Intro: Enhance Your Ceramics With Sugru (for a Heat-proof, Non-slip, Non-scratch, Decorative Base)
Why Combine These Two Materials?
People have been working ceramics for millennia, but modern super-material, Sugru, (a mouldable silicone adhesive) is just a few years old - so what better thing to do than try to work with both of these seemingly very different materials and see what happens. This is the journey of experimentation of a few weeks at Turning Earth Studios and playing around with pots designed with Sugru in mind. (This is not a pottery lesson, check this out if you want one.)
The first part is perhaps a bit detailed in that it shows you how to design ceramics to work best with Sugru, but if you just want at good way to stick Sugru to the bottom of your pots, just skip on to the next section.
Pronounced 'sue-gru', Sugru is a 'mouldable glue' made from silicone, so to a ceramicist this is a fantastic material in that it can be modelled/worked with pretty much like clay, but it has a few notable features:
- sticks to fired ceramics/glass (forms Si-O bonds)
- does not need to be fired itself
- does not shrink (more useful than it sounds initially)
- it's rubbery, so protects pots from shocks/knocks
- it's soft, so does not scratch stuff
- thermally insulating (up to ~180C)
- sticks other things like metal and plastic.
- has a high 'green strength' - so does not run
- is pH neutral, so will not corrode the surface (though it might react with some very delicate lustre glazes - though I have not tested this yet).
- comes in lots of colours (which can be mixed) - so a bit more creative than just Epoxy Putty.
- is waterproof
SECTION 1: How to design pots for a Sugru base (optional).
SECTION 2: How to fix Sugru to the base of a pot (with/out groove).
SECTION 3: How to create colour in-fills with Sugru.
SECTION 4: How to further personalise the patterns.
SECTION 5: Other experiments.
- I do work for Sugru, as Head or R&D, but this is not intended as a plug to sell product, I just think it's pretty cool stuff to use. Similarly, the views, comments and ideas here are my own and do not necessarily reflect those of the company, etc.... and besides, it's my weekend.
- Although many silicone 'bakeware' products are often certified FDA Approved and Microwave Safe, Sugru (made up of silicone but of a different formulation) is a new material and has not yet been certified in either category yet. As such I would stick with non-microwave and non-food *contact* related applications at present. E.g. using sugru at the bottom of the mug is safe but on the inside surface of the mug is not recommended. However, it is Dishwasher Proof, see technical info. (MSDS & TDS) available here, for more details.
- Please give a vote if you enjoyed this. Thanks!
Step 1: Section 1: Part 1: Create Grooves for Sugru
This part is optional - Sugru will stick to ceramics without this whole section, but as with any adhesive, the more you can make it 'key' to a surface the better, and if you are 'trimming' a pot, this is a simple feature to incorporate.
- 'trim' the inside of the pot first - you want the base to be the last thing on the wheel.
- using a stylus, or a hole-borer, scribe a groove in the base.
- if you are feeling extra-fancy, you can 'dove-tail' it to make it an even better key.
- trim the glazing edge, base and sides and you are ready to go!
Step 2: Section 1: Part 2: Apply Handles (also With Variations)
Tips For Applying Handles:
- Clay shrinks between 10-20%, so you want the vessel and handle to be similar in dryness/moisture content. I suggest you leave them in the same sealed bag for 24hrs if in doubt. They should feel 'leather hard'.
- I use a craft knife to score (about 2mm deep) the sides of vessel ready for the handle.
- I collect the clay 'run-off' from throwing pots in a jam-jar, which acts as a perfect 'glue' to stick the handle on with. (The trimmings in water also work well if you forgot this).
- I use a wooden tool to 'burnish' the handle and the vessel together. I try to leave a small 'radius' between the join, which spreads the load better and avoids cracking.
- I use a 'metal kidney' to finish the curves of the handles off and remove any 'sticky bits' that have left a rough surface.
- I also gouged out the inner and outer regions of the handles of a few pots, with the intent to fill them with Sugru. I wanted to see if this was more comfortable (something which clay does not always afford different users) and also if it created a different design element I had not seen before.
- I was also aware I was going to play around with thermochromic pigments and Sugru, so this would be an interesting visualisation of the heat spreading through the handle..but that's another story.
Step 3: Section 1: Part 3: Glazing & Clean-Up
Once you have your bisque-fired pieces back, you are ready to glaze them. Pay close attention to cleaning as much glaze out of the groove as you can - you don't want it flowing out mid-firing and sticking your vessel to the kiln-shelf! Touch-up any glaze defects (tongs marks, etc) with a brush.
Cleaning Glaze Tips:
- use a natural (as oppose to man-made sponge) to wipe glaze (and throw for that matter), as it leaves less marking and also does not disintegrate as easily.
- when wiping glaze off, first 'scrub' the bulk of the glaze off (i.e. your motion is in circles and back-and-forth).
