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Secondhand Injection Moulded Plastic Rail Chairs


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This is probably stating the b. obvious, but beware when buying secondhand K&L / C&L plastic chairs unless you want to end up with a pile of broken bits ! I recently aquired a large quantity off a well know auction site

only to find the plastic had hardened and degraded so badly that, upon trying to thread them onto rail, most of them just fall apart.

 

My bad as they say, and I doubt there is any way of 'softening these' (without melting them !), but if anyone has any suggestions (other than binning the lot and buy new !)  then I would welcome them.

 

Many Thanks !

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Neil,

 

Thanks for the suggestion. I did wonder about that, or maybe even a brief 'warming' in the microwave, but considered that a bit too risky ! 

 

I'll give it a go in a tea mug, one sprue at a time. The failure rate is 50%+ so anything is worth a shot even though I didn't pay that much and, in theory, have enough spare.

 

Once on the rail they are ok and take the solvent as long as only slight pressure is applied to attached them to the sleepers.

 

Pete.

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Can you not give them a thin butanone wash whilst still on the sprue, then let them dry off again fully before cutting them off & using them?

 

Mark

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14 hours ago, MarkC said:

Can you not give them a thin butanone wash whilst still on the sprue, then let them dry off again fully before cutting them off & using them?

 

Mark

Mark, that's a possible option thanks and will initially soften them at least. I find it a lot easier to thread chairs onto the rail whilst still on the sprue though - unless there is a technique I have missed !

 

Pete

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14 hours ago, Rowsley17D said:

You might need some half chairs for points etc so don't through them all away.

Thanks Rowsley, I would normally do that but all the turnouts are built. Just need to do the plain track (onto ply sleepers) which does require a lot of chairs.

 

Pete.

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Pete

 

I have come across this issue before, I have been told this is due to the plastic becoming too hot during the injection process, and may be due to early injection moulding machines either being set too high or overheating. If its got K&L on the packet they are 40+ years old. The system obtains its strength not from individual chairs but the group as a whole, so should be fine but frustrating to use 

 

I myself will only buy very cheap ones on eBay for this reason (not just plastic chairs but most other items), if you buy new from the supplier you have a guarantee to fall back on.

 

All is not lost, firstly pre-prepare the rail a bit more, slide the chairs on that dont break and or mix in some new ones. If you can get one chair per three sleepers/timbers you can set the rail in place and add half chairs to the others after. A bit of a pain ,and the only real loss is your own time

 

As it is I have loads of half chairs (inners and outers) on used special chair sprues which I will use on my own turnouts rather than dispose of them.

 

See it rather than a loss its just a bit of added inconvenience

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I still have lots of the early production chairs, some in the original grey. It’s a mixed picture for me on breakage. The grey are no more prone than later ones, but I do find one hand worse than the other, go figure! I wonder, do the later production/latest chairs still have the round gap so they can be cut in two and placed around rivets? This could be another source of weakness over time. I say this because I have some 7mm chairs I have just used - probably 25/30 years old- and had no issues at all, fitted on the rail quite tightly and none broke. They of course have a more substantial base, no need to fit around rivets etc. Just a thought.

 

Izzy

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1 hour ago, hayfield said:

Pete

 

I have come across this issue before, I have been told this is due to the plastic becoming too hot during the injection process, and may be due to early injection moulding machines either being set too high or overheating. If its got K&L on the packet they are 40+ years old. The system obtains its strength not from individual chairs but the group as a whole, so should be fine but frustrating to use 

 

I myself will only buy very cheap ones on eBay for this reason (not just plastic chairs but most other items), if you buy new from the supplier you have a guarantee to fall back on.

 

All is not lost, firstly pre-prepare the rail a bit more, slide the chairs on that dont break and or mix in some new ones. If you can get one chair per three sleepers/timbers you can set the rail in place and add half chairs to the others after. A bit of a pain ,and the only real loss is your own time

 

As it is I have loads of half chairs (inners and outers) on used special chair sprues which I will use on my own turnouts rather than dispose of them.

 

See it rather than a loss its just a bit of added inconvenience

John,

 

I suspected this topic had previously arisen, primarily because a lot of 'secondhand' C&L (and earlier) items appear on eBay at, what seems initially anyway, a bargain price.

 

In fact the ones I bought have Alan Gibson packaging so they may well be 40+ years old which is quite a surprise. It's no wonder that the plastic has degraded somewhat !

 

Anyway, good suggestion re mixing these in old / new / half chair combinations. The only slight concern is that does this still work ok when forming curves, or is there a danger 

that the gauging can 'slip' if the chairs don't hold the rail fully ? Assume this may not be a concern as long as the majority are set correctly and curves formed correctly.

 

As an aside, not sure whether it is best with custom-made curves to set one side, leave to dry, set the other side, curve to shape then lay, or lay with one side done, set

the curve then lay the other rail 'in-situ'.

 

With flexi-track this is obvious, but with custom made I guess this also depends on the sleeper base type - in my case it's mostly with pre-formed thin ply panels, but I also have

some individual ply sleepers to use with a template.

