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Bl**dy Ratio again


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I have to accept culpability for continuing to purchase Ratio products that i know will present me with unforeseen difficulties because every one I have ever bought previously has, and this one is more annoying than all that difficult, but what, I thought, stupidly, can go wrong with fence posts...

 

GW wooden ones with angled tops and grooves for the wires to fit in, in black plastic, complete and ready to cut off the sprues, clean the pips off, and paint, then you plant them where they are going to go, don't you?  No, you don't, because the paint will not key to the plastic.  I mean, come on, this means I have to either abandon the job, or file each face of each post individually to provide a key for the paint, or just let them be shiny black plastic, not acceptable.  I suppose I can console myself that the pathetic scratchings of the file look a bit like wood grain, but they don't really.

 

Paint is acrylic, and it is possible that enamel would key better, but I do not use this because of the smell in the living area of my flat.  I tried an undercoat of matt varnish, to no avail; this is going to make what should be an easy and satisfying job into a nightmare of handling small parts and hurting my fingers.  I'm just going to have to spend an unsatisfying hour with a file, and hope that works!

 

Grr.

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If you have a can of Halfords Primer lying around it might be worthwhile giving the posts a spray with that and seeing if it will provide a decent key.

 

DT

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Will try the washing up tip first, and if that don't work I'll leave it for tomorrow when I can get hold of some fine sandpaper or emery.  Thanks, chaps!  I've had a cuppa and calmed down a bit now!

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Washing up liquid is definitely what you need. I have made several Ratio kits in the past (over ten years ago), and, unless they have radically changed the plastic used, a pre-wash was essential and successful to allow paint to grip. When they come out of the mould, some sort of residue is left on the plastic, which must be removed before painting. Good ol' Fairy Liquid (other brands are available) has always worked for me, and I used acrylics as I do not like working with enamels.

 

The same is true of resin kits, which I have made more recently, and have some more to make this year.

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It's probably some sort of mould release agent.

 

I had a similar problem with GBL locomotives. I was cataloging them and wanted to attach numbered labels under the cab roofs. They refused to stick until I removed the oily deposit on the plastic.

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I have washed them up, in washing up liquid, but am wrapped up for today now and on my way up the pub with SWMBO (and gone up the pub with; it's a terrible job but somebody has to do it).  Will have another go tomoz and report back!

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If this is the kit I think it is the wire is thin styrene. Once painted of course the 'wire' will not stick to the posts with solvent. I made a drilling jig to drill each post adjacent to the grooves. Then painted and planted the posts. When dry I threaded dark brown cotton through the holes (only the ends need to be stuck). To make it easier to thread the cotton I stiffened the end by twisting in balsa cement.

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I really think that all plastic kits should be degreased and that w/up liquid is best.

the difficulty with the Ratio fencing is the stuff dropping off the sprue.

 

So toothbrush w/up liquid quick rinse off and leave 24 hrs to dry off then undercoat and paint. Micro strip can be used as the wire and does not need degreasing to the same degree.

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Silicone spray is normally used as a release agent ...

Sometimes - not normally. Mould release spray should only be used as a last resort. A properly designed mould tool, set up and run properly using decent quality material should not need mould release spray.

Edited by spikey
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Sometimes - not normally. Mould release spray should only be used as a last resort. A properly designed mould tool, set up and run properly using decent quality material should not need mould release spray.

I haven't seen a set of these sprues, but I would assume that the manufacturer wants to keep these posts as square as possible, so perhaps the mould isn't optimal from the release point of view?

 

Some earlier moulds (Midland coach bogies), did seem rather shiny and slightly brittle, so perhaps their chosen material isn't the top quality?

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... perhaps the mould isn't optimal from the release point of view?... perhaps their chosen material isn't the top quality?

Perhaps indeed. If you want to produce a small moulding as near square as practicable, you need very good tool design, very good toolmaking and very careful setup in the moulding machine, which thereafter needs to be run within quite narrow parameters. The fun starts when you trade some or all of those for production at lower cost. And if you then try to reduce your material costs by incorporating too much recycled material ...

 

However, when you have a good idea of what's involved in the production, packaging and distribution of products like Ratio kits, you know there's both VAT and dealer markups to come out of the price we pay, and we're hardly talking about a mass-marklet product, the wonder is that they keep on knocking the stuff out at the price they do. Some aspects of their kits drive me nuts too, but I nowadays tend to treat them as a means of saving time and developing both my scratchbuilding and painting skills

Edited by spikey
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I'm surprised at the recommendation, by some, to use washing-up liquid as a degreaser, especially as it contain Lanolin, added to help prevent hands from getting dry skin, it's a natural (from sheep fleece) greasy additive. 

Before I need to paint anything, whether plastic or metal, I give it a quick blow over from a can of Halfords Surface Cleaner.

Edited by bike2steam
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There's a previous thread here which might be of use.

 

http://www.rmweb.co.uk/community/index.php?/topic/50302-using-ratio-gwr-fencing/

 

 

 

If using acrylics have you tried the Games Workshop range? They have some very good colours for things like wood and their primer is excellent as it's designed for the white metal figures as well as the plastic ones.

 

 

 

 

Jason

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Wow; I have learned a huge amount about plastic moulding techniques if nothing else from this topic!  The Ratio posts are pretty square, and it is probably the composition of the plastic that is causing the problem.  The kit has been around since god was as an anklebiter, and I don't remember the ones I had in the 1970s being like this, so perhaps the composition has changed over the years; recycled plastic was mentioned.

 

Good tip about the Games Workshop acrylics, which I'd forgotten about, Jason, thank you for suggesting it.  I should be aware of them as I used their 'decaying flesh' green for the formica inside a Lima 117 I converted to a 116 years ago; it was the nearest thing I found to the colour I remembered!  They probably have all sorts of acrylics suitable for scenery and weathering.   Thanks for the link to the previous thread as well; I will not be using the Ratio wire and prefer stiff wire in straight lengths available at my local Antics, but the elasticated wire sounds ideal.

Edited by The Johnster
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Some earlier moulds (Midland coach bogies), did seem rather shiny and slightly brittle, so perhaps their chosen material isn't the top quality?

 

I noticed that with some of their LNWR coaches. Very fine bits such as tie-bars between axle boxes just fractured when I attempted to cut the bogie parts from the sprue. I'd put it down to the kits being rather old and the plastic getting brittle over the years (I'd had them in my 'to-do' pile for quite some time) rather than being poor quality in the first place.

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I have never had the slightest problem with them - and I had well over 40 feet of Ratio fencing on my last layout. I just spray them very simply with Railmatch Sleeper Grime (enamel - rattle can from Howes) and then dry-brush over them when dry to add detail colour with various shades of Humbrol.

 

For the record I NEVER use acrylic (and never will). Have used enamel for the last 45+ years and I'm certainly not changing now. To be fair I did try acrylic once (for all of about two hours) when it first appeared - and frankly couldn't get it to stick to ANYTHING. I never used it again.

 

But I do think that the initial heading to this thread was both unfair to Ratio, who have been a main supporter of the hobby for decades - and a little out of order.

Edited by orford
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Like Coachmann, Larry Goddard, I spray everything with Halford's grey etch primer - metal as well as plastic. Makes a great key for any type of paint. They also make a plastic primer but I have never tried that.

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