Introduction: Custom-Made Wax Candles (Cast Using Sugru Moulds)

About: Black sheep engineer, Chartered, and very silly. Currently living in the UK. I have been fortunate to have lived, studied and worked in Hong Kong, Norway and California. I believe physical models help people…

This Instructable will show you how to make your own Birthday Candle Mould, so that you can cast all sorts of wax shapes, and use them as party candles - including Lego Minifigures!

I recently finished a detailed Instructable on Casting Objects in Sugru. I found that it is possible to cast Pewter into Sugru (a hand-mouldable silicone putty): First you make a wax mould, and then using a technique known as a 'lost wax process', create a second mould for casting the Pewter copy into. The result was a pretty cool Pewter Lego Minifigure.

However, as is often the way in doing creative projects, the 'journey' is as enjoyable as the destination: Although I'm very pleased with the Metal Minifigure, the wax cast was fun too - and I was somewhat sad to 'lose' these colourful lego guys to a 'process'. I thought that it'd be nice to make one into a candle - so added a wick to the wax cast - and the candle worked first time! I shared a quick .gif animation I made of this, and people liked it...

So, this is a fresh Instructable, specifically showing how to mould detailed lego minifigure candles, or if you want to start simple - first try moulding a lego brick. They both last about 20mins and look great any any cake!

Step 1: What You'll Need

Stuff you might need to buy:

Stuff you probably have:

  • Scraps of Card
  • Scalpel (showing 12D blade - but any will do)
  • An old metal dish/pan for melting (note, it will not be good for cooking afterwards!)
  • Lighter/Matches


  • Not shown - heat-source. You can either use a stove, or a gaz burner. I did see that you can apparently microwave Soy Wax, (by Yaley), but have not tried it yet. Please Post/let me know if you do try this!
  • Be Safe:Take care with hot wax. I suggest waring protective gloves, and goggles, as wax can 'spit' if overheated or if any water comes into contact with it. In the event of a fire - don't use water, use a fire-blanket or sand.

Step 2: Create Your Sugru Mould

This series shows me first making a mould using only 1x 5g packs of Sugru. It can be done, but it is easy to end up with it a bit too thin on the sides, when working with Sugru. The final picture shows 1-pack-mould vs 2-pack-mould. I'd say 1.5packs are optimal, so you can of course get a Lego Figure and a Brick mould from a 3pack of Sugru!

Of course other moulding compounds are available, but they often require more equipment and experience to use: I think this is a fairly compelling combination of cost, skill-level and time to get the job done.

Anyway, the process is as follows:

  1. Get your Sugru ready. Knead it for a few seconds.
  2. Dunk your Lego into some water - this helps to stop the Lego sticking. (Adding few drops of liquid soap also helps).
  3. Apply the Sugru to a scrap of paper/card and then press the Lego minifigure into it. Then, using your fingers, (or even a coffee stirrer), push the Sugru into the outline of the Lego. Try to let it above the level of the Lego as shown. Don't spend too long on this, or it will start to stick after 3-5mins.
  4. Pull the Lego out of the mould.
    Tip: If you have pliers to hand, you can grab the Lego by the holes in the back of the legs.
    If you are not happy with the impression you made at first, you can re-dip the Lego in water and press into the mould, to ensure the impression is just right.
  5. Leave to dry/cure for 24hours. (Most likely, overnight is fine).

Step 3: Adjust Your Mould & Add the Wick

  1. This image shows me cutting out the 'core' of the hands of the Lego piece. This makes them less fragile when casting, and the 'arch' is easy to adjust later, as shown in the later steps.
  2. Cut a small groove in the head - for the wick.
  3. Insert the wick, trim off the excess.

Step 4: Cast the Wax

  1. Prepare to melt the wax and dye together. The wax colouring/dye is pretty strong - you only need about 1% to clear/white wax. Add more if you need to.
    (I estimated that a Lego minifigure requires about a Desert Spoon of wax, per mould).
  2. Once you have heated your wax, allow it to cool a little, so that it is not smoking-hot. Having it too hot only makes the cooling process take longer, and it will be more likely to melt the wax around the wick - and leak.*
  3. Pour the wax. Slightly over-filling it, so that it forms a meniscus above the mould. The wax will shrink, so having this extra will help. Allow to cool for 20-30mins.
  4. This is where the paper/card helps - it allows you to gently flex the mould to release the wax casting. Wiggle the Lego-shaped wax cast free by holding the wick. You can make multiple casts from one mould. I have got at least 5 out of one, and is still going!

*If your mould does leak at any point, most likely around the wick, add some Blu Tak to the outside to plug any leaks.

Tip - if you spill any, don't worry, you can simply scrape it up with a ruler or piece of card and reuse it.

Step 5: Corrections

  • This model shows the hands of the Lego minifigure being 'filled-in'. I did this as it gives more strength to the hands being pulled free from the mould. However, if you look closely, you can see the outline of the hand is still visible.
  • Using a scalpel (straight or curved is fine), heat the blade in a flame for a few seconds, then press into the wax hands. You will find it quite easy to melt away the wax excess, and quickly re-defines the hand.
  • While the wax is melting/molten, blow any liquid wax away, making sure to have some scrap paper down to catch the flying drips. I suggest wearing goggles for this bit as well, just in case!
  • The mould is pretty reliable, but this method is also very useful for repairing any larger faults, or breakages in the process - just lightly heat and stick wax parts together again. Also, it allows you to 'tidy-up' the mould by smoothing out any rough areas. It perhaps sounds a bit tricky, but after a few goes, it becomes quite easy to judge how long to heat the blade and what it will melt in turn.

Step 6: Other Modifications: Candle-Holders

The headline picture shown shows the lego men 'standing' on the cake, but of course some wax will run down onto the cake. Although this is not dangerous, it's not that tasty, so you might want to elevate the Lego candles by putting them on a stick. It also makes them less likely to fall over, if not 'stuck' in gooey icing.

You can do this by placing half a cocktail stick into the other end of the mould - and then pouring the wax, as shown earlier. If you really wanted to be very organised, I guess you could use aluminium foil to create wax catchers around the cocktail sticks...

Step 7: Other Lego Pieces May Apply...

I'm really quite impressed by the detail which the Sugru mould picks out - you can see with the Lego bricks, that even the Lego logo is visible!

One thing to appreciate is that the 'back' of these moulds for both the Lego figure and the brick, are 'sunken' and are not that well defined. However, for most people, it's the front that drives the impact (I've had only good reactions to giving both Cakes and Lego Candles to people!) With that said, if you really do want the 'back' as well cast as the front, then you do need to follow the original guide - and make a 2-part mould to fully define the front and the back. Have fun either way, but I think this is great as a simple introduction to casting...

If you've enjoyed it, please vote, tweet, like, etc. And do post any images for 'I've Made It!'.



Some might say it's fate, but after googleing* more about Lego out of curiosity, I realised that it also happened to be Lego's 83rd Birthday today (10 August 2015) too! So here's to you, Lego, thanks for being the reason I (and loads more people) got into Design and Engineering - you rule!!
*Check out this inspiring, moving and lovingly created
documentary on Lego too!
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