Dogtown and Points West

Burnishing pens are good, but a Garryflex block is almost as good for general clean up and won't leave those lethal little fragments which impale your finger ends.  

 

Lolly sticks are also good for holding items while you solder - use them as insulating pads between the job and your fingers.  Bits of balsa will do the same thing, or you can stick components into them while you attach other parts.

 

I'm not sure cleanliness is your problem - it looks to me as though there's not been enough flux or the iron wasn't hot enough.  What did you use for both?

 

 

Looking at your pictures I would say that you need a hotter iron to get the brass and solder hotter.

I've got a variable stick set at about 350 C.   Flux is Radio Shack rosin flux paste.  I don't know if flux can go 'off,' but I've had luck with smaller jobs with the flux.   I'll try at 400-450 next time I pick up the iron. 

 

Stupid question, though.   Will the iron need to sit a bit between joints?

I would say not between the joints but in the joint, so that you are heating both pieces of brass at the same time and to a similar temperature. 

I tend to use phosphoric based paste - looks like water.

What temperature solder are you using and what output wattage is your iron rated at?

 

Last two questions I can't answer.    I don't remember the wattage off of the top of my head.    Solder I've found here stateside isn't sold by temp - only by composition.    I was trying with 60/40 rosin core.   I have some that is high silver, some I think is high tin, and some of what my plumber friend called 50/50.   By some, I mean a one pound reel.

The photos above seem to be a little underexposed but I get the impression that the joints aren't clean.

I use a fibre glass brush to clean up and rosin cored solder, with a 25W iron.

I start by tacking the joint in the centre of the run and then add two more tacks towards each end . That stops expansion which will cause distortion. Then I add more rosin and just join up the tacks with no more added solder unless it's really important to do so. It is important not to melt all the solder in the joint and at least one, and preferably two, lengths of solder should be set at any one time.

If I were the OP I think I would practice on two pieces of brass strip before I'd go further with the kit.

Tony Wright did two DVDs on locomotive construction which include soldering techniques and there are probably tutorials on YouTube.

Cheers

Edited July 10, 2020 by PenrithBeacon

@Gordon A  Iron is a 40w iron.   The solder I was using melts at 188 C.  I also have 183 C and 217 C solder.

 

@PenrithBeacon  I will try the tacking method.

I suggest that your solders are a bit high on the temperature side. My preference is 145 degrees C.

Try the 183C solder with the parts "assembled" around a piece of plywood, using another piece to hold in place.

Saves burnt fingers.

 

Gordon A