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wally7506

British Camo Rubber masks

262 posts in this topic

Re time saving and mats, I had a thought:

With the number of Spits coming through the pipeline, I would think that after a day or two the guys in charge of painting the camo scheme would be able to do it in their sleep, especially after the elimination of alternating 'a' and 'b' patterns. They'd hardly need a line to follow on something like a wing panel.

That's just not how things work in the real world. You have to make things idiot-proof. You have to assume that everybody working on the assembly line is an idiot. Not least, because tomorrow, 'the two guys' painting the cammo may be off sick... or get killed in a bombing raid. And then you have to find two new guys who can do the same work at the same speed, because if they can't, they hold up production.

So you build a system that even an idiot can operate, gaining a consistent speed and consistent results after no more than half an hour of instruction.

If at all possible, you avoid relying on skilled personnel because they are difficult to replace... you sure as hell don't want to be relying on people's artistic ability to see you through the day.

So the whole thing just wouldn't have been designed that way on a Spitfire production line... anymore than they would have had riveters marking out where the rivets went by eye.

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I did wonder if there could be a mental mapping develop after a period of time. Turn left after the third rivet. But it still would lead to inaccuraccies and errors become accentuated in a sort of Chinese Whispers. People get tired and the mind wanders during repetitive work.

Is it possible that minor variations occur because of subtle shifts in position of mats? On a production line there may be misalignments due to pressures of production.

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Just to add to the confusion....

Thirty odd years ago I remember the Father of my then girlfriend saying that he had used Hessian masks

to spray camouflage patterns onto aircraft.

This would be much lighter than the 'horsehair' matting previously described.

BTW we used a lot of that matting back when I was at Odiham in the late 70's early 80's and it is heavy stuff.

We used it as padding for components on shelving & to lie on, especially down the backend of a Wessex.

We once persuaded a painter to mask up Royal Air Farce on the side of a Wessex. It summed up feelings at the time!

Pete

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Just to add to the confusion....

Thirty odd years ago I remember the Father of my then girlfriend saying that he had used Hessian masks

to spray camouflage patterns onto aircraft.

This would be much lighter than the 'horsehair' matting previously described.

BTW we used a lot of that matting back when I was at Odiham in the late 70's early 80's and it is heavy stuff.

We used it as padding for components on shelving & to lie on, especially down the backend of a Wessex.

We once persuaded a painter to mask up Royal Air Farce on the side of a Wessex. It summed up feelings at the time!

Pete

I was at odius then

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That's just not how things work in the real world. You have to make things idiot-proof. You have to assume that everybody working on the assembly line is an idiot. Not least, because tomorrow, 'the two guys' painting the cammo may be off sick... or get killed in a bombing raid. And then you have to find two new guys who can do the same work at the same speed, because if they can't, they hold up production.

So you build a system that even an idiot can operate, gaining a consistent speed and consistent results after no more than half an hour of instruction.

If at all possible, you avoid relying on skilled personnel because they are difficult to replace... you sure as hell don't want to be relying on people's artistic ability to see you through the day.

So the whole thing just wouldn't have been designed that way on a Spitfire production line... anymore than they would have had riveters marking out where the rivets went by eye.

Yeah, I'll agree that the SYSTEM would be designed that way, but that doesn't mean that one of 'the two guys' can't say "I don't need no bleedin' mats!" He'd get a reward because pay was based on productivity- cut the time down and you shared some of the savings with the company. Now, if some inspector started complaining that the pattern wasn't correctly following the diagram...

And before anybody gets too uptight, I'm not saying that I KNOW- I'm just thinking (based on pretty good knowledge of Spitfire production practices and three years working at Boeing on a (very much slower) production line.)

bob

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I think you said the key word - inspectors. Or, to look at it from another point of view, jobsworths. You can't do that, you have to follow the book. painful, but right.

I suspect the workers would be on piece rates rather than productivity sharing. That sounds a bit modern.

Edited by Graham Boak

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It's curious how interest in painting aeroplanes has increased in inverse proportion to the likelihood of getting an answer. 50 years ago there were probably loads of people who had worked in aircraft factory paint shops and could have given chapter and verse on what was done and how. Nobody saw fit to record it for posterity because nobody was that interested. It's not just aircraft manufacture, there are lots of other industrial processes where bits and pieces remain but no clear idea of how it was all done. In archeological terms everything mysterious is the basis for hypothesy about "ritual" - unexplainable artifacts are always attributed to a "ritual" purpose. Sometimes, though, I get a sneaky feeling that the speculation is more enjoyable than the facts. That's probably why the few facts get so blusteringly challenged, because they represent the end of all that nice warm, fuzzy speculation. The "Colo(u)r Spit Photo" thread is a marvellous demonstration of it.

