Severn mill, Top quality 7mm name plates

[steve fay]

Yes you might need it with the weight of Heljan locos!!

I'm very tempted my self, I really should be modelling the 90's

[steve fay]

Hi Steve,

 

The majority of that batch seem to have a very fine recess around the outside edge of the plates. It's highlighted in the pic because the plate colour has settled on it. I know that's correct for some of the GW plates but not for modern ones. Any idea why they've been etched like that?

 

Cheers

 

Tom

Tom

I've had a message from Chris this evening explaining the recess around the plates, so here goes;

 

Many years ago, I was sent some samples of 4mm plates by a trader who wanted me to buy his Range, telling me how good they were, and how they would augment my own CGW Nameplates (my initials), when I was working exclusively in 4mm back in the 1980s. I took one look and declined, as the raised beadings had been badly eaten away, due to the etching from the back having been allowed to continue too long. For those of you who don't fully understand the etching process, and have no idea of the problems that nameplate manufacturers have had to contend with from certain etching firms that view model railways as too fiddly and too demanding on their concentration to get things spot on, I will attempt to explain !

 

Etching firms work to tolerances of + or - .001", which would mean that if the best depth of front etching for say, small LNER cast works plates,( known to railwayana collectors as "Nine-by-fives" because of their size in inches), is .003", then I would have to accept any sheet that was etched only .002" deep from the front, up to and including a sheet etched to a depth of .004". Unfortunately, the lettering is so small on these tiny plates in 7mm scale, that at .002" deep, modellers would struggle to get any paint on them, and the letters would probably be so close together that they would have merged with each other. Conversely, at .004" deep, these same tiny letters would simply be eaten away. I therefore specify that this type of batch should be etched to say .0032" to .0036", which my present etchers have heroically achieved for me over the past six years. Sadly, the vast majority of etching firms are not prepared to take sufficient care to achieve this, or simply do not have the necessary equipment to work to these tolerances.

 

There is a certain thickness of stroke on the letters that cannot be etched, so one has to design the letters very carefully, thickening out the strokes- but if there are too many tiny letters in the words on these works plates, then there is the danger that as you thicken out the strokes of each letter , you widen the letters, and they become too close together to be etched individually. It is therefore necessary to find an etcher who is prepared to work to much tighter tolerances than he really finds easy, so they expect to charge a premium for taking much greater care when doing the etching. Most firms are no longer interested in spending the extra time, even if one is prepared to pay their often extortionate premiums, as they cannot guarantee to whip the sheet of metal out of the machine at exactly the right time, which leads to over-etching, and therefore the sheet will be rejected. There are many reasons for a sheet to be over-etched, such as the strength of the etchant in the machine (which will be diluted if they've just finished a long run of etching a commercial order and which may or may not have been topped up with fresh etchant). The temperature of the etchant can also affect the speed at which a sheet of metal is being eaten away.

 

It is often the case that the front of the sheet will be etched first, then the sheet turned over and the etching continued from the back. In the aforementioned example of the small LNER works plates, these would be etched say .0035" deep from the front, on .012" brass, and the back would need to be etched through for slightly more than .0085", to break through and form the outline of the plates. This is where the problems can start ! Some etchers refuse to etch anything other than slightly in excess of 50% from each side, and those that try to oblige often over-etch from the back. If a sheet is slightly under-etched from the front, then it is going to need to stay in the etchant longer when etching from the back, otherwise the individual plates will not have their shapes cut out; and this is how raised beadings around a plate can get undercut ( or over-cut if you like !) and ruined. It is for this reason that all my plates for the past 20-odd years have been specifically designed with a protective line drawn on the artwork around each plate. This line is then removed for making the front film, so the front of each plate is slightly smaller than the blocked-in artwork that is required for the back film. Yes, I agree that the modeller is left with a bit more work to do, filing the outer half-etched flange away, but would they rather have a plate with half the raised beading eaten away ? There is another point to consider- the edges of etched plates are not a clean vertical cut through the full thickness of the metal- there is always what is known as a cusp, which is like a raised line through the middle of the cut metal, where the break-through occurs to cut out the shape. As most model locos are viewed from slightly above, filing away my protective half-etched edge, at the top at least, means you can get a really clean edge to the plates. The etching process has never been an exact science- too many variables- but my method seems to offer the best compromise.

 

My customers have to file back the half-etched tabs that hold the plates together during etching, although I always cut these back as close as I can when removing from the main sheet of metal. I see my job as being to do the research that others do not have the time to do, and then the designing of accurate plates, strictly based on brass rubbings of original plates that are now in private collections, as well as museums around the country. If I had sold my sets of plates carefully painted, I would first have had to file away the tabs and flanges, and purely from the time point of view, the Range would only be a fraction of its present size, and so I leave the final preparation to my customers. Sadly, not all customers are modellers, or have any idea of model locomotives, or indeed, the etching process. One customer once emailed me to ask what the "projections" at either end of a smokebox numberplate were (he was referring to the half-etched tabs that hold the plates in place during etching) - he said he had looked through numerous books, and could not find an example of a fullsize loco with this shape of plate ! Without these tabs, each plate would simply fall into the bottom of the etching machine, and would eventually disolve away, diluting the etchent much to the annoyance of the etchers ! Fishing them out with a net would not be a solution, as you'd never find the plate you wanted ! For this reason, I hope that my rather long-winded explanation will help all of you to understand why I produce my plates in the way that I do ! And why my hair, what's left of it, has slowly turned white !

I should also note the small grease looking stain on the card is where the small spot of glue holds the plate in place although having removed them off the card a few times in the case of 92220's plates over the period of 4 years !! It has long sinced dried up.

I've a few sets arriving soon so I shall pop some pics up once they arrive.

[steve fay]

I had a nice delivery today of plates, most of these are for the station pilots panniers & 14xx plus a warship

I've also got a new 88A SC plate for lightning as she currently has a 86C plate and in her current condition she should have the later version.