[NSRCA-discussion] CA for foamies

[Russ Little]

More on foam glue from the March 2006 Fly RC Magazine p70 Indoor  
Runways column by Thayer Syme _ thayers at flyrc.com

"FOAMHESIVE
A lot of people use foam-safe CA on foam aircraft because of the near  
instant bonding. Others favor a thin film of 5-minute epoxy. The  
problem with both of these choices is that they cure much harder than  
the surrounding foam. This creates a stress concentration that  
actually weakens the assembly.

Recognizing these shortcomings, Eddie Noble of Nikitas Aircraft  
approached some industrial chemists and came up with a solution.  
Foamhesive is a fast-acting contact adhesive that was specifically  
formulated for use with Depron foam. Foamhesive joints remain  
flexible and strong. The new adhesive allows stresses to be  
transferred across the joints, rather than focussing the energy into,  
and breaking down, the foam beside the glue.

Though not as fast as CA and kicker, you can build stronger and quite  
rapidly with Foamhesive. It is also much faster and neater than  
working with epoxy. Simply spread a thin film on each side of the  
joint, let it air dry for about a minute, then press the parts  
together. Foamhesive is relatively light, and any slop can be rolled  
of the foam and your hands for quick clean up. Foamhesive has become  
my favorite choice for foam models and is available exclusively from  
Billy Hell RC." Charming name. What follows is the blurb from their  
website:

http://www.billyhellrc.com/foamhesive.html

"FOAMHESIVE GLUE - $4.00 - 1 once bottle -

“Foamhesive” is scientifically engineered for laminating foam to  
foam, foam to wood, foam to CF and more. The great thing about  
Foamhesive is that the drying time is short. Foamhesive creates a  
bond that is flexible and NOT stiff. This creates a joint that is  
much stronger than one created by foam safe CA.
To use Foamhesive all you have to is run a bead of glue on one side  
of your two parts, adhere both pieces together and then separate.  
This activates the glue. Let your parts stand for 10 to 30 seconds  
then join the parts together. Glue will instantly join parts together.

The trick to wrapping carbon fiber around a tapered leading edge is:  
Apply glue to the leading edge, apply the carbon fiber to the piece  
with glue and then pull it apart. Let the two pieces set 15 or 20  
seconds. The final step is to apply the carbon fiber to one side  
first and tape, then the middle and tape, and then the other side and  
tape. Leave the tape in place.

You can sand Foamhesive to a degree but it will gum your sandpaper  
since it is a rubber based compound. The only storage requirements  
are to keep out of high heat and sunlight."

Russ Little
Sydney

On 26 Jan 2006, at 12:26 AM, Ron Van Putte wrote:

>
> On Jan 25, 2006, at 2:01 AM, adriancwong at earthlink.net wrote:
>
>> I'm building a foamy by using foam safe CAs.
>>
>> Would like to know is it ok to use any accelerator on the CA, or
>> whether there is one just for foams?
>
> Balsa Products (www.balsapr.com) sells CA (thin, medium, thick) and
> accelerator for non-foam applications.  They also sell CA (thin,
> medium) and accelerator for foam applications.  Good stuff.
>
> Ron Van Putte
>
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