Cookie's Workbench - 7/8ths Alan Keef K40

Steve Cook

Flying Squad
Thanks Steph, I wasn't aware of that! Perhaps my saving grace will be that because everything had been bent the wrong way, all the existing solder is now on the outside, rather than on what will be the soldered joint face. I'm keeping my fingers crossed, otherwise its piercing saw time :(
 

Steph Dale

Western Thunderer
Steve,

It's one of those things where I don't fully understand the metallurgy, but I guess that effectively you're producing a surface of a gunmetal-type alloy in the heating process. It's not an actual gunmetal (copper-tin-zinc), but something similar (copper-tin-zinc-lead) unless the lead evaporates (might explain the pitting - dunno!). Anyway it's close enough to also be a PITA to deal with.

Steph
 

Steve Cook

Flying Squad
I must admit I had never even considered that side of things Steph. I have no idea what solder the chap used - its very reluctant in terms of getting it off the brass, I wonder if it might actually be one of those lead-free ones, just bought down at Maplins because its solder?

For the moment, I've straightened out the larger pieces which form part of the side tanks, they have been annealed again as I could feel the brass work harden during the bend. They are currently soaking in Viakal before a good scrub this evening. I guess I'll know whether its all salvageable soon...

Steve
 

Steph Dale

Western Thunderer
Well, originally brass was made by 'cementation'; mixing raw copper and zinc ore and then heating in a crucible (melting wasn't necessary) so that the zinc was absorbed by the copper. I'm wondering if gunmetal could be formed in the same way (solder + brass + heating). Just a thought. And in your case I'm really hoping I'm wrong!

The same contained heating approach was also used for making early 'blister' steel. The raw ingredients in that case being wrought iron and charcoal.

Steph
 

Steve Cook

Flying Squad
I got a bit carried away today, and what was supposed to be a quick look to see how easy it would be to clean the solder off the body components turned into a full cleaning session...

Victory9 Cleaning well under way.jpg

The easiest way to get rid of the solder is to use a solder wick and plenty of flux, that shifts the majority, the rest is then dealt with using a fibreglass brush. It is a nasty resin cored solder though, and leaves a sticky residue which is a sod to remove.

Victory8 Solder removal.jpg

Its not a quick process, the right hand side cab / tank took just over two hours, although there was a bit of straightening and cusp removal too. There has been some over enthusiastic filing in its history as well, so a couple of panels are missing locating tags etc, however whilst measuring and mocking things up to see how bad it was, I ended up just soldering the right hand side together :)

Victory10 Mock up on RHS.jpg

The edges still need dressing and I reckon some low melt solder used as filler will be required on the front corner of the tank. Its come out OK though and looks to be sitting in the correct place on the frame / cab floor, I just need to face up to cleaning the left hand cab / tank now...

Steve
 

Steve Cook

Flying Squad
Cheers Steph :)
I haven't had to try and solder on any of the previously soldered / annealed surfaces yet, the inner tanks when folded the correct way allowed me to solder on virgin brass, but I shall clean up some of the other parts to see what happens.
I suspect I shall be scratch building some new bits shortly
Steve
 

Steve Cook

Flying Squad
A quick trial piece was the original intention, something that could be completed over a weekend whilst learning a new technique. The victim was a Model Earth 7/8ths scale water tank kit from their budget range.

WT1 Kit Components.jpg

Its a one piece moulding that just requires one edge of the chassis cleaning up

WT2 resin cast feed.jpg

I used a Dremel with a burr outside in the garden, removing the bulk of the material in a couple of minutes, then finishing off with sandpaper

WT3 Dremel action.jpg

The holes for the coupling pins were drilled out on the pillar drill

WT4 Drill.jpg

It was quickly glued together using thick superglue

WT5 Glued together.jpg

After about an hour, the whole unit was primed and shot in some rust shades for the tank. The wooden chassis was roughly brush painted with suitable colours.

WT6 Primed and rust colours.jpg

That got me up to the interesting bit - trying out the hairspray weathering technique. This technique was established by Philip Stutcinskas to fulfil the need of the 1/35 military modelling community who were looking for a way to create scale chips and paint effects on their models. It essentially boils down to painting the colour of your chips on the model, then coating it all in hairspray. Once that has dried, the top coat is sprayed on over the top. A damp brush is then used to agitate the top coat, the water on the brush working through the paint and dissolving the hairspray, thus lifting the paint off. Its like a funky maskol really, where you can control to some extent the amount of paint removed.

You need a low strength hairspray, so I hit up some of Tesco's cheapest and laid down a couple of thin coats, drying with a hairdryer to speed things up.

WT7 Hairspray.jpg

The top coats were applied, a thin coat of light green, then a grey/green mist down from the top to represent some fading in the sun

WT8 Top coats.jpg

After a short period of time to let the paint become dry I started to use a damp brush to try picking the paint off on the corners of the coupling blocks. What I actually got, instead of nice chips was the whole lot coming off in sheets, a bit like peeling PVA off your skin.

