Using plexiglass (PMMA) for molds?

[wilkas]

Any comments about using plexiglass (PMMA) for molds? Can it withstand paraffin heat? Does it react with paraffin or other components? Any difficulties with candle release?

Edited November 28, 2014 by wilkas

[Scented]

I had some a long time ago. The fragrance eats at the surface and I found them to be very difficult to clean. I got maybe three or four uses out of the molds, if I was lucky, before I just grew plain weary of them. 

Edited November 28, 2014 by Scented

[wilkas]

What if wax formula will be fragrance free? Would paraffin, stearin, microcrystaline, color or Vybar eat it? Maybe any suggestions for replacement material that is easy to work with (cutting, drilling, edge smoothing, glueing)?

[Scented]

I didn't make my candles fragrance free and they weren't heavily fragranced either, I can tell you that, because I used these in my early, early days. 

It is possible that it is the heat that just makes those molds an eventual bear to work with. I just don't like plexiglass and it wouldn't work with the way I do my candles now either. I'm not a one color maker so to say and I'm not really a layer one color on top of the other type of person, but I gravitated to that after a few years. 

Before you invest in a whole bunch of plexi molds, buy one and try it out. I will tell you the minute it gets scratched inside it will become harder to use. You can't really heat it and clean it. For me though, just wiping it w/ a paper towel, because I would have to soak the candles in a cold water bath to help with candle release at the time, scratched the mold. 

This is just my experience with them. Try one out for yourself. Only one before you make a huge investment.

 

I would rather go with two piece plastic molds any day and trim the seams and polish the candle than to mess with plexiglass again. I will, though, stick with my aluminum molds where I can do practically anything in that mold and those molds produce very little trouble for me. 

Edited November 28, 2014 by Scented

[Guest OldGlory]

I love aluminum molds too. The first few times you use them they can be difficult to release, but after a few uses, no problem.

Is there a reason you want to use plexiglass?

I wonder if the glue in the seams would be effected by the hot wax?

[Scented]

No the plexi molds are sturdy as far as form. They offer the clear aspect of seeing your candle, but otherwise they become problematic when they get dirty and are hard to clean because you can't scratch the inside of the surface. If wax sticks in there, good luck getting it out without damage. I've had both cylinder and square plexi molds. I'm telling him not to invest in more than one and to try it out, because I didn't. I probably still have the molds. It would be very rare of me to throw anything away, but these type of molds really overtested my patience. 

[wilkas]

Reason is that I want to make my own custom molds. I dont think I could find aluminum to make molds let alone machine it.

[wilkas]

--mobile glitch

Edited November 28, 2014 by wilkas

[Jcandleattic]

I agree with Scented. Plexiglass molds are just not worth the effort. At least in my opinion and experience they aren't. Unscented candles would probably work in them, but I have a hard time finding a steady market for unscented candles, and IMO they were more difficult to unmold than scented ones, but the scented ones, as others have stated ruin the molds within a few uses... 

 

Do you have access to silicone where you are? You could easily make silicone molds that hold up well to both heat and scent... 

[Scented]

Yep, silicone would be a dream. Expensive, but a dream for what you want to do. There's nothing wrong with the two-piece plastic molds either if you can get your hands on them, but in Lithuania, I do not know your suppliers. Two-pieces though are uncannily a pain in the a** to deal with the seams, but eventually you get good at it. When silicone came along it was heaven on earth. 

 

 

That all said, there are shapes that might appeal to you in the tin area of molds too. You cannot do as much with them as you can an aluminum one, but aluminum doesn't bend into too many great shapes. 

Edited November 28, 2014 by Scented

[wilkas]

Am thinking about something like this or more complex: http://zuzutop.com/wp-content/uploads/2009/10/candles1.jpg

[Scented]

So I would look at a breakaway tin mold probably and use mold release on it. That would take a lot of silicone to make it sturdy. I'd almost want to tell you glass, but glass will eventually shatter, but plexi I think will disappoint you. You can try it if you want, but I think you'd still be sinking too much effort into something that won't produce enough results for the investment. Something like this would require quite a bit of silicone just to make the base and provide enough support it wouldn't wilt on top. Rubber (must be flexible) is a possibility too, however it will need a strong support system too. 

Edited November 28, 2014 by Scented

[wilkas]

There is local plastics producer making all kinds of plastics not only plexiglass, and they have scrap pieces at low prices. If I only knew which one to pick. I think that teflon impregnated adhesive foil could help me here if everything else fails.

[Scented]

You need a plastic that would withstand the shock of heat, just call it 200+ and then cold as you might want to get the shine with a water bath in that mold. It will be like plunging one extreme into the other. Tell your plastic person that and what you want to do and see if they can help you. I don't know the type of plastic we're talking about, but most of what I have has a coating, a shiny coating. However, I have to use mold release with them too. You would need that with tin also. 

 

This isn't going to give you a good view of the molds when I say two=piece plastic, but ... it's close. Mine are a hard yellowish/cream color. They fit together, then clipped. There's usually a place for a wick to rest that you tape down. Others you twist around a rod. 

 

http://www.candlemoldvault.com/western-candle-molds-c-34/?zenid=95fd99a80000cc4f5209c45d526ac7b0

Edited November 30, 2014 by Scented

[wilkas]

Have talked to plastics person and they told that they were using polyacetal (POM) to make candle molds. Its a pitty that this industrial plastic is ~3x more expensive than plexiglass and also no scraps available.

[Scented]

It may be a blessing in disguise though so now just to find you something else that will work, only better!! Aluminum is still ideal (ducking) and I wish silicone wouldn't be so dang expensive to make what you want, but it will be. So here's a thought ... a combination kind of mold. One that gives you the shape, the other that allows you to say change your surface looks ... that's where silicone might work its best magic. So if you could get someone to solder together a box in plated tin that would say have hinges or latches (seal any openings when making the candle so it won't leak) and be big enough to lay textures inside that would somehow stick to the surfaces you could have some really cool and long lasting molds. Just saying. I dream big, so take my idea for what it's worth. You'd have a better looking candle than the link you posted IMO.