Monthly Archives: January 2020

Authenticating Your Walter Bosse Hedgehog Ashtrays: Curious Cases – Steel & Ferrous Metal

Walter Bosse Steel Hedgehogs

I recently came across a few strange metal hedgehog sets and was surprised to find that they were all highly magnetic! That is a trait shared only by ferrous metals, or metal with iron in them. So I figured I should put a post together and talk about all their curious traits and how I think they fit into the catalog (if at all).

Copper Plated Steel Set #1:
Walter Bosse Copper Plated Steel Hedgehog Ashtrays
Walter Bosse Copper Plated Steel Hedgehog Ashtrays

This is the first set I came across. I thought it might be another solid copper set like the one I already have in the collection. But like I found out with all the other sets, it is magnetic, and copper certainly isn’t magnetic! The further I looked at it, I could see some of the steel underneath (showing through the copper plating). Here is a closeup photo of it on the spines:Walter Bosse Copper Plated Steel Hedgehog Ashtrays
It seems like this set was cast in steel in some steel alloy and then plated afterward with copper to give it that golden coloration. The whole thing was then put through a patination process afterwards, possibly to give the patina something to adhere to.  The spines and ears all have the copper highlighting, while the body retains most of the patina. The color of the patina ended up more of a grayish color than the rich black you get from a traditional solid brass hedgehog set. Here is an authentic brass hedgehog set next to this copper plated steel set:
Walter Bosse Copper Plated Steel vs Brass Hedgehog Ashtrays
The coloration is very different. As you can see, they are very close in size and look as if they came from the same mold or pattern. Even the baby of the sets look almost identical, though the steel one is more crude (see below):

Walter Bosse Copper Plated Steel vs Brass Hedgehog Babies
I believe this set to be some kind of experimental model, not made for production but more of a proof of concept to see if steel was viable for casting and making hedgehogs.

Steel Set #2:

Walter Bosse Steel Hedgehog Ashtrays
Walter Bosse Steel Hedgehog Ashtrays
This second steel set is identical to the first copper plated steel set, and they were purchased together so that’s not a surprise. They were most likely from the same experimental batch. Where these sets differ is in the execution.  This set seems to be cast in the same metal, and the same copper plating was applied. But that copper patina seems to have been too thin or failed as it was then polished off to reveal more of the steel. The results led to a somewhat two-tone effect, fading from black to copper to silver, that can be seen especially on the front legs of the largest bowl.
Two Tone Patina on Walter Bosse Hedgehog Ashtrays
The patina is also the same grayish tone as the above set, but has some oil-slick rainbow coloration on parts of the patina (see photos below).
Rainbow Patina on Walter Bosse Hedgehog AshtraysRainbow Patina and Rust on Walter Bosse Hedgehog Ashtrays
From my research, this rainbow coloration may be due to the fact that the patina was put on at too hot of a temperature or had a chemical reaction to the steel. Here is a photo of an authentic solid brass set next to this steel set:
Walter Bosse Steel vs Brass Hedgehog Ashtrays
The baby of this set is also identical to an authentic solid brass baby from a hedgehog set .And the babies of the above copper plated steel set are exactly the same as well (see photos).
Walter Bosse Steel vs Brass Hedgehog Babies
Walter Bosse Copper Plated Steel vs Steel Hedgehog Babies
Another curious thing about this set of steel hedgehogs is the fact that all of the eyes have polishing around them. This is something I have never seen done on any Walter Bosse hedgehog ashtray sets in all my time and research. I have to say, I kind of dig it! I possibly like it just because it is different… I would definitely not trade the classic polishing on an authentic solid brass set of hedgehogs. But this is super fun to look at and (I think) certainly suits this set well!
Walter Bosse Steel Hedgehog Ashtrays
As I mentioned with the above set, I believe this set to be some kind of experimental model, not made for production.

Steel Set #3:
Walter Bosse Steel Hedgehog Ashtrays
Walter Bosse Steel Hedgehog Ashtrays
This set of hedgehogs is also highly magnetic and (I believe) made of steel as well. This set differs in that is seems to have black paint applied instead of a patina, or at least a glossy coat of lacquer applied over the black patina. This model seems to be an attempt to try and get the rich-black patina of a solid brass set of hedgehog ashtrays. It looks to have not had any plating process like the above sets, just a light polishing on the tips of the spines and nose. In some spots, orange rust from the steel shows through the black (see photos).
Rust on Walter Bosse Hedgehog Ashtrays
And here is the steel set of hedgehog ashtrays next to an authentic solid brass set of hedgehog ashtrays. They look almost identical to me as well.
Walter Bosse Steel vs Brass Hedgehog Ashtrays
The baby of this set is also identical to an authentic solid brass baby from a hedgehog set. Also, the babies of all three of these sets look identical as well (see photos).
Walter Bosse Steel vs Brass Hedgehog Babies
Walter Bosse Steel Hedgehog Babies
As I mentioned with the previous sets, I believe this set to be some kind of experimental model, not made for production.

