://www.FoundCollection.com/~bollesg/rockets/rockets.html

 
 
 

Fiberglass Fin Building

Post by Jerry Irvin » Mon, 06 Oct 2003 01:17:45




Quote:
> respirator is a better idea than ventilation, anyway.

This makes no sense to me.

Jerry

--
Jerry Irvine, Box 1242, Claremont, California 91711 USA

Please bring common sense back to rocketry administration.
Produce then publish.  http://www.usrockets.com
My articles valuable? Donate at iKobo.com c/o my email.

 
 
 

Fiberglass Fin Building

Post by Mark Simpso » Mon, 06 Oct 2003 03:22:34


Quote:

> Ok, I was trying to learn something the hard way, that is figure it out. In
> particular, how do you properly use fiberglass to reinforce/fillet a fin
> mount?

> Wha I have achieved so far:

> 1) On overpowering headache from the smell of the resin - Ok proper
> ventilation will help that.

> 2) A gooey sticky mess. Here is where I could use some pointers.

> Is it better to mix the resin, apply it to the airframe, and press the dry
> composite into the root or use a paper mache technique where you dip the
> composite in the resin and lay it down wet?

> If there is any reference material available, I'd appreciate it if anyone
> who can point me in the right direction.

> Thanx

If you're trying to reinforce a plywood fin mounted on a Kraft paper
body tube, forget the epoxy.  Use Titebond and triangular balsa to
reinforce your fins at the root.  It's easier, lighter AND stronger.

Mark Simpson
NAR 71503 Level II
God Bless our peacekeepers

 
 
 

Fiberglass Fin Building

Post by Al Gloe » Mon, 06 Oct 2003 03:24:15


I'm not sure what I am using (and will look). It is some stuff I got at a
auto parts store. My only previous experince was in helping a buddy glass a
hood scoop to a car, and that was 25 years ago. Came in a 1 qt can and the
ration is 1oz of resin to 12 drops of catalyst.

Thanks for all the info so far.

A

Quote:
> Ok, I was trying to learn something the hard way, that is figure it out.
In
> particular, how do you properly use fiberglass to reinforce/fillet a fin
> mount?

> Wha I have achieved so far:

> 1) On overpowering headache from the smell of the resin - Ok proper
> ventilation will help that.

> 2) A gooey sticky mess. Here is where I could use some pointers.

> Is it better to mix the resin, apply it to the airframe, and press the dry
> composite into the root or use a paper mache technique where you dip the
> composite in the resin and lay it down wet?

> If there is any reference material available, I'd appreciate it if anyone
> who can point me in the right direction.

> Thanx

 
 
 

Fiberglass Fin Building

Post by David Weinshenke » Mon, 06 Oct 2003 04:40:44


Quote:

> I'm not sure what I am using (and will look). It is some stuff I got at a
> auto parts store. My only previous experince was in helping a buddy glass a
> hood scoop to a car, and that was 25 years ago. Came in a 1 qt can and the
> ration is 1oz of resin to 12 drops of catalyst.

That's polyester resin.
Epoxy, as noted, has much less odor (compared to the
strong distinctive scent of polyester resin) and is
generally easier to work with. Just be sure to measure
accurately and mix very thoroughly for best results.

-dave w

 
 
 

Fiberglass Fin Building

Post by Jim Yani » Mon, 06 Oct 2003 09:32:23




Quote:

>> I'm not sure what I am using (and will look). It is some stuff I got
>> at a auto parts store. My only previous experince was in helping a
>> buddy glass a hood scoop to a car, and that was 25 years ago. Came in
>> a 1 qt can and the ration is 1oz of resin to 12 drops of catalyst.

> That's polyester resin.
> Epoxy, as noted, has much less odor (compared to the
> strong distinctive scent of polyester resin) and is
> generally easier to work with. Just be sure to measure
> accurately and mix very thoroughly for best results.

> -dave w

And different epoxies have different mix ratios,like 2:1 resin/hardener for
RAKA and System 3,and West is,IIRC,5:1 or 2:1 depending on which hardener
you use.

System Three has a really fabulous TRIAL KIT (for 10 BUCKS PPD!!)that gives
you a generous sample of epoxy and hardener,PLUS different fillers like
wood flour,silica,microballoons,and plastic fiber,and the VERY informative
Epoxy Book,which every epoxy user should read.

You can't go wrong in buying this trial kit.

Disclaimer;I'm not an employee of S3,nor financially or otherwise connected
to S3.

--
Jim Yanik,NRA member

 
 
 

Fiberglass Fin Building

Post by Jerry Irvin » Mon, 06 Oct 2003 10:05:50




Quote:



> >> I'm not sure what I am using (and will look). It is some stuff I got
> >> at a auto parts store. My only previous experince was in helping a
> >> buddy glass a hood scoop to a car, and that was 25 years ago. Came in
> >> a 1 qt can and the ration is 1oz of resin to 12 drops of catalyst.

> > That's polyester resin.
> > Epoxy, as noted, has much less odor (compared to the
> > strong distinctive scent of polyester resin) and is
> > generally easier to work with. Just be sure to measure
> > accurately and mix very thoroughly for best results.

> > -dave w

> And different epoxies have different mix ratios,like 2:1 resin/hardener for
> RAKA and System 3,and West is,IIRC,5:1 or 2:1 depending on which hardener
> you use.

> System Three has a really fabulous TRIAL KIT (for 10 BUCKS PPD!!)that gives
> you a generous sample of epoxy and hardener,PLUS different fillers like
> wood flour,silica,microballoons,and plastic fiber,and the VERY informative
> Epoxy Book,which every epoxy user should read.

> You can't go wrong in buying this trial kit.

> Disclaimer;I'm not an employee of S3,nor financially or otherwise connected
> to S3.

This should be in the FAQ.

--
Jerry Irvine, Box 1242, Claremont, California 91711 USA

Please bring common sense back to rocketry administration.
Produce then publish.  http://www.usrockets.com
My articles valuable? Donate at iKobo.com c/o my email.

 
 
 

Fiberglass Fin Building

Post by RayDunak » Mon, 06 Oct 2003 13:32:47


<< Get rid of that stuff (polyester resin) for starters and pick up some US
Composites or West Systems Epoxy. The Epoxy systems have almost no odor to
them. >>

They're also insanely expensive, and hard to find locally. I'd much rather use
polyester resin that I can buy at any hardware store for $20 a gallon, than
spend several times that much plus shipping (and waiting for it to arrive.)

 
 
 

Fiberglass Fin Building

Post by Kevin Trojanowsk » Mon, 06 Oct 2003 22:30:38


Quote:

> They're also insanely expensive, and hard to find locally. I'd much rather use
> polyester resin that I can buy at any hardware store for $20 a gallon, than
> spend several times that much plus shipping (and waiting for it to arrive.)

Many epoxies are easy to find, if you look.  I've found two local
dealers for West, one of which carries the full product line.

-Kevin