Cast iron part modification

[dgjessing]

Nothing to do with model engines, but I thought maybe I could get some good advice here.

I've got a really nice old Waterford cast iron wood stove (a "Reginald 101"). Used it a lot in the past, haven't for a few years, but want to again. The only problem I had with it in the past is that the air regulator won't close tightly. Close it all the way and it's just banked; you can't actually make it go out completely. I've had a look at the parts involved tonight and the issue is that there is a bit of a gap built into the rotating part at the ends of the two air slots. Closed, you've still got four holes about 1/16" x 1 1/4" left open.

Geeze... pictures would be nice, eh?... Well anyway, what needs to happen is that some metal needs to be built up either by welding or brazing in these four places radiating from the center, then machined down flush with the surrounding cast iron.

My concern is warping. It's about a 6 1/2" dia. cast iron disk, perhaps 1/4" thick in most areas. I was thinking about putting it on an electric hot plate, getting it probably *near* red-hot, then brazing in little strips of steel with additional localized heat from an oxy-acetylene torch. Do all four pieces at the same time, then cool it slowly and true everything up in the lathe. Does that sound like it would work OK?

 

[kye]

maybe you could tap the holes and block them with some grub screws, screw them in below flush. that way if for some reason you ever needed the holes again you can simply unscrew them???

just a thought

kye

 

[Jasonb]

May be safer and easier to countersink screw a 1/16 plate to the

J back or front to make up the thickness.

 

[Mainer]

Personally, I would not try to weld it or do anything that would apply localized heat. I think there is a good chance that doing so would crack the stove because of local expansion. My one attempt at brazing over a hole in a cast iron sink led to just such a disaster.

Your part is relatively small, however, and your idea of pre-heating might do the trick.

Before you do this, you may want to consider that the slots were put there for a reason, unknown but presumably sound, as Waterford is a top-notch company.

I like Jasonb's idea of screwing a plate onto the back. Use a piece of 316 stainless and 316 stainless screws, and it ought to last forever, or be removable if you decide it wasn't such a good idea after all. For "proof of concept," a piece of 24-gauge sheetmetal would do okay.

 

[Maryak]

Preheat, Preheat and Preheat before you apply any local heat.

I don't know how close this gizmo is to the main fire but if it's close I would be wary of dissimilar metals and expansion giving rise to cracking.

Alternately make a new disk sized how you would like.

Hope this helps

Best Regards
Bob

 

[ShedBoy]

Welding cast iron is possible but some precautions NEED to be followed. First you need cast iron rods if arc welding which is generally the easiest. Throw it in a fire for a while till it gets good and hot. Old boilermaker told me if you can hold it for more than 3 seconds with welding gauntlets on it is not hot enough. Grind the skin off so it is clean and grind where you put the earth. Weld about 20 to 30mm at a time then peen the bejesus out of it with the chipping hammer once the slag pops off. He believed if you needed to chip your slag off your not doing it right. Reheat when nessecary and continue. It is not an easy job but I have had several successes.
50 year old bailing needle welded back together about 1 inch square into it 7th hay season.
Oddball manifold from a jap import motor which had cracked around nearly a whole tube. I drove for 2 years and may still be getting around.
150mm crack in an antique bath tub which became a horse trough in the end. 12hour job.
Converted a single barrel valiant manifold to a four barrel. Don't know of its existence now.
Practice on something first though that is the same sort of thickness and it is not for the faint hearted.
Pics would be a help.

Brock

 

[dgjessing]

Thanks, everybody. Some pictures...

The door and the regulator - I've run a belt sander lightly on the mating surfaces to make them show better. Note that the ends of the slots are not sealed up:

... resulting in these openings:

On the door there *is* a flush surface all around the slots (although it doesn't show well in the picture).

Not sure what I'm going to do...

 

[Jasonb]

Can the disc be skimmed to give one mating surface?

J

 

[ShedBoy]

You could make a new cover out of steel plate
Brock

 

[dgjessing]

Well that wasn't so hard - got it blazing hot on the hot plate and just laid in some stuff with the MIG (well, flux-core "MIG"):

Cleaned up just fine, and it's good & flat:

;D

 

[ShedBoy]

Nicely done. I know when joining parts together with this method it can become brittle along the edge of the bead but this has not got stress on it. Good simple fix. Heat is back on.
Brock