Admittedly, not a lot of people have a regular need to varnish coils. It’s mainly something that Tesla coil builders and other high-voltage experimenters are concerned with. But since that group probably constitutes a not insignificant fraction of the Hackaday audience, and because there are probably more applications for this homebrew coil varnishing setup, we figured it would be a good idea to share it.
For [Mads Barnkob], coil maintenance isn’t something to take lightly. If you check out his Kaizer Power Electronics channel on YouTube, you’ll see that he has quite a collection of large, powerful Tesla coils, some of which are used for demos and shows, and others that seem to be reserved mainly for blowing stuff up. To prevent one of his coils from joining the latter group, keeping the coat of insulating varnish on the secondary coil windings in tip-top condition is essential.
The setup seen in the video below helps with that tedious chore. Built entirely from scraps and junk bin parts, the low-speed, low-precision lathe can be set up to accommodate coils of all sizes. In use, the lathe turns the coil very slowly, allowing [Mads] to apply an even coat of varnish over the coil surface, and to keep it from sagging while it dries.
[Mads]’ setup is probably not great for coil winding as it is, but for coil maintenance, it’s just the thing. If your needs are more along the lines of a coil winder, we’ve got a fully automated winder that might work for you.
Funny how this wright-up pops up just a day after I finish my first ( very small and low power ) Tesla Coil. This is a great idea for larger coils and even for winding the turns.
Can someone give me a quick rundown on the (organic) solvents in that varnish and doing that indoors, should fumes form? I have a great interest in home workshop safety precautions.Maintenance of industrial health and safety standards begins with yourself.
Poly Acrylic or Polyurethane. Polyurethane offgasses for quite a while, and I know that the oil based options are toxic.
Thanks that was a good tip with the polyurethane, had no idea about isocyanates.
You seem very concerned, so maybe you should look it up yourself. Most people don’t really care that much. If it smells bad do it outside or open a window.
Well until you get elevated liver markers once without the use of alcohol or medication you’ll think different.
The only real answer to that in a home workshop is either a DIY paint booth /fume hood, or a metric ton of airflow.
If you are doing a lot of small painting or chemical experiments, this is probably a really good idea anyway…
If you are doing this in a garage space I would probably just open the door a bit and have a large box off to the side fan pulling air over the workspace.
(If you blow air over the workspace you would likely get a lot of airborne debris in your varnish)
Or/and wear a respirator?
Respirators may or may not do anything against any or most VOC’s.
“The best solution is dilution” or words to that effect…
Frankel, I would not be doing this in a closed indoor room. You can not see it from this video, but its in my garage workshop and it has doors open in both ends and I am not present while its drying up :)
MLAB has a similar tool on their web for about 10 years. They call it RGHE or rotationally gravitational homogenisator of emulsion and is used for making sure that when you spray a PCB with Positiv 20 photosensitive emulsion, it makes a perfectly flat surface.
Ah, a spin coating machine. They work for HaD, providing them titles. Besides that, Positiv 20 is not an emulsion. Mayonnaise is.
In the late 1980’s I used to live near Elmhurst college, Elmhurst Il. USA. They have the kevatron particle accelerator made famous by the University of Chicago nuclear experiments of the 1930’s. The machine is a Cockroft-Walton design. (voltage multiplier) That is where with the help of some of the students I built my first Tesla coil. The unofficial motto of the accelerator lab was “If it arcs – Glyptal.” Glyptal is the varnish used in electrical motor windings and works great at high voltages. One of the cool things I learned from them is that duct tape becomes conductive at high voltages. As a side note I was in freshman year high school at the time. https://www.flickr.com/photos/drogos/albums/72157614296193392/
“ One of the cool things I learned from them is that duct tape becomes conductive at high voltages.”
Even air does! ;p sry..
Hmmm… warning sign “Revolving magenta light indicates radiation! Pull stop chain IMMEDIATELY”
Seems like that would be the kind of thing that you’d want to automate….
Like maybe the first thing you’d want to automate….
@SteveS I visited many years later when it had been converted to an art space. I was talking to one of the students and he posited ” What is the button in the bathroom marked SCRAM for?”. I responded that it shut down the machine and grounded it in case someone turned it on. He asked” Why would you be in the bathroom when somone turned the machine on?”. It’s called CYA! Also there was a submarine dive horn that sounded three times before the start of the machine. AAAAAAAHOOOOOOOOOOOGGGGGGGAAAAAAAAA
” “NoBatron”? No doubt it is one of The Joker’s fiendish inventions, Boy Wonder!
You go first!”
Glyptal was the standard for high vacuum leaks and high voltage. “Corona dope” is better for these Tesla Coils I think.
Actually, we used glyptal for sealing the vacuum system. Glyptal is a thick red insulating paint.
– RushMan (Senior Kevatron operator at Elmhurst College 1978)
sounds like a perfect excuse to buy a g0602
What is all this varnish stuff anyway? Be authentic and use shellac. And the solvent for shellac is ethanol or methanol. You can get shellac flakes and use ethanol for a pretty low hazard unless you are taking certain drugs, like some anti-fungal. In that case the alcohol will tear up your liver.