"Never was so much waffled by so many to so little purpose." :)

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Yeah, I'll agree that the SYSTEM would be designed that way, but that doesn't mean that one of 'the two guys' can't say "I don't need no bleedin' mats!" He'd get a reward because pay was based on productivity- cut the time down and you shared some of the savings with the company. Now, if some inspector started complaining that the pattern wasn't correctly following the diagram...

And before anybody gets too uptight, I'm not saying that I KNOW- I'm just thinking (based on pretty good knowledge of Spitfire production practices and three years working at Boeing on a (very much slower) production line.)

bob

Don't worry, I won't get uptight. You should challenge the idea.

As somebody has already said, the system is checked. I know, I design systems, I design systems for checking the systems, I often get off my bottom and personally go and check the systems... and I sack people for not following the systems. And on a couple of occasions I have sued people for fecking things up because they didn't follow the system after being warned about it! It's to avoid these major feck-up that we have all these peculiar little rituals built into systems.

However, I didn't always have my own office. I was once the boy who made the tea, and I know that on occasions great lengths are gone to to bypass the system. I have know people come in early and work unpaid overtime to beat the system. I have know them post lookouts and send union reps on fools errands. All so they can do things an easier way for half the day, and coast through the rest of the day. Sometimes, the motive is that they want to do a better job! Usually it's because the system is just plain wrong.

However, I can't see it happening in this case.

Firstly, I can say with some certainty that marking a plane out with chalk would not be easier than using a rubber mat as a stencil. It wouldn't be a shortcut -- it wouldn't be quicker or easier. I doubt they were understaffed, they would probably have a few guys employed just to keep the place clean and tidy. I can's see that these mats would be so heavy that a couple of guys couldn't easily place them.

Secondly, you can't just forgo the mats when the foreman goes for tea and use them the rest of the time.

Thirdly, part of the reason for having system is to make sure you don't run out of stuff. The guy who designed the system will know how often the mats need to be replaced and old ones disposed of. If there was a sudden surplus of rubber mats because they weren't being used, somebody would notice. In fact, it's exactly this kind of thing that usually gets people caught and sacked. Of course, it's always a mystery to the workers how the management knew -- they don't know that it all shows up in the spread sheets!

Fourthly, I'm going to go back to the thing where I said, 'I doubt they were understaffed'.

These days companies tend to cut staffing back to the bone. It wasn't always this way, and it has several advantages. Obviously it's nice to have a bit of redundancy so that you can absorb absences and staff leaving. It also means you can absorb extra work by putting on a spurt of speed. They do say that you shouldn't run a company at more than 80% of capacity. The other big advantage of having plenty of staff about (rather than a couple of guys) is that it encourages a good work ethic. The more people you have working together, the easier it is to get them to follow the rules -- they will police each other.

...so, maybe an expert can enlighten us?

If the assembly line was such that there were two guys painting one plane at a time, then who knows what they got up to? But if there were 2-3 crews working side-by-side, then it would take a rebellious person with a very strong personality to be able to poison the workforce.

And to the person who says that they couldn't imagine lifting mats into place with the paint flaking off them. If these were horse hair soaked in rubber, it would provide a good bonding surface. There should be no flaking. In fact, the paint could and should build up to quite a thickness making the edges of the mats stiffer. They might actually get easier to use and lift into place as they aged and became coated in paint. If the paint built up to be half an inch thick, would they still be usable? I don't see why not?

It's curious how interest in painting aeroplanes has increased in inverse proportion to the likelihood of getting an answer. 50 years ago there were probably loads of people who had worked in aircraft factory paint shops and could have given chapter and verse on what was done and how. Nobody saw fit to record it for posterity because nobody was that interested. It's not just aircraft manufacture, there are lots of other industrial processes where bits and pieces remain but no clear idea of how it was all done. In archeological terms everything mysterious is the basis for hypothesy about "ritual" - unexplainable artifacts are always attributed to a "ritual" purpose. Sometimes, though, I get a sneaky feeling that the speculation is more enjoyable than the facts. That's probably why the few facts get so blusteringly challenged, because they represent the end of all that nice warm, fuzzy speculation. The "Colo(u)r Spit Photo" thread is a marvellous demonstration of it.

