[TheForge] More on knife gluing

[James Binnion]

Recently spent an interesting 30 min on the phone with a guy who  
develops epoxy systems for folks at NASA and various military  
applications. A couple of take aways from the conversation.

The best strength comes from epoxies that need heat to cure, not to  
accelerate the cure but need heat to cure at all. Not your typical  
consumer grade material.

His mantra for epoxy on metal is rough surfaces are next to godliness,  
clean is good but nothing beats a 30-60 grit surface finish for  
adhesion. He prefers grit blasting but sanding will do if that is all  
that is available.

If you are gluing different materials together (wood to metal or  
copper to steel for example) you are better off with a epoxy that has  
some flex to it to allow for the differences in thermal expansion  
between the materials.

  Now if I could just afford his epoxy, $1100 for 16 oz. , sheesh.


Jim

James Binnion
jbin at well.com