Lead & PVA?

[Thunderforge]

I’ve heard mention that using lead shot and pva is a bad idea because one reacts with the other and expands slightly.

 

I want to add weight to a card/wood chassis and worried that any expansion might pop it open. Is it true and if so does the expansion happen at ‘drying time’ or over a long period after?

 

And how much expansion? (ie 1%? 5%? etc)

 

Thanks in advance,

Karl

[Derekl]

I have used liquid lead (I think from Eileen's emporium) fixed with PVA to weight some plastic 009 stock. I fixed it about 10 years ago and have noticed no ill effects - there is no noticeable expansion, I have noted that others have had problems, though. I am not sure whether "liquid lead" is in fact lead, which may be an explanation.

[Jol Wilkinson]

Lead shot is known to expand over time if fixed with pva. At least one modeller I know has had two soldered etched boilers split along the seam after several years, so I avoid the use of lead shot and pva.

[kevinlms]

56 minutes ago, Thunderforge said:

I’ve heard mention that using lead shot and pva is a bad idea because one reacts with the other and expands slightly.

 

I want to add weight to a card/wood chassis and worried that any expansion might pop it open. Is it true and if so does the expansion happen at ‘drying time’ or over a long period after?

 

And how much expansion? (ie 1%? 5%? etc)

 

Thanks in advance,

Karl

Earlier discussion says this.

 

 

Based on that, I wouldn't let PVA near lead. After all, it could destroy a good model years later.

Ventilation holes MAY help, but I still wouldn't.

[PatB]

The results do seem to be hit and miss, but I personally would avoid it. Depending on circumstances I'd consider epoxy, cyano, plain old UHU etc. instead. Or do the old trick of mixing lead shot with plasticine to produce a nice heavy, shapeable and sticky material that can be thumbed into place almost anywhere.

[michl080]

there are so many ways to fix the lead, why take the risk.

 

my 2c

 

Michael

[HLT 0109]

On 24/10/2019 at 14:11, Derekl said:

I have used liquid lead (I think from Eileen's emporium) fixed with PVA to weight some plastic 009 stock. I fixed it about 10 years ago and have noticed no ill effects - there is no noticeable expansion, I have noted that others have had problems, though. I am not sure whether "liquid lead" is in fact lead, which may be an explanation.

If you are referring to Deluxe Materials Liquid Gravity, then I do not believe it is made of lead.  i have some now and it recommends (among other things) their Rocket Card Glue so I have used it.  Some of the tiny balls have rusted, suggesting they are made if ferrous material.  The bottle also says "Non toxic" which, in my book, rules out lead.

 

Harold.

[34theletterbetweenB&D]

On ‎24‎/‎10‎/‎2019 at 13:29, Thunderforge said:

I want to add weight to a card/wood chassis and worried that any expansion might pop it open...

You do know that sheet lead is available? Much cleaner to work with than lead shot, and will potentially add strength if bonded to cardboard, can readily be soldered and shaped. I have used sheet and lump lead typically attached where necessary with Evostick over forty years, and not a hint of trouble: the small surface area of the sheet or lump lead compared to shot means considerably less surface area for reaction in any case.

[Fat Controller]

11 minutes ago, 34theletterbetweenB&D said:

You do know that sheet lead is available? Much cleaner to work with than lead shot, and will potentially add strength if bonded to cardboard, can readily be soldered and shaped. I have used sheet and lump lead typically attached where necessary with Evostick over forty years, and not a hint of trouble: the small surface area of the sheet or lump lead compared to shot means considerably less surface area for reaction in any case.

If you're looking for sheet lead, then what you want is called 'Flashing', and can be found at your nearest builders' merchants/ roofing suppliers. It can be cut to size with a tin-snips, or even a Stanley knive. When using it in enclosed spaces (e.g. vans with non-detachable roofs), I tend to put a 'second floor' on top of the lead, to stop it moving about in the future. I also sometimes use a couple of self-tappers through the floor. I had a couple of 'glue issues' in the past, and have no wish to attempt to dismantle another vehicle.

[34theletterbetweenB&D]

The thought crosses my mind that once old mortality has left my model railway equipment of no further interest to myself, an increasingly hazardophobic future will condemn the whole lot as toxic, and require that it be bagged for removal and safe reclaimation, performed by approved contractors wearing respirators and full body protective gear.