Restoring the manufacturers printing on valves.

[Tyso_Bl]

Seeing this forum is about restoration of vintage electronics, and it is possible to justify stuffing capacitors, is anyone able to explain how to restore the manufacturers printing on valves? You know, just to make them look like they should.

I have a number of valves I'd like to practice on.

Who knows anything about how the printing on glass valves was done?

Restoring the print on valves is something I've not thought of as essential to an authentic restoration, but if you're showing off the inside of your radio, shouldn't the valves be properly dressed?

I've had a look through the youtube videos of valvemaking, but not seen how the valves were branded.

What sort of ink was used ?

How was it applied and fixed to the glass?

What sort of machinery did the printing job?

[bikerhifinut]

I wonder if it's possible to get sheets of water transfers made with the desired logos and lettering? You know the sort of thing we used as Kids when building airfix kits.
I know certain of the bulk suppliers will arrange for any logo of your choice to be applied but I imagine its for runs of 1000+

[mike_newcomb]

Hi, suggest googling:-

'make your own letraset'

So much can be done with one's printer these days, in choice and scaling of fonts etc.

Would think it possible to reproduce a valve label, then transfer using Letraset Safmat or similar.

Regards - Mike

[GrimJosef]

Would waterslide transfers or Letraset Safmat withstand the very high temperatures that quite a few valve envelopes run at ? I fear not. I suspect that the process will need some reasonably high temperature ink which will either have to be transferred directly to the glass or, just possibly, sprayed on using a very fine jet.

Cheers,

GJ

[G4XWDJim]

What about emulsion paint and a John Bull printing outfit.

Jim

[Bazz4CQJ]

Not sure this helps, but where I've been testing a number of valves of the same type, I've ID'd them by putting small marks with Tipex on them. It does seem to stick and stay there.

B

[Herald1360]

Stencil and Tippex, then......

[Tyso_Bl]

Quite a few ideas to try, emulsion paint look favourite at the moment with tipex coming second on the list to try, emulsion comes in white and yellow too, the two most important colours. My experience with printing with a john bull outfit is that it squelches out from under the contact surface when its non porous, such as glass.

There is the also the issue of printing onto a cylinder rather than a flat surface, although I suppose I could try to roll the valve across the stamp.

Thing is does anyone know how the manufactures did it?

Keep the ideas coming in.

[richrussell]

They would most likely have originally have been printed by being rolled against a rubber roller with the ink pattern transferred to it from an inked metal roller with the pattern on it, a form of offset litho.

I wouldn't worry about whether any ink or transfer you use will withstand the heat and not fade or flake off after a while. After all, it didn't seem to bother Mullard, Mazda, Philips etc

[pmmunro]

The original markings were probably applied by pad printing -http://en.m.wikipedia.org/wiki/Pad_printing .

This would have been worthwhile for the quantities being produced but perhaps a simplified version could be devised for home use.

PMM

[David G4EBT]

Originally Posted by bikerhifinut

I wonder if it's possible to get sheets of water transfers made with the desired logos and lettering? You know the sort of thing we used as Kids when building airfix kits.
I know certain of the bulk suppliers will arrange for any logo of your choice to be applied but I imagine its for runs of 1000+

Waterslide transfers are very easy to make yourself using either a normal ink jet or laser printer. So easy in fact that I can do it!

The process is very simple - you create your image, then print it onto the waterslide paper, which can either be transparent or white. You let the ink dry for a couple of minutes then overspray it with two or three thin coats of clear acrylic lacquer to prevent the ink from running when you immerse the paper in a saucer of lukewarm water. Having allowed the clear lacquer to dry thoroughly, after immersing the paper for 30 seconds or so in lukewarm water, you use your finger and thumb to check that the transfer is ready to slide off the backing paper. If so, you position the paper where you want the transfer, and carefully slide it off the backing paper and into place. You can move it around to position it accurately, then smooth it down to remove any air bubbles and water.

The paper costs around £1.60 a single A4 sheet, but of course unless you don't care about wasting the paper, you need to have enough images to fill and A4 sheet, which - in the case of labels for valves - might be close on 100 valves, depending on the size of the images.

I've made transfers for dials, for the top of Wartime Civilian Receiver cabinets, valves, electrolytic smoothing caps and so forth. Generally, for valves which have Bakelite bases such as octals, rather than making a transfer, I tend to make a label to attach around the valve base using a thermal printer - the modern equivalent of Dymo tape, but for valves such as say EL84s and the like, I think waterslide transfers are fine. They're quite durable - rather like a thin plastic film, and will stand handling without rubbing off. Not sure how high a temperature they'd tolerate, but I'd have thought that they'd be OK on most valves - maybe not on an 813, with 10V 5A heaters!

I've attached a pic of a valve I tarted up by over-spraying the shabby gold metalising, then creating a waterslide transfer similar in design to the original lettering. Also, a waterslide transfer I created for the can of a smoothing cap, alongside the can before I cleaned it up on the lathe, re-stuffed it and applied the transfer.

I'm sure lots of other forum members have used waterslide transfer paper (often referred to by the American name given to them - 'decal' paper). Quite widely available from the likes of Crafty Computer Paper and e-bay sellers. At Crafty Computer Paper's website, there's a short instructive video on using the paper, and examples of transfers created by the likes of model makers.

Hope that's of interest.