Lumps of lead and track holding

Discussion of model and prototype wheel/rail interaction.
User avatar
John Bateson
Posts: 714
Joined: Wed Jul 02, 2008 6:39 pm

Lumps of lead and track holding

Postby John Bateson » Mon Jul 30, 2012 3:20 pm

I am at the stage where I need to add weight to a couple of steam locomotives. My solution in the past has been to pour liquid lead into araldite and mould it into any crevice I can find, usually with a plasticard former to try to keep things neat.
Is there a concensus on the best material - I have noted concerns about white glue causing bulges in inappropriate places.

And is there any where I can get araldite other than in minuscule driblets costing £5 a throw?

John
Slaving away still on GCR stuff ...
Avoiding the soaps ...
https://www.greatcentralmodels.co.uk

User avatar
grovenor-2685
Forum Team
Posts: 3507
Joined: Sun Jun 29, 2008 8:02 pm

Re: Lumps of lead and track holding

Postby grovenor-2685 » Mon Jul 30, 2012 4:26 pm

Liquid lead has a lot of air space reducing its density, I prefer solid lead wherever it can be fitted in. A roll of lead flashing lasts a long time.
Keith
Regards
Keith
Grovenor Sidings

User avatar
Tim V
Posts: 2523
Joined: Tue Jul 29, 2008 4:40 pm

Re: Lumps of lead and track holding

Postby Tim V » Mon Jul 30, 2012 5:03 pm

I got a large bottle of Z-poxy (30 minute two part glue) from my local model aircraft shop.
Tim V
Scalefour News Editor

User avatar
David B
Posts: 1321
Joined: Sun Jul 20, 2008 5:30 pm

Re: Lumps of lead and track holding

Postby David B » Mon Jul 30, 2012 5:15 pm

I have cut sheet lead and shaped it, then held it in place with some solder. I have done this with both brass (140o) and white metal (low melt). On one loco, I stuffed all the small offcuts of lead down the chimney into the smokebox - how tight can you get?

David

User avatar
Mark Tatlow
Posts: 778
Joined: Tue Dec 02, 2008 11:24 pm

Re: Lumps of lead and track holding

Postby Mark Tatlow » Mon Jul 30, 2012 8:24 pm

John Bateson wrote: I have noted concerns about white glue causing bulges in inappropriate places.


Lead reacts with PVA to produce a form of cyanide. In addition to being rather expansive so it bursts open things like boilers, there is a rather worse reaction if you lick your fingers after handling.

There was a long piece in the letters page of MRJ; about 4 years ago. The general conclusion was don't mix em!
Mark Tatlow

allanferguson
Posts: 378
Joined: Sun Jul 20, 2008 6:27 pm

Re: Lumps of lead and track holding

Postby allanferguson » Mon Jul 30, 2012 10:09 pm

I have recently had the need to fill the top half of a boiler with lead. (There is a motor in the bottom half). And because of the way the formers are fitted I only had partial access (yes, I know I should have planned it earlier.......). My solution was to cut my lead sheet (flashing) into strips approx 2mm wide by the available length, dip them in 5 minute epoxy, and place them in the upside down boiler. Denser and more manageable than liquid lead. I have in the past poured molten lead into rough formers to fill side tanks -- but I can't advise this for a domestic environment!

Allan F

nigelcliffe
Posts: 622
Joined: Mon Jul 21, 2008 8:31 am

Re: Lumps of lead and track holding

Postby nigelcliffe » Tue Jul 31, 2012 6:56 am

Mark Tatlow wrote:
John Bateson wrote: I have noted concerns about white glue causing bulges in inappropriate places.


Lead reacts with PVA to produce a form of cyanide. In addition to being rather expansive so it bursts open things like boilers, there is a rather worse reaction if you lick your fingers after handling.

There was a long piece in the letters page of MRJ; about 4 years ago. The general conclusion was don't mix em!



My chemistry is a bit rusty, but I can't see how PVA and Lead can produce cyanide. Cyanide is Carbon-Nitrogen, PVA consists of Carbon, Oxygen and Hydrogen. Lead is Lead. So, there doesn't appear to be any Nitrogen. There is Nitrogen in the atmosphere, but that is usually inert. Perhaps those who didn't give up chemistry over 25 years ago could add to this....


The damaging lead+PVA reaction is the slow conversion of lead to lead oxide. Lead oxide is a white powder. Lead oxide has a lower density than lead, so takes up a larger volume than the pure lead. Its the oxide (and its expansion compared to the pure metal) which causes the splitting when used in models. Lead and lead oxide are toxic, so wash hands thoroughly before eating or drinking.



For high density ballast, apart from the lead sheet mentioned above, the other I've seen suggested is to use tungsten based weights, which are now used in fishing so readily available.


- Nigel

User avatar
John Bateson
Posts: 714
Joined: Wed Jul 02, 2008 6:39 pm

Re: Lumps of lead and track holding

Postby John Bateson » Tue Jul 31, 2012 8:32 am

Lots of good information here - thanks to all for the chemistry...

I suspect that I may stick with the Eileen's liquid lead suitably immersed in Araldite for the tricky corners, especially around the cab areas where I need to endure there is enough weight in all the small orifices. For the boiler, I have enough bits left over from some roof work so I can add lead until the thing balances.

John
Slaving away still on GCR stuff ...
Avoiding the soaps ...
https://www.greatcentralmodels.co.uk

User avatar
John Bateson
Posts: 714
Joined: Wed Jul 02, 2008 6:39 pm

Re: Lumps of lead and track holding

Postby John Bateson » Mon Aug 20, 2012 9:49 am

Just received an 8ox pack of Z-Poxy, on the face of it much better value than standard B&Q Araldite at £5.50.

In the absence of a model shop that is anything other than totally useless and within 50 miles I finally resorted to eBay!
Will try putting some lead in the fire-box this afternoon ...
John
Slaving away still on GCR stuff ...
Avoiding the soaps ...
https://www.greatcentralmodels.co.uk


Return to “Vehicle dynamics and trackholding”

Who is online

Users browsing this forum: No registered users and 2 guests