Liquid Spiral Wrap

[Tinkerer]

Dipseal seems to be an excellent product. Has anybody measured the amount of capacitance it adds to the coil?
Tinkerer

[bigrex]

I've been told you can just add the carbon powder to regular paint, but you should also have a thin 32 awg tinned wire looped a few times tightly around the shield and then connected on one end to the coax shield and on the other end to the copper core wire along with the two ends of the coil also contacting the coax in the same manner.

[bigrex]

I recently tried adding the carbon to regular glossy white house paint. In my opinion the coat flakes too much when dry, so next time I will try something more like an epoxy. I'll put a layer on, add the tinned wire, and then put a little more over the wire to seal it in around the loop.

[J_Player]

If you wanted to mix your own graphite powder into a paint base, then I would recommend you go to Home Depot and buy a quart of their Behr interior or exterior house paint deep tinting base. This is a premium grade water base paint with the highest quality acrylic resins. The deep tinting base is a can of clear resins without any pigments. The other paint bases have a certain amount of pigments which could upset the resistivity of the paint (pigments are made from minerals or rocks that are ground into powder, including several forms of iron oxides, or rust). By adding the powdered graphite you will only have graphite for a pigment. When this paint dries it is slightly flexible and softer than most of the oil-based resins. The paint should go on fairly thin like house paints do. It would probably be a good idea to brush on a flood coat and let the excess drip off while it dries (and remove the last drop from the bottom before it sets up). It may work better to use 2 coats or more. recoating can be done a half hour after a coat dries.

The only question I have is the properties of the graphite powder. It seems that different graphite powders may have different grain sizes and different grain consistencies which could effect the resistivity of the dried finish. A little experimenting with the mix of graphite and paint base would probably show the right proportions to use. It would be worthwhile check the resistivity at several locations in a dried sample to insure that the coating had uniform resistivity properties.

Some other paint bases that could be tried are clear oil-based varnishes, lacquers and shellacks. Also water-based varnishes, epoxies, polyester glassing resin, and eurathanes.

The water based products generally dry to a more flexible finish that would flex easier rather than developing cracks when the coil flexes.
While the paint bases seem a lot easier to use, the 2-part resins can provide a thicker coating.
There are also 2-part eurathanes that dry semi-flexible, used for filling holes and seams in concrete floors.