Stringer standoffs.
Where the stringer is distanced from the structure I am making up some pretty simple standoffs. I have both a first and second generation to show here. At first I formed this two piece part.
Click image for larger version. 

Name:	IMG_6014.JPG 
Views:	12 
Size:	220.6 KB 
ID:	49825 Click image for larger version. 

Name:	IMG_6015.JPG 
Views:	10 
Size:	190.1 KB 
ID:	49826
This is a weldment of a saddle on a pedestal. This has been in place a year or so.

Recently I have formed what to me are much simpler standoffs.
Click image for larger version. 

Name:	IMG_6016.JPG 
Views:	10 
Size:	219.4 KB 
ID:	49827 Click image for larger version. 

Name:	IMG_6019.JPG 
Views:	12 
Size:	246.2 KB 
ID:	49828
These are formed from some very light mild steel rectangle tube. I have had some of this tube in short lengths for a few decades. I have used it sparingly since I had no viable source for it.
But now I have hundreds of feet of this tube available. For going on five years I have been President of an EAA chapter. Good workers are very hard to come by here. With the many events I host a year I came to realize not many people have a clue how to tie down a canopy. No you do not tie it mid way along a side. And no you do not peg down the bottom of the legs.
So I have been buying two to three canopies a year. Now I know where this thin wall tube is sourced, it is a 10mm X 20MM by about a half mm wall tube. That works out to about 3/8 X 3/4- .020 wall. Now I have an endless supply of light structural support tubing.
One trait I like about these standoffs is you can form them to mechanically grip the round tube. These will work fine for either Aluminum or composite stringer tubes. Once they are painted and the tube bonded in place there should be little chance of electrolysis.

One other tidbit, I will be running my wires to the tail within the conduit. Heck that is what it was made for.