- on the last few wipes - only do this is in one wipe, then rinse, squeeze out. Repeat. (if you don't rinse, it simply re-applies the glaze). roll your hand and the sponge forward as you wipe, to expose a new area of the sponge as you go - it gives a cleaner wipe and a quicker finish.
Step 4: Section 2: Part 1: Preparation of Base
1. You will need:
- 1-3 5g Packs of Sugru, depending on coverage*
- Scalpel to trim excess (and open Sugru packs)
- Spudger Tool (or coffee stirrers if you don't have these).
- Small sheet of plastic (must be clean and free of large scratches) to 'buff' your Sugru on.
- Small cup of water, with a drop or two of liquid soap/detergent.
2. Cut a coffee stirrer into a point ready for working. Scrape out any debris in groove.
3. Give the pot a wipe with a lightly dampened cloth to remove dust/dirt, which will impeded the adhesion of Sugru.
* I've shown the most economical application of Sugru here, but you can of course apply it over the whole base, assuming your piece is worth it! It will be more durable the more you can cover.
Step 5: Section 2: Part 2: Apply Sugru to Base (Groove Is Optional)
- Open Sugru. Knead it for a few seconds.
- Roll-out on plastic sheet (or clean paper will do).
- Press into groove, reshape and repeat - working it in as you go around.
- Use the coffee stirrer to scrape the excess from the outside.
- Repeat all the way round (don't worry about the inner rim yet).
Colour selection is very much up to you. I've used a neutral colour here, which is not white (which might show the dirt in use with coffee). You can of course make a bigger statement with more dramatic choices and mix your own colours. (Sugru's colour does not change when dry).
I'd recommend using Kuler if you have trouble picking colours to compliment/contrast your piece.
Step 6: Section 2: Part 3: Buff-Out the Sugru-Base
- Apply some water/soap-mix on the plastic sheet.
- Press the vessel down firmly, but evenly. Keep pressing down and turning around each press.
- Look for any bubbles/missed areas in the base. If you need to take a little excess and re-apply you can do so, but work it in to the surrounding area.
- Trim the excess off with a scalpel. You can see I'm resting my pinky on the base as I go, this keeps the cut angle steady. I turn the pot round as I go, rather than the blade.
- Cut the inside ring - again using the pinky to stabilise my hand.
- Use the sharpened coffee stirrer to clean out the inner area. (If you do slip - just re-apply and start again. Note - Sugru is ok to be worked like this for around 15mins.
- You may have some Sugru left over... Go use it on something fun.
- Smooth-out the Sugru with your finger (dipped in water first).
As you can see from the last image - there are more advanced variations of this. Sugru is dry in 24 hours, and you can add new colours and re-work parts, which the following steps demonstrate. You could end up liking the base as much as your pot!
A note on 'heat proofing' - Sugru (i.e. silicone) is an insulator, it will reduce the transfer of heat from one place to another, but this is not a guarantee that if you make a red-hot cup of tea in your Sugru-based mug, it will not leave a mark on your antique table top. From my limited experience, the thicker you can apply it, the better (1-2mm is good). However, I can say it does not leave any more 'rings' on my varnished wooden work table, so it must be doing something right, but no promises.
Step 7: Section 3: Insetting a Second Colour
- After 24hours (or longer if you can wait), I mixed up a darker colour of Sugru and packed it into the inner recess of the base.
- I used a larger lolly-pop stick to level it off. I then 'buffed' it out on the plastic sheet again. I needed to go back-and-forth with this process a couple times to get it fully level with the brighter red coloured Sugru from before.
Step 8: Section 4: Patterned Sugru Base
Clearly this uses more Sugru than the 'rim-only' variation, but it offers some opportunity to make some interesting patterns, of even if you wished, you could inscribe your initials, potter's mark, messages, etc.
The black Sugru was applied first, buffed then inscribed with a spudger to make a pattern. Then left to dry.
24hours went by, until the Sugru was cured (did not leave a mark when gently pressed with a finger-nail). The grey Sugru was then worked into the details with a lolly-pop stick (tongue depressors are even better if you have them). At first you can be more focussed on packing the Sugru in the cracks and crevices, but after that, try to scrape off the excess.
You need to aim to get this done in under 15mins to avoid the Sugru starting to cure and hence not scraping off smoothly.
Step 9: Section 5: Other Experiments
Above are some variants of colour and form. I don't usually make such white/minimalist-looking pots, but this was a good way to objectively review the process. It also allowed me to experiment with different positions of the glaze - up the sides, in the handles, etc. I also experimented with Thermochromic Pigments (colour changing with heat), so that the Sugru becomes an indicator of changes in temperature.
Thanks for reading. Please give this a vote if you liked it, and also check out Design Modelling for similar explorations of materials in Design.
Second Prize in the