Solder type at contact points?

[scoopy]

All u have to do is take the 510 apart and put the pin that holds the wire in vice grips or alligator clips and then put a couple pieces of solder in the pin cup and hit it with a torch....The heat never even contacts the spring because it's all apart

[pdizzle]

That's assuming you can get the cap over the silicone coating lol. Try holding the cap and spring away from the torch while melting the solder in the pin. It gets hot when you finally press the wire in and let go of the spring and cap.

[scoopy]

I don't know why u would have the cap and spring anywhere near the heat....I just took the cup/pin and put it in my helping hands alligator clip hit it with a torch and stuck the wire in.....then I just put all the pieces onto the wire in the right order that was already soldered to my out wire on the board....Put It In The Case And Connect It All To The 510 housing.....I Did Bore The Brass Cap Out On My Varitube to fit my 14 gauge insulation through it

[Podunk Steam]

Some 510s use a smaller diameter spring than others that can be a real challenge to get over wire as large as 14 gauge is. I just bored out the plastic in a 510 and used a large enough diameter spring it slid over the 14 without any hassles at all. 

[blueridgedog]

I did this a few times and got acceptable results sliding the silicone jacket down enough for the job (room for the collar and spring) then sliding it back.  IMHO the commercial 510s are poor products for the 200 for the reason discussed and for the pressure they apply.  

[Podunk Steam]

I can't agree with you enough, the humble 510 has seen its day. They're not applicable in transmitting the power being applied to atomizers these days.