Wireless Set No. 52 Canadian - Project

[David Dunlop]

The tool box is now dry to the touch but the paint still has a soft feel to it. The manufacturers instructions advise it takes a good 14 days for the paint to hard cure and finally resist push back happening if any surfaces get a hard rub, and become fully wash tolerant.

I did want to get the touch ups done on the metal hardware, so carefully turned the box upright on my work table this morning and it is now resting on two small strips of wood located under the four lower corner plate screws.

The two photos today show the tool box before and after the touch up work was completed. Now the whole paint job can fully cure for the next 10 days, which it will likely take, now that the cooler, slightly more humid fall weather has arrived.

Even though I elected to go with an eggshell finish, rather than the original full flat, when I had the paint for this part of the project mixed, I am very much pleased with the colour match. The factory original full flat paint on the inside of the lid in these photos matches the new exterior paint perfectly.

I have to thanks Bruce Parker again for sending me his ‘parts’, Coil Aerial Tuning Unit for this project. The interior of it was still the factory original Flat Olive Drab green Marconi had used on all the wooden components of the 52-Set and the back cover of the coil box was what I took to the local paint shop to get matched. This is definitely an interesting paint colour. Depending on the lighting conditions you view it under, it can look either green, or brown, or some sort of bizzare mix of both colours. Even the technician at the shop could not tell and took three scans of it before being satisfied it was indeed ‘green’.


David

[David Dunlop]

Just over halfway through the cure period for the paint on the tool box. It has now taken on a hard feel and the amount of off-gassing has dropped off dramatically.

Time to start practicing with the stencils I goofed on. The one surviving original stencil I have for the 52-Set Project is on the 4-Section Aerials Reel, but it provides a lot of information. The most notable bit is that stencil markings definitely do not have the uniform, consistency of any decal or screened markings. The distribution of the paint throughout the stencil is uneven. Some parts will have a solid buildup of paint, where other parts will have the colour over which the stencil was applied, clearly ghosting through.

Closely associated with this is the complete lack of any sign of runs in the paint having taken place. The application of the paint was very much to the light side and built up quickly with several thin layers where it was deemed necessary to do so.

80 years later on, this all gives the ‘rookie’ a lot of leeway to get the replication right.



David

[David Dunlop]

This morning, I was able to measure up and trim the stencil for the Tool Box markings to fit properly on the front of the box, when the time arrives to do the stencil.

Once I figure out how to hold it in place while doing the stencil, I should be good to go. My options at the moment are tape, rubber cement, or some combination of the two.


David

[David Dunlop]

This last weekend I finally found the BNC Cable I had been looking for and as I suspected, it was a perfect match for the one required for this Wattmeter and it is now stored inside the cover of the meter, along with the Probe.

David

[David Dunlop]

I have completed a round of stencil tests with the brushes I recently purchased. I did not try the 3/4-inch brush as it was far too large for the size of stencil I am using.

The first attempt was the letter 'N' lower centre in the photo with the 1/2-inch brush. Way too much bleed under the stencil on its own so I stopped with the one letter. the next attempt was the test block to the right side with the 3/8-inch brush and the plain stencil. Cleaner, but still way too much paint bleed under the stencil. Both of these tests were done with multiple thin coats build up with the brush.

The last test was the block to the left. For this, I secured the stencil to the test folder with a coat of Rubber cement, pressed the stencil down with a pencil eraser to ensure the stencil was as flat as possible and I let the rubber cement dry for 20 minutes at room temperature. I then rubbed the excess cement off the top of the stencil with my finger and used a round toothpick to clean up any excess cement inside each stencil segment. Then out came the 3/8-inch stencil brush again and multiple coats were build up until the majority of the folder colour vanished.

A very slight bit of paint wicking took place, but overall, I am very pleased with this result and kit will be the process I use with the tool box stencil.

David

[Bruce Parker (RIP)]

There must be an easier way. The factory would have been pumping these out by the hundreds and wouldn't have fought as you are fighting. What was their secret? Any chance they were screened on?

Originally Posted by David Dunlop

I have completed a round of stencil tests with the brushes I recently purchased. I did not try the 3/4-inch brush as it was far too large for the size of stencil I am using.

The first attempt was the letter 'N' lower centre in the photo with the 1/2-inch brush. Way too much bleed under the stencil on its own so I stopped with the one letter. the next attempt was the test block to the right side with the 3/8-inch brush and the plain stencil. Cleaner, but still way too much paint bleed under the stencil. Both of these tests were done with multiple thin coats build up with the brush.

The last test was the block to the left. For this, I secured the stencil to the test folder with a coat of Rubber cement, pressed the stencil down with a pencil eraser to ensure the stencil was as flat as possible and I let the rubber cement dry for 20 minutes at room temperature. I then rubbed the excess cement off the top of the stencil with my finger and used a round toothpick to clean up any excess cement inside each stencil segment. Then out came the 3/8-inch stencil brush again and multiple coats were build up until the majority of the folder colour vanished.

A very slight bit of paint wicking took place, but overall, I am very pleased with this result and kit will be the process I use with the tool box stencil.

David

[David Dunlop]

Hello Bruce.

