Honda CB750 Sandcast

Tank Striping - Paint, Decal or Transfer

kp · 19 · 5597

kp

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I thought I'd start a new thread on this because of the debate and discussion that it may generate. Remember when we (well some of us) had this board debate of painted cases vrs unpainted cases. I can't remember which camp I was in but probably was the unpainted camp. Well that debate was settled years back and it is the accepted view cases were painted.
Here we go again. I've always been in the painted stripe camp as are many others. Well Gerard has brought a wealth of knowledge and opinion to this forum and I and others have never dismissed out of hand what he has ever posted. He just posted on the thread "Your Stripes are Wrong" about stripes maybe NOT being painted so I decided to have another look at this question. I armed myself with a light magnifier and 2 of the 3 original tanks I posted about a few days back. The third tank was repacked and I wasn't inclined to unpack it again.
Armed with this magnifier, camera, good light I've studied these 2 tanks, one a double wrinkle 17 litre and the other a 19 litre. All I can say is it was a most enlightening exercise as I discovered several things.
The first thing was that the front of the right side stripe is approx 47mm wide whereas the left side stripe at the front is around 45mm wide. This oddity is on both tanks and the measurements are more or less exact. This cannot be a coincidence. This oddity can not be so if striping was done manually. I just don't believe that such exact measurements can be so random with these tanks if striping was done by hand. Template yes but not by eye. The other thing is I could notice lines outside of the stripe, say about 1mm wide for the full outline of the stripe. It's not a decal line as it's too faint, but, maybe a water transfer line ????????
Attached are the photos I was able to take that does shed some light on this and I'm sure will generate some further discussion. Taking photographs of what I can see with my eye is very difficult but I think I've been able to capture what I saw.
Do any of you remember the days of plastic models. I was an avid model builder through the 60's and early 70's and war planes was my special interest. In those days (the good ol days) vinyl decals were not common at all and the poison of choice in them there days was the water transfer. These model kits had a sheet of water transfers which when soaked in water came away and were easily placed on the model. Usual detail was the aircraft insignias and the name transfer I believe was used because one transferred the insignia from the paper to the aircraft using water to release the insignia from the paper. When this insignia was still wet it was placed on the appropriate area of the model and allowed to dry. You could then paint over the transfer if required.
Although not totally convinced, I'm starting to think Gerard is maybe right about this. Needs more members to comment on their findings
Just added some more photos
« Last Edit: April 13, 2019, 01:28:53 am by kp »
Yabba Dabba KP


kp

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Here are some not so perfect photos of the measurements I took. I'll just flag it's a little hard to hold the vernier and take a photo.
I didn't take photos of all measurements undertaken on both tanks but take it from me that were the same for both.
Interestingly, the right stripe was around 2mm wider than the left at the front of the stripe, however when I measured both stripes around 6 to 8 inches towards the tank badge, both stripes on both tanks were the same width of around 45mm which was the same as the left side stripe at the front. Hope I've not confused
Yabba Dabba KP


4pots1969

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That's exactly what I wanted to tell you Kp, but my English does not allow me to find the right words, in French I find that the vocabulary is more "rich" and it is easier for me to me express with precision ...
The cost of manufacturing this bike should be as cheap as possible so that the selling price is too, that's why I do not believe that the Honda factory is made the decision to manually paint the strips on the tanks This is why I put forward the idea of decals soaked in warm water to make a placement on gas tanks faster and especially less expensive.

Anyway, it could not be the same painter who manually painted strips of more than 300 tanks per day, so it would have been impossible with a dozen painters to have a very good regularity of the bands between each gas tank ... It's Impossible, and besides, it's not at all consistent with an industrial production ...
« Last Edit: April 13, 2019, 06:07:03 am by 4pots1969 »


Sgt.Pinback

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Very interesting stuff as always. Until today I would have said they were painted but now I see it in a different light.

Can you measure the depth of the paint?
Cheers, Uli (Leonberg, Germany)


Steve Swan

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good stuff!  you guys have MAYBE finally put the hand-painted vs. decal controversy to rest.

KP, the pics you emailed me, appears MAYBE unmistakably a water transfer, no small feat applying one that size. i'd be surprised if anyone is producing a water transfer....  am sure there are plenty of stick on decals, but the fact it is a stick on decal is going to create a raised area whereas a water transfer will not and a stick on decal will have a different appearance than a transfer.

for what it is worth, back in the teen's through the late 20's Harley-Davidson was producing around 20,000 motorcycles a year, and the very elaborate hand pin striping on the fenders, tanks, battery and tool boxes is maroon, gold and black as well as a large water transfer on each tank.  so, i do not think it out of the realm of the natural world to paint stripes on 7,414 gas tanks in the span of a few months.  HOWEVER....  you guys have now proved MAYBE beyond any shadow of doubt water transfers were used on the early CB750 tanks.


Steve Swan

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here is a picture KP emailed me which i do not see posted, there is unmistakably a clear outline at the periphery of black stripe showing what APPEARS the clear portion of the water transfer.

