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Posted: Sun Jan 11, 2009 3:18 am
by lt.luke
Ronnie Guin wrote:...When I removed the firewall pad it had only the yellow-green zinc chromate primer with no OD sprayed over it. This would indicate the firewall pad was in placed when the OD was sprayed on...
I do not beleive this was always the case. I would like to see a photo of the yellow zinc chromate primer, so I can be sure, but all the stuff that I removed from my firewall had OD underneath it.

Mine's from Dallas.

Posted: Sun Jan 11, 2009 6:17 am
by Tom Wolboldt
Hello Luke,

The assembly plant should not matter in regards to the primer of a Ford built GPW since all of the production bodies were made at the Highland Park Ford plant and shipped to the assembly plants in a mostly completed form. The fenders, hood, windshield, and grill were shipped bolted to the body as well.

Posted: Sun Jan 11, 2009 7:12 am
by lt.luke
Ok, Tom that's very interesting. So do you think that all of them had the firewall padding installed over the primer, then final painting took place? I distinctly remember OD Green under the filterette on 12078, but it was not a Ford Filterette, so maybe not the factory one?

Posted: Sun Jan 11, 2009 6:04 pm
by Ronnie Guin
Luke, here is a picture under the dash of GPW 2956 after removing the original firewall pad. My jeep is a 3 owner jeep counting Uncle Sam. The second owner never removed the firewall pad and he bought it from the Army in 1946.

Image

Primer

Posted: Sun Jan 11, 2009 6:52 pm
by David H. Morganthall
Hi Guys! I thought the primer was from a Bubba repaint. Count me in for having this on GW<>38679.

Posted: Mon Jan 12, 2009 7:38 am
by lt.luke
Thanks Ronnie. HHHMMMM...I seem to remember some of that. I'm a little embarrased actually, as I thought it was some sort of OD. What was under the filterette was darker than that. I think I had the same on 12078, and I know my firewall pad was the same construction. Probably won't be lucky enough to have photographic proof, though.

Re: What colour was the priming coat on 1st contract GPWs?

Posted: Tue Jun 27, 2017 3:13 pm
by 17thAirborne
This is a very old post and worth a continued infusion of recent discoveries. Within the next 2 years I wanted to begin restoration on GPW 3742 which is on a Midland GPW marked frame. I wanted to be sure I use the correct color of primer on all of the right parts. A search of Zinc primer opens a few dozen threads with sporadic information. Anything new is appreciated,.

FOR EXAMPLE:

1. what parts such as the Midland frames are notoriously not primed in Zinc Chromate?
2. what source is the best for a realistic match for the ww2 color, is it yellow-green or more green -yellow?
3. what other areas such as behind the firewall pad were left in the zinc color and not painted OD?

Re: What colour was the priming coat on 1st contract GPWs?

Posted: Tue Jun 27, 2017 4:19 pm
by 17thAirborne
Just for reference ad I hope to find the actual color codes to match, here are three examples of Zinc Chromate that are available
zinc.jpg
zinc.jpg (51.01 KiB) Viewed 3246 times
Regarding Aircraft color, but perhaps somewhat useful if debated: http://www.alliancecoatings.com/warbirds.php

Zinc Chromate Yellow

In US aircraft use in the 1930s to 1940s, the Zinc Chromate primer was frequently used in the raw mixture yellow tone. This is sometimes referred to as Zinc Chromate Yellow. Like stated above, there is no definitive color pattern as this may have varied between manufacturers and batches of these primers.

In the immediate pre-war and early war period, the raw yellow Zinc Chromate primer seems to have been dominating.

Zinc Chromate Greens

Sometimes, Zinc Chromate was mixed with Lamp Black paste to give a bit more UV resistance (Zinc Chromate is very sensitive to photolitic reactions) and more durability in high wear areas.

Mixing with black gave greener tones, which, depending on the amount of black added could run from apple greens to medium olive greens.

There were many variations in Zinc Chromate Green. Originally, manufacturers were expected to mix raw Zinc Chromate, black enamel and aluminum paste or powder. Several blacks and grays could substitute for the black enamel, and a shortage of aluminum powder/paste caused a reformulation without it in 1942.

Some aircraft manufacturers ordered pre-mixed Zinc Chromate Green (Curtiss Cockpit Green, ordered from Berry Brothers, being an example of this).

There is evidence that such variety of shades occurred in the manufacturing practice of US aircraft factories. Where sufficient color evidence is available, it is possible to find all three colors used on the same aircraft - for example, the yellowish raw color in the wheel wells, the apple green tones in the gun bays, and the darker green in the cockpit.

And as a note: Recent studies have shown that not only is zinc chromate highly toxic, it is also a carcinogen.[17] Exposure to zinc chromate can cause tissue ulceration and cancer.[1][3] A study published in the British Journal of Industrial Medicine showed a significant correlation between the use of zinc chromate and lead chromate in factories and the number of cases in lung cancer experienced by the workers.[18] Because of its toxicity the use of zinc chromate has greatly diminished in recent years.

