Help with tinning pipes and rib

[jsdyer]

Hail and well met....
I am building a Hawken style half stock cap gun.  I need to solder ram rod pipes to my barrel rib and am using 5%silver/95% tin solder for the joint.  I have filed a flat surface on each pipe and in the appropriate configuration on the rib so that I have a solid joint.  I've brushed on the flux that came with the solder and am using a propane torch to heat the work area.  I cannot get the solder to "tin" on the heated flat surfaces.  Even on the pipe, which has low mass and therefore easy to heat up, the solder just seems to puddle and not wet the surface.  I have been able to solder the pipes to the rib, but am not confident that this is the strongest possible bond, since I did not have solder along the entire joint.  Could I get some advice on this?  Also, should I have taken the rib off of the barrel before soldering, or would this cause the rib to warp?
I look forward to your input.
Regards,
Jeff

[Dave B]

Jeff,
You need to secure the rod pipe so that you can scrub the surface of the place you want to tin. I lke using the long nose vice grips for this. I heat the flatened area of the pipe then when the solder puddles scrub the surface with a piece of steel wool that has the same flux on it that the solder came with this shoul leave you with a thin film of slolder over the entire surface. Obviously you need to have the surface clean from all oils ect... The same goes for the rib with regards to tinning. only then do you join the two and heat till they both flow together.

[T.C.Albert]

Also, I think all solders flow twards the heat source, so you can essentially pull solder from the back of the joint if you heat the front of the joint too much, and vice-versa...I think a really good quick even heat is needed to get solder to flow evenly?
TCA