 

Pete.

 

 

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1 hour ago, Izzy said:

I still have lots of the early production chairs, some in the original grey. It’s a mixed picture for me on breakage. The grey are no more prone than later ones, but I do find one hand worse than the other, go figure! I wonder, do the later production/latest chairs still have the round gap so they can be cut in two and placed around rivets? This could be another source of weakness over time. I say this because I have some 7mm chairs I have just used - probably 25/30 years old- and had no issues at all, fitted on the rail quite tightly and none broke. They of course have a more substantial base, no need to fit around rivets etc. Just a thought.

 

Izzy

Izzy,

 

In my case I think it's a mix of age and early moulding issues. The chairs do seem thin / brittle around the base and break in half (some worse than others) so I guess the injection process (whether heat/plastic type/moulding) was not quite what is it nowadays.

 

I have also used older 7mm chairs on previous layouts (now converted to 4mm) and not had this problem, so agree it was a quality control and/or design issue on 4mm items.

 

Pete.

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1 hour ago, purplepiepete said:

John,

 

I suspected this topic had previously arisen, primarily because a lot of 'secondhand' C&L (and earlier) items appear on eBay at, what seems initially anyway, a bargain price.

 

In fact the ones I bought have Alan Gibson packaging so they may well be 40+ years old which is quite a surprise. It's no wonder that the plastic has degraded somewhat !

 

Anyway, good suggestion re mixing these in old / new / half chair combinations. The only slight concern is that does this still work ok when forming curves, or is there a danger 

that the gauging can 'slip' if the chairs don't hold the rail fully ? Assume this may not be a concern as long as the majority are set correctly and curves formed correctly.

 

As an aside, not sure whether it is best with custom-made curves to set one side, leave to dry, set the other side, curve to shape then lay, or lay with one side done, set

the curve then lay the other rail 'in-situ'.

 

With flexi-track this is obvious, but with custom made I guess this also depends on the sleeper base type - in my case it's mostly with pre-formed thin ply panels, but I also have

some individual ply sleepers to use with a template.

 

Pete.

 

 

 

Pete

 

I think 1 in 3 is fine, but even every other one is better than not using them. It is highly likely that the inside of the curve will be the stress point, now especially with the keyed outer half ensure the key goes into the web. On one half you may even have to trim the base that goes under the rail slightly to ensure both parts but together. As I said an inconvenience more than anything else

 

As for gauge slip on all but the tightest curves 1 in 3 should be fine. On straight track you should get away with 1-4/5,  I always use a ruler on straight track to line it up anyway. If both sides fit snugly into the web they should work. I always lay one side first. let it dry then fix the other with gauges, but the gauges must not be too tight on the rail, the head needs to rotate in it whether its a full or half chair

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I think the danger with the rail on the inside of curves is that it will always try and sit up straight, or even lean/cant outwards. Unless you are careful it can pull the inside chair base upwards due to the cant angle so I always arch the rail length a bit before attempting to curve to suit. The outer rail doesn’t need this of course it will just cant inwards as intended.  It’s not the end of the world though, just gives a bit of gauge widening....

 

Izzy

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7 hours ago, purplepiepete said:

Mark, that's a possible option thanks and will initially soften them at least. I find it a lot easier to thread chairs onto the rail whilst still on the sprue though - unless there is a technique I have missed !

 

Pete

Once they're dried off, Pete, then you should be able to follow your normal building routine, I would think.

 

Mark

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Semmingly asking the obvious, are you putting the rail in the right way up? Many of us have tried to thread chairs on rails then found the rail was wrong way up! Also file a slight taper on the end of the rail before threading chair, it makes life easier.

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15 hours ago, roythebus said:

Semmingly asking the obvious, are you putting the rail in the right way up? Many of us have tried to thread chairs on rails then found the rail was wrong way up! Also file a slight taper on the end of the rail before threading chair, it makes life easier.

Roy, yep always check that - and the taper - but it's a mistake I have made in the past, usually by not having my correct glasses on !

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Quick update - I tried the hot water (boiling in my case) soak and was surprised how effective this was. 

 

I didn't really expect ageing plastic to respond too well, but having put about 10 sprues (100 chairs) into a mug of boiling water, leave for about 5 mins, the chairs were a lot less brittle.

 

Not sure how long they stay more pliable, or the optimum immersion / water temp time, but working quickly to thread them after careful recovery from the hot dipping they went on without too much breakage.

 

Thanking Neil for the tip !

 

Pete.

 

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21 hours ago, Izzy said:

I think the danger with the rail on the inside of curves is that it will always try and sit up straight, or even lean/cant outwards. Unless you are careful it can pull the inside chair base upwards due to the cant angle so I always arch the rail length a bit before attempting to curve to suit. The outer rail doesn’t need this of course it will just cant inwards as intended.  It’s not the end of the world though, just gives a bit of gauge widening....

 

Izzy

Thanks Izzy, the curves should not be too severe (and in theory need a check rail) so hopefully will avoid this, but will take extra care on the inside rail and use the better quality chairs on that side to ensure a good chair to rail / sleeper grip.

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