Now epoxy bonds, was Gauge Bezels

["James J." <m1garand@speakeasy.net>]

Ah, Grasshopper, you must pause and consider.....  A reinforced epoxy 
can have an ultimate strength far higher than steel and other exotic 
metals, but the limiting factor here is the bond between an epoxy and a 
metal surface.  Epoxy w/o fiber reinforcement is often weaker than 
ferrous metals.  There is no chemical or crystaline bonding between the 
epoxy and the substrate in this type of repair , just a 'bite' dependant 
on the surface roughness of the prepared metal.  We're talking about 
adhesion vs. cohesion here.  Welding literaly melts two like materials 
together, although the Heat ffected Zone (HAZ) is usualy weaker than the 
parent metal if the parent has had any heat treating.
I think OEM's use it and approve epoxy only in places where welding is 
overkill.  Epoxy bonding (between metal and metal) is applicable where 
brazing or soldering is acceptable, in my humble opinion based upon my 
observations (not having seen any OEM documentation describing their 
decision process).  Having said that, some people have brazed entire car 
and airplane chassis to ease field repairs, so adhesive bonds can be 
quite strong, none the less.
James J.
p.s. I didn't mean the Grasshopper comment to be either serious or 
condesending, hope it didn't sound like either.


James Nazarian wrote:

> AFIK it is as strong or stronger then welding and is in wide use by both
> OEMs and collision shops.
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