Monday 4 March 2019

The Cross of Coronado

It belongs in a Museum!

Next on my hit list of Indiana Jones props was the Cross of Coronado, the crucifix seen at the beginning of the third Indie movie. I've seen some awesome recreations of this prop that are as wonderful as they are outside my budget so I thought I'd have a go at making one for myself.

After examining all the reference I could find I started to plan out how I was going to build this. 3D printing is a wonderful tool but it's not always the right one for the job. In this instance I decided traditional making techniques would be the best way to achieve the antique finish I was looking for.

I pasted a scale plan of the cross on to a sheet of board I'd rescued from some packing material and using this as a guide I cut the rough form of one of the arms using my scroll saw. This was then sanded to shape.

Various thicknesses of plasticard were superglued to the arm to build up detail.

Any large areas were filled with Miliput then sanded.

For the gem settings I bought a few different sizes of Evergreen plastic piping however none of them were quite the right size. In the end I printed exactly what I needed on the 3D printer (so much for traditional craft skills :P).

The fine detail was extremely fiddly. I trimmed tiny pieces of plastic and placed them carefully, using a tool with a blob of blue-tack on the end.

The gaps were filled with more Miliput then I sprayed the piece grey so I could see any imperfections. I sanded the surface and resprayed a couple of times until the finish was at a point I was happy with.

Oop, it's turned red!
The laminated hardboard had started to bow a little so the finished arm was glued to a piece of wood to hold it flat (along with the beginnings of the reverse half), then a wall built around it so I could take a mould.

I walled off some extra areas to try to save on silicone

The first castings had a lot of air bubbles as the silicone had got under some of the parts. I used a scalpel and a pair of tweezers to delicately open up areas that looked like they might trap air, then lightly dusted the mould with talc to draw the resin right into the corners. This did the trick and the resulting casts were far cleaner.

I made four of the arms in epoxy resin, then cut these down and joined them together to make the cross. Once again I filled any gaps and sanded to remove any imperfections.

I performed a similar process on the reverse section then traced the latin text and details onto the back of the cross. The etching was carried out with a small file and some pointed tools. The resin was fairly soft so this wasn't too much trouble.

The first attempt looked pretty rough so I filled it all with Miliput and redrew it using circle templates and a ruler to keep everything straight.

The figure of Christ I created in sculpy over a foil base. I made a rough form first which I baked before going back over the model and refining the detail, cutting away areas I did not require and adding material to create the features. The halo was made from plasticard using a circle cutter and three layers of thin plastic, the detail cut in very carefully with a scalpel.

With everything complete I set about making a final mould of each piece then cold cast everything in brass.

Bit of cleanup to do on the mould. 

You can see my rough calculations to help judge how much silicone I would need. 

Turns out the calculations were well off and I had to mix two batches. Hey ho...

Unfortunately the sculpt did not survive the moulding process. 
I had to use a LOT of brass powder to achieve a finish I was happy with. I made sure to reinforce the chain loop at the top with a length of wire set in the resin. The resulting cast was buffed with a wire brush then burnished with the back of a spoon to bring out the shine.

Not bad for a first pull. 
I struggled to find a method to simulate the enamel inlay. Eventually it was my better half who came up with the idea of using nail varnish. I flooded the areas I wanted to be enamelled with a combination of blue varnishes then cleaned any overspills with acetone and a cue-tip once the varnish had set.

Some recreations of the cross use a mother of pearl inlay down the edges but although I'd acquired some interesting material to recreate this my research indicated this probably wasn't accurate to the original prop. Instead these areas are filled with the same blue enamel as the rest of the cross.

Once all of this had set I assembled the elements using an epoxy glue for strength.

For the gemstones I managed to get my grubby little hands on some genuine 10mm Blue Lace Agate Cabochons all the way from Jodhpur (thank you Etsy). I'd looked at acquiring real pearls but they were a bit pricey so went with imitations. I set 12 x 4mm faux pearls in the ends of the cross.

Genuine blue lace agate cabochons.

Not so genuine pearl cabochons. 

I put a dark blue nail varnish over the light blue to give it some depth. 

Starting to look the part now...
Perhaps the most time consuming part of this build, was the chain. I acquired some 3mm brass rolo chain from a Turkish Etsy vendor then used a fine gauge brass wire to combine two 3ft lengths side by side. I blue-tacked the two lengths next to each other on my desk then wove the wire through alternate links effectively doubling the thickness of the chain. It took me a couple of weeks, doing a few links every day between other tasks but it was definitely worth the effort.

I fixed the chain to my desk with blue-tack to hold it in place whilst I worked. 
Three foot of chain finally finished! 
I passed the chain through a brass ring at the top of the cross then closed the ends of the loop with the excess brass wire. I mixed up some brown and black acrylic paint to weather the chain a little and help it match the slightly darker finish of the cross. 

Finally I went back over the cross and corpus with some gold paint to add a little shine and sparkle to the raised areas.

So there we go, not too shabby. After this I'm probably going to be focussing on painting for a little while so you can look forward to some blog entries with a slightly different focus over the next few months. Happy making!


  1. Goodness me...this is stunning! Well done, you talented person, you!

  2. Can you message me via email and i'll send you a file? at