Mustad 91715D spoiled under curing - why??

[Bucho]

I keep having problems with this hook dulling out and loosing its protective chrome surface under curing. I first thought it was the oil on the hooks so I carefully de-greased them with alcohol. I still have severe problems and just spoiled an entire badge. Worst thing is that I cannot reprocude it. Just tried a whole bunch of hooks of several sizes, degreases some - all came out fine (see loose hooks left side of picture).

What can it be that spoils the painted hooks? I had them stored on different metal hangers, maybe only some of the hangers react under curing and dissolve the chrome? :huh: :huh: :huh: 

 

[gaspumper]

Try curing at a lower temp for longer period.

 

[Bucho]

I already got the lowest possible setting since I learned from mix ups with tin heads. Never changed it, and the blank test hooks did well, too. Must be something else.

 

[Pup]

If I encountered this, I'd try wrapping each hook with reflective tin foil.  Wrap with the foil's duller side inward over the hook.

 

[Jig Man]

Don't have an answer for ya bud, I have the same problem with red sickle hooks. Red flakes off real easy after curing...

 

[Hawnjigs]

I encountered that problem once with 91715D 4/0. It appeared some hooks were made using rusty wire with too thin plating that vanished, in my case with the heat of casting. Out of the box bad hooks didn't look right, dull finish with rusty spots visible where the plate didn't stick.

Curiously, I notice your hook eyes seem unaffected?

 

[Fatman]

Are the jigs still usuable?? X2 with Hawn on why the hook eyes didn't do it. Did it actually flake off or did it just dis-color them???

Never had problems with the red chrome sickles flaking.

 

[Bucho]

I`m not in the shop right now but as I remember it some eyes were less affected  - but still significantly effected. The jigs are useable in a way, I mean I will not spend 10min worth of labour on them and put my name on it selling them in the shop when they look like that and rust away in a matter of 1 or 2 trips to the salt.

@ hawnjigs: They all looked perfect when they came out of the (same) 1k box. Like the ones beside on the pic which went trough the whole baking and degreasing process.

 

[Hawnjigs]

Apparently what you're seeing is the wire in original defective condition before the Duratin process. The mystery is what happened to the "plating" which appears to have literally vanished into thin air? Maybe Mustand could provide an explanation.

Were other jig heads in the same batch OK, and you only showed the bad ones in the pic?

 

[duffy]

What are you using to flux your lead with? Anything that could contain an acid? The plating on those (and most) hooks is very very thin and is  generally simply a tinning coat that can disappear real easily. Just think how a gum wrapper vanishes in a fire. Only thing I don't get is the ones with the eye's that are ok. Have you tried rubbing the flat hooks with a cloth to see if they will polish back up?