Circloy
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Posts posted by Circloy
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I've several options ranging from a rechargable unit from Lidl or Aldi for light work away from the bench.
On the bench I have a proxon drill which has speed control built in, this is then plugged into a proxon power unit which also has speed control. I don't think they were itended to be used togther but one consequence is by turning both down I can get ultra low speeds to the extent that the drill will cog as each motor pole is powered in turn. Once a load is applied, e.g. by starting to grill or grind, the electronics kick in and smooth the rotation out. this can be useful at times when you need extreme control.
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Rust
in Armour Chat
Quick wash, service, new battery & fresh fuel and its odds on it'll start first time
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Rust
in Armour Chat
13 hours ago, Longbow said:Rust is a funny old thing.
Heres a Stug III, still in its original Tropen paint, lost in a lake in Russia sometime between December 1942 and February 1943.
Pulled out of the lake not too long ago.
Note how only the mild steel parts have really rusted.
lack of heavy rust is probably due to lack of disolved oxygen in the lake
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3 hours ago, Matt P said:
the biggest problem you may face with large amounts of resin is heat when curing.
Are there any cold cure clear resins available?
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Rust
in Armour Chat
5 hours ago, Bozothenutter said:Austenitic, martensite, brinell....🤯
Didn't want to get to that level.
I'm less special steels thee days & more super alloys.
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Rust
in Armour Chat
9 hours ago, StuartH said:Many thanks @Circloy. Very informative.
What determines the shade/colour of rust? i.e. from a yellowy/light orange to a deep red/dark brown.
Is it the metal itself and any element additions/contaminants or more due to the atmospheric conditions and speed of rust?
The colour of rust - good title for a film and I can vouch that there are more than 50 shades.
The formation of rust is complex, Iron will not rust in either pure water or dry air (even pure dry oxygen) it requires the presence of both even then the reaction is slow. However the world is not perfect and our atmosphere is not just made up of oxygen and nitrogen and water is never found pure in nature.
Air contains not just nitrogen and oxygen but also small amounts of other gases including carbon dioxide, carbon monoxide, nitrogen oxide nitrous oxide, sulphur dioxide in various concentrations, these gases, including oxygen, disolve in water (during rainfall) to form very mild acids. Additionally as water wends its way back to the seas and oceans it will come into contact with minerals and salts disolving some along the way.
This has now set up the conditions required. Iron, oxygen and acidic/salty water all in direct contact allows for electrochemical reactions to take place forming rust.
Iron oxdes & hydrated iron oxides exist in two forms Iron(II) & Iron(III). Initial formaton of rust exist in the Iron(II) form which is much the colour of the two burnt out tanks pictured above. This form is relatively unstable and continued contact will result in the reactions continuing though various intermediary form concluding with Iron(III) oxides & hydrated oxides.
The Iron(II) form of rust is the orangy form Iron(III) is the dark, at times almost black, form.
Other than delayng the rate of rust formation the alloying elements appear to have little influence on the colour of rust.
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Rust
in Armour Chat
Thanks @Kingsman hopefully can meet those expectations.
Armour.
The specification for armour up to around 2000 when we ceased production was mainly MVEE 816, developed by the Military Vehicle Engineering Establishment @ Chobham and issued around 1970. It had been developed from the alloys used in WW2 & was more to incorporate the benefits of newer production methods. Towrds the end of our production newer specifications were being developed again benefiting from other new technologcal developments and catering for higher hardness plate.
The alloy itself is not too exotic (.3C, .6Mn, 1.5Cr, .7Ni, .3Mo) The Cr & Ni will impart mild resistance to rust.
Electric arc melted from scrap and alloying additions, cast into ingots, of around 2 to 3 tonne (from memory), forged or pressed into slab form and rolled into billets suitable for plate rolling, cutting to squares, heat treating. Plate was then either laser or plasma cut to the profile required vehicle manufacturer before being despatched.
From my metallugical understanding
The structure of an ingot is not dissimilar to that of an ice lolly which when snapped across the diameter shows fingers of ice, jut as the juice forms these fingers the metal as it solidifies forms long thin crystals of steel, growing from the outside of the ingot towards its centre. As metal shrinks when it cools voids can form down the cetntre of the ingot known a 'pipe'. Controlling the cooling and making provision for a 'head' of molten metal will minimise it. An ingot will have little intrinsic strength which can be improved by controlled cooling on initial pouring or re-heating the ingots and furnace cooling will allow these crystals to restructure themselves and alter the properties favourably. Controlling cooling rates on large sand casting can be difficult and is most likely the reason fo the poor balistic performance of cast bodies when compared to constructed bodies.
