Plug Cleaning?

[Larry Renger]

I have several Norvel plugs (now unavalabilium, sadly) that no longer work right.  The coil is black at the top and white after about 1/3 coil down.  Is there anything that will clean these back to shiny finish without dissolving the rest of the glowhead?

If there was a source for fresh glowheads, it wouldn't be a problem, but they are now discontinued. 

An alternative is the Galbreath/Nelson head, but I have not been able to get good needle settings despite trying up to 5 gaskets.

Anyone out there with solutions?

[Alan Hahn]

Larry,
This isn't going to help, but I had a similar problem, where the element looks "frosty", which is what I think you say is white. When that happens, I would have to progressively lean the mixture until it would get so lean the engine would begin to sag. I never really figured out how to deal with it (other than put in a new plug). It seemed to happen to me whether I was running 20% nitro or 15%.

I did go the way of the Galbreath-Nelson head, but I don't recall any particular issues, but it has been some time since I last flew the plane (TF Baby Flite Streak with a Big Mig 049 and a Grish Tornado Black Magnum 5-3 cut to 4.75".)

I thought you were using the AP Wasp 061, don't they have plugs? I assumed they were like the Norvel Glow Plug since the rest of the engine looked like it was a copy.

One possible fix would be to have someone replace the glow element itself. I have a friend in the area who says he could do it, but he is so busy making glowplugs that I don't want to bother him. I have been saving the carcasses of my old Cox and Norvel plugs "just in case". Since he also makes "Turbo" plugs, it might be easier to just buy a compatible head and get some Turbo plugs.

[Roger Vizioli]

Larry,
Strange situation.
I am really pleased with the Galbraeth/Nelson combo. and its repeatability, BUT, 
I did have an engine run problem awhile back -

  The "O" ring seal between the venturi and crankcase extrudes over time and creates a  leak path. Sometimes obvious/noticeable if venturi is loose in crankcase and other times not noticeable if venturi is not loose in crankcase (ie good clamping action from the venturi mounting screw). When this happens, NV mechanical position/setting doesnot change but the engine runs vary as engine temp climbs and air gap at the "O" ring opens providing an air bypass around the venturi/NVA changing your fuel/air ratio.

"Might be part of your problem, it is all I can think of at this time.
Not sure why it only happens when you use the Galbraeth/Nelson combo.   
  Hope it helps.
Roger V.

[Roger Vizioli]

Larry,
" ---------------------------------------------------------------------------------------
One possible fix would be to have someone replace the glow element itself. I have a friend in the area who says he could do it, but he is so busy making glowplugs that I don't want to bother him. I have been saving the carcasses of my old Cox and Norvel plugs "just in case". Since he also makes "Turbo" plugs, it might be easier to just buy a compatible head and get some Turbo plugs.

I've been told, never tried it, that Nelson will take old plug carcasses in trade.
Roger V.

[Stan Bidowski]

Nobody makes a VERY tiny sandblaster for cleaning glowplugs that I know of, however
I've had some luck with cleaning plugs by GENTLY scrapping away deposits with
a teenie pin, or even an Exacto knife- while the plug was sitting upright and flooded with
fuel and also attached to a glow plug clip with the setting on low.  It will get hot pretty
quick, and the fuel will burn away quick too.  But the deposits will loosen up 'some' with
the heat and fuel.   It will give off a bit of a stink too  , as the fuel and gunk burn off.
When you get some of the goop loosened up, turn the plug over and dump out and
shake/flick the now dirty fuel out.  Repeat as required, turn off the glowdriver before
adding more fuel to it- ie: don't burn yourself!     You have to be careful, as
you can and will short out the element, so the glowdriver has to be set low,
otherwise you will burn out the plug!  Sometimes this works, sometimes the plug
is too far gone or too dirty.  Give it a try on more plentiful, available plugs first.
 Maybe someone else has a better cleaning method??

  Stan Bidowski   

[Garf]

I tried something once. I took some fouled plugs and put a drop of muriatic acid on the element. This has to be done VERY CAREFULLY. This acid is very dangerous. I rinsed the plugs then tested them. It seemed to help.