suggestions of the prevention of bubbles

[slv]

Hello all. I am new. Does anyone have any additional tips on how to prevent bubbles from showing up in the finished candle? I teach candlemaking lessons and my students' candles are judged. Bubbles unfortunately put the student at a definate disadvantage. Since I am paid well to teach them, I feel responsible if they end up with a less-than-perfect candle. The beginner's division is the hardest because it is required that they make a simple pillar candle. I'll add that I find it amazing that I can make 30 pillar candles, while using the same exact procedure on every one, and some of the candles come out perfect while others have their share of tiny bubbles.

I do everything I have learned thus far to prevent them. We add vybar (which is the biggest aid thus far), we pour the wax at 190 degrees. We pour it slowly down the inside of the tilted mold, which is metal. We tap the sides of the mold, wait 1 minute and insert it into a cold water bath...

Any other suggestions or is it up to fate at this point? Someone once told me that the weather (the barometer) may play a part. Is that true?

[Scented]

Try pouring at 180-185. Speed of pouring (pouring too fast), dirty molds, rapid cooling can all play a part. If you look down the side of your molds you can see them. They're shiny bumps. You could run say a chopstick along the inside wall after pouring. That might dislodge them too. I'll usually hit my mold with a heat gun if they're too stubborn and won't come up.

[slv]

Thank you for your response.

Would you suggest that I do not use the cool water bath, thus preventing too rapid of cooling? Somewhere I had read that a water bath may aid in the prevention so that's why I started doing it.

Also, I have a heat gun and could easily begin using it on the sides after pouring. It's worth it if you think that could help.

[Scented]

You can still do the water bath. If anything a water bath tends to make candles more shiny. Just don't pour and stick it in the bath till you've checked for bubbles.

With the heat gun, I use it only aluminum molds. Aluminum seems to take the heat better. If you use it on a tin mold, keep it away from the seams. Don't use it on plastic or acrylic or polycarbonate molds though.

[sthncmft]

I know that a water bath will give the candle a more shiny finish, but I've never heard of it preventing air bubbles.

[Candle Kitty]

It's one of those things that you need to get the timing down, once the wax begins to harden, there's no chance of any more air bubbles forming but you've got to double check to make sure you don't have air bubbles to begin with or you'll end up with pinholes.

If you can do a slow pour at the right temp, check the sides of the mold for bubbles, use a heat gun to release them or run a chopstick like Scented said and then drop it into a bath, you're pretty much guaranteed no pinholes. I actually softly tap the sides of my molds AS I pour, then place it in a bath and I've yet to get pinholes in sleek candles.

[fredron]

I disagree with the water bath entirely. The longer the cooling process, the more time for bubbles to rise & dissipate. I use a cooling box made from foam board insulation to retard the cooling, and bubbles have never been a problem for me. Pour hot & cool slow.

Fredron

[Scented North]

I find warming the molds while mixing the wax helps prevent those pesky air bubbles and pinholes. I usually warm to between 100 - 125 degrees, then after pouring, tap the the sides until I don't see any more bubbles. I don't use a cold water bath as I work in the basement where it's nice and cool year round.

[Dee]

I have also found that warming the molds helps. You have to be careful not to make the molds too hot though. I just take the chill off them with a heat gun so no tiny pieces of wax stick to the sides of the mold on contact as you pour. Practising with votives first, helped. I usually don't use a water bath, but was once also asked to teach classes and know that you are limited for time and need faster cooling.

[SatinDucky]

As you can see, this is like everything else about candles. What works for some, doesn't work for others. IMO, air bubbles and pin holes are caused by different things so it really depends on what the "bubbles" look like. The type of mold also makes a difference.

The atmosphere can make a difference, like fingernailing, but not likely to cause bubbles...

[ChrisR]

I can honestly say that in my 8 years of candlemaking, the only pin holes I got on my pillars was from a dirty alum. mold or incorporating too much air in the melted wax when stiring in my FO. I work in my basement (warm in summer, cold in winter) and have no problems with cooling them on my work bench overnight, no insulating, no heating molds, no water baths. I melt my wax to 185, add FO immediately, stir about 30 sec. or so with a chop stick and pour. It may be my wax combo also, but knock on wood, never a problem!!

[Sharon in KY]

Maybe heat molds in hot water, leave in water and after the air bubbles are all out then put ice in water to cool it off quicker. Maybe a presto pot with a spigot and the french fryer basket to hold the mold/molds. Never done it but sounds good to me.... Can you tell I'm not a pillar master?

[Candlemwoman]

Are you pre heating your mold? Think of it this way, you are pouring a 190 degree wax in to a 40 to 45 degree mold. This can cause not only the bubbles but also cold shock.

Try heating your molds, and letting it cool on its own. I agree that if it is cooling to fast it is not having time to for the air to release, there trapping it in the candle.

Good Luck