Cast Iron Set:
Walter Bosse Cast Iron Hedgehog Ashtrays
Walter Bosse Cast Iron Hedgehog Ashtrays
I’ve shown this set in previous posts but thought I’d bring it back in because it is also ferrous and super magnetic. As I stated before, this cast iron set is super heavy and very crude because it is quite a bit harder to get detailed casting out of cast iron. Cast iron is also more brittle and some spines are missing as well as some chunks of overcasting. These were not ground down or polished in any way. They come out of the mold looking very much like they do now. The base metal on the cast iron set has a warmer tone to it, as opposed to the steel (which has more carbon in it) and usually has a cooler or more neutral grey tone (see photos).
Walter Bosse Cast Iron vs Steel Hedgehog Ashtrays
Right off the bat, all 3 of the “steel” sets seem to have been made with the same mold even though they were purchased from different places. The cast iron set seems like it may have been made with a different mold, at least the baby in the set it indicative of being from a different mold (as it has the X leg configuration). See below a comparison between all the steel babies (with the cast iron one in the 1st position on the left) and a comparison between a solid brass baby and the cast iron baby.
Walter Bosse Cast Iron and Steel Hedgehog Babies
Walter Bosse Cast Iron vs Brass Hedgehog Babies
And here is a comparison between the full set of cast iron hedgehogs and an authentic set of brass hedgehog ashtrays.
Walter Bosse Cast Iron vs Brass Hedgehog Ashtrays
Steel Baby:
Walter Bosse Steel Hedgehog Baby

And last but not least is a random little steel baby I came across. It didn’t come with a full set, just a lone baby. It looks like it is just raw straight out of the mold and never had a patina applied (nor was it polished in any way). Here it is next to the authentic brass baby. Looks like the exact same mold was used again.
Walter Bosse Steel vs Brass Hedgehog Babies
In Conclusion:

All the sets match up almost exactly with a known authentic brass set made by Walter Bosse. I’m inclined to say they were all experiments by Bosse or one of the foundries he was working with. At the time, a few of the foundries he worked with also had the capability of producing iron and steel products. One of those is Kurt Jesch KG, who was later sued by Bosse for selling his works without permission or proper royalties paid. If I had to guess, I bet these came from the Jesch foundry during Bosse’s time in Germany in the 1960s. Whether Bosse oversaw the making of these or not is a mystery that will probably never be able to be answered. But if I had to guess, because of the attention to detail of the castings and similarities to authentic brass models, I would say someone with an artistic eye worked on these… maybe that was Bosse himself!

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How It Works – Lost Wax Casting for Walter Bosse

Walter Bosse Hand Ashtray Casting Progression

Let’s dive into a little bit about the handmade casting process to understand a little more about what makes Walter Bosse and Vienna Bronze items special. The casting process used is “lost wax casting” or “investment casting.” Here all the steps and love that go into the creation of a Walter Bosse model:

Walter Bosse Hand Ashtray Master and Finished Model

1. Starting with a “master”

The process begins with the artist’s “master” pattern. There are several ways to make a master: A. directly from wax to mold; B. from wax to cast metal to mold; and C. from mold to master to secondary mold.

A. If we create a master out of wax and form a mold from it directly, the wax master could be melted down or damaged in the process. With this method, the master may be lost, along with the ability to create future molds from it. But at least we have one mold for the catalog.

B. Walter Bosse’s most common method of making a master was to sculpt the wax model by hand, create a metal cast from it, refine the metal model into a finished master, and then create a new mold. This way, the metal master is saved in order to continue making future molds. This is especially useful if the original molds get damaged or need to be replaced due to use over time.

C. If the master has been lost, but the mold is still available, we can cast from the existing mold, finish the model and save it for future mold making. The only downside is that there is about 1.52% shrinkage. (The general shrinkage allowance of brass is 3/16″ per foot.) We would not want to keep doing this over and over again, or the model’s size will continue to shrink with each new iteration. It’s good to keep a master with each mold if possible.

Walter Bosse Hand Ashtray Master to Wax to Mold

2. Making a mold

Rubber molds are preferred due to their longer shelf life. The creation of a rubber mold requires a vulcanizing press, which solidifies the shape using heat and pressure. Since quite a few of the original masters were lost, today remastering is often done with vintage Bosse pieces. In these cases, the vulcanizing process is less suitable, as the heat and pressure can be rough on vintage originals. Silicone molds are therefore used to preserve the quality of the vintage original (though the silicone molds do not tend to last as long). The vulcanized rubber molds end up lasting 1020 years with regular use, while silicone can last only 25 years.

It is necessary to cut a sprue hole in the mold, preferably somewhere inconspicuous on the model, running from the widest or thickest part to the thinnest part. This will be the path the wax/metal flows most easily into the mold. The master must then be cut from the mold, either by prying the mold open enough to remove the master, or cutting it in half entirely to make a two-part mold. It is best to cut the mold with a very sharp blade, such as a scalpel.

Walter Bosse Wax Tree

3. Wax

Molten wax is injected into the mold through the sprue hole. The wax model is then removed from the mold. An extended sprue is attached, which is then connected to a sprue base/post which makes up the center of the wax tree. We add as many wax models to the tree as possible to fill up all the available casting space.

Walter Bosse Casting Flask

4. Adding investment

Once the wax tree is full of models and ready to cast, it’s time to add the investment. The investment is what’s left when all the wax is burned out, leaving space for molten brass to be poured in. The flask/cuvette is placed around the tree. The investment medium, usually a type of plaster material, is mixed and added around the wax tree inside the flask. All of the bubbles must be sucked out, best performed with a vacuum or vibration method. Once the investment is cured, we are ready to burn out the wax.

Walter Bosse Casting - Molten Brass

5. Casting

The molten brass is poured, and begins to cure. Once the metal has cooled, the tree and investment material are removed from the flask. The investment is slowly and carefully broken away from the brass models. Once the models are fully cleaned of investment, they can now be snipped off the tree, ready for finishing.

Walter Bosse Finishing Process

6. Finishing

The models get a thorough grinding and polishing to ensure there are no flaws. They are then stamped on the bottom with “Bosse Austria,” and undergo the patented patina process. The model then goes through a second polishing in selected areas to highlight the gleaming beauty of the natural brass.

Walter Bosse Figurines

With finishing complete, a beautiful new Walter Bosse work of art emerges, ready to find a home!

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