wefalck

I don't think that Biddlecombe will be of much help. In neither of the plates such gaff is shown. I have seen it on some 'clipper' ship depictions of around the middle of the 19th century. If the drawing above wasn't by Beaugean, I would have thought that draughtsperson misinterpreted a square gaff top-sail. Incidentally, it was something specific to the late German deep-water barques, particularly the flying-P-liners, that they had a double gaff with a triangular gaff top-sail. The surviving KRUSZENSTERN ex PADUA, the PASSAT, the PEKING, and the German sail training vessels GORCH FOCK I and II are still rigged in that way. However, I don't know, whether the second gaff has any specific name.

What do you mean by "the size is 1/8" ? The volume of the part ? 1/96 and 1/100 are close enough, there is only a 4% difference in length, however, the difference between 1/100 and 1/76 is 24% ! In other words, piece of 100 cm length would be in 1/100 scale 1 cm long, in 1/96 scale 1.04 cm, but in 1/76 scale 1.32 cm

Why would you ?

In 1:1 scale the process looks quite similar:

So you got hold of a copy of the book on the history of her builders, good !

As said, this technique is very versatile for many small parts. Here the sequence of creating a ventilator from round brass stock using some fancy machine tools and accessories: Turning the shaft of the ventilator in an excentric 2-jaw-chuck. The future cowl is to the left. One could have this done in an ordinary 3-jaw-chuck or collet, but would have needed round stock of about twice the diameter and needed to remove a lot more material. After parting off the ventilator it is transferred to the upright dividing head in my micro-mill, where the back of the cowl is round-milled. The dividing head is driven by the worm-drive for this milling operation. Then the inside was milled out in the same set-up. The back of the cowl is shaped on the micro-grinding machine using a diamond disc. The back is closed with some copper shim soldered on and then hand-shaped. Collection of ventilators produced from round brass stock in this way. The height of the head of the smallest is 3 mm and the shaft has a diamater of 1.2 mm. Using this technique I have produced a variety of parts for my current project (SMS WESPE 1876), including rectangular bollards, chain stoppers of various kinds, etc. Another application was milling the outside shape of 2 mm-blocks in brass and Plexiglas: In the same set-up they were then drilled and slotted, or rather the sheaves were part-milled by turning the blocks in the dividing head over the predetermined angle. For all the machining operations I made myself a table in which I calculated how much the mill had to be fed in what position of the set of future blocks held in the dividing head. This is a powerful technique, particularly when you can transfer parts from the lathe to the mill and vice versa without loosing concentricity and, hence, the reference point. Paul is right in saying that it requires a good kit-out and some practice in machining, but it is quite do-able with a bit of patience and I am entirely self-taught.

Just to say: I had a look at a couple of German textbooks on rigging, one of 1869 and one of 1903. As expected, the latter only talk about steel masts, but the former does not mention this kind of masts at all. There are, however, proportional dimensions for different steps on the mast from which one perhaps can deduct the information you need.

Has there ever been a video recorded, showing you sculpting ? I am particularly intrigued by the repetive accuracy. Getting one ornament right is one thing, but getting them all looking the same is quite another thing. I know, you are using a proprietary Czech sculpting material, but would you have any experience with a brand available in other parts of Europe and you could recommend ? It seems that your material becomes rather smooth and translucent after baking, which is good for the following gilding. I am not aware of another sculpting material that reacts like this.

Nice work, indeed. I gather the real challenge is still to come, as the shape becomes more complex and as this is going to be the part that you are planning to leave unpainted.

To get back to the original topic: this technique is also useful for producing flat identical parts of complex shape. The outside shape is milled as per the video and then you saw off the parts of the desired thickness with a circular saw. In order save material, you may start with some rectangular stock to which a stem or spigot is hard-soldered. If you have a independt 4-jaw-chuck for your lathe, you can also turn the stem onto the rectangular stock, which may be the method for materials that cannot be soldered. Talking about parts for polystyrene models: I would probably make those from Plexiglas stock, as this can be glued (or better 'welded') to polystyrene with either the usual liquid cement or with methylene chloride.

The material Doris uses are plastic foils, I exchanged with her on this years ago. These foils have been popular in the 1960s and 1970s in Western Europe as a quick-n-dirty fix for cheap furniture or interior decoration. In Germany there is a brand called d-c-fix (https://www.d-c-fix.com/). Over the decades the material degrades due to its high content of plasticisers. While Doris does nice things with them, I would be very much concerned about the longevity.

I have used the method frequently and designed my shop-made micro-mill with that method in mind. One can use it also on somewhat larger parts and economise the material consumption by hard-soldering a thinner spigot to it. One can do this also with bar stock or thicker sheet. The method also works for Plexiglas or Aluminium, of course.

I tend to use two screws to fix my models to their display cases the same nuts that are inside the hull also are used for temporary mounting screws that hold the model to a piece of wood that in turn can be held in a vice etc.

Actually iron-on veneers are what the name says, not foils. It it is what industry uses to cover say chipboard in proper wood. One can buy it in sheets for DIY use and the iron-on edges in real wood are the same. While it is a useful DIY material and can turn out well, when sanded, filled and polished with shellac, I would advice against its use in planking. Such veneers are produced by shearing off thin layers on a sort of lathe. This process damages the wood structure. That doesn’t matter too much in an ordinary DIY context, but the resulting wood structure is far too coarse for model purposes. There is another variant that is/was sold in Germany under the name Mikro-Holz (micro-wood), a very thin, but dense veneer backed with an self-adhesive paper. I used it on one of my first model in the 1970s and it still sticks. It can be treated like real wood with fillers and polished with shellac.

