Fred the Red Shirt wrote:
On Mar 16, 7:46 pm, I am Tosk wrote:
In article ,


Did you ever say what it is you are trying to make?



I'm looking at materials and techniques that would be useful for a
homebuilt glider.

--

FF


I thought you have a set of Texas Parasol plans, Fred.
Light and cheap techniques there.

--

Richard Lamb
http://www.home.earthlink.net/~cavelamb/

On Mar 19, 3:53*pm, cavelamb wrote:
Fred the Red Shirt wrote:

On Mar 16, 7:46 pm, I am Tosk wrote:
In article ,

Did you ever say what it is you are trying to make?

I'm looking at materials and techniques that would be useful for a
homebuilt glider.
...

I thought you have a set of Texas Parasol plans, Fred.
Light and cheap techniques there.


Yes I do and have found no better (where 'better' is defined
in terms of strong, light, fast, and not too expensive) way
to make a fuselage.

I think with composites I can make a lighter wing, considering
that a glider wing will be longer, thinner and have a shorter
chord than the TP wing.

--

FF

Fred the Red Shirt wrote:
On Mar 19, 3:53 pm, cavelamb wrote:
Fred the Red Shirt wrote:

On Mar 16, 7:46 pm, I am Tosk wrote:
In article ,
Did you ever say what it is you are trying to make?
I'm looking at materials and techniques that would be useful for a
homebuilt glider.
...

I thought you have a set of Texas Parasol plans, Fred.
Light and cheap techniques there.


Yes I do and have found no better (where 'better' is defined
in terms of strong, light, fast, and not too expensive) way
to make a fuselage.

I think with composites I can make a lighter wing, considering
that a glider wing will be longer, thinner and have a shorter
chord than the TP wing.

--

FF


The traditional primaries were quite heavy.

Think aluminum angle primary glider type fuselage and take the wing and tail
from the Texas Parasol.

The whole mess wouldn't weight 100 pounds.


--

Richard Lamb
http://www.home.earthlink.net/~cavelamb/

No longer relevant to boat building so I've crossposted and set follow-
ups.
Thanks, r.b.b. guys!

On Mar 19, 8:55*pm, cavelamb wrote:
Fred the Red Shirt wrote:



On Mar 19, 3:53 pm, cavelamb wrote:
Fred the Red Shirt wrote:


I'm looking at materials and techniques that would be useful for a
homebuilt glider.
...

I thought you have a set of Texas Parasol plans, Fred.
Light and cheap techniques there.

Yes *I do and have found no better (where 'better' is defined
in terms of strong, light, fast, and not too expensive) way
to make a fuselage.

I think with composites I can make a lighter wing, considering
that a glider wing will be longer, thinner and have a shorter
chord than the TP wing.

--

FF

The traditional primaries were quite heavy.

Think aluminum angle primary glider type fuselage and take the wing and tail
from the Texas Parasol.

The whole mess wouldn't weight 100 pounds.


Cool! It needs to be under 150 to qualify as a FAR 103 UL glider.

How much does one TP wing weigh? How much does the
whole plane weigh, sans engine?

A 12' SkyPup wing with a 52" chord and weighs about 26 pounds,
but that has no drag spar or ailerons. The whole Pup weighs 205
lbs.

--

FF

In article ,
says...

On Mar 16, 7:46*pm, I am Tosk wrote:
In article ,


Did you ever say what it is you are trying to make?



I'm looking at materials and techniques that would be useful for a
homebuilt glider.

Sounds like a blast. Are you starting from some plans or are you designing from
scratch? I may have missed it before but what materials are you going to use
for stringers and fabric?

Scotty

--
Rowdy Mouse Racing, no crybabies!

No longer talking boats so I've crossposted and set follow-ups
accordingly.

On Mar 20, 12:17*pm, I am Tosk
wrote:
In article ,
says...



On Mar 16, 7:46*pm, I am Tosk wrote:
In article ,

Did you ever say what it is you are trying to make?

