Nichrome oddity.. Advice?

[Chez]

So I just got some 28ga Nichrome to try out. I normally use any of kanthal 28ga, 30ga, .7 or .8 ribbon.

I wrapped a microcoil for my kayfun, measured it with a fluke meter (1.0ohm - perfect) mounted it and did my usual routine of pulsing it in, then heating it up and pinching it (making sure to let off the fire button first so as not to short it) and it seemed fine. Lit it up again fine and then nothing.

Put it on my zmax and it told me there was a short.

So I thought I'd try again.. So I wrapped another and the exact same thing.

I did notice it was heating up the kayfun base more than normal so I checked to make sure my insulators were ok.. They were.

Then I did the exact same thing with 28ga kanthal (a wrap or 2 less as it has slightly higher resistance) and it's working perfectly.

I've never used Nichrome before, so thought I'd ask if you guys had any idea what's going on?

The only differences are the fact that it was Nichrome and that it took a couple of extra wraps to get to the same resistance. I made sure it wasn't touching the airhole or anything it shouldn't be..

Odd.

 

[vapdivrr]

i believe nichrome needs to be sort of oxidized. try flaming the wire first before wrapping. also once you made the coil you need to heat & squish to make them tighter, if not tight i think they short more easily then kanthal.

 

[Chez]

I flamed it first then wrapped it, then flamed and pinched, mounted it then fired the mod until hot, released the button and pinched again..

I'm wondering if perhaps this last step removed some oxidation and shorted it?

I never have an issue with kanthal doing this

 

[pdib]

I personally haven't had such issues with Nichrome (use it alot). I've torched, pinched, blah blah done all that without troubles. What Vap says is what I read too. I think Kanthal has some aluminum oxide or something coating it. Or it forms a coat of oxide (which is why aluminum is part of the composition?).

There were a few people having their 26 Nichrome coils kin'a melt down / short out a little while back. so, it happens, we just never figured out why. There was the "bad batch" theory on the 26g.

 

[vapdivrr]

I flamed it first then wrapped it, then flamed and pinched, mounted it then fired the mod until hot, released the button and pinched again..

I'm wondering if perhaps this last step removed some oxidation and shorted it?

I never have an issue with kanthal doing this

the advise I told you was just something I heard but if there is anyone who knows about nichrome it is the one above, pdib almost vapes nichrome exclusively so maybe his theory on a possible bad batch might hold some water. I however have never used it, but did see a video on it one time where it seemed to short out slightly until it was pinched a lot. good luck