What colors were radars painted on USN WW2 warships

[Bill Oreto]

In the old ship kits instructions always called out to paint radars on warships silver. Looking at picture of Destroyer Squadron 23 in USNI Naval History magazine 4/2026 and there is a definite shine to MK-4 radar above the MK37.

[MartinJQuinn]

Photos seem to show them unpainted, like this one of DeHaven in Ironbottom Sounds, a few days before her demise.

[MartinJQuinn]

Here is another photo, this one was the one I was thinking of, it's via USNI Press:

[Bill Oreto]

That is the photo I am referring to. Kind of odd the whole ship gets painted by not the radar?

[TF48]

Paint would have interfered with the radar’s effectiveness. They were left bare metal with weather protective varnish which allowed them to have the shiny metal look.

[Rick E Davis]

TF has the correct answer.

Actually the problem wasn't as much "the color/contrast" of the varnish coatings used initially, as it was the reflectance of the varnish. The early varnish was great at reflecting the bright sun. Actually, the design of the FD (Mk-4) radar antenna to produce a narrower radar beam for tracking targets, also worked in the visual spectrum. The Mk 4 antenna produced a bright visual return when viewed within its beam width.

This problem with early Mk 4 antennas was reported back to BuShips from the forward areas and the varnish formula was adjusted to make it duller, hence less reflective and added some color closer to the camo paint being used. Some ships used the newer varnish, while other ships had new antennas installed during availabilities.

[El Santo]

Any idea whether the antennae were made from steel, aluminum, or some other, more exotic material?

[Rick E Davis]

My research in official records at NARA, not engineering design and production records with drawings, etc of radars, didn't mention specific metal used in making the antennas. Equipment like radar and weapons were contracted separately from the ships and provided to builders as "Government Furnished Equipment". Not built by shipbuilders and not included in ship engineering drawings. But, likely they were constructed from steel given the priority given to aircraft manufacturing during WWII. However, I wouldn't rule out that they were made with aluminum. Nothing exotic would be used during WWII.

For the purposes of modeling, material is not important.

[El Santo]

For the purposes of modeling, material is not important.

You don't think? I would have expected unpainted steel to come out noticeably darker and duller than unpainted aluminum.

[FFG-7]

El Santo, even varnished steel compared to varnished aluminum?

[Bill Oreto]

Camo paint of that era must have had lead in it so yes good possibility camo paint may have played hob with the radar emitter. Late in the war you don’t see the sheen off the radars so they must have found a solution,

[FFG-7]

what makes you think there was lead in the camo paint?

[Tracy White]

Well, I have a formula here for the tinting paste used in 5-L and 5-O that lists Lead naphthenate... here for flight deck stain (no, I am not suggesting they used this on radar antenna), and here for the tropical greens.

[Bill Oreto]

Lead in the paint. Ever wonder why our ships look like rusted poop? It was discovered that ships layed up were peeling off paint with high levels of lead which got into the sea water and then into the sea’s ecosystem Lead in the seawater was a no-no which led to a reformulation of naval paints. That a few other chemicals that were a no-no. Lead was removed from house paints and gasoline. Why lead was used in mixture I have no idea possibly a binder.

[Rick E Davis]

OK. Lead was used in paint for many reasons, but the primary reasons to improve durability, accelerate drying, and maintain a fresher appearance over time. No one realized the dangers in its use until more recent times.

Closeup views of the Mk 4 and Mk 12 antennas during WWII aren't common. But here is a view of the Mk 12/22 antennas on the Mk 37 director of USS BRAINE (DD-630). You can see the darker "color" (this is a B&W photo after all) of the antennas. Compared to the "assumed" 5-N paint worn by time at sea. they aren't an exact match. But, the antennas VARNISH and ship's PAINT were likely closer in grayscale appearance when freshly applied.

The antenna screens DIDN'T emit the radar signal, they only reflected the signal produced by the dipoles located if front of the reflective screens.

The second image shows a SC-2 antenna in "post-WW2" varnish coatings to match peacetime Haze Gray paint.

One of the reasons I suspect that the reflective surfaces of these antennas used steel, was because the welding was generally easier to manufacture. The little circles in the second image marks areas of corrosion (rust?).

[El Santo]

Rick, do you have an inception date for the use of tinted varnish? Obviously, as you say, its use on any given ship afterward would depend on when the ship in question last visited the yard, but it would be useful to know the earliest date from which tinted vs. untinted varnish becomes a question worth investigating.

[Tracy White]

Bet you I know a place we could find out.....

[Killerbeans]

What I've gleaned so far: early WWII USN radar may be a steel/ bare metal, while mid war/ late war would be black(ish)?

[Rick E Davis]

Radar antennas were VARNISHED, not bare metal. Only the darkness of the varnish changed. And no I have no idea of what “specific color” the varnishes used were.

I don’t have the specific date when the revised darker varnishes were “directed”, much less when those varnishes were AVAILABLE and APPLIED. Photos give a clue that the change took effect in ABOUT the Fall of 1942. But, there wouldn’t be a field mod done (even if BuShips would be shipping a container of new varnish) to each ship so involved. I would have to look through my scans to see if I scanned that subject or in my hand written notes for the reference. Among the details of configuration changes done on 175 FLETCHERS, the “COLOR” of antenna varnish wasn’t on my list to document. Besides, other than in photos taken, it is something that BuShips and individual ships didn’t note. I would have an easier time documenting what typewriters each ship had. (CO’s complained in memos to BuShip when they were NOT issued their favorite typewriter brand)

[El Santo]

Among the details of configuration changes done on 175 FLETCHERS, the “COLOR” of antenna varnish wasn’t on my list to document. Besides, other than in photos taken, it is something that BuShips and individual ships didn’t note.

Ah, okay. From your initial comment above, I got the impression that you might have stumbled upon a copy of a memo or an order or some such thing in the course of your research.