"Never was so much waffled by so many to so little purpose." :)

To exercise the little grey cells. That is the purpose.

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I think you said the key word - inspectors. Or, to look at it from another point of view, jobsworths. You can't do that, you have to follow the book. painful, but right.

I suspect the workers would be on piece rates rather than productivity sharing. That sounds a bit modern.

Not sure what the official term was, but in "Spitfire Odyssey" the author went into it in great depth. Essentially, workers (or reps thereof) and "management" agreed on how long a job was likely to take, they added a percentage to that, and then if the job got done in less than the budgeted time, half (or some amount) of the savings went back to "the company" and half to the worker. That way, both sides had an inducement to be efficient. The times got adjusted when necessary to adjust for improvements or inaccurate estimates. When this method got transplanted to a workforce with a different background at Castle Brom, they misinterpreted it to their advantage and that is part of what a strike was about (I'm thinking 1941, but am likely to be wrong).

Now quoting Dan:

Firstly, I can say with some certainty that marking a plane out with chalk would not be easier than using a rubber mat as a stencil.

I didn't say anything about chalk! I've got a spraygun in my hand, a (roughly) flat wing panel in front of me, and I've sprayed the same simple pattern 50 times. If I'm paying any attention at all, I know where the lines run. Oh, I was an inch off the drawing- do you want me to touch it up? Is the inspector really going to refer to the drawing, get out his scale, and complain because it says there that the line should be 3.5 inches inboard of that panel line?

I think it is too broad a question, though. Are we talking wings built in house by Supermarine in spring 1940, or at one of the dispersed "small shops" (still Supermarine) in 1942 or at a sub-contractor in 1938 who is (likely) supplying "complete", painted wing panels, or at Castle Bromwich in 1944 or... People have observed in the past that early Spits had very sharp edges between the colors on the upper surfaces, but that this was less true on later Spits.

As for "man"power, they weren't working with a cushion. Individual workers were working LONG days, seven days a week at times, at least at the beginning of the war. I think it is safe to say that throughout the war the typical work-week was far beyond what would be considered acceptable in today's world. Generally speaking the factories did not go round the clock- third shift was considered, but rejected. And they still had their periodic "vacation" weeks, where the whole line shut down. The aircraft industry, and the war industry in general, were up against a finite limit of people, and this was a definite limiting factor for the folks that had to figure out just how many ____ could get built.

We've veered rather off the point of this thread, but not without value. I like Nick's 'inverse interest' rule- now that we can't ask Uncle Jim or Mum how they did stuff, we find we've got all these questions. Isn't it always the way...

bob

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I'm afraid that, with all the talk of speed of production, you're all (well some) missing the main reasoning behind the mats.

1/. It isn't going to speed things up in a M.U., if a replacement wing's pattern doesn't match the fuselage to which it's being fitted, and touching up the difference becomes necessary. This would (or should) apply to any replacement painted component.

2/. The mats were there to keep overspray to a minimum (witness Bill Matthews being told that 1" was the permitted tolerance on freehand spraying.) Overspray=rough paint=drag=loss of airspeed. In 1942, 50 man-hours were added to each Spitfire's production time, to allow for the filling of rivets, and panel lines on the front 20% of the wings, then smoothing, then smoothing down the already smooth-surface paints. Is it really likely that, having made those provisions, a sprayer would have been permitted to waft several inches of overspray onto the rest of the airframe?

As for the weight, we have eye-witness, and user, evidence that two men could handle the mats. Having been a carpet fitter, I regularly lifted 50' x 4'6" rolls of rubber underlay, and 25' x 12' pieces of foam-backed carpet, and laid them in place, alone, so even the largest mat shouldn't have been too difficult to handle, and set in place, for two men.

Then there are (some of) the variations. Try laying something that, though flexible, is still fairly stiff, onto a curved surface, and, in places, it's going to hang clear, so the spray goes underneath. Do you respray, or simply rub down the offending overspray, and carry on?

Edgar

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Then there are (some of) the variations. Try laying something that, though flexible, is still fairly stiff, onto a curved surface, and, in places, it's going to hang clear, so the spray goes underneath. Do you respray, or simply rub down the offending overspray, and carry on?

Edgar

I'm not sure if this is a rhetorical question because of the way you have phrased it...

