Norvel glow head insert lapping techniques?

layback209 Mon Apr 26, 2021 10:48 pm

Hi everyone, hoping to bend your ear for some more advice. I have a norvel big mig who has a leaking glow head. When the clamp is tightened down you can see bubbles come up the insert when flipping the motor over.

Also there is about a 1.5mm spot I can see on the head buttons machined sealing surface where gases havd been escaping. I've tried different copper gaskets but none seem to work. There is no obvious imperfections in the aluminum glow head insert mating surface. You can see nice machined lines still.

I'd like to salvage it if possible. I think it's the head button that's the issue, I put a Cox one on with a std plug glow plug style and it sealed for break in really good.

Should I try a mirror water and some super fine sand paper to try and get the odd high spot (I'm assuming) out? What would you suggest. Figure 8 sanding pattern on the mirror?

Did some searching but didn't come across anything specific, but did learn about some cool glow head recycling things out there.

dckrsn Mon Apr 26, 2021 11:10 pm

Hey there Layback. I don't have much, but if you
want to true the insert clamp sealing surface, use
a light oil, instead of water. Whenever you thread,
grind, machine, hone or sand bare metal etc., oil is
usually the way to go. Sorry if you knew that.
Also, carefully inspect the female cylinder threads.
An acumination of aluminum bits(swarf), might
keep you from seating the insert clamp.
Keep us posted.
Bob

Surfer_kris Tue Apr 27, 2021 12:30 am

Check the thickness of the "lip" on the insert. It might not have an even thickness around the circumference, and the two surfaces of that lip have to be very parallel.

layback209 Tue Apr 27, 2021 2:08 pm

Thanks for the feedback. I'll check those items as well. I do have a set of calipers I can use to see if the thickness is consistent around the lip. Also look for any debris.

davidll1984 Tue Apr 27, 2021 8:21 pm

Maybe the wrong insert How much gasket is used? The insert can be different it is possible to use a spacer With a different machining angle on both sides i use this on m'y cox tee dee .051 modified for cars wit a mutch larger heatsink use two difrent glow insert one wit a spacer For the slimmer model glow plug insert did The head screw to the bottom To almost touch the cylinder ?? there should be a good gap

getback Thu Apr 29, 2021 7:18 am

Oil Yes , i just go round and round clean and check very often! as to not take too much off you should see if there is a in perfection right at first few seconds . Thumbs Up

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Norvel glow head insert lapping techniques?

Norvel glow head insert lapping techniques?

Re: Norvel glow head insert lapping techniques?

Re: Norvel glow head insert lapping techniques?

Re: Norvel glow head insert lapping techniques?

Re: Norvel glow head insert lapping techniques?

Re: Norvel glow head insert lapping techniques?

Re: Norvel glow head insert lapping techniques?