New Boilermaker Needs Novice level help on Model M

[DetroiTug]

I second or third the stick welder and 7018 rod suggestion. I have had issues with leaking welds using mig and tig, and none with the stick welder. Used the stick welder to repair teh leaks on the mig and tig welds. Use good rods and make sure to chip slag and clean out on each pass. For the shell and heads, Root pass, small fan pass and then a large fan pass.

Annealing welded boilers. They should be, but few people do and never heard anyone having an issue as a result.

Regarding threaded water tubes, the boiler below was reportedly built by George Whitney with right and left hand threads. This is the boiler that was originally with a Whitney compound that has been copied out east and in a few boats. It was listed for sale in Modern steamboats in back of one of the issues and purchased many years later.

-Ron

[CannonFodder]

Thanks gentlemen.
That is good news on the annealing. I'm willing to have one less major process!

I did find the butt weld steel fittings, that is a great option.

I do have a larger MIG, up to 230 amps, and I have been checking the penetration at various settings. I feel pretty good about my recent practice welds. I increased the distance between the OD of the upflow tubes from .5 inch to .6 inch and that improves the access of the MIG nozzle quite well. I have already fabricated the components for the water grate and mudchests which only have .5 inches between tubes. But if the MIG doesn't reach well, I will try to reflow the questionable part with a torch.

[fredrosse]

Looks like very nice work you are doing on the boiler.

As far as MIG welding in tight spaces, you can feed the MIG wire some distance from the gun so that the gun nozzle is clear of the tight places. With flux-core wire this requires no adjustments. With a regulated shield gas (which it appears you are using from the looks of your nice tack welds) you may want to increase the flow slightly.

One method I have used to make boiler "waterwall" tubing, where we want the tube spacing close together, but need space for welding, is to swage the tube ends. For example, say 1 inch tubes, with 1-1/4 inch centerline spacing. This allows only 1/4 inch clear space for welding the tubes to the mud drum, a tight problem. If you swage the tube ends down to 3/4 inch diameter, and drill 3/4 inch diameter holes in the mud drum, you now have 1/2 inch gaps at the weld locations, much easier to weld. This also makes for much lower stress in the mud drum ligaments, as they now have twice as much metal area to resist bursting at these high stress points.