Why has a cavity formed?

[Chris_S]

Ok so im testing new wicks in a new sized container and iv just lit one to test burn it as this is also the first time iv ever used such a large wick and container so wide.

So first the making of the candles didnt go exactly to plan in that i used too much wax so had to improvise the holding the wick central. But have never experienced this kind of cavity. I have a few photos and will explain whats what in the pics below

Ok so first one is one iv just taken while wick has gone really weak it was going well until it had burned for about 5-10 minutes when it became clear a cavity under the surface had formed.

The second photo is when it was still burning ok but you can just about see the cavity.

The one thats had this issue is the one with the metal central device thing it was slightly touching the top of the wax but only slighly something i didnt notice until this morning when it had gone solid. Wondering if anyone knows why this might of happened and is there a way of fitting another wick has anyone successfully cored out the center refitted a wick then repoured wax to set it? If so how was this done. The way i had thought of was to use a heat gun to melt it all down again and then remove the current wick and set another in. Would this cause the fo to evaporate? This wouldnt be a massive issue as it would still give me the information i need for burning ect but is far from ideal

 

[lenarenee]

I’m just a dabbler in candles, but when a test burn results in “tunneling”, the wick isn’t right. You will either need to wick up, change types altogether, or double wick.

To test candles with less waste, there’s two things you can try. Use a cake pan filled with prepared wax, then place wicks several inches apart in it, then test all at once. This is for early tests to get a feel for how the different wicks might do in an individual candle.

And yes, you can pour wickless candles ia container, then use a skewer to poke a hole in the wax, insert test wick, and burn. Some melt the hole to fit the wick, some don’t. If they wick seems to fail quickly, you can pull it out and stick in a new one.

Candles are a lot of testing, testing, testing! And patience and attention to detail.....which is why I can only handle it about twice a year!

 

[Chris_S]

I’m just a dabbler in candles, but when a test burn results in “tunneling”, the wick isn’t right. You will either need to wick up, change types altogether, or double wick.

To test candles with less waste, there’s two things you can try. Use a cake pan filled with prepared wax, then place wicks several inches apart in it, then test all at once. This is for early tests to get a feel for how the different wicks might do in an individual candle.

And yes, you can pour wickless candles ia container, then use a skewer to poke a hole in the wax, insert test wick, and burn. Some melt the hole to fit the wick, some don’t. If they wick seems to fail quickly, you can pull it out and stick in a new one.

Candles are a lot of testing, testing, testing! And patience and attention to detail.....which is why I can only handle it about twice a year!

Its not tunneling its a cavity that formed under the top surface if the candle which is probably why it looks like its tunnelled. Iv done plenty of testing while candle making so i know what im doing but iv never come across a cavity forming under that seemingly flawless top surface only showing once burning has started. Im going to search for an apple corer get the wick out and then remelt the cavity out of it.
It was more that i needed to know what i did or maybe didnt do to cause the cavity.

Thanks for your help though

 

[LilyJo]

Yep, happened to me too!

TBH I never had a problem with holes, air pockets or anything with CB135 and once I moved to the replacement waxes it happened much more frequently.

Simple things can really affect holes (although some waxes and some batches are more prone than others) stirring too much and creating air bubbles, the pouring/cooling temperature and some FO seem to make it worse as well. My favourite testing fragrance gives air pockets every single time - no matter what wax I used!

I have cored the centre out to change the wick in the past and yes it does work but IMO it doesnt give a true test. I have a variety of containers but only test wax/FO/wick using one tin where I know the parameters - how big are these and what size wick are you using? They look like 300ml or maybe bigger?

 

[Chris_S]

Yep, happened to me too!

TBH I never had a problem with holes, air pockets or anything with CB135 and once I moved to the replacement waxes it happened much more frequently.

Simple things can really affect holes (although some waxes and some batches are more prone than others) stirring too much and creating air bubbles, the pouring/cooling temperature and some FO seem to make it worse as well. My favourite testing fragrance gives air pockets every single time - no matter what wax I used!

I have cored the centre out to change the wick in the past and yes it does work but IMO it doesnt give a true test. I have a variety of containers but only test wax/FO/wick using one tin where I know the parameters - how big are these and what size wick are you using? They look like 300ml or maybe bigger?