I'm looking at materials and techniques that would be useful for a
homebuilt glider.

Sounds like a blast. Are you starting from some plans or are you designing from
scratch? I may have missed it before but what materials are you going to use
for stringers and fabric?


Designing pretty much from scratch. My inspiration is Mike Sandlin's
airchairs. But also check out the ULF - 1.

As for materials -- that's what I'm exploring now. At preset I favor
a
dacron fabric covered riveted aluminum frame for the fuselage (Like
the
Texas Parasol) and fabric covered composite wings like the UL SkyPup,
substituting carbon fiber tapes and rod for the spar and rib caps.

I suppose if I wind up cobbling something together from diverse
sources
I should call it the Frankenglider.

--

FF

In article , keillorp135
@chartermi.net says...

On Tue, 16 Mar 2010 13:42:41 -0400, Paul Oman
wrote:

wrote:
On Mar 14, 12:31 pm, Paul Oman wrote:

wrote:

Two questions for people with knowledge or experience with the UV
curing polyester resins:

1) Are they (any of them) compatible with polystyrene foam?

2) Once the UV light has initiated the polymerization, will it spread
through the layup even into places where the light did not
penetrate? I'm thinking, for instance about the underside
of carbon fiber cloth.

Thanks.

--

FF

it makes more sense to use thermo set epoxies. Stronger, better bond,
probably cheaper.
epoxies will not dissolve foam


Thermo set meaning that they don't begin to cure until they are
heated?
I ask because I am looking for a very long working time.

If so, do you have a recommendation?

Otherwise, can you answer the first question? I was quite aware of
the
other issues.

----------------------
thermo set means a chemical reaction between parts a and b and these
reactions produce heat. This is how epoxies work. You can get slow
epoxy curing agents and you can also slow down the reaction by working
in cooler temps.

paul oman - progressive epoxy polymers inc

More importantly, it means crosslinks between molecules, as when parts
a and b or their reaction intermediates have more than two reaction

That's a bit beyond my area of expertise, but are you saying Epoxy that
is mixed more perfectly, has more heat resistance? At least that is what
I am getting from your post.

Scotty

--
For a great time, go here first... http://tinyurl.com/ygqxs5v

On Sun, 21 Mar 2010 12:10:58 -0400,
wrote:

In article , keillorp135
says...

On Tue, 16 Mar 2010 13:42:41 -0400, Paul Oman
wrote:

wrote:
On Mar 14, 12:31 pm, Paul Oman wrote:

wrote:

Two questions for people with knowledge or experience with the UV
curing polyester resins:

1) Are they (any of them) compatible with polystyrene foam?

2) Once the UV light has initiated the polymerization, will it spread
through the layup even into places where the light did not
penetrate? I'm thinking, for instance about the underside
of carbon fiber cloth.

Thanks.

--

FF

it makes more sense to use thermo set epoxies. Stronger, better bond,
probably cheaper.
epoxies will not dissolve foam


Thermo set meaning that they don't begin to cure until they are
heated?
I ask because I am looking for a very long working time.

If so, do you have a recommendation?

Otherwise, can you answer the first question? I was quite aware of
the
other issues.

----------------------
thermo set means a chemical reaction between parts a and b and these
reactions produce heat. This is how epoxies work. You can get slow
epoxy curing agents and you can also slow down the reaction by working
in cooler temps.

paul oman - progressive epoxy polymers inc

More importantly, it means crosslinks between molecules, as when parts
a and b or their reaction intermediates have more than two reaction

That's a bit beyond my area of expertise, but are you saying Epoxy that
is mixed more perfectly, has more heat resistance? At least that is what
I am getting from your post.

Scotty

I was just saying that "thermoset" refers to a crosslinked resin,
which epoxy may or may not result in, depending on the hardener.
Actually, epoxy is a reactant, there ain't any left in the finished
product. Most epoxies are dgeba (diglycidyl ether of bisphenol A)
with various oligomer mixes left in. Commonly reacted with various
high functional amines to make thermosets. I also reacted epoxies
with difunctional amines and various difunctional organic acids to
make a bunch of different thermoplastics.

