Popular Post Station Master Posted May 2, 2019 Popular Post Share Posted May 2, 2019 Just a cautionary note from someone who decided that adding rodding to a layout would a great idea. Indeed, I thought it would add a terrific look of realism. I purchased lots (and lots) of packs of rods, cranks, etc, etc - enough to run multiple metres of rodding from 2 signal boxes. Then spent hours and hours and hours painting/weathering before painstakingly fixing the rodding alongside tracks, under tracks, fiddling with cranksed rod ends, nested cranks etc. And finally the result that I ended up with was great. I was very proud. The rod ends were butt-jointed, as recommended with liquid poly. The bases were glued down using superglue and then ballast added around the bases and glued with PVA. But then the British weather arrived. My layout is confined to a shed. It seems the small temperature difference between the start and end of spring has a massive effect on this rodding. It seems this plastic rodding expands more than metal! Nearly every joint on the rodding it distorted - either bent to the side, or lifted-up in the air. I've attached a photo of a typical joint: I am very, very disappointed. Having phoned Peco, they told me that it would do this in a shed. It was suggested scarf joints might help, but then you'd be cutting through the moulded "bolt heads" at the rod ends to achieve this and would spoil the effect. And I don't see how this would stop expansion. So I just want to advise fellow modellers that unless they have their layout in a temperature-controlled environment, don't waste your time. If you are in a shed, garage or loft, you may get disappointing results. And I know that there are probably people out there screaming at me now, expecting me to have known that you can end up with this sort of result. But I didn't know and I'm sure there are others out there that also don't know. So just trying to be helpful. 1 7 12 Link to post Share on other sites More sharing options...
Miss Prism Posted May 2, 2019 Share Posted May 2, 2019 1 hour ago, Station Master said: It seems this plastic rodding expands more than metal! The temperature coefficient of expansion for many plastics can be 10 times that of metal and up to 20 times that of wood. 1 3 Link to post Share on other sites More sharing options...
RMweb Premium John Isherwood Posted May 2, 2019 RMweb Premium Share Posted May 2, 2019 1 hour ago, Station Master said: It was suggested scarf joints might help, but then you'd be cutting through the moulded "bolt heads" at the rod ends to achieve this and would spoil the effect. And I don't see how this would stop expansion. A scarf, or angled overlap, joint would allow one section of rodding to slide against the next one, thus absorbing the expansion / contraction. The actual expansion will only need to be tiny to create the bowing that you have experienced, The scarf joint need not be at the actual joint - this could still be a glued butt joint. If the sliding joint were to be within a length of rodding; perhaps even disguised within a pedestal; it would be nigh-on invisible. A bit late now, I know, but it may help others. In your case, some cuts in the rodding, adjacent to pedestals, should provide enough expansion gaps to permit you to remake the butt joints. Regards, John Isherwood. 1 2 Link to post Share on other sites More sharing options...
RMweb Premium Ian J. Posted May 3, 2019 RMweb Premium Share Posted May 3, 2019 Can you put occasional overlapping expansion gaps in the areas within the supports so that the gaps would be unseen? 1 Link to post Share on other sites More sharing options...
RMweb Premium John Isherwood Posted May 3, 2019 RMweb Premium Share Posted May 3, 2019 59 minutes ago, Ian J. said: Can you put occasional overlapping expansion gaps in the areas within the supports so that the gaps would be unseen? Presumably you did not read the previous post to your own? Regards, John Isherwood. Link to post Share on other sites More sharing options...
Miss Prism Posted May 3, 2019 Share Posted May 3, 2019 In a metal rodding exercise of many years ago, some sliding expansion fits were put in on the longer runs, the incision of the split being supported by a stool. With plastic, I would guess a lot more expansion fits would be desirable. 1 Link to post Share on other sites More sharing options...
RMweb Premium John Isherwood Posted May 3, 2019 RMweb Premium Share Posted May 3, 2019 3 minutes ago, Miss Prism said: In a metal rodding exercise of many years ago, some sliding expansion fits were put in on the longer runs, the incision of the split being supported by a stool. With plastic, I would guess a lot more expansion fits would be desirable. That's exactly what I had in mind. Regards, John Isherwood. Link to post Share on other sites More sharing options...
