Re: [TCML] Envirotex Lite , High Torque drive

[DC Cox <resonance@xxxxxxxxxxxx>]

The Envirotex Lite certainly does produce an excellent finished coating.
Unfortunately it does not seep deep in between windings to provide really
good HV insulation.  It's a good idea to use some varnish (I prefer AC-43)
to thoroughly insulate the coil prior to applying the EnviroTex Lite.

On Steve W's coils it certainly is proven that it can stop secondary damage
when a rogue sec spark strikes the sec coil.  It splashes out into a wide
area coupling it's energy into the winding with capacitive coupling.  This
wide area insertion provides excellent sec coil protection.

Dr. Resonance




On Sun, Aug 2, 2009 at 5:03 PM, Brian <brianv@xxxxxxxx> wrote:

> [Brian] I was reading the post regarding the Envirotex Lite coating and
> after a little research I came across this post, Looks like Scott Hanson
> was
> the original poster and it explains the process of using that type of
> coating and is quite informative:
>
>
> [Brian] Original poster: "Scott Hanson" <huil888@xxxxxxxxxxxx>
>
> Terry, all -
>
>
> I have used Envirotex-Lite for coating secondaries since 2000, and have
> developed a process that works very well for me. I posted this procedure
> once several years ago, but I couldn't find it in the TCML archives, so
> here
> it is again:
>
>
> The epoxy material I use is "Envirotex-Lite", and it's advertised as a
> "pour-on" coating. The manufacturer is Environmental Technology, Inc, and
> their website is www.eti-usa.com.
>
>
>
>
> There are a large number of consumer and industrial epoxy's that are
> suitable for coating secondaries, but this particular one is carried
> locally
> (So California area) by the Ace Hardware chain at a reasonable price. There
> are several different "kit" sizes; the quart kit contains enough material
> for at least (4 ) 6" X 30" secondaries.
>
>
>
>
> (Here is a process for applying epoxy coatings that I have posted before,
> but may be of use again as there seems to be a renewed interest in using
> these coatings for secondaries):
>
>
>
>
> I strongly suggest that anyone who is contemplating coating a finished
> secondary, and can cobble up any type of a motorized "rotisserie" device to
> keep the thing turning at slow speed, consider using a two-part epoxy
> instead of any type of solvent-based coating (varnish, Glyptal, etc). I
> recommend a DC gearmotor with an adjustable speed control; this allows you
> to set the optimum surface speed regardless of secondary diameter.
>
>
>
>
> Having coated at least a dozen secondaries with epoxy, I can assure you
> that
> NO solvent-based coating can remotely begin to compare with the appearance
> of a correctly-applied epoxy coating. First of all, a single "light"
> application of epoxy provides a cured coating thickness of at least
> .030"-.050". It would take many, many coats (dozens!) of varnish to
> generate
> a similar thickness. The total "wet-time" of these multiple coats is many
> times that of the single coat of epoxy, greatly increasing the time that
> the
> coating is susceptible to picking up dust, etc.
>
>
>
>
> Because the epoxy stays "syrupy" until it starts to jell, you can flow on a
> heavy coat very quickly, then allow the coating to "self-level" while
> rotating. This results in a finished secondary that appears to have the
> windings encased in a glass sleeve. Any type of solvent-based coating
> begins
> to lose solvent, thicken, and skin-over the instant that the lid is removed
> from the can. It's impossible to "level" the entire coating on a coil at
> once when using a solvent-based coating.
>
>
>
>
> In the end, the coating ends up being LESS costly then a varnish coating!!!
> I have used a 1 quart kit (2 half-quart bottles) to coat (2) 6" X 32"
> coils,
> (2) 3.5" X 20" inch coils, (1) 4" X 12" coil, a 2" X 5" coil, and at least
> two others. Add the paint thinner, rags, quality brushes, etc, etc,
> required
> apply multiple coatings of varnish, and I guarantee it exceeds the cost of
> an epoxy coating. I think my 1 quart kit cost $17.00 at Ace Hardware.
>
>
>
>
>
> Tips:
>
>
>
>
> 1. Set up a completely dust free, draft free area to work in. I use a