Following casting the first process will usually be hammer forging or press forging this occurs at high temperature and not only changes the cross section of the material will, at the right temperatures, close up and 'weld' any internal voids. An additional benefit is that the crystals structure is further distorted & re-arranged.
Subsequent thermomechanical processing adds to the this distortion and re-orientation of the crystal structure.
The final plate rolling operation involves rolling in one direction, spinning the plate by 90 degrees and re-rolling and repeating until the plate reaches the final thickness.
This ensures both the structure and properties of the steel are uniform.
Once at final thickness plates would be smithed, or thicker sections pressed, flat. The surface cleaned by shot blasting prior to heat treatment.
First plates would be hardened (800/850 C)in a gas fired furnace, little to no excess oxygen to prevent oxide formation, and quenched in oil. Plates would then be at maximum hardness with a dark smooth surface.
Tempering (approx 500C) would follow to achive the required/maximum hardness, impact and other mechanical properties. This was done in a rolling bed furnace open to air so surface oxidation would occur, this would be thin and tightly bound to the surface, little more than discolouration of the surface.
If the batch of plates was intended for use in vehicles destined for the UK armed forces a test coupon would be supplied to the test range @ Eskmeals for balistic testing.
At 17 mm thick the resulting plate is capable of withstanding direct 90° impact from a high speed 20 mm shell without penetration or spalling from the rear of the plate.
Our approved production range 3 - 17mm was at the thinner end of the specification limited mainly due to the need to manhandle material in our plate mill.
An insight into armour production but from a modellers perspective what does it mean.
Surface - Rolled homgeneous armour plate does not have a heavily textured surface as portrayed on some of the more modern kits, neither is it bright as grinding of armour is not permitted. for me I prefer Tamiya's typical kit surface.
Rust - Armour plate is moderately resistant to rust, we held stock outside for years unprotected with only a light rusting that was nowhere near some of the effort seen. Protected by paint on an acive in-srvice vehicle I'd seriously doubt any rust being present. I'd bow to your experience in this matter @Kingsman. We were not involved with tracks so I can't comment on those but when i hear manganese steel i think of railway crosssings & frogs. In place for years, unprotected & not heavily rusted on non wearing surfaces.
Welding - very limited experience so little to add. Rods of the same or similar alloys are suitable for using, there is a datasheet for suitable welding rods on the web - these have a 20% Cr content which would explain the bright weld many years on. pre-heating would potentially destroy the temper & properties of any heated area if the temperature exceeded the temperature stated above. Electrically formed welds would have a limited heat affected zone.
I don't think that when explosive welding is referred to above that they are referring to Thermite welding. My thinking, and I could be very wrong, is that shaped charges are being used to blast a jet of molten metal along the joint of two disimilar metals to fuse both together much in the way a shaped charge directed at armour plate will burn a hole through to a tanks interior.
Hope this has been useful and helps understanding at a material level.
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Rust
in Armour Chat
Such a fast moving, twisting, thread its been hard to keep up & add to the discussion.
I was quality contoller at a Tool & Special Steel manufacturer in Sheffield which included in its product range armour plate & I believe we were the last to melt armour in the UK, production of armour at the British Steel corporation ceasing 2 years previously. Any armour production in the UK is done using foreign sourced plate.
I'd been compiling a point by point answer on some of the items raised when @Kingsman posted on the information he'd located which looks to have covered most of what had been questioned before. Now we appear to have moved even further on and raised more queries.
Whilst I'm not a trained metallurgist, actually more a nuclear chemist (untested) hopefully I picked up enough in nearly 4 years in the metals industry to get by.
Let me start by attacking the old enemy rust (Iron Oxides)
It is an undisputable fact that chemically Iron & Oxygen are attracted to each other, otherwise we'd find metallic iron ores, the result of this is that all iron based alloys rust. I've seen 18/8 Stainless steel (think cutlery) as rusty as those two tanks, I've also seen mild steels that have stood many years in the open with, what appears to be, a rust free surface.
Numerous factors come into play to determine the rate of rust formation these include (but are not limited to):
Alloy composition - It's a well known fact that adding elements such as Chromium & Nickel to steel reduce the rate that iron oxides form (stains less)
Temperature - as with most chemical reactions iron oxide formation will be faster at higher temperatures.
Surface condition - iron oxides will start to form at surface defects and spread from the formation points, highly polished surface has less defects from which rust can start.