What is now troubling me is the ragged edges seen in the black stripes suggesting possibly the stripes were hand painted...  Or is it possible in the making of a water slide transfer that, that before the transfer was produced that it was hand painted on something other than the tank and then converted to a transfer???  the fact of ragged edges -AND- one stripe being 47 mm wide and the other being 45 mm wide creates the questions of "Why would transfers that were machine produced be different widths in the process of making a water slide transfer?"  "Was some sort of hand process used to create a "template" that was then used to create a water slide transfer?"

DO WE KNOW FOR A FACT THAT A LAYER OF CLEAR COAT WAS LAID OVER THE BLUE-GREEN AND RED PAINT?

IS THERE ANYONE HERE IN THE GROUP WHO IS FAMILIAR WITH HOW WATER SLIDE TRANSFERS WERE MADE IN THE 1960'S ???



bojje

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Hi!
Today I have checked the original and never repainted fueltank of #31/66. It looks as they used a very thin sticker at first, then covered the sticker and finally painted the candy ruby red. The red paint hides the edges of sticker with about 0,3-0,5 mm.
Kind Regards, Bo from sweden.


4pots1969

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If I understand the translation of Bo :
I do not think that the red painting of origin Candy Red was made after the transfer ... It's not possible


hondasan

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Interesting subject, particularly as I need to get #1120 painted this year in the UK, and getting the stripes right is equally as important as getting the colour right (IMO). Unfortunately the tank for #1120 does not have its original paint for me to be able to make measurements from.
I do however have measurements I made some years ago on the tank from #665. Unfortunately I only measured the RH stripe. The measurement at the front edge was 50mm, so greater even that that which KP noted? The reported variation is surprising.

Chris R.
Chris R.
302/338


DW69K0

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KP,
Very Interesting Topic!
I for one, DO believe the tank strips ARE painted on based on my evaluation of original paint wrinkle and non-wrinkle tanks.
Curiosity get the best of me, so I went out to the shop and started to examine several different tank stripes under magnification. Under 10x and 20x magnification, I could clearly see where the striping was masked and I found cut lines from a Knife or razor. The edges of the striping clearly had distinguishable places where the paint was not perfectly aligned. I say they are painted.
I don't believe for one second the tanks were clear coated. I've spend many hours polishing original paint tanks from Sandcast and early K0 CB750s and the paint color always comes off on the polishing cloth.
You can bring the color back out on the faded stripes to gain a lot of color from these faded surfaces. Candy Blue Green tanks are preferred, as the Candy Ruby Red has a gold base coat that becomes very apparent when the sun fades out the red pigment.
I have one tank that clearly shows brush lines on the stripes.
Perhaps the process changed as production numbers increased, but early tank striping through early 1970 models sure seem to be painted beyond a doubt when viewed under magnification. That is quite an amazing feat of craftsmanship, if this was the truly the correct factory process.
There could have been multiple suppliers during the production runs and maybe different processes were used, but I firmly believe a strong case can be made for painted stripes on early wrinkle tanks.
Best,
DW


4pots1969

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Hello DW69K0,

Okay... And you think the strips were painted with a brush, is that it?
And how do you explain the transparent halo around the band stripe on Candy blue gas tank?
So, do you also think that Kawasaki factory also painted the gas tank stripes on its 500 Mach III ?

It should not be forgotten that a water transfer is nothing more or less than a printing with a special ink on a transparent synythetic support, and that this ink can deteriorate with time and light exactly like a paint...

4pots1969



« Last Edit: April 17, 2019, 06:51:15 am by 4pots1969 »


DW69K0

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Gerard,
No brushes and no Kawasaki's mentioned, but I will show you a photo of what appears to be cut lines in an original paint tank stripe. I have many original paint Sandcast and K0 bikes. I question the theory that only water transfers were used. Maybe there were two methods used? See attached photo 1
I can clearly see on several of my tanks a clear film on outside edges (water transfers) but NOT on every tank in my possession.
See photo 2.
Maybe two methods were used?
There was also mention of clear coating tanks, don't believe that ever happened on the candy colors.
Best,
Duane


4pots1969

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Hi Duane,
"I have one tank that clearly shows brush lines on the stripes."
I translated and he tells me that there are traces of brush in the stripes, but it is the translator who says it, it's not me, and what he translates to me is often misinterpreted, that's why it's complicated to talk to you all  :-[

I think Honda had to do like its competitors, but maybe you're right and that on the very first sandcast the stripes were painted, and then they realized they could not keep up the pace when the demand exploded, so they then change the method for stripes...
« Last Edit: April 18, 2019, 06:02:13 am by 4pots1969 »


DW69K0

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Gerard,

If I wrote brush line, I wrote that in error, sorry for any confusion! (The gold tank in my photo 2 probably could be confused for brush lines).

What I was trying to express are two ideas:
     1) The stripes have paint on them and are not a decal or sticker (Looks like I need to do some research on Water Transfer processes). The center Gold portion of the stripe is a metallic based paint by appearance when viewed under magnification.
     2) Second, I have in my possession, what I believe are several tanks with original painted stripes that do not have clear transparent edge lines. A knife or razor appears to have been used in the process.to cut through masked areas of the stripe.the majority of the tanks I inspected have the water transferred (let's call them that) stripes, but several do not, those appear masked and painted over the base color.

I agree with KP, the stripes are consistently 46mm wide as he pointed out.

Best,
Duane