When I was in Junior High School, the Father of one of my friends was an Illustrator who owned a sign shop. He had a lot of silk screen equipment in their basement, and I wish I had paid closer attention to it all at the time.

I do remember the screens were a two part item consisting of the thin fabric screen and a mask bonded to one side somehow. You cut the design through the mask and peeled away the bits you wanted the paint to pass through. The huge advantage of this printing technique is the design and any characters therein can be solid and continuous. By comparison, a stencil requires webs in the characters to hold them together. It would absolutely be possible to cut a silk screen mask that looked exactly like a stencil, but why?

Screening was definitely used with wireless equipment during the war. You can see it on any 19-Set Spare Parts Box, or Spare Valve Box, and if it is minty enough, you can often see the fabric shadow in the white paint under a low angle light.

Looking on the web today, there are a few commercial, line production stencilling machines available, but most seem geared to working with electronic circuit boards and other small, thin items of that nature. It is entirely possible these modern, compact machines evolved from much larger equipment from decades ago. We may never know.

Regarding the various boxes/cases for the 52-Set, I have photos of two different tool boxes with original markings, one in Canada and the other in England. The stencil markings on both are spot on identical in both form and location on the two boxes. I also have on hand, two Spare Parts Boxes and again, the stencil marking shadows are spot on identical in form and location.

In the pre-computer era, Sign Painters and Illustrators, were highly skilled positions and there was probably a lot of cross reference to other closely related skills like screening, stencil making and even engraving…all hand done. These physical skills are largely lost today. The station on the line for stencilling these boxes/cases was probably occupied by a lot more than just one person to keep production numbers up as you have noted. It would not surprise me at all if each work table was set up with jig options to hold the various cases/boxes in a specific spot, and perhaps even some form of mechanical arm which could swing the stencil down to the same spot for each type of case/box being worked on.

The viscosity of the paint is also critical. Too thin and it will wick under the stencils in a heartbeat. Too thick and it becomes hard to apply and you risk it drying out. Just right, and a skilled worker, and away you go!

Sorry for the length of this reply, Bruce. It amazes me what the older generations were able to accomplish with pure mind power and great hand/eye coordination and as much as I would love to know how they accomplished things like applying these markings, an answer may never be found. In the meantime, I shall muddle along and try and honour their collective skills as best I can. That probably means I end up drinking more than any of these workers ever did, but that is not a complaint…

David

[Bob Carriere]

.....works good BUT will leave permanent mark on flat OD paint like truck doors. A stencil cut on 15mil acetate held in place with magnetic strips works well with very thick stencil paint and foam dabber.

Flat OD paint will mark very easily and cannot be repaired short of repainting the whole door skin... trying to re-spray patch always mess things up and stencil paint has to be re sanded to bare primer.

Cheers

[David Dunlop]

Bob raised a couple of interesting points last week regarding the use of stencils and to be on the safe side, I decided to double check both factors before proceeding further with work on the tool box.

The first potential problem was the use of rubber cement on flat paint, or even semi flat paints.

Years ago I restored a pair of M38 CDN’s and painted them both the original semigloss factory green. I was lucky at the time a company called Rondex here in Winnipeg, still had the original paint sample catalogs for Dulux paints and it covered all the Canadian Military Vehicle colours from the factory new M-Series back to 1944-45. When it came time to apply the CFR Numbers I used stencils mounted to the vehicle with rubber cement with no problem at all, but the paint in question was an enamel semi-gloss. Today, the term ‘semi-gloss’ seems to have disappeared from paint terminology, being replaced with names like ‘Eggshell’ or ‘Satin’, and most paints today are latex or other water-based variations.

So my first test last week was to coat a small piece of oil board with rubber cement and stick it to the bottom of the tool box, wait five minutes, peel it off, let the cement dry completely and rub it off to see what happens. As per the first three photos, the solvents for the rubber cement did not alter the finish on the satin latex paint at all. Good to know.

The second point Bob mentioned was the use of those small foam paint brushes to apply the stencil paint. Debbie happened to have quite a selection of these in her crafting supplies so I borrowed one of the small, black rectangular ones with the chisel tip to test it out.

The last photo shows the results of this test in the lower left corner after the stencil had been glued down with rubber cement and the excess cement cleaned off prior to painting. Directly above that test is the sample done with the 3/8-inch stencil brush on the same glued down oil board and off to the right the same brush on an unsecured oil board. After looking at the results for a bit, my quality ranking would be the top left result with the small stencil brush is best, followed pretty closely by the foam brush below it and a distant last place is the unsecured stencil and small brush to the right side.

I think the problem with the foam brush test is more a factor of the small size of the stencil cutouts, rather than the foam brush. With the narrow openings of the characters, too much of the foam is on top of the stencil and the foam has difficulty getting in close to the edges. As a result, the sections of some of the characters have varying widths to them. With the small stencil brush, some of the bristles clearly hit the face of the stencil, but not enough that they still flex and allow the other bristles to reach down inside the cut-outs and fill it more evenly with paint.

I think with larger sized stencils, a foam brush could easily hold its own with a bristle brush for stencil work.

So with that out of the way, and thanks again Bob for raising these points, the next step will be to apply the required stencil to the tool box.


David