Cheap and very easy greenhouse heating

[karlbrown78 10]

Hi all, recently I have seen allot of people using the tea light method to heat there greenhouse, although this is a good idea they only last for up to 8 hours, I want to make my own candle using a baked bean tin, the only problem I have is I want to use scrap candle wax because it is very cheap, but it is scented and want to know if this scented wax will affect my young seedlings, anyone that know the answer to this please reply.

 

---------- Post added 22-12-2013 at 22:42 ----------

 

Link to youtube video for this method -

 

Thanks

Edited January 11, 2014 by karlbrown78

[Janus 28]

Hi Karl,

I watched the YT clip and found the idea interesting while being simple and effective. I thought the idea of the terracotta pots to retain & radiate heat was quite ingenious-good idea.

 

Regarding your question about fumes, I would guess it will not be a problem. I have a large candle in the house and the outer 6mm of it is scented, but it gives off virtually nothing in respect of fumes.

 

Where are you going to get the wax from?

[karlbrown78 10]

I've found on EBay a couple of people selling scrap wax by the kg, 1, 4, 10 or even 25kg, this wax is far cheaper than unscented. I've worked out that if I make it in a tin-can baked bean size the burn time should be around 3.6 days and hold around 316grams of wax, so from 1kg I will get 3 tins full with 11 days burn altogether, this gets rid of having to take a new tea light out every 4-8 hours instead i just take a new one out every 3.6 days.

[Janus 28]

That’s interesting Karl, and you have obviously thought it through. I like ideas of this nature. I got some large tomato cans from a restaurant owner, for putting my jacket potatoes in to prevent them burning when I put them in my incinerator after burning garden rubbish. If it is of help you can have a couple. They are 6 inch wide x 6 inch deep. Maybe then just replace the candles once per week?

 

I guess you will need to cut the base out of the bean cans with a can opener to help with candle removal. If you use the 6 inch cans, maybe just drill a 1 inch dia hole in the center so you can help push the candle out, and use the can again. If you encounter any problems with the can method, I guess you could use a tapered shaped mould like a terracotta pot.

[karlbrown78 10]

That’s interesting Karl, and you have obviously thought it through. I like ideas of this nature. I got some large tomato cans from a restaurant owner, for putting my jacket potatoes in to prevent them burning when I put them in my incinerator after burning garden rubbish. If it is of help you can have a couple. They are 6 inch wide x 6 inch deep. Maybe then just replace the candles once per week?

 

I guess you will need to cut the base out of the bean cans with a can opener to help with candle removal. If you use the 6 inch cans, maybe just drill a 1 inch dia hole in the center so you can help push the candle out, and use the can again. If you encounter any problems with the can method, I guess you could use a tapered shaped mould like a terracotta pot.

 

Im going to keep the wax in the can to prevent the wax from spilling down the sides, so all the wax will be burned and none waisted, once i have used one of the three I create I will make another, this way I will always have 2 ready made just incase I have any problems with one, as for the larger cans when you go over a certain diameter you have to have multiple wicks, but on that thought the use of a bigger tin with several wicks would be ideal for the larger greenhouse where a single candle wouldn't be enough.

 

As for doing my research yes I have done engineering at university so this comes in handy for working out different things like burn time etc.

Im guessing you have an allotment, just got mine 2 months ago on Meersbrook site also known as Gleedless site, if you do have allotment where is it and how long you had it?

[Janus 28]

I don’t have an allotment. Had one years ago with chickens on that I hatched in my incubator. I do have decent size gardens front & back. I’m keen on doing stuff in the garden. I’ve got 50 garlic growing in the back at the moment. I used to grow shrubs from cuttings and sell them from home on a weekend many years ago. I’ve still got quite a few bulbs to go in if I hurry up . I like unusual ones-have recently put 4 fritilliaria in-they grow about 5ft tall. Going to have a go a small Dahlias from seed this season-spectacular colours. Also got two or three walls planned for around the garden, so plenty going on.

 

I recently fetched about a dozen bags of manure from the stables for the compost heap. Also got a small wormery going in the out-house with tiger worms from eBay.

 

What are you doing on the allotment? Your shed/greenhouse combi sounds useful. How is it joined together? Did you build the shed from brick and join it to the greenhouse?

[megalithic 10]

Probably doesn't need saying but be sure to vent before you go in there, even candles give off C02. Wouldn't want to find you sideways on a tray of cabbage plugs.