But anyway, I'm not sure how thick or heavy or stiff these rubber mats would have been. Horse hair has been mentioned... it could be they were fairly flexible and need not have been that thick.

As for the over spray matter - reducing over-spray makes a great deal of sense, but on the other hand, what you describe doesn't -- so much.

How much overspray you get is dependent on one main factor... how quick the paint dries. If over-spray lands dry, it is rough but comes off easily. If it lands wet its quite smooth but is a b'stard to get off. The extent of the overspray really will depend on the paint you are using, but eitherway you are going to get some land wet, and some land dry depending on how far away the area is from the painting. Over-spray will contaminate areas 12-15' away to the extent that they require cleanup. (And if you ever need an over-spray decontamination service, you know who to talk to. My company provides this at £40 per hour plus vat. ).

But yes, over-spray is going to be a problem if you want the leading surfaces smooth. And yes, it does make sense to make provisions to reduce it. Dust sheet are the usual method.

My problem with you saying that the mats are primarily for reducing overspray is that if you smooth down all the paint, and then spray on the disruptive colour,

1. the disruptive colour paint is not flattened and smoothed.

2. the disruptive colour areas will be subject to overspray too. The area you painted 5min ago will get fallout from the area you are doing now.

None of this is a major problem, but using the method you describe it would mean flatting the aircraft after the first coat of paint, and then doing it again after the disruptive colour has been applied... effectively doing roughly half the aircraft twice. This is hardly efficient.

It would be far more sensible to file the rivets and joins and then wait until the plane is fully painted and then flat all the paintwork. This wouldn't give you any difference in end result but would give you at least a 30% time saving and negate the need for the mats.

Does that make sense?

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Well, no, not to me. Fill rivets, where required, spray primer, smooth down, spray grey(as an example) all over, wait 'til dry, lay mats, spray green, lift mats, smooth down resultant surface; that's the sequence that I've always been told. Remember that the aircraft were built, and painted, in sections, even separate factories, then assembled. Control surfaces, for example, had to be balanced before final assembly; not much point if there's a chance of misdirected paint spray landing on them afterwards.

Edgar

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It still doesn't make sense to me Edgar... but then again, I don't know the order of assembly.

for example... If you are going to balance control surfaces, and overspray is going to make a difference to the balance, wouldn't the disruptive colour also make about x50 more difference? And if these are painted, then balanced, and then fitted to the aircraft, wouldn't it make more sense to either fit them after the main fuselage is painted, or just cover them with a dust sheet. Rubber mats wouldn't make a difference in this case.

In the vast majority of cases over-spray can't be seen, it can only be felt - it is that slight. So if you are flatting the whole surface anyway as you have just described, why worry about mats to prevent over-spray?

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I'm not sure why, but I seem to making a complete Horlicks of this. They were not "flatting" the surface, they were smoothing it; different finish entirely. The mats were not used after smoothing, they were used first, then the final (two-colour) finish was smoothed. Control surfaces were not sprayed one colour, then balanced, they were finished in both colours (still using said mats,) smoothed, then balanced. I did actually say that parts were built, and painted, before final assembly, and that's where the mats would make a heck of a difference; without having used them, how could you be sure that the pattern(s) would match, when all of the relevant parts were brought together?

It needs to be remembered, too, that the "smoothing" process didn't start until 1942, with the introduction of the smooth paints. Prior to that, as far as I can discover, the only use for sandpaper was the removal of any overspray, and it was discovered that over-enthusiastic use tended to remove paint from rivet-heads, necessitating a repaint.

Edgar

Edited by Edgar

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I did actually say that parts were built, and painted, before final assembly, and that's where the mats would make a heck of a difference; without having used them, how could you be sure that the pattern(s) would match, when all of the relevant parts were brought together?

Edgar

I can see that. And that is a perfectly good reason to use mats. As I said in my origional post... it would be madness not to.

Sorry, not trying to have an argument. But I think if you understand the production and assembly proceedure, and plan it out, we must be going through the same planning process they did when they set up their production lines. There is a very good chance we'll come up with the same solutions they did.

Anyway, with your edit to your last post, the penny has dropped!

If rubber mats were used with a matt paint, it starts to make sense.

Matt paint would give you a 'high build' overspray which would be far nastier than from the 'smooth paints'.

The irony is that matt paint is softer because the matting agents tend to be soft, and they produce a rough surface which by it's nature is what gives you the matt, and is also more delicate.

