A question about vertical boiler construction

This forum is dedicated to the Live Steam Hobbyist Community.

Moderators: Harold_V, WJH, cbrew

User avatar
steamin10
Posts: 6712
Joined: Sun Jun 08, 2003 11:52 pm
Location: NW Indiana. Close to Lake Michigan S. tip

Re: A question about vertical boiler construction

Post by steamin10 » Thu Aug 16, 2012 10:10 pm

I replaced a water system in an older laundromat, putting in 2" copper pipe. That was an experience. The copper conducts heat away very quickly, and is a trial even with soft solder, you must chase the 'melt line' around the pipe for a good seal.

Common brass should not be used, for boiler fittings as mentioned. common bronze and plumbing bronze are fine. Bronzes can be jusdged by color when new, as brass has that light goldly color, bronze a much darker copper hue. Not a guarentee of course, but a quick guide. If in doubt, cut a sample before you machine bushings, and silver a blurb on a test piece. That will tell all. It is what I do when I use waste and salvage pieces of unknown metal.
Big Dave, former Millwright, Electrician, Environmental conditioning, and back yard Fixxit guy. Now retired, persuing boats, trains, and broken relics.
We have enough youth, how about a fountain of Smart. My computer beat me at chess, but not kickboxing
It is not getting caught in the rain, its learning to dance in it. People saying good morning, should have to prove it.

User avatar
Bill Shields
Posts: 5508
Joined: Fri Dec 21, 2007 4:57 am
Location: Somewhere in the World
Contact:

Re: A question about vertical boiler construction

Post by Bill Shields » Fri Aug 17, 2012 6:42 am

when in doubt with copper, GET A BIGGER TORCH :lol:

I never use leaded bronze for boilers in solder areas. Silicon bronze is OK. Al bronze a no-no.

As Dave says, a test lump is the best way to go if unsure.

Last weekend at PVLS, a young fellow, running a rather (40+ year) old highline steamer had a very bad experience.

The blowdown valve blew COMPLETLY OFF his operating loco, with expected results - all the water blew out in less time than it takes to read this text.

He was left with a hot fire, no water and fortunately NO PRESSURE.

Cause?

Brass fitting....got old and decomposed, gave up and let loose.

He says that it had gone through a hydrotest a few weeks earlier. I have no reason to doubt him.
Too many things going on to bother listing them.

User avatar
GlennW
Posts: 6757
Joined: Sun Apr 15, 2007 9:23 am
Location: Florida

Re: A question about vertical boiler construction

Post by GlennW » Fri Aug 17, 2012 7:46 am

Bill Shields wrote:As Dave says, a test lump is the best way to go if unsure.
Seems like the best way to go if "unsure" is to purchase something that you are sure of...
Glenn

Operating machines is perfectly safe......until you forget how dangerous it really is!

User avatar
Bill Shields
Posts: 5508
Joined: Fri Dec 21, 2007 4:57 am
Location: Somewhere in the World
Contact:

Re: A question about vertical boiler construction

Post by Bill Shields » Fri Aug 17, 2012 8:05 am

SURE....then keep an exact record of every lump of bronze sitting in the 'cut-offs' tray. :evil:

I guess other people's shops are a lot more organized than mine. :lol:

I have bins for:

Brass
Bronze
Monel
Stainless
Aluminum
Steel
Cast whatever

USUALLY, stuff ends up in the correct bin.....

Sometimes one bin gets full and overflows into another.

Fortunately it is easy to tell the difference between Aluminum and steel. :shock:
Too many things going on to bother listing them.

User avatar
steamin10
Posts: 6712
Joined: Sun Jun 08, 2003 11:52 pm
Location: NW Indiana. Close to Lake Michigan S. tip

Re: A question about vertical boiler construction

Post by steamin10 » Sat Aug 18, 2012 9:47 am

Actually, I am a pilot. I pile it here, and some over there.....a bucket of shorts is a common target. I dump it out for the Nth time and grab what seems best for the moment.

