Better adhesion WITHOUT prepping surface?????
Better adhesion WITHOUT prepping surface?????
(OP)
My epoxy saga just gets stranger by the week. I'm doing some testing on how best to epoxy AL to 301 1/2 hard SST. I've found an epoxy that works almost OK. I've been trying to find a reliabe method for preparing the surface to maximize the surface bond strength. It appears that, if I rough up aluminum-yes, I can get some crazy bond strenght. HOWEVER, it appears the surface bond strength on the SST, is notably less when I either sand blast or rough it up with sand paper.
How can this be, it's counter-intuitive! I get better adhesion by just simply cleaning the SST, than roughing it up?! Up is down, black it white! What's going on!
Jim
How can this be, it's counter-intuitive! I get better adhesion by just simply cleaning the SST, than roughing it up?! Up is down, black it white! What's going on!
Jim





RE: Better adhesion WITHOUT prepping surface?????
Have you tried a light acid etch or pickle on the SS? That might be a more reliable surface to work with.
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Plymouth Tube
RE: Better adhesion WITHOUT prepping surface?????
Isn't the whole idea of roughing up a surface to INCREASE the contact surface area.
I think this product has acidity to it already, because on the parts that failed, I can see where it's no longer shiny, it looks etched.
I need Dr. House and his cronies to run differentials on this topic.
Jim
RE: Better adhesion WITHOUT prepping surface?????
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RE: Better adhesion WITHOUT prepping surface?????
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Plymouth Tube
RE: Better adhesion WITHOUT prepping surface?????
RE: Better adhesion WITHOUT prepping surface?????
RE: Better adhesion WITHOUT prepping surface?????
Not a stainless guy but this thought occurred to me.
If 301 SST is 310 stainless steel then the surface has different properties than the underlying material because stainless steel forms an oxide layer. When you roughen the surface you remove that layer which did bond pretty well. After you have roughened you need to reestablish the surface.
Thomas J. Walz
Carbide Processors, Inc.
www.carbideprocessors.com
Good engineering starts with a Grainger Catalog.