Soldering Question

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simon - 01 May 2008 20:59 GMT

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

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Greg Procter - 01 May 2008 21:42 GMT

> 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
[quoted text clipped - 12 lines]
> Cheers,
> Simon

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

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simon - 01 May 2008 21:53 GMT

>> Bought an old built Nu-Cast B1 recently, very nicely made but a bit
>> mouldy
[quoted text clipped - 31 lines]
> Greg.P.
> NZ

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

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Greg Procter - 01 May 2008 22:33 GMT

> >> Bought an old built Nu-Cast B1 recently, very nicely made but a bit
> >> mouldy
[quoted text clipped - 42 lines]
> Cheers,
> 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.

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Nigel Cliffe - 02 May 2008 12:02 GMT

> 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
[quoted text clipped - 9 lines]
>
> Any help appreciated.

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.

Signature

Nigel Cliffe,
Webmaster at http://www.2mm.org.uk/

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simon - 02 May 2008 20:33 GMT

>> 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
[quoted text clipped - 25 lines]
> 5) Appropriate solder; probably 188C lead-tin. But might try something
> around 140C if worried about melting the wheels.

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

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Just zis Guy, you know? - 02 May 2008 21:44 GMT

>2) Flux. Without knowing what the pins are made of, difficult to recommend,
>but Carr's green will work well on brass.

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

Signature

May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

85% of helmet statistics are made up, 69% of them at CHS, Puget Sound

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:Jerry: - 02 May 2008 12:18 GMT

<snip>

> Any help appreciated.

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 this Message

simon - 02 May 2008 20:39 GMT

> <snip>
>>
[quoted text clipped - 4 lines]
> track standards) if not build a completely new brass/NS chassis - but
> thta's not really what you're asking!...

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

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:Jerry: - 02 May 2008 21:12 GMT

<snip>

> 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.

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?

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simon - 02 May 2008 21:22 GMT

> <snip>
>> Dunno, these look quite good and new ones are expensive - at £10 per axle
[quoted text clipped - 6 lines]
> you sure that price of £10 for Romfords is not per loco driver set, or
> indeed loco set?

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

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Model Forum / General / Railroads / May 2008

Soldering Question