LOST WAX CASTING PROCESS

In June 2022, I get the chance to visit again Ouaga and to work at the same studio than usual (in Soum Bounkougou’s yard), doing some bronze jewellery with the lost wax casting technique. Interested to follow the process? In Burkina, it is a ancestral way to do it: simple element and a lot of skills…

Step 1: All begin with wax (bee wax in this case – see the raw block in pic. 1) that you will model, solder eventually different pieces together. So you need fire around: to keep the wax soft and to heat your soldering iron (a simple piece of metal kept warm) (and to make tea!). That’s why you have these small furnace (pic. 2: furnace is on the left). That’s step 1, my favorite.

After 2 weeks of production, time for step 2: add the pouring/casting joins (what will allow the access of the metal in the future mold) (pic. 1). One or more « tubes » are soldered to the pieces, to be sure it will be well « irrigated ». That’s a technical part: I still need a externe eye for validation. Thanks Adama for the follow up!

Step 3: the mold … this step is itself a series of few steps. The pieces are first dipped in liquid clay, to ensure that the impression is as precise as possible. For that, the clay must be the finest possible: we will have to crush and sift it.

Photo: Left: adding the pouring/casting joins // Middle: crushing the dry clay to have it the finer possible // Right: pieces with the casting joins, dipped in liquid clay

Step 3 / part 2: Then a second layer will be applied, a mixture of clay and donkey dung (yes, you read well 😉.. the fiber of the dung ensuring the solidity of the mould). The mixture is first crushed (pic. 6) so that it is as homogeneous as possible. Since the molds are small in my case, they will be assembled and a single mouth will be placed (this will be the entrance for the molten metal).
If i do myself the first layer, i’m still not so skillfull than Adama or Yambou for the second layer #ceramicskills

Photo: Left: crushing the clay with donkey dung to have a homogeneous mix // Middle: making the 2nd layer – ceramist skill! // Right: The molds drying

Step 4: Gently warming the mold to melt the wax and empty it. We have now a empty mold to welcome the metal. Adama is so stressed Icould break the mold that he insist to empty them himself #InCharge. Feeling like a (lucky) bubble-wrap child. That is burkinabe hospitality: be sure nothing bad happen to your guest, even by her/his own fault! #overprotected #humility

Photo: Left: Gently warming the molds to melt the wax // Middle: Recuperation of a part of the wax. If one part is absorbed by the mold, it is not a total « lost wax » process // Right: filling the crucible with the scrap of bronze.

For now the bronze price in Ouaga almost double because a Indian company is buying all scraps to ship abroad. Another problem for the bronze makers, who already have less outlets than before (no tourism for now in Burkina Faso and less people from abroad living there). #globaleconomylesson
More to come on the situation of the country.

Step 5: Preparing the cast.
Fill the crucible with scrap metal (among them, the scrap of 4 years of work in the studio), fill the furnace with charcoal (under, around, on top of the crucible) and manually operate the bellows to set the fiiiirrrrrreeee. At the same time and in another fire (did I tell you this process is fire all along?), heat the molds to red, to prepare them to receive the molten metal. #fire #myelement
We’re heating up the place!!!

Photo: Left: here we just see the furnace, the second fire to warm de mold is 2 meters away on the right… // Middle: This workshop must be one of the last i know with a manual bellows (they mostly electric now): a bicycle wheel with a handle and a piece of rubber to action it. For a small casting as this, it will take a min of a hour and a half of action. #meditationpractice // Right Crucible in the furnace at the moment we will add some more metal in it, now that the first part is melted.
Crucibles were traditionally made out of clay and redone for each casting. For now, cut gaz bottle are used but it could be use for max 3 casts. When lucky, they got some material from abroad, made in refractory material (the case of this one).

Step 6: CASTINGGGGGGGG

Taking the molds out of the fire one side, pouring the melted metal out of the crucible from the other side.
For big casting, there is a minimum of 4 people involve (i will show you in another post) here it is a small one but, as usual, no way Adama Bonkoungou will let me put the mold out of the fire. #overprotected #burkinabehospitality

It’s now 15 years i’m doing this and i remain as amazed as the first time i saw it.
I totally understand there than sometimes metalsmith (of all type) could be seens as having other (magical) power.

In background, you here the news in Moore – not sure now if it’s Savane FM or Radio Omega.

Step 7: Time to broken the molds (it is as opening a surprise package!).

Then cutting the main casting/pouring joins. And cleaning the most leftover of burned clay.
For this step, i received help again, this time not to protect myself but because time is short and it make definitively more sens to let pouring join at the studio in Ouaga: it will be reuse in the next casting. #reuse #economy

Now i’m doing the last steps in my studio in Jamaica: all the finishes: cleaning the leftover clay from small infractuosities (happy to have a bit of Burkinabe soil here with me!), filing leftover of the pouring joins, likkle defect to put out, precising the edge, polishing, putting the pendants on necklaces.
Finishes is my « least favorite » part of the job, and a loooooooonnnng one. #understatement

Picture here under, wax models on left and right, bronze casting before finition in the middle. Soon posting the finished pieces…