I read about this idea and decided to try it out.  I went to my local 'Do-It-Best' store and went through their trays of Nylon Washers.

I found the 0.68x.125 washer is PERFECT for battery isolation.  Note at my store it was the only Nylon washer with this diameter - the one larger was 0.75" diam and the one smaller was .625" diam.

I also used Permatex I put a small bead around the outside edge and gently pushed it in from the front so it was abou 1/16" below the metal tube's end.  I then ran a bead between the tube and the Nylon washer.

It seems to be working great.  The hole in the middle is large enough for the center spring to pass through and contact the battery, and by having the nylon washer slighly below the top edge the outer spring can rest on the end of the metal tube to complete the circuit.

Washer cost is $0.25 each and they come perfectly sized.  My suggestion is to use a file and carve a groove in the outside rim of the washer so the Permatex gets a better grip (a good mechanical  lock).

Thanks for the idea KClapp!

Quoted: Quoted: I have two SF 6R's that I have turned into 6P's and always wondered if I could turn them into 9v lights somehow.  Any idea if this is possible?  I think the tube is longer than 3 batteries are and the lamp would not take that many volts, but I see that SF sells a metal spacer that one can use to put two batteries in the full length 6R tube rather than taking the extension off.  I wonder if it's possible to make a smaller spacer, get a 9volt lamp and use three batteries? On your 6R you should be able to remove the 2 cell extender and then add the A19 adapter plus change to either the P90 or 91 lamp and have the 9v system you want.

Well, I knew what the P90 and P91 lamps were...but the A19?  That was greek to me...so I punched it in on the SF website and voila..."flashlight battery adapter, 6P to 9P."  Cool!  I never knew there was such a thing.  I've called there and asked about turning my 6P into a 9 volt light before and all I got was silence on the other end.  Thanks for the help!

Now for the next test question Mr. Smarty-pants...can I turn my 6R/6P into a 12 volt?

Quoted: Quoted: Now for the next test question Mr. Smarty-pants...can I turn my 6R/6P into a 12 volt? Yes, by using two A19's and a turbohead bezel with the MN60, MN61 or N62 lamps.  You can't really use the 6R extension to go to 12v.

Well, there you have it!  I guess that makes sense.  I saw the 12 volt lamps on the website, but have not seen the bezels.  Is it cost effective?

Quoted: Well, I knew what the P90 and P91 lamps were...but the A19?

Here's the setup (bottom light) Brightflashlights set me up with.  I can go 6V or 9V at will