Alternative leading edge material?

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AdrianS

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Jul 5, 2014
Messages
719
Location
Australia
Hot Wings has a VERY valid point regarding cardboard. I am reminded of the great advances that have been made to this simple medium every time I open a new case of beer. It also brings to mind the designer [name slips my mind] with a pusher who advocated very thin
F/glass to cardboard as an excellent material.
We have used epoxied cardboard for various non-structural parts in rally cars for years.
 

dog

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Dec 29, 2019
Messages
578
Concerning cardboard,or wood based materials,In another thread someone posted a newer composite material that was composed of pure celulose,with the lignin removed somehow.
So thin metal,the 3m adhesive sheet( with layer of foam), and a composite layer.
This thread is based on a shared tap tap tap,of a finger nail on a leading edge and the knowledge that after that tap tap tap,its gona nag atcha.
I beleive that in another thread touching on the
same issue,and the notion that building the leading edge too stiff could (speculativly) somehow interfere with the structure designed
to carry torsional loads instead of a D cell,
to which Pops detailed the leading edge in one of his builds that used plywood?(from memory) and clearly wasnt going to be stove in
with a finger.
 

Steve Gawler

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Joined
Dec 18, 2019
Messages
5
Hot Wings has a VERY valid point regarding cardboard. I am reminded of the great advances that have been made to this simple medium every time I open a new case of beer. It also brings to mind the designer [name slips my mind] with a pusher who advocated very thin
F/glass to cardboard as an excellent material.
When I built my Kitfox I cut off the drooped part of the wing tip to fret a “Speedster” style tip. I used cereal boxes as the mold, glassed both sides. Worked perfectly because it was very moldable and lightweight.
 

galapoola

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Jun 4, 2017
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151
Location
NJ
Has anyone tried polycarbonate sheet? When I was looking for some .125" at a big box they had .07 or thereabouts and that thickness was very bendable. It is of course "bullet proof" glass so it should hold up, shouldn't ding easily.
 

Victor Bravo

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KWHP, Los Angeles CA, USA
Has anyone tried polycarbonate sheet? When I was looking for some .125" at a big box they had .07 or thereabouts and that thickness was very bendable. It is of course "bullet proof" glass so it should hold up, shouldn't ding easily.
Steel sheet would be even tougher, and Tungsten sheet even tougher than that.
 

challenger_II

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Jul 15, 2009
Messages
497
Location
Fisher County, Tx. USA
Mentioning model airplanes, and cardboard, in the same sentence jogged my feeble memory.
The Modern Day model aeronuts have moved from cardboard, to Dollar Tree foam board. Has a paper coating on one side, that is easily removable. Take said foam board, cut/fit/stick in place. Then, do the fiberglass resin thing. In this application, I believe thinned-out T-88 would do. For ultimate smoothness, use waxed plastic sheeting (think painter's drop cloths} pulled tight over the treated area.

TFF, you are a genius!

The issue with cardboard is lifespan and it’s heavy if protected from elements. I have built cardboard RC planes and they can be fun. If you varnish the cardboard for protection, you have two glues; one glue holding the fibers together and then a second to protect. Double of something you want one of. Waterproof cardboard that is not waxy or glossy that you can cover with airplane covering. It can’t be able to absorb water. Wash, rain, or humidity. Cant rot or mold easily. Starting to ask for a miracle material. It would be well known if it was out there.
 

challenger_II

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Jul 15, 2009
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497
Location
Fisher County, Tx. USA
Coroplast can be lots of fun to get stuck together. The SPAD boys have tried lots of things.
However, I have found a 3M adhesive process that sticks it together to where the material will be destroyed, rather than the glue joint, when you attempt to get it to come apart (test to destruction stuff).
Jog my memory, later, so that when I get home from work, I can look up the materials, and process used.

Gluing Corplast to airplane specs is hard. It wants to play Teflon non stick
 

Norman

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Nov 28, 2003
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3,132
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Grand Junction, Colorado
Mentioning model airplanes, and cardboard, in the same sentence jogged my feeble memory.
The Modern Day model aeronuts have moved from cardboard, to Dollar Tree foam board. Has a paper coating on one side, that is easily removable.
If all you want is the foam why not cut out the middleman and hotwire a couple of insulation foam panels into 1/4" sheets? You don't even need a hot wire bow, just run a couple screws into work bench and stretch a stainless steel guitar string across the table. Slide the insulation panel through the hot wire and 8' long sheets slide out the other side. Glue Dacron to the surface that will be inside the wing and wrap it around the leading edge. Then apply the wing skin and voila you have a sandwich leading edge suitable for very low performance airplanes.
 

dog

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Joined
Dec 29, 2019
Messages
578
Coroplast can be lots of fun to get stuck together. The SPAD boys have tried lots of things.
However, I have found a 3M adhesive process that sticks it together to where the material will be destroyed, rather than the glue joint, when you attempt to get it to come apart (test to destruction stuff).
Jog my memory, later, so that when I get home from work, I can look up the materials, and process used.
Jog,3m adhesive.
 

challenger_II

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Jul 15, 2009
Messages
497
Location
Fisher County, Tx. USA
As promised:

3M PR1500 adhesive
3M SI1500 adhesive, as an alternate
3M AC77 Primer (the KEY ingredient!)
3M Scotch-Weld Surface Activator (a must-have item)

Go to the 3M website for proper instructions.
I have empirical data that this process successfully PERMANENTLY sticks Coroplast to Coroplast, and wood to Coroplast.

Note of caution: do NOT let this stuff get any where close to foam! :)

Jog,3m adhesive.
 

dog

Well-Known Member
Joined
Dec 29, 2019
Messages
578
As promised:

3M PR1500 adhesive
3M SI1500 adhesive, as an alternate
3M AC77 Primer (the KEY ingredient!)
3M Scotch-Weld Surface Activator (a must-have item)

Go to the 3M website for proper instructions.
I have empirical data that this process successfully PERMANENTLY sticks Coroplast to Coroplast, and wood to Coroplast.

Note of caution: do NOT let this stuff get any where close to foam! :)
Thanks.
I am gathering any info on dissimilar materials
bonding in HBA,as I would like to panel my
wing,which is wood,with intended fabric covering,with thin PV built on stainless sheet.
One panel on the fueselage and two pair
on the inboard part of the wings,leaving the main part of the wing as fabric.
Will start with a fueselage mounted panel first
and do more based on experience.
Writing this stuff down in my book of HBA
 

davidjgall

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Joined
Oct 7, 2010
Messages
130
Location
Northern California, USA
Concerning cardboard,or wood based materials,In another thread someone posted a newer composite material that was composed of pure celulose,with the lignin removed somehow.
 
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