Coil building issues

[Dan_The_Viking]

I have made a couple threads on here regarding issues I have been having while building coils for my RSST. Recently, I have been using 400 SS mesh with ribbon wire, 4/3 wrap that has been coming out to .9 to 1.1 ohms. I have also done the SS Mesh with an ekowool sleeve (which seems to have a muted flavor but thats another issue)

The coil will work perfectly for a couple of hours, but then it is getting hot spots, or sometimes 2-3 of the wraps start glowing and I get metalic taste. I can't post pics because I am at work right now and my RSST setup is at home. Coil doesn't appear to have any gaps, I don't believe it is chocking the wick. Has anyone experienced this or know what the issue is? I have just been rebuilding consistantly and have the same issues. I don't know what to change though. Any help is appreciated.

 

[folkphys]

Sounds like your wick cannot keep up with your coil. Usually the hotspotting happens towards the top of the coil/wick, yes? If so, then your wick is drying out towards at top before it can replenish its juice supply. Are you are running ribbon that is less than 0.8mm? You want full coverage from top to bottom of your coil on your wick in order to maximize vaporization per toot and maintain evenness of juice consumption (again, per toot). If you'd rather not increase your coil number, spread out your coils or use wider ribbon, perhaps sliding your current coil down closer to the deck might help....though in my experience this can lead to other problems like top-leg-hotspots when the top leg is longer than the bottom leg and in-tank-juice-cookery when unvaped juice above/below the coil is simply heated then reposited back into the tank. In my RSST, I used 0.8mm ribbon in a 4/3 wrap coming out to 0.7Ohms with a shorter-than-stock topcap and a 4/5 wrap (0.9 ohms) of the same with the stock cap.

 

[Plumes.91]

I agree, could either be a wicking issue or possible shorting. If you know you did everything right you can rule out the shorting. If you wrapped the mesh in ecowool, I doubt it's a short. But the could could be a bit too tight around the ecowool OR the ecowool could easily be choking/stopping-up the wicking abilities of the mesh. Try direct dripping onto the coils and see if the red goes away. If it does, you got yourself a wicking problemo.

Me thinks.

 

[Dan_The_Viking]

Thank you both for your advice. It is much appreciated.

 

[vapdivrr]

as you stated your coil starts out good but once heated it starts to produce hot spots. this is simply the wire expanding and contracting. once this happens the proper tension is lost. because of the use of ribbon wire, this expansion is intensified because ribbon wire is just harder to use compared to kanthal. for one, it just doesn't bend or mold as good, also the way in which the ribbon is caught in the connections. this makes it harder for it to STAY. it simply is moving and loosening once it heats . do you drill bit the coil first or wrap the ribbon around the wick by hand?

 

[Dan_The_Viking]

as you stated your coil starts out good but once heated it starts to produce hot spots. this is simply the wire expanding and contracting. once this happens the proper tension is lost. because of the use of ribbon wire, this expansion is intensified because ribbon wire is just harder to use compared to kanthal. for one, it just doesn't bend or mold as good, also the way in which the ribbon is caught in the connections. this makes it harder for it to STAY. it simply is moving and loosening once it heats . do you drill bit the coil first or wrap the ribbon around the wick by hand?

vapdivrr, I have been trying each, and also wrapping around a bit that I placed in the wick hole. I wrapped around a bit and then connected to the posts last night. Seems to be working thus far, but I only used it for about an hour before bed last night. If I don't tilt, the top coil was starting to glow very faintly, but if I tilt it goes away. I must be choking the wick or something, as said above. I'm going to keep working on it.

Another question. I am out of SS mesh right now, but I have just been re-using the same piece of mesh for the last couple of weeks. Is there a problem with doing that? I don't see why there would be.