RMweb Premium Roger Sunderland Posted May 3, 2019 RMweb Premium Share Posted May 3, 2019 This is very dissapointing for you. Can I ask if the affected rodding, in the shed, is exposed to the sun. The reason I ask is that I have used Wills rodding on our exhibition layout and also on my own layout. The exhibition layout is stored in the back room of a factory. Temperatures vary between 0 degrees in Winter to around 70 degrees in Summer. It can be even higher in some exhibition halls. My own layout is in a garage. Temps vary here between around 40 degrees up to over 80 degrees. in both cases I've seen no joint buckling (yet!). Neither layout is ever exposed to sunlight though, which even in Spring can cause very high surface temperatures. we recently attended an exhibition where our fiddle yard was in the sun for at least half the day. Despite there being expansion joints at track joins we experienced quite severe bending of the track due to the heat from the sun. Again this had never occurred before , despite the above mentioned temperature variations . 2 Link to post Share on other sites More sharing options...
Jeff Smith Posted May 3, 2019 Share Posted May 3, 2019 Perhaps a mix of Wills parts with brass rods. Many years ago I bought square section brass wire from the Scalefour Association. It's been installed for many years (using etched parts) but in all honesty the layout has not been exposed to sunlight or temperature extremes....but maybe brass would expand less than plastic. Link to post Share on other sites More sharing options...
RMweb Gold Enterprisingwestern Posted May 3, 2019 RMweb Gold Share Posted May 3, 2019 How about a sliding box joint here and there, can be covered by a bit of walkway planking? Mike. 1 Link to post Share on other sites More sharing options...
RMweb Gold The Johnster Posted May 3, 2019 RMweb Gold Share Posted May 3, 2019 My father, an inveterate bodger, 'converted' our attic for my layout in my teens; it was the first time I'd used flexible track and the layout tore itself literally to pieces because of expansion and contraction. Temperature ranged from below freezing in winter, a small fan heater being unable to cope, and well into the 50s on hot sunny days. I learned a few things from this, including never to let dad build me anything, but mostly that model railways are by and large designed to be used in the properly heated and ventilated environment of a domestic home, and that if you can't afford the very considerable cost of providing this on a constant, 24/7, basis in your loft, garage, or shed, then you are on a hiding to nothing. My current layout is happily domiciled in what I call a railway room with a bed in it, but the squeeze calls a bedroom with a railway in it. The railway preceeded her occupation, or I doubt I'd be allowed to get away with it! I did not previously realise that plastic expands and contracts more than metal, though; this is a revelation! Link to post Share on other sites More sharing options...
Station Master Posted May 7, 2019 Author Share Posted May 7, 2019 Just a quick reply to say thanks for the suggestions from various people. For info, the rodding was put down in March. It was a bit chilly, but certainly not anywhere around freezing. The problems were then observed in April, so the temperatures were not extreme at either end. I'm a bit loath to make any changes until the height of summer, And the rodding was not in direct sunlight either. The main problem is that each base is glued-down, so that the run remains straight. If I were to use a different style of joint, to try to allow the sections of rodding to slide against each other, I would have to do this for every single section. And then I can't disguise this using planking, etc Alternatively, I could just glue-down every few bases and leave the others floating, but then any expansion is likely to cause the run to buckle as a whole. And in fact, by adding ballast and landscaping around the rodding would almost inevitably result in some glue of some description fixing down the bases by default. So in reality, I don't think there is much that I can sensibly do to alleviate the issue. I'm not giving up yet. I shall try to improve the situation because I don't want the hours of effort already spent to be thrown away. If I find a method that seems to work better, then I shall post again. Link to post Share on other sites More sharing options...
Jeff Smith Posted May 7, 2019 Share Posted May 7, 2019 I think if you used brass rodding you would have no significant expansion problems, especially if allowed to move within the bases. Link to post Share on other sites More sharing options...
Darwinian Posted May 9, 2019 Share Posted May 9, 2019 It seems odd, if Stationmaster has glued down all the rodding stools which was my understanding of the OP, that there isn’t a similar distortion of rods between the stools. The rods and stools appear to be moulded in one piece so the rods cannot slide through (I’m not familiar with the product so may be mistaken in this). Could it be the particular type/ quantity of solvent used at the joints causing this? Link to post Share on other sites More sharing options...
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