Ahh, I already had withdrawal symptoms 🥴

Ah, ok. It is a rather simplified version of a 1860s picket-boat fitted with a spar-torpedo. The pictures indicate that the boiler is of the return-flue type, stoked from the smoke-box side. Most of the time such picket boats had a locomotive-type boiler that is stoked and operated from the same side I think. The fire-box is totally encased in the boiler, which explains that the lagging is going all around. The prototype boilers would have had much more elaborate fittings, with double sight-glasses, double check valves, double feed-pumpes, manometer, safety-valve, etc.

What kit(?) is that ? The boiler seems to be very rudmentarily fitted, going by the drawings above. There is no fired door and the wood lagging should not cover the fire-box (where is it actually ?). There is no pressure gauge, etc.

What time of milling-cutter was used ? Must have been a ball-nose mill of 1 mm or less, I gather.

One has to also look at the alternatives the men had and how the conditions were on land then and there. Crews main recruited from the lower echelons of society - being an agricultural labourer could be equally bad and depriving, if you had a bad landowner. And it was even more difficult to escape, if you were a serf. Serfdom wasn't lifted around Europe until the middle of the 19th century or even later.

Maybe chrome-plating or spraying of the engine would give it a more 'contemporary' look ...

Will she be painted later a per prototyp e? Seems to be a pity to hide the nice mahagony under some paint ...

Fresh rust is FeOOH (ferric oxihydrate), which is brownish red and fluffy. This is easy to remove with a wire brush. However, I often had to deal with pitting rust, where the FeOOH was converted, due to subsequent dry storage over decades, into Fe3O4 by dewatering the FeOOH. Fe3O4 is of a dark brownish, sometimes metallic colour and hard. This is very difficult to remove with a wire brush, but cleans up nicely with the tea-leave method. The pits, of course, remain.

As I said in an earlier post, black tea, particularly the cheaper and more fermented varities, contains a lot of organic acids, the stuff that makes it taste bitter and sour, and look brown. The longer you let the leaves soak in hot water the more you get this stuff out of the leaves. Therefore, also using the leaves from your earlier cup'o is fine. These organic acids dissolve the the rust, bringing the iron into solution and keeping it there by forming stable chemical complexes. These acids are too weak to attack metallic iron. In practice, you have to first brush off any loose rust and degrease the parts in e.g. acetone or cleaner for motorcycle chains or another degreaser. Rust soaked with oil is not being attacked by the organic acids. This is particularly important, when you used creeping oils, such as WD40, to make parts move for dissambly. You then take a bowl or other vessel that allows the part to be completely immersed. It may be wise to use a disposable vessel as the deep black iron-organic compounds are very staining and stick to any rough surfaces. Also wear gloves and protect your clothing - it is almost impossible to get these stains out of clothing. This vessel you fill with a thick soup of tea-leaves and you completely immerse the part in it. Any surface that is exposed to air may begin to rust, so complete immersion is important. Leave for 24h and check the progress by taking the part out and rinsing it. You can basically leave it in as long as you like. Move it from time to time to bring the surface into contact with fresh solution. Once you are satisfied with the progress take the part out and brush it under runnging water e.g. with an old tooth brush. You may need to do this also in between for knurled parts to remove the conversion products. When clean dry the part immediately and very thoroughly. Compressed air is a good idea, if you have it. Otherwise, you can immerse intricate parts, such as knurls, into acetone to be sure that the water is displaced from all crevices. For simple, smooth parts you may be done now, but for intricate parts, where the conversion products have settled in crevices, you may need to apply a wire-wheel. I have used this technique for decades on my antique machinery, where it is important that you don't change the geometry of load-bearing surfaces. Just one word of caution: some people also recommend using Coca Cola for that purpose. This drink contains inter alia organic acids and phosphoric acid. While the organic acids dissolve the rust, the phosphoric acid will form solid iron-phosphates (a mineral called Vivianite) that are quite insoluble, once precipated on surfaces. You have to constantly remove and clean the part to prevent these phospates from precipating in crevices. They are virtually impossible to remove from there. This property is used in so-called 'rust converters', which are basically phosphoric acid solutions, in the automotive sector, where you want to convert the rust in situ into something that replaces the metal and sticks to remaining metal. These Vivianites are very hard, harder than the iron/steel and are difficult to grind down - not a good thing to have on surfaces that have to geometrically exact for mechanical reasons.

For the knurls, I would use tea-leaves and then a wire-wheel. This is pretty much what I used in 25 years of restoring watchmaking machinery.

When using 'sandpaper' you will probably change the shape of the part. So you really have to know what you are doing. The other 'abrasives' metioned are more compliant and are less likely to change the contour of the parts. Of course, it depends also on whether you work on old agricultural tools or on fine measuring tools. I gather we were talking about the latter. When you know what you are doing, you can regrind flat surfaces, such as the sole of planes, on a piece of fine wet-and-dry attached to a perfectly flat surface, e.g. a glass plate. I indeed used this technique in reconditioning machine tools. For measuring and machine tools it is also important to remove all abrasives residues carefully.