G-Flex epoxy temperature resistance?

S

shqxk

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Mar 26, 2012
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According to Nick Rossi post in knifemakers group on facebook. What do you guy think?

 
That's lower temperature than I would have assumed.

There are people on this forum parkerizing knives after glue-up (old threads). I don't recall which epoxy.

System 3 T-88 still has 1000 psi lap shear strength in an aluminum/aluminum bond at 180 F.
 
One of the problems Cekakoating hollow handle knives is that they use G-FLex which "sweats" oil when the knife is heated in preparation for the Cerakoat.

By contrast the nylon cord will hold up to 200 degrees...

By spraying quickly the paint on my particular Lile, the oil sweated slowly enough to go "over" the already applied paint, not under...

Don't use the knife to roast stuff over a fire....

Gaston
 
what epoxy was it ? gflex makes different formulas/types for different applications. anyone know the fail temperature for CA glue?
 
I'm also curious to know which gflex it was. I generally use the thicker stuff. I have some blade bond but haven't used it.

Edit to say I also mechanical fasteners and have had blades left in very hot vehicles with no noticeable difference. However, I'd still like to know a little more.
 
I use mechanical fasteners (pins or screws) & do a good surface prep with coarse paper & acetone on all parts prior to assembly.

I'm wondering what surface prep he did, the grit used to rough up the parts, the cleaning method for flat surfaces & how it was actually made. Just curious about this stuff, so far no problems on mine yet....
 
Guys, you need five minutes to check the temperature can withstands epoxy you use :) As far I know from my personal expirience ..................most of them I use on 140 celsius will melt .
 
This is from West Systems, look at the comment about returning to room temperature before stressing the bond.

"We have glued two blocks of mahogany together with WEST SYSTEM® epoxy, allowed it to cure for one week at room temperature, and then exposed the whole assembly to 200°F for 3 hours before forcing a chisel into the glue line to fail the joint. When the joint was examined closely, we found that the primary failure was in the wood and not the epoxy. Experience has also shown that while heat tends to soften epoxy while it remains warm, if WEST SYSTEM epoxy is not exposed to damaging heat (exceeding 230°F for extended periods), it will return to full strength when cooled to room temperature."
 
I just had a client's mother-in-law put their knife in the dishwasher on a pots and pans cycle and there was no G Flex (604?) left when they passed it to me for repair. The pins were easy to pop out, so I'm afraid I have to confirm. Luckily managed to rescue it, but it had me thinking!


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My understanding is that curing epoxy at high temperature will dramatically increase its glass transition temperature. I regularly cure my epoxy at 160 F, and thought most epoxies would respond well to a similar treatment (?)
 
It depends on the blend. Remember that JB Weld is epoxy and AVCOAT,the stuff used for the Apollo ablative heat shields, used an epoxy/phenol based resin.
 
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