I am having trouble soldering .3-1mm brass wire together. I currently use a standard soldering iron and fluxless paste. The wire is clean, but the solder either clumps or doesn't take. I tried using a pen torch, but it burns through the wire. Can anyone suggest how to go about this?

relatively new to using Solder on brass parts myself, but have you tried using the iron under the wire, getting the wire good and hot and holding it up with the iron then touching the solder to the iron with the wire in between? I would also recomend flux, it might help hold parts together till solder is ready and help it flow..

The solder I am using specifies that flux is not needed. But, that may be the problem. I had not thought about placing the iron under the parts.

let me know how you make out!! I strongly suggest the flux too.. i have had it make the difference more than once '

The solder might not need flux but the copper needs to be clean for the solder to take . One thing is to check the heat of the soldering iron , if it's too hot the solder won't take and just slosh off . The torch is too hot if it melts the copper , you could silver solder with that torch then .

Depending on what you're doing, you may want to use some heat sinks as well. For pieces requiring several joints close together (I did a Sho't Kal turret basket years before the kit camwe out)get some alligator (roach) clips and place them between finished joints and the one you're working on. Otherwise, excess heat may undo your previous joints.

Matt,
Brass pieces that fine usually need a good flux, and need to be "tinned" first for the best join. There is no such thing as a "flux-less" or "contains flux" type of solder that works well for miniature applications. So get yourself a good liquid or paste flux (I buy mine from Micro-Mark, but I've used solder and flux from Radio Shack too). Try "tinning" the wires first by applying flux and finely "chopped" pieces of solder (no bigger than the head of a pin--less is more here), to the end of one wire and apply low-wattage heat to the other end about an inch away. After about 30 seconds (depending on the gauge of the wire), the solder should flow towards the heat. Once cooled, you can apply flux to the other un-tinned wire, and applying heat to either the opposite end, or directly to the joint while mated against the previously tinned piece, the solder should flow towards the heat. There's a pretty good tutorial over on Paul Budzik's modelling website for soldering (along with many other great modeling tips) you can find it at Fine Scale Modelling with Paul Budzik at paulbudzik.com
VR, Russ