Advertised as 400ml but as i weigh in grams i can only say that they fitted 300g plus 24g FO. I think given how little burnt its worth a try using a corer and rewicking it. I made 3 candles in the same night but in different batches but cant think of anything i did differently wuth temps stirring ect not drastically different anyways. only major difference is that the one that had the cavity i held the wick in with a centering device which was slightly touching the top surface of the wax. The other 2 i used too much wax and had to improvise with getting the wick straight. Is there any way to tell that an air pocket has formed besides burning it? If i was to start selling these it would suck to sell one with a cavity without knowing and get a poor reputation as a result

 

[LilyJo]

Dont think you can tell until they actually burn hence the old test, test and test again - its one of my bugbears that everyone (NOT YOU!) thinks candle making is so easy, melt wax, chuck a wick and any old fragrance in and off you go - ooh I know lets start selling them! Its why social media is full of candle makers and part of the reason we stopped!! Candle making is unpredictable, technical and at the end of the day you are asking a customer to light a pot of wax and chemicals - the reason why good candle makers test EVERYTHING!

...and breathe....now I have finished my winge (its Monday, its allowed!) I will try and be more positive! Whats the diameter of the pot? I am guessing these are off the shelf wicks that may be a little short? If so you might need to make your own to get the correct length. Aside from that, the only possible difference I can see is that a different centering tool may have caused the wax to cool unevenly. Have you burnt any of the other pots?

 

[Chris_S]

Dont think you can tell until they actually burn hence the old test, test and test again - its one of my bugbears that everyone (NOT YOU!) thinks candle making is so easy, melt wax, chuck a wick and any old fragrance in and off you go - ooh I know lets start selling them! Its why social media is full of candle makers and part of the reason we stopped!! Candle making is unpredictable, technical and at the end of the day you are asking a customer to light a pot of wax and chemicals - the reason why good candle makers test EVERYTHING!

...and breathe....now I have finished my winge (its Monday, its allowed!) I will try and be more positive! Whats the diameter of the pot? I am guessing these are off the shelf wicks that may be a little short? If so you might need to make your own to get the correct length. Aside from that, the only possible difference I can see is that a different centering tool may have caused the wax to cool unevenly. Have you burnt any of the other pots?

Yes that was my third test candle each with different wicks. I couldnt tell you which wick is in that one without checking the tin and my notes. They are all raw unwaxed wicks when i bought them so i cut them all to size and waxed them ect myself.

One other thing not directly related to this is i have a bunch of candle votives i made using a wick pin and recently found out the wicks i was using were poorly burning and not giving off a good scent iv test burnt them and they seemed fine to me but got feedback that they werent burning of letting off scent i did sell some of them due to having ordered a fo specially on someones request that i wouldnt of bought had she not asked. But ended up refunding her yet other people have said they can smell them fine. My issue is more with trying to rewick them i used pre waxed wicks in them orginally and need to add my new test wicks in for new test burning but im really struggling to get them through the hole the pre waxed wicks fitted in any suggestions of how to thread them? I used a votive mould and wick pin so the hole should be big enough i got some of the new wicks in but only the ones that were very thinly coated in wax even some of them i struggled with because they are not strong enough to push through the hole. Is there a way of threading it through the hole?

Height is 77mm dia is 90mm so iv tested eco 14 eco 16, cc series wicks think it was 16 and 18 but dont know without my notes. The eco 14 is in a different scented candle but in the same tins. I did that because i realised i was better off testing with a fo i knew i had enough of as i was using one iv only got 500ml of and found one i had more of and this new one is strawberry which is generally enjoyed where as the other is more an aquired scent. Iv given about 50 candles away with feedback forms so i can maybe narrow down any issues with the votives regarding wicks and scent throw. Iv been relying on feedback because the soaps i have curing in my lounge generally overpower the candle scent or mix it up so i struggle to assess the scent throw so all i can really do is check the burning ect and hope ill get honest feedback from people iv asked to test them.

Think i covered everything there lol

 

[Susie]

Here is a video I found about cavities in candles:

 

[Chris_S]

Here is a video I found about cavities in candles:

Thank you that was really helpful and pretty convinced now that the centering device is what caused the cavity in the candle.

 

[Cherrydene soapy]

This video is really informative I hope I have shared it properly as I have never copied a video before. His channel on YouTube is great

 

[Chris_S]

This video is really informative I hope I have shared it properly as I have never copied a video before. His channel on YouTube is great

Iv just today found a shop that sells apple corers so got one and have tunnelled into the candle to get the wick out so just need to wax another wick do some melting wizardry and should be all sorted. It was more why it had happened and how to avoid it happening again i knew how to fix it. Just couldnt work out why it had only happened with that candle and none of the others. O will give the video a watch later though thank you