1/72 Zeppelin-Lindau (Dornier) Rs II

[lone modeller]

I have decided that as showing a photo of the hull coated with talcum powder and dope filler would not cause much excitement

Yes it would! I couldn't decide how to do this for the floats on my Nieuport X so I clad them in styrene sheet. If they had been curvier I would have been stuck

Come on, show and tell

Richard


Yes please Stephen.

As Richard has requested.

Your build is amazing and every step is of great interest!

Eagerly awaiting your next progress report. 

Evening All,

This is the method that I and other modellers of a certain generation use/have used to fill wood grain. I discovered it in the pages of Airfix Magazine where it was used by the late Alan Hall: I am not sure whether he invented the idea or he picked it up from somebody else, but it was originally suggested for balsa wood. However it works well on basswood too and I have used it on other woods when I have made parts from them. The advantage that it has with balsa is that it provides a hard shiny surface which can be easily painted and takes some knocks without denting easily as balsa can do. It does not crack either, so the paint retains its cover as on plastic surfaces. I am aware that there are other methods to fill wood grain, but this is the one which I prefer.

The method is simple but of the bucket chemistry approach.  The ingredients are talcum powder which can be found in any pharmacy or large supermarket, and clear cellulose dope used to stretch tissue paper on flying models:



I put a quantity of dope, (the amount depends on the surface area to be coated), into my mixing container and the puff some talcum powder into it and mix with an old medium sized paintbrush. If the wood is balsa and has a fairly open grain I mix enough talcum powder to make a thick paste - rather like thick glue. This is plastered over the wood and if the wood is joined to plastic overlap the plastic slightly too. The surface will be lumpy: so when it is dry sand it down with medium and then fine glass paper until it is almost smooth.

Now mix a second coat of powder and dope but this time make the mixture thin - like a runny glue. Paint this on to the wood making sure that all of the remaining gaps and hollows are filled. When dry repeat the sanding operation until the surface is smooth.

In the case of the hull for this model I only used the thin powder and dope mixture followed by the dope because the grain is so tight that two coats were sufficient to seal the grain.

Finally coat the surface a third time with clear dope only, and when this is dry polish with some of the fine glass paper used previously. This should give you a hard shiny surface which will be indistinguishable from plastic. To clean the brush after each coat I use propriatory cellulose thinners but remember that these are inflammable and should be used in a well ventilated room. They used to reek of pear drops in the past but modern thinners no longer smell so much.

Just to illustrate what the finished and painted product looks like, (the hull of the current model does not look any different through a camera lens after it had been coated), here is an image of the engine of a Manchester which is made from three pieces of balsa, (main nacelle, upper and lower air intakes) which I converted from the Airfix Lancaster in the mid-1970's in an earlier incarnation as a modeller. The wing outboard of the engine is also made from balsa wood and all have powder/dope grain filler:



I hope that this satisfies your curiosity. If you have any questions please do not hesitate to ask and I will try to help.

Thanks for looking.

Stephen.
 

[boggie]

G'day Stephen 

Thank you for your very informative explanation.

Nice Manchester mods.
i would not have guessed the items are not plastic!

Standing by for your next post on this very interesting project.

cheers   

[lone modeller]

Evening All,

Thanks Boggie for the kind remarks and compliments.

I have been working on the ailerons. I had cut out the sections from the wings where the ailerons will go, but I need to make new ones as the later versions had balance ears and the outboard trailing edge curved upwards in a similar way to those on the Ago C II. That meant that I had to cut new pieces from 60 thou card with a laminate of 60 thou card:





These look rough at the moment but that is normal for my scratch builds. Once again I decided to use my new tool to make life quicker and easier as there was a lot of plastic to remove:



By judicious use of the file I was able to remove the underside and introduce the curve on the outer part of the trailing edge. I also thinned the trailing edge and rounded the ear and leading edge. The junction of the two pieces of plastic also needed treatment with Mr Surfacer and the whole units were given a polish with fine worn glass paper. Now they are ready for the ribs to be added which is what the pencil lines are for.





Thanks for looking.

Stephen.

[lone modeller]

Evening All,

I have been working on the part of scratch building WW1 aeroplanes that I enjoy the least - the wing and other flying surface ribs. They are not difficult to put on but shaping and scraping them can get a bit tedious, especially if there are lots of surfaces or if they cover a large area. In this case both apply!


The method is simple enough: transfer from the plans the positions of the ribs on to the flying surface with a pencil line. I use Evergreen strip and select a suitable size for respective surfaces. In this case I used 10 x 30 thou for the wing and 10 x 20 thou for the stub wings, and tail surfaces. If the wing ribs sound large just remember the size of the original aircraft - there were lightweight girders in there! The main ribs were added first by applying liquid cement to the wing surface and laying the strip on to it. Liquid cement was then run along the strip to ensure that it was properly held down - these are long strips and the cement dries quickly:



I added the small leading edge ribs in the same way:



In the case of these short ribs I had drawn a line span wise along the wing to make sure that they are all of the correct length, in addition to the chord wise lines for each rib. After what seemed like a long half of an evening I had this:



On to the other flying surfaces and the same procedure was followed. Everything was left to dry overnight. Then I could do what I like doing best with this task which is to trim off the leading and trailing edge pieces of strip. Before I sanded the ribs I added some filler to the edges to help smooth them into the general flying surface. After sanding they are ready for priming:



Any irregularities which show after priming will be filled with Mr Surfacer and sanded and primed again. These are the ailerons, elevators and horizontal stabilizer for the tail. From the top the ailerons and upper elevator are complete and primed, the lower elevator has still to be filled and sanded and the horizontal stabilizer awaits trimming:



Still a lot to do on these surfaces before they are ready, so I will plod on....