Heat resistance is partially related to crosslink density (affects Tg)
but more related to the backbone molecule. Bisphenol A based resins
generally had a Tg around 100 C. Novolac and resorcinol based resins,
etc. could be higher. All of it gives up under enough heat to destroy
the chemical bonds in the backbone. That's why I used fluidized bed
burnouts to clean dies and stuff. Nothing I made would stand 900 C.

None of this is important to boat building. The very high temp resins
are way too expensive, and were developed primarily for use in
aerospace. Garden variety epoxy has plenty of temperature capability
for boats.

Getting the mix right does directly affect crosslink density, and is
important in developing the correct properties of the resulting resin
matrix.

In article , keillorp135
@chartermi.net says...

On Sun, 21 Mar 2010 12:10:58 -0400,
wrote:

In article , keillorp135
says...

On Tue, 16 Mar 2010 13:42:41 -0400, Paul Oman
wrote:

wrote:
On Mar 14, 12:31 pm, Paul Oman wrote:

wrote:

Two questions for people with knowledge or experience with the UV
curing polyester resins:

1) Are they (any of them) compatible with polystyrene foam?

2) Once the UV light has initiated the polymerization, will it spread
through the layup even into places where the light did not
penetrate? I'm thinking, for instance about the underside
of carbon fiber cloth.

Thanks.

--

FF

it makes more sense to use thermo set epoxies. Stronger, better bond,
probably cheaper.
epoxies will not dissolve foam


Thermo set meaning that they don't begin to cure until they are
heated?
I ask because I am looking for a very long working time.

If so, do you have a recommendation?

Otherwise, can you answer the first question? I was quite aware of
the
other issues.

----------------------
thermo set means a chemical reaction between parts a and b and these
reactions produce heat. This is how epoxies work. You can get slow
epoxy curing agents and you can also slow down the reaction by working

I think I get it. In simple terms can I assume parts or molecules of
resin that are not activated by the correct molecules of activator, will
just stay resin and never really "harden" (for lack of a better term)?

--
For a great time, go here first... http://tinyurl.com/ygqxs5v

On Sun, 21 Mar 2010 17:16:00 -0400, I am Tosk
wrote:

In article , keillorp135
says...

On Sun, 21 Mar 2010 12:10:58 -0400,
wrote:

In article , keillorp135
says...

On Tue, 16 Mar 2010 13:42:41 -0400, Paul Oman
wrote:

wrote:
On Mar 14, 12:31 pm, Paul Oman wrote:

wrote:

Two questions for people with knowledge or experience with the UV
curing polyester resins:

1) Are they (any of them) compatible with polystyrene foam?

2) Once the UV light has initiated the polymerization, will it spread
through the layup even into places where the light did not
penetrate? I'm thinking, for instance about the underside
of carbon fiber cloth.

Thanks.

--

FF

it makes more sense to use thermo set epoxies. Stronger, better bond,
probably cheaper.
epoxies will not dissolve foam


Thermo set meaning that they don't begin to cure until they are
heated?
I ask because I am looking for a very long working time.

If so, do you have a recommendation?

Otherwise, can you answer the first question? I was quite aware of
the
other issues.

----------------------
thermo set means a chemical reaction between parts a and b and these
reactions produce heat. This is how epoxies work. You can get slow
epoxy curing agents and you can also slow down the reaction by working

I think I get it. In simple terms can I assume parts or molecules of
resin that are not activated by the correct molecules of activator, will
just stay resin and never really "harden" (for lack of a better term)?

Pretty much. More likely, the molecule would be reacted on one end
and not the other. Reaction kinetics will usually favor one end
reacting first. The end result is lower crosslink density, unreacted
groups, and less than full development of cured properties.

Pete Keillor