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Old 18-01-22, 02:28
David Dunlop David Dunlop is offline
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Join Date: Feb 2006
Location: Winnipeg, MB
Posts: 3,384
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Good Evening, Bob.

We are just hunkering down here for a potential storm supposed to arrive sometime in the next few hours and last until Wednesday morning with up to 20 cms of snow and winds on the plus side of 70 kms. Still lots of holiday wine left, so we are good.

The paint I have found to be the closest match to the wartime ‘Gloss Navy Grey’ is an Armor Coat product from their rust paint series. It is called ‘Misty Grey’ with a nice high gloss finish. Their stock number is #47002RP522 and I can find it locally at either Canadian Tire or RONA.

It goes on with an almost orange peel look, which is a bit alarming the first time you see it and it stays a bit tacky to the touch for the first 24 hours at room temperature, but as it skins over, the oils off gas through it, the skin tightens and the orange peel look flattens out. After 48 hours, you end up with a slick, smooth finish and I always let the parts hard cure for two weeks before working with them. It is a very close match on its own to the original, but with a grey primer under it is pretty much spot on.

It appears that the majority of all the Canadian and American wartime wireless equipment, if not all of it, used a grey primer. I have only ever found red oxide under postwar overhauled equipment so far.

The go to primer for me is Rustoleum’s Tremclad ‘Grey’ #274103522, which I use on all the steel bits. Just prior to priming, I wipe the parts down with alcohol on a cloth.

For the cast zinc parts, there are two on the 19-Sets and three on the 52-Set, I use Tremclads ‘Galvanized Metal White’ #274101522. It actually dries a cream colour when applied.

I used to worry about the possible plating on a lot of the sheet steel components on the wireless equipment because the two common ones were zinc and cadmium. What I have discovered over time, however, is that the main reason the old wartime paints come off so easily is that the plating oxidizes and the original bond between the metal and primer fails, so once the paint is off, there is little, if any plating left to worry about. I think humidity plays a big part in that paint bond failure.

I have only ever used a quick acid etch as a final step before rinsing off parts before electroplating them, and for that I use Muriatic Acid cut 50/50 with water and dip the parts for only 20 to 30 seconds. So far so good with that approach.

Your comments about soldering brought back memories, Bob. In High School Metal Shop we used big heavy wood handled irons. They had solid copper heads about 1.25 inches square and when new, the heads were probably 6 inches long, cut to a pyramid point. They had twisted wrought iron shafts between the head and handle, about a foot long and at the front of each workbench was a cast iron, gas fired oven that would hold two such irons, a large can of flux and a horse hide towel. You started with two clean irons in the oven, when they came up to heat, you pulled one to work with, dipped the tip in the flux, which produced a big green flame and then proceeded to do your soldering work, usually with bar solder. When the iron started to cool, you wiped it on the towel and returned it to the oven and picked up the second iron ready to repeat the process and keep the workflow going. Our Electrical Shop had electric soldering irons almost as big and heavy as the manual ones in the metal shop! It still impressed me today, the quality of work craftsmen, and women, 70 plus years ago accomplished with that equipment.

Hope this helps, Bob. Stay warm!

David
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