Thanks for looking.

Stephen.

[RAGIII]

The flying surfaces are looking great! Brilliant method for achieving the was out on the ailerons!
RAGIII

[pustota]

Fantastic work! I lern a lot from your build, its like a master class.

[Juan]

Wow Stephen, your efforts are well worth it.  Looking really good, you must have the patience of a Saint.   

[Des]

Thank you Stephen for your dope and talc technique. You are doing a superb job on the wings, very time consuming but rewarding.

Des.

[Jeff K]

wow. superb work on those complex curves of the fuselage (hull? what the heck do you call it on a flying boat).

i love seeing all the techniques in these scratch building threads. funny i'd filled wood pores in 1:1 scale projects, never occurred to me to use wood as the basis for something small...

[lone modeller]

Evening All,

Many thanks to Rick, Pustota, Juan, Des and Jeff for your very kind and encouraging words which I really appreciate. Juan I can assure you that I do not have the patience of a saint: you obviously do not live near to me or you would hear the language which I use at the times when my frustration levels reach breaking point.....

.....I have to write that I am currently very fed up with repeated sanding, filling and priming of ribs.... only to find still more holes!!! I gave up for a while this week and took a break to make something else, but still took a little time on them which I am pleased to report are now nearly ready....sigh.

I forgot to explain how I made the stub wings which are on the lower rear of the hull. They are made from 30 thou card and bent in a pipe of near-boiling water as described by Stevehed. The method is very good for making curved card for wings and other flying surfaces. (I just wish that I could have used the technique for the wings of this model but they were too thick). They were then filed and sanded to aerofoil section in the usual way:



The stub wings have been given the rib treatment too and are now primed and ready to have the ends drilled to take metal pins: these will be used to attach the stub wings to the hull later.

For a change I went back to the hull to drill out the cockpit area. I am not proposing to add internal detail for two good reasons. The first is that I have absolutely no idea of what the internal structure looked like other than the fact that it was built from girders like the wings, and secondly the hull is solid wood and trying to hollow out a section and fill it with detail which would never be seen anyway seems to be going too far, so I have settled for a minimal approach, rather like Airfix and Revell kits of the early 1960's where all you had was a pilot and seat if you were lucky. In my case there will be two seats as the pilots sat side by side. I will put control wheels in too and a generic instrument panel which I think was behind the windshield. Well that is where mine is going!

I drilled out the cavity for the cockpit and then lined it with 10 thou card so that it could be painted. I also tidied up around the hole with filler to smooth out the surface:



The next item was the windshield which sits in front of the pilots. I carved a male mould from balsa and push moulded one from 30 thou card.....and did not think that it looked right. I had been following the drawing but the result looked different from the photos, so I tried again...and again and finally got a shape which I think is close to what the original may have looked like:





It is not glued into place yet because I still have to make the instrument panel and fit that first. While I was moulding the windshield I decided that I would also make a mould for the propellor spinners. This was a piece of 1/4 inch (6mm) dowel with the end shaped to the correct curve. I made 6 spinners to make sure that if I make a mess of one or two (highly likely) I will have enough to complete the job without having to go through the moulding process again. Just to test things I also carved a propellor from some strip wood which I use for the purpose, (please do not ask what the wood is because I have no idea - it was given to me by my late father and he did not know what it is either). The result:



Only three more to make.

One thing that struck me when I was sanding the elevator surfaces was the size of them. On the aircraft they form a biplane structure which was at the extreme rear of the aircraft, and they hinged as a single unit. Just to give an idea of their size I got out my model of the Avro biplane of 1912 which is to the same scale: the span of the elevators is the same as the span of the wings of the biplane! (5 1/2 inches: 14 cm).



Thanks for looking.

Stephen.

[RLWP]

If this build doesn't work out, you've got a speedboat!

Richard

[RAGIII]

You are moving right along now! Amazing size comparison!
RAGIII

[lone modeller]

If this build doesn't work out, you've got a speedboat!

Richard

Well it is supposed to be a flying boat! I just hope that I can get the wing to fit properly when the time comes....shades of Lance and Rick with the Fokker E VIII here. I know that I may have to build a proper jig for once.

Stephen.

[lone modeller]

Thanks Rick for the encouragement. Yes this is rather bigger than my usual models, but when I saw the photus of this machine I just could not resist the temptation to have a go!

Stephen.

[IanB]

It really gives an idea of the size when you say the cockpit has 2 side by side seats! This is going to be enormous!

Ian