Brass choice

[Lopez Mike]

I'm getting ready to order up the brass strips to hold my boiler lagging in place. The most convenient source for me is Online Metals in the U.S. as my local supplier in Seattle has a $150 minimum and fairly serious shipping and handling charges.

The choices are either 260 (ASTM B36) cartridge brass or C464 (ASTM B171) naval brass. They are both copper/zinc alloys, about 60/35. The naval brass has a little bit of tin to help with corrosion. The prices are close.

My application needs little strength. I need to form the ends of the strips to clamp them around the lagging. Maybe braze on some lugs. More to the point, will one or the other of these look nicer when polished up? Also, any advice on how thick it might need to be to make it form a nice curve around 2" strips on a 24" (37-38 segments) diameter circle. Is .040" thick enough?

I see very nice brass on a lot of the British boats. Is this a secret alloy from the mines of old Asian colonies? Or elbow grease.

Jack? Pete? Either of the Rons? Any of you guys have horror stories or good advice to share?

[barts]

Since you're going to be running in salt water all the time, this will turn green pretty quickly unless you polish it frequently.

- Bart

[marinesteam]

Naval brass should have better corrosion resistance to seawater than cartridge brass. I'm not really sure that this translates to less discoloration on a polished surface or on one that's being cleaned regularly. Try both and tell us what you find.

I'd go with the Naval Brass just because of the name. Sounds like it belongs. Admiralty brass would be a good choice for a fancy boat .

Ken

[steamdon-jr]

Mike,

I am too currently looking for brass strips for our boiler, I took a peek at online metals since you posted and they do not have anything longer than 48 inches. If you boiler is 24 inches diameter then your circumfrance would be approx 76". I too am going with the block and bolt method as opposed to many screws into lagging. Only person I can find on east coast is Beckman boatworks who can get it in 1.5" x 144" and I believe it is closer to .080, I plan on brazing the block but may also run a small mechanical fastener from behind as well

[Lopez Mike]

Ken,

I see what you are saying about the 48" max dimension on the sheet stock. But when I enter in a custom cut of 1" x 76" it accepts it. I'll call them on Monday and see what is available.

I have a backup plan of going to stainless. Any larger sheet metal shop has it in sheets 96" long and can sheer off strips for me. The stack is stainless and I have one S.S. strap from the old setup so it is an aesthetic question more than anything else.

Now that I'm considering non-traditional options, has anyone seen such a thing as painted straps? It could be in a color that worked well with the engine and accessory colors. I can braze or weld lugs on mild steel and paint it. Cheap too!

[Lopez Mike]

Last post should have been directed to Don. Sorry.

And Ken, it turns out that Admiralty Brass is Naval Brass under a different name. Oh, well. Maybe just call it Paris Hilton Custom Brass. She has a lot of brass.

[barts]

Ken,

I see what you are saying about the 48" max dimension on the sheet stock. But when I enter in a custom cut of 1" x 76" it accepts it. I'll call them on Monday and see what is available.

I have a backup plan of going to stainless. Any larger sheet metal shop has it in sheets 96" long and can sheer off strips for me. The stack is stainless and I have one S.S. strap from the old setup so it is an aesthetic question more than anything else.

Now that I'm considering non-traditional options, has anyone seen such a thing as painted straps? It could be in a color that worked well with the engine and accessory colors. I can braze or weld lugs on mild steel and paint it. Cheap too!

I've seen black iron banded straps before.... can't quite remember where.

Why not make your own T-bolt style band clamps for stainless banding? Looks a little industrial, but they're strong and provide excellent clamping force. I made one to retain the propane cylinder I use as a accumulator for the fire effects on my Burning Man art car.... simple and strong.

- Bart

[DetroiTug]

I used 1/8 X 1 hot roll 1014. Painted them black. Just bent 90 degrees on the end with holes to cinch up. They work really well with a lot of holding power. I stained the lagging, put the bands around it, and varnished the wood and bands all in one shot. Sounds disgusting, but it looks really good, the exact look I was after.





Ron

[fredrosse]

Naval Brass 1% tin 40% zinc, base copper.
Admiralty Brass 1% tin 30 zinc, base copper.
Thus about 10% more copper in Admiralty Brass vs. Naval Brass.
Evidently the tin addition helps to inhibit dezincification. Admiralty Brass should cost more because of the higher copper content, how much this means with respect to steamboat boiler band duty, anyone know???

[Lopez Mike]

Thanks Fred. My brain runneth over with brass stuff. And now I have Ron telling me to think about plain old steel!

Ron,

Is there insulation under that wood? If so, are there any sort of rings under or near to being under the external straps?

I have an 1.5" thick fiberglass blanket between my boiler and lagging and am planning on plywood rings that width under each external strap so as to not compress the insulation.

I just this second got the O.K. from Barbara to go with black steel but she is balking at varnish over the black. It looks like varnished wood and glossy black lacquer on the steel straps. I dunno about 1/8" thick though. I might back off to around 80 thou. or so. 14 gauge or so. Depends on what the local shop has and can sheer off for me.

Thanks all for the advice. I'll be back with another half baked idea soon.