you are over thinking your radial situation.
I totally get you want to maximize efficiency with what you have to work 
with...but seriously, when it comes to radials you simply have to use 
something that won't rot over time, something that is conductive, and 
something affordable.
Metal conducters are the best to use hi hi...stranded, solid, insulated, 
uninsulated, it really doesn't matter.  You are creating an artificial 
ground plain for the antenna to work against and at the end of the day, it 
really doesn't care what sort of metal is down there, as long as it is 
conductive...coat hangers will work as good as anything else if you have 
enough of them.
Having the radials is the important bit, what they are made out of is not. 
When you are told that the radial system is very important with a vertical, 
it's having that radial system in place, not what materials you make it with 
that is the key.

73
Colin, V A6BKX
--------------------------------------------------
From: "Richard B McDonald" <[log in to unmask]>
Sent: Friday, July 04, 2014 11:03 AM
To: <[log in to unmask]>
Subject: Bare Versus Insulated & Solid versus Stranded Copper Wire to Use 
for Radials

> Hi!
>
>
>
> See the below Amazon link for this 16 gauge copper wire I am thinking 
> about
> for use in making radials for a vertical antenna.  16 gauge is thicker 
> than
> the 18 gauge recommended by MFJ for radials, so I like that.  However, 1)
> this wire is "stranded" versus "solid" and 2) "insulated" versus "bare". 
> I
> am not sure if "stranded" is the same as "braided", or if it matters if
> radial wire is solid/stranded/braided.  Also, I understand that it does 
> not
> matter if the wire is bare or insulated.  Is this true?
>
>
>
> http://www.amazon.com/Coleman-Cable-16-100-16-16-Gauge-100-Feet/dp/B000HAB82
> M/ref=pd_sim_hi_1?ie=UTF8&refRID=12AN8JXN3WW2KME3BT1X
>
>
>
> 73,
>
> Richard KK6MRH