Cheers!
Big Dave, former Millwright, Electrician, Environmental conditioning, and back yard Fixxit guy. Now retired, persuing boats, trains, and broken relics.
We have enough youth, how about a fountain of Smart. My computer beat me at chess, but not kickboxing
It is not getting caught in the rain, its learning to dance in it. People saying good morning, should have to prove it.

User avatar
Orrin
Posts: 307
Joined: Sat Jan 04, 2003 12:24 pm
Location: SE Washington State, near Moscow, Idaho

Re: A question about vertical boiler construction

Post by Orrin » Thu Aug 23, 2012 10:03 pm

If in doubt, cut a sample before you machine bushings, and silver a blurb on a test piece. That will tell all. It is what I do when I use waste and salvage pieces of unknown metal.
You're ahead of me on this one. How do you test for brass versus bronze? I can guess, but would like to know your method.

My guess would be to machine a scrap. In my experience the swarf is altogether different.

Orrin
So many projects, so little time.

User avatar
steamin10
Posts: 6712
Joined: Sun Jun 08, 2003 11:52 pm
Location: NW Indiana. Close to Lake Michigan S. tip

Re: A question about vertical boiler construction

Post by steamin10 » Fri Aug 24, 2012 6:29 am

Color first, yellow brass, and (copper hued) bronze. I have never found red brass (bearing mtl) in small bar stock, only large cored stock. All of these copper alloys are consistant in color, or they would be something else. Aluminum Bronze is a pleasing color, that has for the life of me, a silver sheen to it. It is a bear to machine and very hard. Copper alloys tend to follow copper in work hardening. So making a trial cut can reveal a lot if you are used to the materials, otherwise without hands-on experience, your probably lost in the woods. (I have to admit I do some noggin scratchin too!) Just remember that even bought material winds up in the save bucket with everything else, and it becomes mix and pick from there.
Big Dave, former Millwright, Electrician, Environmental conditioning, and back yard Fixxit guy. Now retired, persuing boats, trains, and broken relics.
We have enough youth, how about a fountain of Smart. My computer beat me at chess, but not kickboxing
It is not getting caught in the rain, its learning to dance in it. People saying good morning, should have to prove it.

User avatar
GlennW
Posts: 6757
Joined: Sun Apr 15, 2007 9:23 am
Location: Florida

Re: A question about vertical boiler construction

Post by GlennW » Fri Aug 24, 2012 7:04 am

steamin10 wrote:Just remember that even bought material winds up in the save bucket with everything else, and it becomes mix and pick from there.
Number stamps work well around here.

Steel, SS, and Alum get color coded with rattle cans.
Glenn

Operating machines is perfectly safe......until you forget how dangerous it really is!

Doug_S
Posts: 27
Joined: Thu Feb 21, 2013 8:56 am
Location: Battle Creek, MI

Re: A question about vertical boiler construction

Post by Doug_S » Thu Feb 21, 2013 3:00 pm

Hello All!
I am new here and just found this post about the RCDon Boiler. As luck would have it, I am currently building one of these boilers with a few changes. I am just to the rivet stage and have not done any soldering yet. I am not exactly new to building boilers as I built a PM Research boiler a few years ago that has about the same construction as the one I am working on now with the exception that the one now is larger. I want to be able to operate the boiler at 100psi with one safety valve set to 105 and the second to 110.

From the consensus here, I should be using hard silver solder instead of the soft silver solder that RCDon used. I have been looking at the SSF-6 MuggyWeld to do the job. I see here that one of you recommends it but wondered of anyone else had used it for boiler construction. (Safety in numbers!) My experience here is limited to the soft silver solders and I haven't used the true hard solders yet.

I am going to make my own boiler bushings out of bronze (McMaster-Carr #544) instead of the brass ones that RCDon used.

I have not decided what fuel to use yet (propane vs coal)...I haven't found a propane ceramic burner large enough yet but still looking. It would be nice to be able to use either one if possible.

