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peizio wont work!

Unread postPosted: Sun Apr 01, 2007 12:08 pm
Author: lukemc
ok i finally got around to upgrading my simple combustion ignitor for lantern sparker to peizio electric and the thing wont ignite!! just a few questions for those of you more experienced in this area than me

1. does it matter the placement of the spark? (i have mine on the bottem of the chamber right after my chamber fan)

2. does the spark have to be in the middle or can it be near the edge

3.does the amount of spark matter (mine jumps about 1/4 inch)

yes it sparks i can see it and yes my fuel is right please help if you can

Unread postPosted: Sun Apr 01, 2007 12:13 pm
Author: noname
The gap does matter, can you see the spark arc across it?

Unread postPosted: Sun Apr 01, 2007 12:37 pm
Author: lukemc
its kind of hard to see because of my chamber fan but im pretty it arks a bit im going to unscrew the screws slowly until i it dosent spark then put them back a bit so i get the longest spark posible

Unread postPosted: Sun Apr 01, 2007 12:40 pm
Author: mopherman
try putting your skrews closer together

Unread postPosted: Sun Apr 01, 2007 12:52 pm
Author: lukemc
that dosent make sense then there will be a lesser spark

Unread postPosted: Sun Apr 01, 2007 1:09 pm
Author: mopherman
woops :oops: im not great with combustion

Unread postPosted: Sun Apr 01, 2007 1:32 pm
Author: SpudBlaster15
lukemc wrote:that dosent make sense then there will be a lesser spark


The size of the spark does not matter very much. A 1/8" long spark will ignite an air/fuel mixture just as easily as a 1/4" long spark.

Since you are unable to determine whether or not a spark is actually being produced, and the air/fuel mixture is not igniting, you are probably not achieving one at all. Like mopherman suggested, try moving the electrodes closer together.

Unread postPosted: Sun Apr 01, 2007 1:44 pm
Author: lukemc
yes it is sparking i found out that if i turn the fan on i can see the electrodes and the spark. i guess my real question was does deodeant fuel float and dosent ignite from the bottem

Edit: i just tryed it again with the loonger spark and it works 100% thanks for the comments though :D

Unread postPosted: Sun Apr 01, 2007 3:50 pm
Author: SpudBlaster15
If lengthening your spark gap solved the problem, then your original gap must have been absolutely tiny (<3mm).

Unread postPosted: Mon Apr 02, 2007 1:42 pm
Author: jimmy101
If lengthening the spark gap solved the problem then the spark gap wasn't the problem in the first place.

A spark is a spark is a spark. If it's an electric arc it is hotter than the surface of the sun, makes no damn difference if the spark is 0.01" or 0.5" long, it is more than enough to ignite the fuel.

If your sparker is inconsistent or fails frequently then here are the most likely causes;

1. Gap is to big and there is no spark. The breakdown voltage of propane + air is a little higher than pure air. It is possible to get a spark gap that'll spark with air in the chamber but not spark with fuel in the chamber. Keep the gap small.

2. Piezo has died. Perhaps cracked the crystal or broke a wire connection or broke the internal spring or hammer that makes it work. (Easy to test, just connect the electrodes to your tongue...)

3. Spark isn't getting to the electrodes. The sparker is putting out something in the vicinity of a couple thousand volts. Most wire is rated at 300V or less. If the wires get too close together, and you have a big spark gap, the path of least resistance for the current may be to just arc between the wires (through the insulation).

Of course, the above assumes you actually have a well mixed combustable mixture in the chamber..

Unread postPosted: Mon Apr 02, 2007 1:51 pm
Author: SpudBlaster15
jimmy101 wrote:If it's an electric arc it is hotter than the surface of the sun, makes no damn difference if the spark is 0.01" or 0.5" long, it is more than enough to ignite the fuel.


With aerosol fuels, mixing is often inconsistent, and so an ignitable fuel mixture is often not achieved between the ignition electrodes, resulting in an ignition failure. I have had it occur numerous times.

Unread postPosted: Mon Apr 02, 2007 2:00 pm
Author: lukemc
it was probably that it wasnt sparking with the fuel in it because with the mixture i would try to spark it a few times and nothing happened so i twisted my lantern lighter (its mounted on my end cap) and it went off. also i hade the electrodes as far apart as it would spark so its possible that with a fuel mix it wouldnt spark

Unread postPosted: Tue Apr 03, 2007 2:15 am
Author: Insomniac
If I were you I would get a new end cap. They are weak anyway, and mounting a lantern sparker in it makes it even weaker. Instead, mount it in the side of the gun, going through a double layer of pvc (where the fittings are)

Unread postPosted: Tue Apr 03, 2007 5:40 pm
Author: jimmy101
SpudBlaster15 wrote:
jimmy101 wrote:If it's an electric arc it is hotter than the surface of the sun, makes no damn difference if the spark is 0.01" or 0.5" long, it is more than enough to ignite the fuel.


With aerosol fuels, mixing is often inconsistent, and so an ignitable fuel mixture is often not achieved between the ignition electrodes, resulting in an ignition failure. I have had it occur numerous times.


Well duh.

Heck, with aerosol fuels the mixing is always inconsistent.

A bigger spark gap won't help if the mixture at the gap is non-combustable.

I can't believe anyone is using a gun without a mixing fan.[quote]