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Raising the MP of Paraffin


Jaye
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Does anyone have any ideas on how to do this? Vybar 103 maybe? I tried my hand at making a forever pillar yesterday... and failed miserably! It looked wonderful, and I was so proud of my first attempt... but after about an hour of the tealight burning, the wax around the votive holder began to melt, the side cracked, and wax leaked out the side. It was a chunk candle - chunks made with 4045H and overpour made with 4045H with a little (1/2 TBLSP P/P?) Micro 180.

Any help is very much appreciated! :smiley2:

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Vybar is a very effective wax hardener. Increasing the hardness of the wax may be the best you can hope to accomplish, but that's different from increasing the melt point. If the wax is melting, it will still melt. It just won't sag as much.

Small amounts of additive don't have a very big effect on the melt point of paraffin. I suppose there are additives that would have a useful effect in larger quantities, but they would be difficult and expensive to use that way.

I doubt that stearic acid is the answer. It's true that it's used to prevent wax from sagging. In that respect, 10-20% stearic is equivalent to very roughly 1% concentrations of other additives. However, stearic doesn't raise the melt point either. In fact, it lowers the melt point of paraffin.

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I think you may be right Top, because even with the addition of stearic AND Micro 180... it still melted. I think I'm just going to have to bite the bullet and buy some hurricane wax. The pics below were taken an hour and a half after lighting the tealight.

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attachment.php?attachmentid=19015&stc=1&d=1267215367

attachment.php?attachmentid=19016&stc=1&d=1267215367

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I thought it would raise the MP of paraffin with a MP lower than it (150-ish):

From: http://www.howtomakecandles.info/cm_article.asp?ID=ADDIT0003

How and when to use Stearic acid?

In our domain, candlemaking, Stearin (that's how I'll call it from now on) is available in powder or granulated form, has a pure white color and feels a little fat when you touch it. Its melting point is 158°F.

It is mainly used:

to raise the melting point of the paraffin it gets mixed with (logically, one part paraffin with a melting point of 130°F mixed with one equal part paraffin with a melting point of 150°F results in a mixture whose melting point averages 140°F). Adding a substance with a high melting point - like stearin - to paraffin has a tendency to raise the average melting point of the mixture,

on the contrary, to lower the melting point of a high melting point paraffin,

to give the colors a pastel shade,

to "harden" the candle. Stearin can act as a hardener,

to make the candle burn longer (due to the fact that the melting point is higher).

also http://www.happynews.com/living/create/using-stearic-acid.htm

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Well, you can't believe everything you read. :)

Mixing two different substances doesn't give you a predictable melting point. Many combinations of substances form a eutectic with a melting point lower than either of the two components. For instance, there are metal alloys with a lower melting point than either of their component metals. Adding salt to water doesn't increase its melting point, as you probably already know from sprinkling it on your driveway in the winter.

Stearic acid and paraffin form a eutectic as well. The attached chart shows the melting point of paraffin/stearic mixtures based on two different grades of stearic.

post-710-139458463911_thumb.jpg

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Well, nice, thanks for clearing that up :). I'd only heard eutectic as regards SnPb solder. Also explains why I had a no stearic 3 wick sag, but not blow out, and a 3% melt right over. Well, could be other causes ... OTOH, 10% does make my tapers not drip. Not sure why, somehow slows down how much melts vs is consumed, and don't see how that works if MP is lower. Curious.

Hadn't though hardness and MP could be separate. Guess it makes Paraffin more like palm wax.

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Hardness and MP are completely separate. Hardness is measured by how far a needle penetrates the substance when applied with a certain force. MP is measured with temperature cooling curves, or if there are no cooling curve flats, by the temperature at which it drops off a thermometer (the "drop melting point"). There is no relation between the two. A 130-MP paraffin can easily be much harder than a 140-MP paraffin. Add a little Vybar and it will become even harder at the same melt point.

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Hardness and MP are completely separate. Hardness is measured by how far a needle penetrates the substance when applied with a certain force. MP is measured with temperature cooling curves, or if there are no cooling curve flats, by the temperature at which it drops off a thermometer (the "drop melting point"). There is no relation between the two. A 130-MP paraffin can easily be much harder than a 140-MP paraffin. Add a little Vybar and it will become even harder at the same melt point.

I thought they were one and the same, too. A natural assumption would be that the harder the wax, the higher the melt point. After reading your explanation though Top, it's all starting to make sense. Slowly but surely!

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When you notice a difference in the hardness of paraffin wax, that's because of its composition rather than its melting point.

Paraffin container blends are composed to a significant extent of materials other than what you'd think of as plain, ordinary paraffin. They are concoctions of ingredients, and it's their high oil contents in particular that account for a lot of the softness.

The same is basically true about plain, straight slab paraffins, but it's more subtle. The straight paraffins that candlemakers normally deal with vary somewhat in hardness, but at room temperature there's no connection with the melting point. Their hardness is determined by what type of paraffin molecules are in the material and whether it's narrow-cut or broad-cut paraffin or some kind of blend. That's what accounts for the differences in hardness, brittleness, mottling and whatever.

As far as stearic acid hardening paraffin is concerned, stearic has been used for ages to keep molded paraffin candles from sagging as the wax gets warm. We know it works for that, but I'm not sure specifically why. It might indeed be hardening the paraffin, but I've never actually seen penetration numbers showing that it does that. Maybe it works for some other reason. But what it definitely doesn't do is raise the melt point--that's a very common misconception.

Edited by topofmurrayhill
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