Epoxy vs CA

[Frank Weston]

----------
> From: Glen_Deligdisch@sil.org
> To: Pianotech@ptg.org
> Subject: Epoxy vs CA
> Date: Tuesday, March 17, 1998 8:00 AM
> 
>      Dear List,
>      
>      I want to thank all of you that responded to my 30 minute epoxy 
>      question.  The information you gave was just what I needed.
>      
>      Just one more little aside.  Talking to the folks in the hobby shop 
>      revealed some interesting opinions.  They said that model builders 
>      coming to their store preferred epoxy over CA.  I asked why. 


As one who has more than a little experience in aviation, both model and
otherwise, I can unequivocally state that the opinion expressed by the
store is pure hogwash.


 They 
>      said that CA glue dissipates out of the wood glued joints,
eventually 
>      nullifying the bond.  Epoxy remains permanently.  Model airplane 
>      builders say that they find CA joints begin coming apart after about
1 
>      and 1/2 years but epoxy joints never break at the joint again.  

Again, based on significant experience, I can testify that most flying
model airplanes have a life expectancy of less than a week.  How would
anyone know if CA joints come apart over time?  I have had a lot of
experience with both CA and epoxy in wood bonding and have never had any
problem with CA durability.  Both adhesives have their advantages and
disadvantages, but durability is not one of the tradeoffs.  

They 
>      say they use CA glue for those on the field emergency repairs but 
>      prefer epoxy during building times.
>      
>      Have any of you that use CA glue for repairs noticed these repairs 
>      coming apart at a later date?

Yes, I once had a radio controlled sailplane enter a terminal dive from
about 1000 feet.  On impact, the nose was driven into the ground up to the
wing roots.  The wings and empenage shed from the fuselage, and some CA
joints did fail.  But come to think of it so did a few epoxy joints, along
with the wood to which they were attached.

Seriously, don't worry that "CA glue dissipates out of the wood".  Before
it ever does there will be a lot of other problems to worry about, things
like asteroids striking Earth.
 

Frank Weston