So using sandpaper to remove it is overkill on a massive scale. You could easily rub it off with a cotton cloth. However, this is effectivly polishing it off and would also polish the painted surface. The only way to retain the matt WOULD BE to wet-sand it... which is overkill.

So the best way to avoid the problem is to avoid the overspray... hense the matts.

I'm with you now.

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Sorry to resurrect this old chestnut but I was sorting photos out on my computer and found this one. I don't see how that could be sprayed without some kind of mask.

hurri9.jpg

Steve

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Hi

Well I finally got around to viewing this thread, been meaning to for ages.

I personally can see both being used, mats and also that a skilled painter doing it without them.

I would be very suprised if a inspector of aircraft failed a much needed frontline aircraft due to a deviation in a paint sheme, i would imagine he would be very quickly replaced..it was after all wartime... The only experience in a 'wartimeish' enviroment I had was in a naval dockyard during the falklands, and the book basically went out the window very fast, paint was mixed by the painters when they didn't have the right colour, different paint batches were mixed together, different manufacturers supply batches mixed as well. ( things never normally allowed).Also things by passed the drawing office and were designed and installed by use of the back of a fag packet. i remember the most often heard phrase, 'just get it done, don't care how you do it,where you get it from, just get it done.'

You could look at two frigates side by side in 'south atlantic grey' and they were a different colour..

As they say in the end it's your model, do it how you like it.

Cheers

jerry

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The Falklands was a sudden panic. We are talking about normal procedures in an aircraft factory or Maintenance Unit carried on from prewar. High states of adrenalin and rushing about were not sustained for months let alone six years of war.

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I wonder if some of the variations in pattern we see on the photos were the result of the masks being produced with a manufacturing tolerance?

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...I had was in a naval dockyard during the falklands, and the book basically went out the window very fast ...

I remember that time. We were slamming Wessex's back together from Major Servicing in hours instead of weeks. When the war was over, people could be seen surreptitiously inspecting bits and pieces that had been 'signed off' without a thought in the panic. Lol.

Sorry, I'm wandering off topic a little but I thought you might be interested.

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I wonder if some of the variations in pattern we see on the photos were the result of the masks being produced with a manufacturing tolerance?

Actually, you've hit the nail squarely on the head; a couple of weeks ago I found, in a file on camouflage, at Kew, a (possibly scale) drawing of the Spitfire camouflage pattern "A," dating from early 1937, which, even at that early stage, advocates the use of "stencil mats." The drawing has 1' squares superimposed on it, and the instructions go to great lengths to point out that they are for guidance only, which I take to mean that the pattern did not have to be slavishly followed, but that some leeway was allowed. It's totally impossible for me to put it on here, since it's over 50Mb, and would give Mike apoplexy; it's also a TIFF file, which I've found won't register on Photobucket.

The actual wording (or some of it) is, "Stencil mats to be made approximately to the scheme shown. Scheme "B" being the mirror image of Scheme "A" 1'-0" squares have been drawn to give the necessary guidance for laying off colour contours." The drawing also includes precise dimensions, and placement, of the roundels and underwing serials (no fin flash at that time.)

I've also found evidence that the talk of "skilled" and "experienced" painters/sprayers is sadly misplaced; during a mid-war inspection of badly-painted airframes from Handley-Page, the company pointed out that their skilled men had all been drafted into the forces, leaving them with unskilled, even infirm (my italics) staff.

Edgar

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Edgar;

email me the TIFF. I'll convert it to a JPG and re-size it.

modeldad@verizon.net

Edited by Steven Eisenman

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Edgar,

you could also compress the TIFF file with WinRAR, 7Zip or similar and upload it to a file-sharing service such as Megaupload, Filesonic, Hotfile or similar, they're free.

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Hi

Also usually it is possible with programms like acdc, to save a tiff file as a jpeg file.

cheers

Jerry

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"The actual wording (or some of it) is, "Stencil mats to be made approximately to the scheme shown. Scheme "B" being the mirror image of Scheme "A" 1'-0" squares have been drawn to give the necessary guidance for laying off colour contours." The drawing also includes precise dimensions, and placement, of the roundels and underwing serials "

So that's it then....we modelers can go the 'approximate' route and be confident that our models are close enough to the specs of the day........... :analintruder:

Masking Cheers,

ggc

Edited by CPNGROATS

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