WT13 Sheeting bugger.jpg

Not quite what I had hoped, so I started to try and remove all the green paint with a liberal application of water.

WT9 Sheeting Hell.jpg

This was partially successful, but I chose to strip the model and start all over again.

WT10 Stripping.jpg

After some primer and rust colours this afternoon, I'm back to where I was a couple of weeks ago.

WT11 Back to primer and rust.jpg

Next job tonight is to paint some wood colours where required, then let it all dry ready for another go tomorrow. The big change will be moving away from Vallejo Air for the top coats to Tamiya. Since the disaster, I have found out that Vallejo Air is an acrylic vinyl, and the chipping technique requires an acrylic lacquer to work best, of which Tamiya is a good example. A test piece showed that I should be able to get the effect I want with the current Vallejo Air rust colours, two thin layers of hairspray and then a couple of thin coats of Tamiya paint.

WT12 Practise Piece.jpg

I hope it all holds out tomorrow, I shall report back either way...

Steve
 

unklian

Western Thunderer
Can I suggest that you are perhaps putting too much hairspray/acrylic on. It might need to be speckled or spattered on so that when you clean off the top coat it only comes off in dots and splashes where the hairspray had built up. I have seen a similar effect using Maskol .
 

Steve Cook

Flying Squad
I'm not sure that speckling on from a distance will give the effect I'm after Ian, but I agree that I put too much hairspray on which was not helpful the first time round. To my mind, successful chips have corners and are not rounded which is why my previous attempts with maskol were great for long lengths of removing paint but poor for chips.
I daresay it will take some attempts to master, but if I can replicate the test piece above I will be happy for this model.
Steve
 

mickoo

Western Thunderer
Have you thought about the salt granules treatment, spray base colour, sprinkle salt on and hold lightly in place with hairspray, over spray final colour and when dry pick off the salt to reveal the base colour, sorry if that's find egg and suck lol.

MD
 

Steve Cook

Flying Squad
I tried that a few years ago Mick using table salt, it gave some interesting effects, not all of which were particularly welcome!
D32 G3 Newsletter1.JPG

The biggest issue was where single grains of salt left 'dimples' in the paint, I could never satisfactorily sort that out (see bottom of doors for worst case). Using crushed rock salt would have been a better idea, but then I think the hairspray will be more rewarding and give a better effect - its only downside is needing to do all the top coat scrubbing / chipping within a couple of days of spraying the hairspray.

So many different things to try :)
 

Ian_C

Western Thunderer
Re chipping technique - I've had success with AK Interactive 'Worn Effects' acrylic fluid and 'heavy chipping' acrylic fluid. The worn effects holds on to the paint more strongly and gives the rust blobs starting to show through paint effect. The heavy chipping has less grab and is good for paint peeling off in big pieces to reveal rust underneath. All good for rusty steel mineral wagons. Below a diagram 1/115 in P4 with the speckled rust patches using the 'worn effects' fluid from AK. Rust undercoat/primer - worn effects on top - acrylic top coat over that - wait a few minutes then scrub away with an old toothbrush to chip off some paint. Couldn't ever get that effect with a paint brush or air brush.
diagram 1-115 24 t mineral wagon P4.jpg
Never got on with the salt technique. Hard to control and a right mess to clear up afterwards. Can be used to great effect but you need the practice to be skilled in the art.

There's a lot we can learn from our military modelling buddies. I'm surprised there isn't more cross-over.
 

Steve Cook

Flying Squad
Nice work Ian :)
I have some of the Vallejo chipping medium to try, I shall see whether that acts as a small chip generator or a peeling paint effort. I do like the 'worn effect' on your wagon above, its very in-scale as well and as you say, difficult / impossible to replicate with any other method.

Steve
 

adrian

Flying Squad
Below a diagram 1/115 in P4 with the speckled rust patches using the 'worn effects' fluid from AK. Rust
That looks very good. Just curious how do do apply the worn effects? Do you coat the whole surface with 'worn effects' and the speckle effect is the toothbrush just lifting some of the paint? or do you dab on patches of the 'worn effect' fluid and the toothbrush is just lifting all the spots of fluid?
 

Captain Kernow

Western Thunderer
Re chipping technique - I've had success with AK Interactive 'Worn Effects' acrylic fluid and 'heavy chipping' acrylic fluid. The worn effects holds on to the paint more strongly and gives the rust blobs starting to show through paint effect. The heavy chipping has less grab and is good for paint peeling off in big pieces to reveal rust underneath. All good for rusty steel mineral wagons. Below a diagram 1/115 in P4 with the speckled rust patches using the 'worn effects' fluid from AK. Rust undercoat/primer - worn effects on top - acrylic top coat over that - wait a few minutes then scrub away with an old toothbrush to chip off some paint. Couldn't ever get that effect with a paint brush or air brush.
View attachment 80466

Adrian - this video by AK shows it in action and should answer your question

That's extremely impressive, Ian and a most interesting video, Steve.

