Hi all,

I paid a visit to a local scrap metal dumpster while visiting my grandparents, and pulled a fluorescent lamp choke out of an old stove. It's a Frost model FBAK-10 rated for 13 to 22 watt lamps and 0.36A. I've tested it, and it works perfect, even after being exposed to the elements for who knows how long.

Unfortunately, copper thieves had already gotten to the stove, and pulled one of the leads from the choke, leaving just the bare, thin magnet wire. The other lead was left intact. I want to solder a new lead onto it, but I'm afraid if I go by my "gut feeling", as I do with a lot of stuff, I'll end up breaking the magnet wire off, or something equally tragic. So I'm wondering if anyone has any tips to help me go about pulling this off?

I've already torched the end of the magnet wire to burn the lacquer off it. What I'm thinking of doing next is just simply soldering the new lead (stranded copper) to it, and then adhering that end of the lead to the choke using super glue and/or RTV silicone so it doesn't move around and bend the magnet wire. Sound good?

If everything goes well, I might use this thing to convert my F20T12 strip light to preheat.

Thanks guys.

Make sure you seure the lead wire so, the magnet wire isn't strained at all, keep there even some "stress relieve" bends.
The "superglue" or similar do not work well, they are too hard and brittle.
Better is some epoxy resin.
What would work is a piece of PC board with (two) plates fixed onto the ballast body by screws. Both wires (the magnet from the choke, as well as the lead wire) are then soldered onto this PCB. But that arrangemen makes there exposed electrical connection, so it is usable only, when the fixture design allows for that (sufficient covering,...)

Thanks for the tips. I figure RTV silicone probably won't hold great, either (I don't think it's meant for an application like that), so I think I'll invest in some epoxy putty.

Well, the deed is done. I soldered a piece of wire onto the magnet wire, and had a heck of a time doing so. I don't know if it's my dinky 25 watt iron, cheap chinese eBay solder, or just what or how I'm trying to solder.   But eventually I did get it. Then I bought some J-B Weld Kwik Weld ($10 at Canadian Tire), mixed a blob of that up and adhered the end of the new lead to the choke with it. Says it should set in 6 minutes and cure in under an hour. Hopefully it works.

Correction: It cures in 4-6 hours. Which is a relief since it's been 45 minutes and it's still somewhat rubbery. 

It strongly depend, how you dose the components (the hardener) and how well it is mixed. But most makers specify the full strength is at least after 24hours. Generally warming the thing up cures it way quicker (many proffessional materials are on purpose composed so, they harden only at the elevated temperature, this allows more time to work on the thing before it hardens; then it is put into an oven for few hours)

The stuff I bought comes in a syringe which spits out equal amounts of the two compounds. That's pretty much the only reason I bought it, and in retrospect I wish I had gotten just the regular J-B Weld (which comes in two separate tubes) instead. I read reviews on the Kwik stuff, and many people said it doesn't harden all the way, and is generally poorer in quality than the original stuff (which I suppose you should expect for something formulated to cure in a quarter of the time).

Luckily for me, the ballast came out good. Indeed, the stuff is not rock-hard like J-B Weld should me - it's more like very hard rubber. But the new lead is very secure nonetheless, so I'm happy. I'm giving the ballast a test run right now. Hopefully the heat doesn't make the stuff soften.