Steel cable transmission

[fspg2]

Peter,
It looks fine
Such kind of projects I love!
History is somehow alive again! If stones could talk

[Peter_T1958]

Also the scale that you are working in is quite small, so though you want to express and give the feel of the finish and texture of the individual stones, you dont want to overdo it or exagerate it, because it could quickly become a bit of a caricature.
Marc

If you move a #11 blade over a piece of plaster at an angle close to 80 degrees so that it digs in a little (not dragging it across) it will start to "chatter" (common machinist term used when the cutting tool does not dig in correctly and jumps up and down, or chatters.  You can hear it too.)
This chatter will create many smaller chipping cuts not unlike hammering with a masons chipping hammer.  You need to rotate the piece to make sure that the chipping is not in one direction.  This is how I dress all of my stones that require a hammered finish and it's fairly quick to do once you get the hang of it.
Russ

That's why I love this forum so much. I can learn a lot from you guys - thanks!

Such kind of projects I love! History is somehow alive again! If stones could talk
Frithjof

I totally agree with you! When I first saw that photo with you, your father and little sister at Buntbahn.de I understood why you are going to start such a impressive project. It is turning back the clock indeed. I could stare on the old photographs for hours an hours...


By now a first test run in stone production happened. I intended to do some different masters of each required size with some softish stuff and modified each exposed face seperately.
Afterwards the castings were done with a porcelain-like casting compound. So the "stones" could be painted easily without damaging the surface too much!
This is plan A and there is no plan B at the moment ...
   


Peter

[Chuck Doan]

Those are looking very promising. Your going to need a lot of them!

[Malachi Constant]

Those stone blocks look great!  -- Dallas

[marc_reusser]

Peter,

Is it just the photo, or my imagination,....but the cast stones you made look smoother than the last set of sample/test pieces you made?

I am wondering about the porcelain material....though, as you say durable, I worry that because of the hardness and lack of absorbancy, thefe is a chance that the finish stines could end up looking "painted" rather than like a natural material. ( this often happens when you see painted resin or plastic stone/brick/concrete castings).

[Peter_T1958]

Thank you very much for your encouraging words.

@Marc

Is it just the photo, or my imagination,....but the cast stones you made look smoother than the last set of sample/test pieces you made?

At first I apolgize for the poor quality of my photos. My "equipment" is a simple pocket camera and for close up pics a magnifer glass has to do it.
The shot of the cast stones was made under artificial light; the first test pieces in daylight.

I am wondering about the porcelain material....though, as you say durable, I worry that because of the hardness and lack of absorbancy, thefe is a chance that the finish stines could end up looking "painted" rather than like a natural material. ( this often happens when you see painted resin or plastic stone/brick/concrete castings).

Good spot! And I share yours sorrows. Here I am stuck between a rock and a hard place. On the one hand I have the imagination, that the original pylons could have looked something like this:



On the other hand that would mean I have to paint it anyway at least in part. If I have to do so with any methode whatever the cast stones should be robust.
But be assured I have absolute no experience in modelling with such material so I am deeply grateful for constructive criticism or hints of the experts here.

Peter

[Peter_T1958]

As already feared and also noted by Marc working with the porcelain material ist quite tricky. Not that there are substantial differences between the two sorts of stones, but as you can see in this photo, the porcelain materials sometimes shows tiny air bubbles on the surface (yellow arrow), sometimes not at all (red arrow).



I suppose it's due to a chemical reaction. Now I ask myself how to prevent these annoying bubbles ...

My wife happened to see the photo and mentioned in passing: Aren't they a bit too pronounced? To my mind they should be more smoother..! Now I'm quite a bit confused ...

Peter

[lab-dad]

To eliminate air bubbles I put about half
of the plaster in the mold.
Then using a stif brush "stab" at it.
Then i gently drop the mold on the bench
until no more bubbles appear.
Since doing this i have no issues wirh air bubbles.
Marty

[marc_reusser]

Looking at this photo, I cant tell that those are air bubbles...looks fine to me.

If you are concerned that these stones appear too rough, you could cast some smoother ones to mix in. I thing that this is now more noticeable, because you have a larger grouping/assemblage of weathered stones.  Maybe if you do some slightly smoother ones...use more of those mixed in for the areas of the abutment that got less wear and erosion, and the rougher ones for around the base and water sides.

[Malachi Constant]

Also, keep in mind that you're looking directly at an extreme close-up of ONLY stones ... which will be part of a larger scene ... I suspect that when they are seen "in context" (surrounded by scenery materials, etc.) they will "appear" or "look" close or very close to what you have in mind.  Cheers, Dallas

[NE Brownstone]

Yes! To what Marty said.   Most bubbles are due to pour pouring practice and doing what Marty says helps dislodge any bubbles and gets them away from the surface.  All it takes is one twitch of the hand while pouring and you can have a nice crop of bubbles.  Surfactants help, but one must remember that a surfactant is basically soap and with enough agitation like a splash can cause the bubbles that it is supposed to eliminate. 

It seems like a PIA to have to do extra steps as opposed to just pouring, but if you don't want  to have to fill in scale bowling ball holes it's worth the extra effort. 

As for the bubbles in the above picture, "what bubbles"   Your stones look marvelous!

[Peter_T1958]

If you are concerned that these stones appear too rough, you could cast some smoother ones to mix in. I thing that this is now more noticeable, because you have a larger grouping/assemblage of weathered stones.  Maybe if you do some slightly smoother ones...use more of those mixed in for the areas of the abutment that got less wear and erosion, and the rougher ones for around the base and water sides.

Hey Marty, Dallas, Marc and Russ,

Many thanks for your kind words and your advices and that helped me to move into the right direction. Marc, you hit the nail on the head. However as things are now I am not satisfied with my current attempts (bottom row is not completet yet):



All in all the chiseling pattern is too rough compared to what I have as impression from the original photos such as this:




I think this would be not too bad for scale 1/32 and larger but not for 1/50 :-(

So back at square one, I will try to achieve a smoother surface but with about the same texture. No idea how to put that into practice. I've already replaced the steel brush with an brass one. Now I will try a glass fibre pen. Hope this will work ...

Here a photo that reveals wonderfully the atmosphere on the Rhine banks towards the end of the 19th century...



Peter

[finescalerr]

Imperfect or not, that wall looks very, very good. -- Russ

[marc_reusser]

What about using a different material for the master, something that is more pliable,...something like styrene, that is soft enough to take and retain very small and fine impressions.

...along that same vein, what about building up a texture, in the same manner that armor modelers create cast iron and rusted surfaces...you can use thinned Tamiya putty, Mr Surfacer and liquid plastic solvent/glue to get different effeccts. These can then be smoothed, eased and sanded using steeel wool and/or fine sandpaper.....afterwards you can also go back in and add additional chisel marks and impressions with dental tools and such.....and if you get too rough in one area/point, you can ease/smooth it by applying some liquid solvent.

Just a thought.

[nk]

I've cast a lot of individual bricks and I always add a drop or two of dishwashing detergent into the plaster before pouring into the cast. This reduces the surface tension of the water and consequently reduces the amount of bubbles significantly in the final cast. If you are looking fior variation in the quality of stone tooling you can use a variety of wire brushes: steel, brass, nylon etc.

You are getting great results, so please take my suggestions with a grain of salt.

I also belive that Schaffhausen has another interesting feature, started by a gentleman from Boston, The IWC factory.