Watching the video, I guess that the beige colour he had used as the base colour on those jam jar lids (or whatever they were) would equate to a rust colour that we would spray onto our wagons, as per your mineral wagon above.

It wasn't quite clear to me from the video how long one should leave (a) the AK088 or AK089 before over-painting with the top/main colour (in our case, presumably BR wagon grey for the mineral wagons) and (b) how long one should leave the top coat to dry, before having a go at it with the paint brush or tooth brush.

It also wasn't quite clear exactly what the difference is between the AK088 and AK089. I got the impression that the main means of getting a different effect was whether one used the paint brush or the tooth brush, and how each were wielded as you have a go at the top coat.

Presumably you could use any kind of paint for the underlying rust colour (which would have to have dried hard) but you'd need something water-soluble, like acrylic, for the top coat?

Sorry for lots of questions on your thread, Steve (some of which are also aimed at Ian!), but I really like this method of weathering and I'd like to try it myself.

Thanks.
 

Steve Cook

Flying Squad
Sorry for lots of questions on your thread, Steve (some of which are also aimed at Ian!), but I really like this method of weathering and I'd like to try it myself.

No problem CK, this is what a forum is for - demonstration, learning and the sparking off of discussion :)

Watching the video, I guess that the beige colour he had used as the base colour on those jam jar lids (or whatever they were) would equate to a rust colour that we would spray onto our wagons, as per your mineral wagon above.

Yes - the base colour sprayed is the colour you want your chips to be - ie the underlying surface colour - that can be rust, a previously painted colour, wood etc

It wasn't quite clear to me from the video how long one should leave (a) the AK088 or AK089 before over-painting with the top/main colour (in our case, presumably BR wagon grey for the mineral wagons) and (b) how long one should leave the top coat to dry, before having a go at it with the paint brush or tooth brush.

Generally, its measured in minutes. For the chipping mediums, with a good even coat, by the time you've cleaned the airbrush out for a change to colour, it wont be far off. I'd lay money that you could speed the process up with a hairdryer as you can when using hairspray. The same applies to the top coat - you're going to be spraying thin coats of acrylic which take very little time to dry properly.

It also wasn't quite clear exactly what the difference is between the AK088 and AK089. I got the impression that the main means of getting a different effect was whether one used the paint brush or the tooth brush, and how each were wielded as you have a go at the top coat.

The difference was to do with the size of the resulting chips and the ease of generating them. The worn effects required much more agitation and come off in smaller sizes, the heavy chipping came off much easier to create larger expanses of the base colour. You could happily use paint or tooth brush on either medium - the paint brush offers finer control and encourages smaller chips which is probably better for modelling in 4mm - arguably my 7/8ths stuff will require a more aggressive approach.

Presumably you could use any kind of paint for the underlying rust colour (which would have to have dried hard) but you'd need something water-soluble, like acrylic, for the top coat?
Yes, but as per my experience, choose your top coat of acrylic with care, or at least try a test piece first :oops: Tamiya is highly recommended, if you want to dive in further then look up the work of Mike Rinaldi - there are various videos on youtube with him explaining and demonstrating the technique. I'm not quite sure what the difference is between hairspray and the chipping mediums offered by AK Interactive, Vallejo etc, but they do the same thing - provide a soluble layer between two coats of paint.

To add to the mix, the thicker your top coats, the harder it is to get the chipping started - thus you can control how much chipping you get by influencing the amount of coats of paint applied. Light uneven coats will chip easily, so bare that in mind. Ian's model shows some lovely variation in top coat depth before the chipping was instigated, its a nice example of what you can do. I've a cake to bake, then I shall start on mine...

Steve
 

Steve Cook

Flying Squad
Pre-lunch report :)

A change of hairspray from the first go - the test piece used a weaker hold version which I understand helps with creating smaller chips and is probably more akin to the 'worn effects' mentioned above - it certainly seemed to work so that what I have gone for. You can also seen the lovely cardboard skirt to keep the wheels from getting any paint, first time round I painted them body colour and then wished I hadn't.

WT15 Hairspray .jpg

Two thin coats, applied at arms length to create a fine mist, were applied - the first being flash dried with a hairdryer. You can just make out the even sheen that the hairspray has generated.

WT16 Hairspray sheen.jpg

The topcoat colour choice for today is Tamiya 'cockpit green', with faded effects to come from 'sky'.

WT17 colour choice.jpg

The paint is diluted 50% with Tamiyas own brand thinners, then a first coat wafted over the whole model.

WT18 Light first coat.jpg

There then followed a small 'droppage' as the weight of the wagon and spray base toppled the cardboard box its all standing on...minimal paint damage to the top surface so I got away with it (caught it before it hit the floor) but definitely a 'no sharp objects day' :oops: Perhaps I should get on with making the support shelf...

Anyway, another coat of cockpit green was applied, then a light dusting of sky from the top down. I did mix a tiny bit of grey into the left over sky paint to give a slightly more random colour variation and dusted that mix over the model has a whole.

WT19 Top coat and shading.jpg

Moment of truth to come shortly...
 
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