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Electric screen washer heater on the cheap

Crispin

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Not being able to tinker (or fix) on the 150 has me bored. I've long wanted the heated screen washer gadget but refused to pay the silly money for the Power shot. This got me thinking - how to make an electric one cheaply.

You need a source of heat: £5.00 on ebay and two glow plugs from a pug arrive on my doorstep.
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We need something to hold the heat: £2something from ebay and a 25x50x100 aluminium billet arrives on my doorstep.
20130120_204316.jpg

We need something to control the heat: £4something and 20 thermostats arrive home Hong Kong
Disc-Thermostat-KSD301-P-121A-.jpg


Part-finished product:
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With the help of Tony, his drill press, tap set and a shed which would cause an Eskimo to say "FFS it's cold in here", we knocked together the start. (Thanks BTW!)
The two glow plugs are tip to tip. We drilled all the holes as small as possible to minimise the gap between the glow plug and the ali block. While there are parts that are touching, there are air gaps. I was thinking of heating the block (a lot) putting in a drop of molten lead in them and quickly screwing the glowplug back in.

I still need to drill the main channel through the block which will be a ±12mm hole, tap both ends and put a threaded hose barb in.
Another idea I had is to drill two 6-8mm channels next to each other and use it in a U-turn way. I prefer option one as it gives you a small reservoir of hot water.

Electrically, the thermostat switches off at 45c and will drive a relay to turn the glowplugs on and off.

Does it work? Well, the block of ali was left outside and cooled to 9c. Turn it on and it reached 20 degrees in about 10 seconds. Plenty to melt the frost on the window. About a minute later it was 45c. :)
In under two minutes it was 70c and my desk started to smell like hot paint. :shock:




Another, maybe simpler, cheaper option would be a round ali bar, plugs at each end and copper tube wrapped around it.

Assuming you have a set of taps, you could knock this together for £10-15. I've not seen inside the power shot but guess it's not much different?

The longevity of the glow plugs might be a problem but at £2.50 each, 30 seconds to swap one, it's not the end of the world.
Instead of a relay to turn them on and off, you could drive them with something cleverer and ease their life.

I'll be getting the rest of the bits this week and should finish it - will update.
 
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interesting idea, you must be very bored :lol: I think the bar with copper pipe wrapped round it idea would be more efficient and less parts / drilling and tapping involved and you could wrap it up in some insulation. What's the current draw like on one of those glow plugs?
 
The down side of owning a 150 eh?

Gra.
 
I've bought some copper tube and a round piece of Alu to try that as well.
Another idea I had was to use something like Roger's design. Fix the glowplug to the one end (either by nut or bash the copper to crimp the nut on the plug) and then fill the cavity with molten lead from the "spare" flashing on my neighbour's roof and the cap the end. It too would work pretty well. Could you even make a hybrid of the two :dance:

The draw per plug is (apparently) about 14A. Unfortunately the thermostat is 5A rated hence the need for the relay :(
 
Crispin, lead freezes extremely quickly and you may not even get the block hot enough to stop it freezing as you pour it in. You can try, but be prepared.

Nice work btw. My £4 plastic pipe heat exchanger solution is still working well. I know it's not hot from start up, but within a very short time, it's producing warm water on the screen.

Let me know if the CJ workshop can be of any help.

Chris
 
I remember making my own sinkers from car batteries many many moons ago (before I knew what dangerous was) Baked-bean can + fire + lead = fun :)

One thing I was thinking about, not sure if your lathe skills are up to it though :)icon-cool:) is to take a round alu bar and cut a spiral groove into it to seat the copper tube for better contact with the hot stuff. Does your lathe have the auto-feed thingy (I remember doing it at school)
If so, I would certainly take up the offer :)
 
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Yes it does. I can cut that sort of thing. I'd probably need a round tip on the tool to cut a snug groove. I'd also need there to be some spare length on the rod so that it could amount in the chuck. But essentially all you are doing is cutting a thread.

Chris
 
Crispin you make me laugh! Brilliant project :) hope it all works out
I've got Chris' plastic hose design and it works great too..
 
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