TIG welding Cast Iron

[aametalmaster]

Bob: So you are saying just plug the holes with a normal MIG unit set up for steel? What wire and gas? Never tried cast iron with my MIG unit - I have heard it does not work very well but that may be in high temp/high stress applications.

No sorry with cast iron mig wire. It has the same properties of stick rod drawn out for mig wire. I love it and thats why i bought it for odd jobs just like yours. Seems like i get some every now and then...Bob
http://www.crownalloys.com/TechSheet...ew_Warning.pdf

[turbo38t]

Guess I wasn't thinkin. I just remember breaking a lot of bits trying to drill cast.....too slow and they snag and snap.....too fast and u burn em up. ....I have definitely welded more cast than tapped it though.....haha

why would it not work very well??

engine blocks, machine tools and all manner of cast iron devices are routinely drilled and tapped without problem... what have I missed??

[H80N]

Seems to me you're going to also have to change the size of the orifice.

If turning the gas down now still still outputs too many btu's, plugging a few (or even a row of holes) is only going to result in more gas flow thru the remaining holes that haven't been plugged.

Plugging holes hasn't changed the volume of gas that passes thru the orifice. All it's going to do is increase the velocity thru the remaining holes.

YEP....Unless.............. it has a control valve like on the burners of a gas range or gas grill....

[Shark Bait]

Seems to me you're going to also have to change the size of the orifice.

If turning the gas down now still still outputs too many btu's, plugging a few (or even a row of holes) is only going to result in more gas flow thru the remaining holes that haven't been plugged.

Plugging holes hasn't changed the volume of gas that passes thru the orifice. All it's going to do is increase the velocity thru the remaining holes.

Sundown: You are absolutely correct - any change in the number of "Ports" will drive a reduction in the size of the orifice and a corresponding change in the air shutter adjustment. I have researched this aspect of the project and know exactly what size orifice will be needed based on the number of "Ports" I block.

Thanks for bringing this up - some folks may not understand the importance of the orifice & air shutter .

[aametalmaster]

Seems to me you're going to also have to change the size of the orifice.

If turning the gas down now still still outputs too many btu's, plugging a few (or even a row of holes) is only going to result in more gas flow thru the remaining holes that haven't been plugged.

Plugging holes hasn't changed the volume of gas that passes thru the orifice. All it's going to do is increase the velocity thru the remaining holes.

Sounds like he needs a globe valve installed before the burners to regulate the flow of gas...Bob

[Shark Bait]

Sounds like he needs a globe valve installed before the burners to regulate the flow of gas...Bob

I guess I should have included a little more information when I started this thread. The burner is on a "Commercial" style range. It has six of these burners each having a maximum Btu output of 23K Btu. Being on a range it has a very high quality adjustment valve for each burner that has a large range, is linear and smooth. The issue is it won't go low enough.

I have it adjusted where the outer ring has very few "Ports" burning on low and it is still too hot for a low simmer. On low there is a separate "Low End" adjustment you make to the valve (Like an idle mixture screw on a carb). I can adjust it so low that flames will go out. Bottom line is the burner cap has too many ports for very low temperature simmering. What I am trying to do is take one of the burners and make it into a low temperature "Simmer Burner".

One of the folks on a forum I frequent has blocked the two outer rings using Permatex Muffler and Tailpipe Putty. It works but looks like crap!

[BD1]

Not being a smart as$ but did you take gas pressure readings ? Could it be a regulator adjustment upstream of the equipment ? just thinking. We had a gas service where the local Gas supplier upgrade the meter and pressure and the inside regulators were now on the high side {still within limits** so we had to drop down pressure to match equipment specs. Just curious.

[Shark Bait]

Not a bad question. But no I have not measured the pressure as it exits the meter/regulator. However the range has it's own internal regulator and it appears to working normally.

The real issue is the basic design of the burner. The manufacturer (Capital) has tried to make one burner do it all - from ultra low simmer to mega heat. This range has the hottest burner (23K Btu) of any residential range. All of the other upper end ranges use a dedicated simmer burner. This issue has been brought up to the manufacturer and I am told they are working on a "Solution".

However, since being a hot rodder and welder since the 60s I figure I can do it myself, better. Additionally, doing stuff like this is fun.

I do appreciate the recommendations and suggestions.

[SundownIII]

Shark,

You say that the "ports" are .10" in dia. That makes them too large for a ight fit for 3/32" SS filler.

If it was mine, I would drill out the holes to 7/64 (1/64 shy of 1/8") and measure the distance from the top of the burner hole to where an inserted rod would seat. I'd then cut lengths of 1/8" 304 SS filler to that length. Insert the filler (tight fit) and then just hit the tops of the filler with the tig arc. The filler is going to melt before the cast iron becomes fluid and seal the hole.

PS. You may have to drill the holes a full 1/8" depending on how the cast drills, but you do want a tight fit.

[Shark Bait]

SundownIII:

Thanks for the ideas. If I take this approach with the short pieces of 304 what 200 DX settings would you start with?