That does not mean we can't mix a suitable looking color for realism

Re: What colour was the priming coat on 1st contract GPWs?

Posted: Tue Jun 27, 2017 4:31 pm
by 17thAirborne

Re: What colour was the priming coat on 1st contract GPWs?

Posted: Tue Jun 27, 2017 4:54 pm
by Old Pal
13551 had zinc chromate primer on all body panels and the tub.

Re: What colour was the priming coat on 1st contract GPWs?

Posted: Tue Jun 27, 2017 7:45 pm
by 17thAirborne
Thanks for that update. These are some comments that I gleaned from the other VEP threads regarding ZC primer. Sorry I do not have the author. All posted on the G elsewhere, but here as cut and paste, If the moderator wants me to delete this part since the comments are not complete, I'll gladly do so if a breach of etiquette or source of confusion.

"right air cleaner bracket on GPW 8015"

"Fords used zink chromate primer on early gpws, this is what got me started. Do veps have f marked scalloped axles? this one has unmarked and they have zink chromate primer under the od as does the hubs."

"I know that some early veps used non gp marked axles, I own one. Here is the interesting thing, the (willys) axle has f marked leaf spring pillow blocks, so it is not a case of switch-er-out. plus the primer is zink chromate."

"I restored what I found when I stripped everything. You will also notice a GREEN tall crossover tube. That's what I found when sandblasting, crud, then OD, then Zink primer (I think it was red oxide primer on the bell housing). On the crossover, I left the inside untouched"

"The driver side mirror arm on GPW 30926 was painted zinc chromate."

"My GPW 12798 DOD 3-30-42 has the standard windshield in height but does not have the rifle rack brackets and no sign of them ever being there. It also does not have the outer hole for the top retainer bottons on each side. I have inspected the entire jeep and all of the body parts are original as every one of them has the exact primer and paint right down to the original yellow zinc chromate color primer"

"As a note we believe that the early frames built by Midland Steel for Willys and Ford we shipped to the plants in a black primer or paint. This is just our observation of GPW-713 and two slat grill frames which had black primer/paint as their first coat."

"GPW 2956 had the yellow-green zinc chromate primer on the tub, hood, grille, and fenders. When I removed the firewall pad it had only the yellow-green zinc chromate primer with no OD sprayed over it. This would indicate the firewall pad was in placed when the OD was sprayed on. GPW 2956 willys frame had black paint under the OD. It looked laike shiny black to me and most of the OD flaked off when I was restoring it. According to Tom's research of my data plate this is a Louiville built jeep."

"The assembly plant should not matter in regards to the primer of a Ford built GPW since all of the production bodies were made at the Highland Park Ford plant and shipped to the assembly plants in a mostly completed form. The fenders, hood, windshield, and grill were shipped bolted to the body as well."

Re: What colour was the priming coat on 1st contract GPWs?

Posted: Wed Jun 28, 2017 10:41 am
by m3bobby
GPW6008 frame has black primer under a coat of Green Chromate or light OD with a top coat of normal OD. The body and hood have the yellow chromate with a green chromate/ light OD over that with a top coat of OD. I thought the yellow chromate was aircraft primer as my jeep had lots of Military aircraft fasteners, switches, wire and clips and assumed the jeep had been used to commute to an airforce base or production plant after leaving military service (and kept running with aircraft parts at hand).

So I now know its original so thanks for resurrecting this post.

Re: What colour was the priming coat on 1st contract GPWs?

Posted: Wed Jun 28, 2017 11:35 am
by lt.luke
m3bobby wrote:GPW6008 frame has black primer under a coat of Green Chromate or light OD with a top coat of normal OD. The body and hood have the yellow chromate with a green chromate/ light OD over that with a top coat of OD. I thought the yellow chromate was aircraft primer as my jeep had lots of Military aircraft fasteners, switches, wire and clips and assumed the jeep had been used to commute to an airforce base or production plant after leaving military service (and kept running with aircraft parts at hand).

So I now know its original so thanks for resurrecting this post.
Your point about chromate being aircraft primer isn't incorrect. Remember 2 things about Ford. They built aircraft during WWII and he was stingy. I have primer for airplanes, it sticks to jeep metal too.... It also simplifies the logistical train... "order primer"

Re: What colour was the priming coat on 1st contract GPWs?

Posted: Sat Jul 08, 2017 5:30 pm
by tractor12
5235 green zinc chromate

Re: What colour was the priming coat on 1st contract GPWs?

Posted: Mon Jul 17, 2017 3:50 am
by m3bobby
Found this thread on Early MBs and they show midland frames being black primered followed by a phosphate primer so it looks like midland shipped them primed in phos rather than Ford doing it.

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