[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Tesla coil with metal and bugs in pvc repaired.
Original poster: "Garry Freemyer" <garryfre@xxxxxxxxxxx>
Well, I finally got done rewinding my Big five foot spark gap Tesla coil and
it seems to be lasting and working well as ever ....
1. I used a file to grind away all the burned plastic and dig out the metal
pieces. I then covered the gouges in silicone seal and smoothed it out with
a flat spatula and then let it harden. I repaired the pipe because I had a
theory that any material that might create sparking, would probably have
already created flaring arcs. In fact I covered the entire tube in this
stuff thinking it might provide some extra insulation and stability for the
windings. I found wire shaped metal in the plastic of the other coil.
Conclusion - It was a mistake to cover the entire tube with silicone seal.
While using this material to fill in gouges worked ok, the silicone is far
too prone to attracting unwanted dust and caused my hands to sweat in worry
about getting it wound before more airborne trash settled on the tube and
the silicone seal appeared to repel the epoxy in step two in places, leaving
areas seeing devoid of epoxy and had to keep dribbling epoxy on these areas.
Rather than providing a stable surface, it provided a rather slippery
surface to try to wind the wire around.
2. I used a poor man's winder that was just a knob attacked to a piece of
steel and bolted to an end plug with each end being supported by an L
bracket with the bolts through holes in the brackets and c-clamped to the
3. I used the pour on epoxy that comes in two eight ounce bottles,
apparently sometimes these bottles do NOT contain equal amounts of hardener
and polystyrene epoxy, for after carefully measuring these amounts and
mixing them, there was quite a bit more hardener than epoxy left having
mixed 10 ounces each. I am glad I did not mix in more hardener but trusted
that I had mixed equal amounts for if I was wrong, the end would have been a
sticky mess. Never mix in coldish areas. It can separate instead of setting!
This goes to show, if you buy this stuff, better compare the content levels
before buying a pair or you may end up scratching your head wondering what
happened. Mixing cups that with vertical sides instead of slanting sides
would provide less chance of error.
Using the poor man's winder, I was able to turn it and keep away the drips
except for a few places.
The result was a rock hard think coat of epoxy that had an uncanny tendency
to bang into chairs, table edges, walls, doorknobs and all manner of things
that that would cause a fastidious coiler to grimace. I really do think that
Jedi Light sabers must be coated with this epoxy and this is why they seem
to block and hit everything, even light beams! :)
The mineral oil was replaced by paraffin wax, but I kept getting water into
it and I could not figure out why till after several tries I noticed water
dribbling off the pan I removed from the water bath into the other pan.
Water and Wax repel each other, except when over electric ovens, they seem
to produce sudden mushroom shaped cloud spouts of water, that seep into the
lid and hide under the melted wax!
4. A very careful re-melting of the wax in the plastic container in the oven
set to just under 200 degrees ensured a uniform wax penetration. In
retrospect, I think a vibrator on the side might have been a help in
distributing the heat and shacking out any bubbles.
Now I don't have this slow leak of oil to worry about
5. Was contracts as it melts, I hope this don't result in cracking. That
could be a problem.
I'm wary of this encasing in wax. I seem to remember reading about why it
might not be a good idea but forgot where, and read some reports from others
who had success with it. Well, it seems to be holding well so far.
I used the ?? Lau vortex gap, surrounded by a sort of muffler and light
shield made from a plastic Pepsi bottle with foam attached to the inside,
and cut in half to form two C shaped, and attached to the gap leaving some
openings for air to get inside.
It actually seemed to improve the length of the sparks, or reduced the
blindness so I could see the sparks better.
6. Many bug corpses were sacrificed to the pvc filing during this endeavor.
I remain unrepentant! :)