Drilling through boiler tube

[jeffsmith]

I use standoffs for attaching items when I can but some item were bolted directly to the boiler shell. I shall use steel studs lock-tite sealed.
Thanks for your help.

[jeffsmith]

How would brass studs stand up to the heat and moisture of a boiler.?

[NP317]

Brass can de-zinc, loosing strength. Bronze could be a possible material, but not as strong as steel.
RussN

[Glenn Brooks]

Conventional wisdom seems to be to use mild steel fasteners (grade 5 or less) in boilers. When they eventually need replacement, it’s possible to drill them out if they get frozen into place. Very difficult to impossible to do with stainless. As Russ mentioned common brass (fittings and threaded rod/bolts/screws) are prone to early failure.

I recently took apart the steam dome on my 1904 4-4-0 boiler. The original, 116 yo mild steel bolts all came out with ease. Except one that snapped off at the bolt head. It drilled out quite easily and cleaned up well with a tap.

See the other another, current thread that mentions using naval bronze (954) for boiler fittings. Contains lead and tin in the formulation, so excellent resistance to corrosion. I think aluminium bronze would work very well also- it’s a bit stronger and less prone to deformation than gunmetal in the smaller diameters.

Glenn

[Marty_Knox]

One of my big objections to using stainless steel in a boiler - you can't cut it with a torch!
With plasma cutters that is not as much of an issue as it used to be.

[Fender]

See the other another, current thread that mentions using naval bronze (954) for boiler fittings. Contains lead and tin in the formulation, so excellent resistance to corrosion. I think aluminium bronze would work very well also- it’s a bit stronger and less prone to deformation than gunmetal in the smaller diameters.

Glenn

C95400 is aluminum bronze. I think you meant C83600 naval bronze. Or, the more common C93200 bearing bronze. The latter two contain lead, and are easy to drill and tap. Al bronze is good for wearing surfaces, but can be a bear to drill and tap.

[Glenn Brooks]

Thanks Dan, yes, looks like I got the numbers reversed.

Just did a quick search for naval bronze. Here is a site that came up with a pretty good summary of the apparently huge variety of brass formulations. Looks like c460 is also a naval brass, with no lead. Add a tiny bit of tin and it becomes an excellent resistor to corrosion.

https://www.avivametals.com/products/c4 ... -lead-free

And a brass chart from National Brass.com

https://www.nationalbronze.com/pdfs/spec_reference.pdf

Looks like worth exploring, for the variety of choices regarding working with brass for loco and boiler rehab.

Glenn

[jeffsmith]

Thank everyone for your response. I'll haft to check out the naval bronze. I would need to make the studs, I doubt anyone makes them.
It would be nice to not haft to worry about them rusting up solid.

[NP317]

McMaster-Carr does list bronze fasteners in at least 6 different alloys.
Includes threaded rod, too.
RussN

[Glenn Brooks]

I found a couple of places on line that sell naval bronze stock. It’s a little spendy, but seems to be available in small quantities. Seems like you should be able to fab in bronze with a successful outcome, if you wish to... sounds like the leaded bronze is the most machinable, and corrosion resistant. let us know your outcome...

Glenn

[10 Wheeler Rob]

Word of caution when drilling thru boiler shells, make sure the drill bit can't grab as it breaks thru and go in deep enough to poke a hole in a boiler tube. And that a tap will not project thru and do the same. Saw it happen to someone once on a copper boiler and the tube had to be replaced.

Rob