Hulll Red Question

I can stand to be corrected but if memory serves me the red coloring was more of a protection from barnicles (spelling ?) than any other purpose. Red lead comes to mind. And therefore may look the same.

Mike

The red on some ships is red oxide. I think both are used. Red oxide is a bit darker than lead, but red oxide primer, easily found in auto parts stores, makes a good hull paint for vessels with red oxide primed bottoms.

I've had good results using Floquil "Zinc Chromate Primer" (a railroad color) for hull red. It's a nice dark color and a fine, almost semigloss, texture.

Italian WWII ships seem to have used green for the underwater color.

Close but only a plastic cigar. It is an antifouling coating and is more designed to keep seaweed from rooting than barnacles. Barnacles are slow growing but in tropical and semitropical waters a ship can rapidly sprout a seaweed beard. Red lead is also a misnomer here, while it may have been one of the pigments there's a lot more to the chemistry involved. The USN, RN, DKM and IJN all had similar but noticeably different colored antifouling coatings. Modern USN uses black on most deployed subs and a much redder color than WWII on recently launched subs and surface ships. As commissioned CVN-65 Enterprise had a special green epoxy and not red.

A number of modern ships, especially smaller ones do. I think it is a copper-containing paint.

And unless you are building your ship as freshly-launched, it realy doesn't matter a hill of beans, since anti-fouling paint is among the fastest-weathering paints in the world. Even after a few weeks it noticably changes colour. {After less than a year, the hull of HMCS Chignecto was actually light greyish-green instead of the deeply saturated hull red that she wore fresh out of refit (Tip: do not run over waterlogged logs with your screws turning if you want to avoid an embarrasing drydocking).} Whatever dark rusty red that looks 'right' to you is by definition "right" because no one colour can possibly be "right". If you've weathered the uppers, the hull should be equally weathered, and you can tell the colour police from me to go eat their FS decks. Here endeth the lesson : )

Oops!

Heh. Indeed. :)

It bounced up in our wake looking like a couple of huge sharks had each taken a bite out of it. The quarterdeck was shaking so badly we could hrdly stand on it.

In message , Ron writes

Modern underwater paints are formulated with two major features -

1- They contain an active biocide (copper based now that tin based ones are banned) to discourage the growth of marine organisms on the surface 2- They are self polishing i.e. the top surface of the paint is worn away by the action of the water passing over the hull when under way.

The self polishing action removes the spent paint on the outside that all the biocide has leeched out of, leaving a new active layer exposed.

The object is to keep the underwater section of the hull as smooth as possible to reduce underwater drag, keeping fuel consumption to a minimum and speed up.

The active ingredients to achieve this may have some outcome on the final colour of the paint, but pigments are used to give different colours, and there are many different colours of underwater paint, typically reds, purples, mauves, greens and greys.

A typical application to a hull will use 2 different colours applied in alternate layers, e.g. dull red, mauve, dull red, mauve, dull red.

There are a couple of reasons for this, during application it helps the painter build up the required paint film thickness in thin even layers. A thin even coat is put down first over the primed substrate, then the next coat applied after the relevant drying time. Using a different colour enables the painter to spray the paint just thick enough to cover the previous colour, thus helping maintain a constant film thickness ( and also for the Paint Inspector to check this is being done correctly - the science and politics of paint application in a dockyard has to be seen to believed!)

When the ship leaves the dock it should have one even colour over the whole of the submerged surface. Prolonged berthing / anchoring with no polishing action taking place will lead to build-up of marine growths, and regular service will see the outer layers wearing away to reveal fresh paint underneath. The wear will be uneven, with more exposed areas and those subjected to higher water velocities wearing faster. This will lead to and alternate contoured colour effect which shows up areas of higher paint wear very well. This effect is used to help determine remaining paint thickness and calculate the remaining effective life of the paint, which can be used to determine when the next docking will take place and how much paint will be required for re-coating.

Bumps, bangs & scrapes will also leave a multicoloured effect down the hull ( with the hull colour of the victim also being apparent) and tugs, tenders and dockside fenders leave dirty black streaks along the hull, and of course the ever present tin worm will leave rusty streaks and blisters on the surface. Anodes will always be left bare metal (usually zinc, which corrodes to white zinc oxide)

This leaves ample room for modellers to do their thing, everything from pristine one colour finish to totally worn, rusted and weathered.

This all applies to RN ships (the Real Navy ;-) ), Grey Funnel Line (Her Majesty's / Uncle Sam's Finest ) vessels may have additional requirements for underwater coatings such as radar and sonar reflectance and absorption, but I very much doubt this has much to do with it's final colour. The only vessels concerned with camouflage colour are submarines, which tend to go for black or dark greys all over or on the exposed upper surfaces. For most other vessels if the under surface is exposed, camouflage is the least of your worries.

That reminds me of a sailing dinghy I once saw which was painted to read SET UP down the side of the hull. A bit strange perhaps, but when capsized the underside was decorated with UPSET!!! in very large letters.

All the above applies to modern ships (post WW II) Historically underwater hull protection has included such things as Tar or Bitumen (black) Lead Oxide paint (white) or copper sheathing (copper coloured, turning light verdigris green) to protect the underside of wooden vessels. The copper sheathing stopped tropical worms eating the timber, and was the origin of the term "a copper bottomed investment" i.e. on that wouldn't get eaten away. With the advent of iron and steel a protective coating was required to prevent it rusting, and red lead paint was developed as a primer. The active ingredients gave it it's distinctive colour, and as it wouldn't be generally visible once the ship was afloat it wouldn't be over-coated with a more expensive pigmented paint, hence the predominantly red undersides of metal hulled vessels until more recent times. With faster speeds, fuel economy and longer times between docking being more and more important, the chemistry of the paint has been developed to what it is now.

Hope that someone finds all that interesting and useful in finishing a model.

If it's USN it's a lower maintenance epoxy coating first developed for CVN-65 as they did not envision drydocking her very often.

USN WWII painting schedules call for a minimum of five layers of paint over the raw steel, the next to last is metallic brown. I forget the rest but it's one of things in my research and copy list at NARA.

The USN changed from red lead in the 1920's after conducting experiments at Norfolk Navy Yard. There's an entire photo series devoted to the paint tests and USS Olympia was a guniea pig with something like 20 different paints on her underwater hull at one time. Both Norfolk and Mare Island each had at least two antifouling paints for major surface vessels during WWII and which was used depended on the vessel and type called for in her painting schedule...that makes at least four known paints for WWII USN. This does not include the paints used for wooden hulled boats and ships, that was called "copperoyd or copperoid" We do know that Norfolk's two major paints were color matched, the jury is still out on Mare Island's.