Soldering Question

Bought an old built Nu-Cast B1 recently, very nicely made but a bit mouldy in places. Had never been run so had a go at cleaning up chassis - white metal, solid as the proverbial brick outhouse.

It has what look like old Romford wheels with rods held in place by solder. Had to remove a couple of rods but when tried to put them back found the crankpins to be of a solder repellent metal. Anyone know what the metal is or more importantly how to get solder to stick to it ? Have filed pins so theyre clean and once in a rare while they do stick buut its very rare.

Any help appreciated.

Cheers, Simon

Reply to
simon
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Soldering to a Romford crankpin seems an odd way to waste your time! ;-) I don't quite understand why you would want to do that. Are you perhaps trying to fit an excentric to the drive wheel crankpin?

I use a (16BA*) cheese-head screw with a brass tube sleeve for the coupling and connecting rods so that the excentric can be trapped between the end of the sleeve and the screw head.

  • I bought a packet of 12 years ago and still have several in an unmarked tin along with spare Romford crank-pin screws. Brass tube from the K&S range, cut to length with a Dremel abrasive cutting disk.

Greg.P. NZ

Reply to
Greg Procter

But if was capable and brave enough todo that would have to remove current crankpins. they may be screwed into the wheels but they dont have a thread on other end. I know the current crankpins are slotted and can be removed using a Romford screw driver, but these arent. Be certain they would break if tried to remove them.

Cheers, Simon

Reply to
simon

If that's the case then I'd be fairly sure that the crank-pins are brass and peened over at the back of the wheel(?) The problem there will be that you can't get enough heat into the crank-pin to get it up to soldering temperature. OTOH if you do get enough heat in you're liable to melt other bits. :-(

I'd suggest you chicken out and buy new Romford wheels, crankpins etc to fit and put it (the financial cost) down to experience.

Regards, Greg.P.

Reply to
Greg Procter

Assuming Greg's stuff about fitting screwed crankpins isn't an option and you're sticking with solder.

1) Lots of heat; you need a powerful iron and ability to be in and out fast. Otherwise the heat-sink of the wheel will take the heat away too quickly. Stand wheel on a wadge of wet tissue paper to help protect it (but it increases the heat-sink!). 2) Flux. Without knowing what the pins are made of, difficult to recommend, but Carr's green will work well on brass. 3) Something to stop the rods soldering up. Paper washers, pencil lead on inside of rod bore. 4) I'd use a new crankpin retaining washer. Either nickel silver or very clean brass. 5) Appropriate solder; probably 188C lead-tin. But might try something around 140C if worried about melting the wheels.
Reply to
Nigel Cliffe

My opinion would, unless one is attempting to keep the model as built, to at least re-wheel (old Romford like wheels are not really up to modern track standards) if not build a completely new brass/NS chassis - but thta's not really what you're asking!...

Reply to
:Jerry:

thanks, will try hot iron. Crankpins arent brass cos when filed fresh face is more a dull iron colour - not magnetic either.

Not sure if can use new Romford washer as crankpins seem much greater diameter. Can find washer though.

Cheers, Simon

Reply to
simon

Dunno, these look quite good and new ones are expensive - at £10 per axle would be tempted to buy a Bachmann chassis and save lots of effort - so going to try and keep wheels. Plus its got a 5 pole 'x04 lookalike' motor.

Cheers, Simon

Reply to
simon

I'd be tempted to use a set of Gibson wheels in, £6.57 per axle set (inc. 1/8th axle and c/pins) plus a another £5 for the bogie wheel set... Are you sure that price of £10 for Romfords is not per loco driver set, or indeed loco set?

Reply to
:Jerry:

Me and Gibson dont get on - cant get crankpins in straight. Isnt average Romford £4.50 per wheel, so £9 per wheel pair. Add axles, P&p gets near enough £10 per axle.

CHeers, Simon

Reply to
simon

On Fri, 2 May 2008 12:02:54 +0100, "Nigel Cliffe" said in :

Yes, but my First Rule of Soldering is:

  • Clean it
  • Clean it
again
  • Check that you have a really sound mechanical joint, 'cos solder is as weak as anything
  • Clean it
some more
  • Make sure it's clean
  • Clean it
again, just to be on the safe side
  • Flux
  • Tin, if practicable (I find this yields major improvements in reliability of joints)
  • Flux
again
  • Solder

I only jest a little bit: a soldered workpiece cannot be too clean. We've been low-temperature soldering the white-metal Warhamster stuff the kids like, clean, flux, tin, flux, stick is the proven route there.

Guy

Reply to
Just zis Guy, you know?

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