> bathroom, damp-mop everything, close all windows, etc, etc. A carpeted
> floor
> is useless; any movement stirs up a cloud of fibers.
>
>
>
>
> 2. Very thoroughly wipe down the completed coil with a clean cloth
> moistened
> with 90% isopropyl alcohol to remove any trace of oil from the windings.
> Even fingerprints may cause "fisheyes" in the completed coating.
>
>
>
>
> 3. After all traces of solvent have fully evaporated, I do a very careful
> wipedown with a cabinetmaker's "tack cloth" to pick any residual lint or
> dust.
>
>
>
>
> 4. Carefully calculate the volume of material required, based on a
> thickness
> of .040" or .050". Always err on the high side. I know the panic of having
> to mix up another ounce to finish the last inch of an almost perfect
> secondary. As a portion of the coating will "wick" down into the windings,
> the final coating thickness will be less than .040" or .050". DON'T TRY TO
> APPLY TOO THICK A COATING! Even with the spindle turning at a very low
> speed, circumferential rings may develop on the OD of the coil. At first it
> may seem that there is not enough material to completely cover the
> windings,
> but continue to spread it with the foam brush. Add more coating only if it
> is impossible to get coverage.
>
>
>
>
> 5. Mix VERY thoroughly in a meticulously-cleaned, completely dry container;
> glass is preferred, and DON'T use a waxed paper cup.. Use a clean piece of
> wooden dowel to stir. I end up with a froth of bubbles, but they seem to
> all
> pop during the coating application.
>
>
>
>
> 6. Turn on the spindle drive motor & adjust speed to about 5 RPM (depending
> on the diameter of the secondary). LEAVE THE SYSTEM RUNNING UNTIL THE
> COATING IS COMPLETELY CURED! (4-6 HRS).
>
>
>
>
> 7. Position a 3-4" wide disposible FOAM paintbrush (NOT a bristle brush)
> against the top of the secondary, and start pouring a very thin stream of
> liquid immediately in front of the brush. The first rotation will only
> spread the liquid slightly, getting better coverage with each turn. At this
> point, the brush is being used as a squeegee. Reduce your movements to
> avoid
> stirring up dust & lint; stand in the same spot without walking around.
> Have
> all your tools and materials laid out in front of you at arm's reach.
>
>
>
>
> 8. Get an initial spiral of liquid applied from end-to-end of the coil,
> then
> go back and spread it into a uniform coat.8
>
>
>
>
> 9. As the coating flows together, reduce pressure on the brush until it is
> barely contacting the surface of the coil.
>
>
>
>
> 10. Keep the coil rotating, and inspect for tiny pieces of lint, etc. Use a
> pin to lift them from the surface. Stop the rotation only long enough to
> remove the lint.
>
>
>
>
> 11. By this time, 99.99% of the bubbles should have disappeared. Use a hot
> air gun to sweep areas with any remaining bubbles. DO NOT HEAT THE COIL!!!
> Invariably there is air trapped under the windings. Applying excessive heat
> will cause this air to expand and bubble out into the coating. The hot air
> gun temporarily thins the very top layer of the coating, and at the same
> time causes the air in the bubbles to expand. Most of the remaining bubbles
> will pop by themselves. Finally, use a pin to pop the last few remaining
> bubbles, if there are any.
>
>
>
>
> (The use of carbon dioxide to cause the bubbles to pop is a myth. There is
> no physical or chemical reason why CO2 should cause the bubbles to pop. I
> tried directing streams of pure CO2 and pure nitrogen on early coils I
> coated, and the gas had no effect on bubbles. However, mild heat from a
> heat
> gun or hair drier works instantly. The heat causes the viscosity of the
> surface of the epoxy to decrease instantly, and the heat also visibly
> expands the bubbles. Someone has also suggested the use of a propane torch;
> this is ludicrous.)
>
>
>
>
> 12. Inspect the coil for bubbles, pinholes, lint, thin areas, etc. When
> satisfied that everything is perfect, slowly walk out and VERY SLOWLY close
> the door. Make sure no one opens the door until the coating is fully cured.
>
>
>
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