Probably another 'how long is a piece of string' topic

[rab]

There have been a lot of discussions on the forum about problems with layouts due to extremes of temperature and humidity.

 

I'm interested to know what folk consider are acceptable ranges for both. 

[polybear]

Impossible to say I think - so much depends on track standards, clearances, materials used for construction etc. etc.

More important would be to keep things pretty stable as far as possible - building a layout in the arctic then moving to Nevada wouldn't help.....

[Barclay]

My layout is in the loft, with no insulation. I have a max/min thermometer up there and in the last 12 months I've recorded temps. down to 3 C and up to 46 C. Track is mostly copperclad construction with decent expansion gaps, but I've had no issues in the 20 years I've been working up there (None for the layout you understand - me, that's a different matter!)

[Forester]

Worth mentioning there is evidence that mazak problems are often associated with, or perhaps just amplified by, excessive humidity especially in a warm environment.

 

[Nearholmer]

Even in the UK gardens can experience quite a range of conditions, -10 to +39, and months of drought to months of downpours in middle England where I live, and garden railways seem to cope OK.

[34theletterbetweenB&D]

3 hours ago, Forester said:

Worth mentioning there is evidence that mazak problems are often associated with, or perhaps just amplified by, excessive humidity especially in a warm environment...

Warmth and high humidity can lead to surface corrosion, not that serious an issue.

 

The change in crystalline structure typically caused by lead in the Mazak alloy known as 'zinc pest' or 'Mazak rot' is accelerated by low temperatures. Comfortable room temperature range is best if you have a piece with evidence of this failure developing. Uncontaminated Mazak alloy is fine at low temperatures.

 

The only model item that was troublesome outdoors was the Peco code 100 rail joiner (no alternatives tested) some of which were failing by splitting apart on bend lines after 4 years. My theory, repeated frost action, trapped water exerting pressure as it froze. By no means all of them failed, probably 30% over the roughly ten years outdoors.

[Nearholmer]

I found the plastic used for sleepering in SM45 by Peco began to suffer some slight embrittlement after as little as five years outside, whereas LGB plastic seems just as tough as it ever was after ten.

[The Johnster]

My teenage layout, in an attic insulated by Father, so effectively uninsulated, tore itself apart with expansion and contraction; winters were palpable colder in those days.  Not sure what, if any, effect humidity had, but it was pretty dry up there.  But it got uncomfortably hot even on freezing winter days if the sun was on it, so the layout would be subjected to temperatures of over 100F in the day and below 0F, 32 degrees below freezing point in Farenheit, at night.  I suspect it was the rapid transition between these extremes that caused the damage rather than the extremes themselves.

 

It led to a condition that applied to any subsequent layout; that it had to be located in the normal living area of the house or flat, or an attic, garage, or shed converted professionally to that standard of heating and ventilation, and I've never been in a position to afford the latter or to heat and ventilate them.  The disadvantage is that I have perforce had to forego a layout as I had nowhere within the specification to put one for many years.  The advantage is that the layout is instantly accessible, comfortable to operate or to model near, and costs nothing in heating or ventilation because those have to be paid for to make the flat permanently liveable anyway (retired so home most of the time and currently shielding); turning on an extra radiator makes little difference and as the door to the living room is usually left open it can mostly be left off.

 

If the microclimatic conditions in which they are to be used are considered at all by the manufacturers, I would imagine that the criteria used are those for indoor living spaces, with the exception of the likes of LGB or live steam which is specifically designed for outdoor garden use.  Legislation where it applies regards RTR models as toys, and they are built to adhere to such legislation.  This must have an impact on the materials that are permitted, which may or may not make such products more or less susceptible to damage or degradation from the environments in which they may be used.  But much of this is assumption on my part.  

