Sinkholes

[thewaxman]

Hello, new to candle making, and everything has been going fairly well except a problem I keep having with sinkholes developing by the wick during the cool down period. They even appear after a second pour. I have been researching the subject online, and there are many suggestions on how to deal with this problem, so I was hoping someone on here might have an understanding as to what works best. One suggestion that I fancy is to allow the candle to completely cool before the second pour, but to be sure and not re-pour past the first pour line. My other re-pours are done after 1 hour of cooling, which is the time recommended by the book I use as a guide.

[topofmurrayhill]

Hello, new to candle making, and everything has been going fairly well except a problem I keep having with sinkholes developing by the wick during the cool down period. They even appear after a second pour. I have been researching the subject online, and there are many suggestions on how to deal with this problem, so I was hoping someone on here might have an understanding as to what works best. One suggestion that I fancy is to allow the candle to completely cool before the second pour, but to be sure and not re-pour past the first pour line. My other re-pours are done after 1 hour of cooling, which is the time recommended by the book I use as a guide.

Hello! To be helpful, we would need to know what sort of candle you're making, and with what wax.

[Guest OldGlory]

A picture of the problem would help as well

Edited to add:

Some people describe a slight dip in the surface as a "sink hole". Others describe a relatively smooth surface with a small hole that goes pretty deep as a sink hole. Still others refer to the cratering effect on the top of a soy candle as a "sink hole". To help you correctly diagnose what is actually happening and fix it, we just need to know what you are actually experiencing.

Edited June 15, 2015 by OldGlory

[Jcandleattic]

Yes more information would be helpful. 

Are you poking relief holes before your second pour? At what temp are you pouring your original pour and then pouring your repour? (the type of candle and wax would come in handy here) 

[kandlekrazy]

Also what wicks, are they flat or round.  There are a couple of things that might help out but really need to know what wax. 

Pouring temp is huge especially with soy waxes, pouring very slowly when filling the container, actually pouring the wax down the wick & allowing the wax to completely set up before your 2nd pour.

If it's pure soy, you may not need a 2nd pour unless you poke relief holes.  I use a heat gun if my tops aren't smooth.  If you see bubbles with the heat gun, you know there is a hole and need to poke where

the bubble(s) are and repour.

[thewaxman]

It is a 8oz. jelly jar container, using 126 melt point paraffin wax, 1/8 vybar  260, 1oz fragrance, and zinc-core wicks. The candles in the pictures were poured at 180 for both pours. My last two candles which are not shown here, were poured at 190, so I made a 10 degree adjustment for these, but it doesn't seemed to have helped. I have been poking relief holes, but as an experiment for my last two I did not, but it did nothing to help with the sinkholes. The holes are rather large, and occur near the wick.

[Guest OldGlory]

Thank you for the picture, it's much more clear now!

Your surface sank in the middle because the outside of the glass cooled/hardened faster than the inside/center. That also happens with paraffin pillars.

You just need to do a repour, only to the level of the first pour. You can poke holes if you want but I don't think it's required since it is a container. (I don't make paraffin containers so someone else may have more information for you.) Just keep a little extra in the pouring pot and reheat it when you are ready to fill in the dip.

[grama]

That happens with paraffin, sometimes more and sometimes less.  Don't need to poke relief holes for a container candle.  Just top it off with left over wax that is heated a little hotter than the original pour.  Don't know anything about the wax you are using.

[PhoenixFyre]

Yep, been there, done that (and still doing it, lol). My straight paraffin container candles do the same thing in an 8 oz jelly jar. I don't have my notes in front of me, but I think I poured a little cooler than 180...I think around 175 mark...and I would also zap my containers with a heat gun before pouring. It would help a little with the sinking, but I still always had to do a second and sometimes even a third pour.

[thewaxman]

Thanks everyone for the responses, I do really appreciate that. Like I mentioned above, I have been using this candle making book as a guide, and the book explains that the second pour should be done 1 hour after the original pour. Next time I will follow the general consensus concerning this topic, and do the second pour 24 hours afterwards. Any advice I've gathered about this problem has been implemented e.g. heating in oven before the pour, spacing candles while cooling, cooling on wire rack, poured at cooler temp, and tapped jar after pouring. Temp at the time of both pours was around 75 degrees, so only a couple of degrees shy of the recommended pour temp.