As a fairly new builder, I am looking for any tips from the group that would help me as I want a safe boiler and want it to last for my great grand kids.

Thanks in advance for any help
Doug

User avatar
Bill Shields
Posts: 5508
Joined: Fri Dec 21, 2007 4:57 am
Location: Somewhere in the World
Contact:

Re: A question about vertical boiler construction

Post by Bill Shields » Thu Feb 21, 2013 3:04 pm

There is a company called SCHWANK USA that sells the ceramic burner plates of a size that will be useful to you.
Too many things going on to bother listing them.

User avatar
steamin10
Posts: 6712
Joined: Sun Jun 08, 2003 11:52 pm
Location: NW Indiana. Close to Lake Michigan S. tip

Re: A question about vertical boiler construction

Post by steamin10 » Thu Feb 21, 2013 6:04 pm

Doug: Most table top models dont require that high a pressure, and around 60 lbs is common for an operating boiler, which by the way also is the top range for using soft and silver bearing solders for construction.

Larger boilers for RR engines and things that do work, may need more pressure to ease the operation and get things moving, and that changes the requirements for the subsystem that is called a boiler. Rivets, screws and hard (silver) soldering become the norm for the increased pressures and stresses invoked.
Big Dave, former Millwright, Electrician, Environmental conditioning, and back yard Fixxit guy. Now retired, persuing boats, trains, and broken relics.
We have enough youth, how about a fountain of Smart. My computer beat me at chess, but not kickboxing
It is not getting caught in the rain, its learning to dance in it. People saying good morning, should have to prove it.

User avatar
Rich_Carlstedt
Posts: 1478
Joined: Sat Dec 21, 2002 12:16 am
Location: Green Bay Wisconsin USA

Re: A question about vertical boiler construction

Post by Rich_Carlstedt » Fri Feb 22, 2013 9:10 pm

The solder I am using is a 1% Tin, 97.5% Lead and 1.5% Silver solder that has a melting temperature of 588° F.
Glenn Wegman wrote:Here it states that the 97.5% lead solder melts at 361°F, which is far more believable than the claimed 588° that he posted.

http://www.all-spec.com/products/KW44110.html
Glenn wrote:He apparently has his facts all mixed up…so there is no telling what he actually used.
I find many errors here in communicating about solder. First,, understand Tin/Lead solders Tin Melts at 450 F` and Lead melts at 620 F ~
When the two are mixed you can get a number of melting points, but the LOWEST point is called the eutectic point.
The eutectic point for Tin/lead is 361 degrees F when you have Tin at 63 % and Lead at 37 % By the way, this is the solder used for electronics.
No matter what metal gets greater percentage wise from that point, the temperature goes UP.
For example, a common solder in Industry is called 2%. That means it has 2 % Tin and 98 % Lead and melts at 610 degrees.
Since Silver lowers melting points ( in this case.) I would believe that a 97.5 % lead, 1.5 % Silver and 1 % Tin would fall to about 588 degrees.
What is totally wrong is the comment about 97% lead melting at 361 degrees ( see the above about Eutectic point and ratios !). This can't be as we know the lowest point is 361 with 37 % ( Typo ?)
There is another problem. The solder mentioned with a melting point of 430 degrees is a Tin Solder with a small amount of Silver. This solder is commonly called "Stay Bright", a "lead free" solder

I don't mean to be picky, but when talking about boilers and stressed fittings, it's very important to get accurate information.

As far as the boiler video is concerned, please note the extra effort the builder made with rivets !
Heavy and plenty of them ! That is the pressure absorber. The solder is just a sealer in his construction.
Now, I would not build a boiler using such constuction, and would stay with hard solder ( 1145 degrees - 56 % silver).
The problem with "Tin" solders is they grow ( yes, they get larger !) and that makes them spongy and eventually they fail ( many years later)

Rich

Glenn, this was not aimed at you, I just used the comments you had in your post for convience- please no offense

Post Reply