 

Mazak has a microcrystalline structure which is prone to damage from temperature changes, and there are other problems associated with it as well.  It needs close quality control and monitoring at the casting stage, and I am surprised that we do not suffer more problems than we do given the widely geographically and cottage industry nature of the Chinese suppliers.  The legal restrictions on materials available for use in toy manufacture prevent some of the more stable alternatives being used.  Some other sort of lead compound alloy would be best for chassis blocks, from the point of view of ballast, but it lead cannot be used in toys and if it were alloyed with ferrous metal it would oxidise.  And of course any such material has to be easy to cast, work, and store as well as being cost effective.  Mazak has served the hobby well since Hornby Dublo days but is not ideal, and I have been very lucky in never having a problem with it in over 60 years; the destruction of a well loved model not long out of warranty must be heartbreaking.

[Forester]

3 hours ago, 34theletterbetweenB&D said:

 

The change in crystalline structure typically caused by lead in the Mazak alloy known as 'zinc pest' or 'Mazak rot' is accelerated by low temperatures.

 

 

Not heard mazak rot is accelerated by low temperatures before. Where have you seen that?

[34theletterbetweenB&D]

Metallurgical reference, found by a metallurgist colleague, when I asked of him why both my Father in law's naval dirk grip was splitting, and also some of the instrument casings on his circa 1930 Alvis Firebird were crumbling. (Going back near 50 years here, I had no thought of application to models when I asked this.) He told me how the lead contamination that was the principal cause of this had been tackled by  eliminating the use of lead alloy seals on the canvas bags commonly used to transport the alloy from the manufacturer to the casting operation: the overwhelming temptation in the casting shop was that the operative threw the seal into the melt pot.

[rab]

2 hours ago, The Johnster said:

It led to a condition that applied to any subsequent layout; that it had to be located in the normal living area of the house or flat, or an attic, garage, or shed converted professionally to that standard of heating and ventilation, and I've never been in a position to afford the latter or to heat and ventilate them.  The disadvantage is that I have perforce had to forego a layout as I had nowhere within the specification to put one for many years.  The advantage is that the layout is instantly accessible, comfortable to operate or to model near, and costs nothing in heating or ventilation because those have to be paid for to make the flat permanently liveable anyway (retired so home most of the time and currently shielding); turning on an extra radiator makes little difference and as the door to the living room is usually left open it can mostly be left off.

 

If the microclimatic conditions in which they are to be used are considered at all by the manufacturers, I would imagine that the criteria used are those for indoor living spaces, with the exception of the likes of LGB or live steam which is specifically designed for outdoor garden use.  Legislation where it applies regards RTR models as toys, and they are built to adhere to such legislation.  This must have an impact on the materials that are permitted, which may or may not make such products more or less susceptible to damage or degradation from the environments in which they may be used.  But much of this is assumption on my part.  

I think you have provided the answer I need.

I am in the process of converting my garage

for use as a railway room and want to aim

for the best conditions for the layout.

If I monitor the temp and humidity ranges

indoors during various weather conditions

that will give me benchmarks to aim for.

 

Simples

[cypherman]

Hi all,

Many years ago when I was a teenager(Yes I can remember that far back.... ) I had quite an extensive loft layout. One day while I was out at school my father came up with the great idea of soldering all the rail joints to make sure they had good contact. He spent all day doing it and was quite proud of his achievement. It worked great until later that summer when the heat was so hot the rails glowed and every thing buckled due to the lack of expansion space. Can you guess the year...… If you got 1976 when there was a water shortage and stand pipes due to the reservoirs drying up you would be correct. That was an extreme summer for high temperatures, But they are getting more common with global warming.

The loft was insulated and had good ventilation but it was just not up to the extreme weather we had that year. So the moral is most of the time the heat range in the UK is ok. But we will get times when it is so hot things go beyond what we had planned for. So what ever heat range you think of add a few degrees to the top and drop a few from the bottom.

Edited June 19, 2020 by cypherman

[AndyB]

I think you have to consider combinations of temperature, humidity and air movement, too. The baseboards on an early garage layout suffered from low air movement, low temperature and moisture coming in from an outside wall. Ideal conditions for mould.