Surface coatings - paint, oil, grease etc provide a barrier to prevent oxygen getting to the iron.
Environmental conditions - presence, or absence, of other elements , electricity will accelerate or decelerate the formation of rust.
Processing - complex but the whole operational sequence (forging, rolling, cross rolling, cold rolling, heating, cooling, heat treatment cycles, furnace conditions etc., etc.) all contribute, mainly via the surface condition, to controlling the rate of rust protction.
I'll come back later and fill in what I can regarding armour plate specifically, It's been a long day.
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On 03/02/2024 at 16:35, brewerjerry said:
You won't fall of the edge,
elf n safety installed a fence on the edges
Cancelled when the risk assessment reported it had sharp edges that could cut.
Latest word is that it needs to be at least 30 miles from the edge, the installers use a safety rig that bonds them to the centre of the earth and the dome that keeps the stars out is double glazed at the same time.
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Just had some corporate training on e-mails & was told we had to use the OHIO method - Only Handle It Once.
Someone at the back blurted out to the meeting that around here connectons are that bad we have to resort to the CHICAGO method - SHit I CAnt Get Online.
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Placed a last order today just before the 2:00 deadline. Couple of oo scenic items, Their last 1:35 kit (GAZ wheels) which will come in handy and a pre-order* for a pair of industrial loco's.
Had notification that the order had been processed within 10 minutes from placement.
* Hattons own brand, already commited into production and payment on despatch so I have no concerns.
I for one will miss them always found them to be a better trader than the local box shifter.
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Look at whats available from Dolls house suppliers or model railways. 'Stone' paper may not be available in 1:35 (or 1:32) but 1:24, 1:16 or 1:12 would give BIG stones whilst O or OO gauge would represent small stones.
However, stone/brick paper has no texture and tend to look flat and unrealistic, Slaters Plasticard & others produce vac formed/embosed polystyrene sheets that has relief.
https://slatersplastikard.com/assets/pdfs/EmbossedFlyer.pdf
(No connection, just a satisfied customer)
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Think I've been conned.
Just bought an all weather, digital, cordless,wireless signalling device
Still its an advance on the daytime model
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Not just the price of kits, misplaced a cutting broach to enlarge a few holes & with Bolton coming up thought I'd buy new rather than go hunting for the missing one(s).
Same supplier, same set, what cost around £12 ten years ago, was now priced @ the £40 mark. soldering iron tip cleaner was £5 now £18.
Think I'll dig the old toolbox out.
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No isues with the build turned out fine,
It annoys me though when people refer to the loco as DP1. It was always referred to as 'Deltic' by the builders, BR & enthusasts and subsequently the science museum. DP1 is a myth drawn up over @ RMweb which needs de-bunking.
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Mike for your needs, 1:35, wheels scale @ around 4.35 mm thick in total of which the flange is about 1.45 mm, leaving about 2.9 mm of flat*. the flange adds about 1 mm to the overall dia.
(Scalled from Slaters O gauge wheels)
* Note the profile in the drawings referred to, this is essential for a loco, wagon or coach to say on the rail. Wheels to your simplified profile wouldn't stay on even perffectly straight track
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Remember, a condom is not for life.
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On 21/01/2024 at 08:03, Black Knight said:
It seems like nothing is made in the UK anymore.
I just bought a TV and it said built in antenna
...I don't even know where that is.
Unlike the one I got that was built by Aunt Emma
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The water effect on that sub is superb. I can almost feel the gale as it grabs hold of the sea draining from the bow and stirs up those wave tops.
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Enjoyable day & some Bargains to boot.
1/35 Conqueror, 1/35 Ferret, 1/35 Cable spools, 1/48 Cromwell & 1/48 DH9 plus some tools and entrance all for just over 100 notes - Can't be bad.
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Railway modellers do it using DCC (Digital Command Control).
Not just engine sounds but doors, horns etc.
Not cheap & I suspect you'd need to produce your own sound files, but not restricted to larger scales - the linked video is n guage - think 1:144.
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15 hours ago, Nigel Bunker said:
(I bet the DC-3/C-47 holds the record)
For a jet?
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7 hours ago, Alex Gordon said:
You haven't seen my welding have you...
I get that on the car, always thought it was bird sh..
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They should have given me time to reconsider my review...too late now!
in Chat
Posted
Best thing is to stick to facts that can be demonstrated e.g. 'Not delivered within agreed timescale. After 3 months* refunded by E-Bay" these then can't be refuted in court.
* If it was months - you have the dates.