[karlbrown78 10]

Theres plenty of gaps in the greenhouse to get rid of the CO2 produced from a single candle, but thank you for the concern, this will be an issue for anyone burning several candles at once, amount of CO2 wont be enough to knock you out but will be strong enough to make you very dizzy and fall causing injury.

 

As for the allotment Iv'e only had it for a couple of months, but done plenty of gardening/growing veg on my back garden, I also have a greenhouse on my back garden which is where I use the candles for propagation.

 

On the allotment I fell very lucky in getting my ideal setup, this is a brick built shed with a 3m x 7m greenhouse connected onto shed with a door leading from shed to greenhouse, the greenhouse is also half brick built.

 

Only thing that is growing at the minute is strawberry in a new bed that iv'e just dug and five apple trees and one pair tree.

 

Im going to hopefully start a youtube channel with ongoing updates, I will post link here when I have started videos.

[Chez2 10]

I've found on EBay a couple of people selling scrap wax by the kg, 1, 4, 10 or even 25kg, this wax is far cheaper than unscented. I've worked out that if I make it in a tin-can baked bean size the burn time should be around 3.6 days and hold around 316grams of wax, so from 1kg I will get 3 tins full with 11 days burn altogether, this gets rid of having to take a new tea light out every 4-8 hours instead i just take a new one out every 3.6 days.

 

I wouldn't buy scrap wax unless you know its all the same type. I made the mistake of using recycled wax from my own candles when I had a dabble at being a chandler. If the wax has different melting points it will mess up your candle shape and burn time. It will cause problems working out which wick size to use for the diameter of your candle.

[karlbrown78 10]

I wouldn't buy scrap wax unless you know its all the same type. I made the mistake of using recycled wax from my own candles when I had a dabble at being a chandler. If the wax has different melting points it will mess up your candle shape and burn time. It will cause problems working out which wick size to use for the diameter of your candle.

 

Thanks for the heads up, i'm not that clued up on candle wax so didn't know they had different melting points for different waxes, guess its back to the drawing board and I best get looking for some cheap wax from one supplier. Would it be a problem if the candles only had a diameter of no more than 3/4 inch?, also do you know of any toxins scented candles create that are toxic to plants?.

 

Thanks again for the info

 

Karl

[Chez2 10]

Some parts of the candle will melt before others, depending what the melting point of the wax is and how well it was mixed. I thought it wouldn't matter once I had mixed my melted wax but my candle didn't melt the same way as you would expect. I have only dabbled with candle kits so I'm not an experienced chandler. I'm part of a craft forum and do hear the complicated issues of matching each wax and wick type to a specific size candle. People who make candles as small businesses have to experiment a lot before they get it right. I would either use cheap tea lights or use another heating method.

 

For many years I insulated my greenhouse and kept it frost free using a fan heater. When its really cold I can't see the heat given off from candles being sufficient. Work out how many watts of power you would need for different outside temperatures, taking the size of the greenhouse into consideration.

 

Are you trying to keep it frost free all winter of to start seedlings off? I have used my greenhouse for tropical plants but don't bother now. I use a small electric propagator for seedlings in spring.

 

If I was intent on increasing growing temp of soil and air I might use the hot manure bed methods used by gardeners in the early part of last century. This would work better in a cold frame rather than a greenhouse.

[karlbrown78 10]

I don't think I will have a problem with the candle going misshaped as I am burning the wax in the tin can, and so long as the wax burns, how it burns isn't a problem, I only use the candle to keep the greenhouse from frosting over on the inside and the greenhouse is only used to propagate seeds and young plants until its time for them to go out into the allotment, the greenhouse is dual wall polycarbonate so is very insulated already and keeps out most of the cold, I only need a temperature of about 10 degrees.

 

I have used the candle method before and it work fine I just want to make bigger candles but at a reduced cost to the ones that can be bought in the shops, the idea of using scrap wax did seem a good idea and I might still try it to see what happens the biggest problem I have is I don't know if there are any effects to the plants from the scented wax.

 

---------- Post added 29-12-2013 at 20:11 ----------

 

Just a note that all the thanks for the candle heater goes to blusterdave as he was the first to show this but I cant find his video with it on, Cheers Dave.

 

If anyone wants it heres Dave's you tube channel http://www.youtube.com/user/blustardave

Edited January 11, 2014 by karlbrown78
wanted to add a few things