If your candles are not behaving as you would like, take heart. I am sure the problem and solution can be found here.
Many people make candles that look absolutely fabulous in their native state, BEFORE they are lit. All sorts of issues can occur when a candle is made and most of them involve the wrong wick size. The correct wick will be one that has the right size burn pool, does not drown before time and has the right sized flame. There should not be a lot of black smoke or soot created and should burn well through the life of the candle. Test burning candles is the only way to truly know that it will burn well from the initial lighting right to the bottom. Having the top burn correctly does not mean the whole candle will burn the same way. Each candle maker should test their wicks in their own glassware with their own additives to ensure they have the right choice for their own application. Colouring choices, fragrances and different additives can all make the candle burn differently, so how you choose to create your candle is individual and so should your wick choice. Options given on this website are guidelines only and you should adjust your wick size according to the results of your test burn.
1. The first problem we will look at is the melt pool as this determines the flame size and burn capacity of your flame. This is directly linked to the size of the wick. Too large a wick will melt too much wax so making too much fuel available to the candle to burn. Pillar candles will have too much heat applied to the walls and will melt them also, causing them to collapse. The excess heat will also burn off your fragrance rather than release it, so your candle is not so aromatic. The greater need for oxygen will cause incomplete combustion and therefore soot production from the unburned carbon. Mushrooming is also a product of too large a wick, or possibly the wrong wick type altogether. A build up of only partially burned fuel caused by too much wax feeding the flame leaves solid carbon build up which rolls into the form known as a "mushroomed" wick.
Then again, if the wick is too small it risks the possibility of not melting enough wax to fuel the candle, so resulting in a small flame, or not burning it quickly enough to not drown itself in a pool of its own making. Another outcome of a wick too small is known as "tunnelling", whereby the candle burns down the centre only, leaving the majority of the wax untouched.
Work in progress.... more to come