Subject: Re: Tender Tank Questions

From: [email-masked] (-F.KERFOOT)
Date: Tue, 11 Apr 1995 14:42:53 GMT

In article <[email-masked]>,
JOHN JOHNSON <[email-masked]> wrote:
>I have some questions about the fabrication of the tender water tank on my live
>steam locomotive.  I have thought about making it out of brass,  instead of
>steel as it is on the prototype.  I think that brass would be easy to solder,
>keep water tight, and not have the potential rust problem.   The problem that I
>have now is how do I re-engineer the tank to work in scale.
>...details removed...
>scale?  Would say 1/6 brass plate be strong enough, or should I go thicker? 
>There is a series of internal baffles which I could make thicker to carry more
>weight.  The prototype is riveted together.  I thought I could use escunsion
>pins to represent the rivets and solder the entire tank together.  

I have been considering exactly the same issues for my 1 1/2" scale
Atlantic, where I am just finishing the tender frame, and about to start
on the tender tank. I also plan to ride on the tender. I haven't decided
yet, but there are lots of approaches others have used, apparently with 
success.

- Build a steel outer structure (perhaps 1/16" sheet steel, with some kind
of a substructure, such as corner braces, etc.), and protect it from the
water. I have seen separate internal water tanks of brass, copper and
stainless steel. The internal tank can rely on the steel outer shell for
strength, especially if you use copper. I have also seen "paint on" protection.
Epoxy resins (not polyester) bond well to steel and provide good protection.
I don't know anyone who has succeeded with ordinary paints. One local
fellow tried roofing tar, and had to scrape it all out, since it clogged
his water pickup. Note that in general, the "internal tank" approaches 
yield less tender capacity than the "coat the inner walls" approaches,
unless you have a relatively simple shape or make a vary complex internal
tank. For instance, the examples I have seen of internal tanks do not
go up into the legs along the coal hopper.

- The other general approach is to use a corrosion resistant material for
the outer shell. Brass would be fine, but expensive. I expect that you
would want more than 1/16" to sit on, or you need to use more bracing,
along the lines of the prototype (vertical braces along the flat wall 
surfaces, etc). The prototype used this to withstand the static and
dynamic forces of the water inside, and you want it to hold a rider,
but the bracing needed looks similar. You would need to brace the top
more carefully than the prototype did. Another issue is that it is harder
to get paint to bond well to brass (for the outside). Soft soldering the
brass to seal the joints, rivets, etc. is relatively easy. I also don't see
a problem with euschion pins as rivets, if you can get them large enough.
You may want to consider small brass rivets. I have also seen complete
stainless steel tender tanks, but that is a real labor of love, in my opinion.
I have also seen all-fiberglass tanks, but I assume they came from a mold,
which would be a lot more work for just one tender.

I would be interested in any other opinions you get, and in knowing what
you decide. I am leaning toward a steel tank (strong, cheap, easy to
work with and paint, etc), protected with epoxy resin. If anyone knows
of others having problems with that approach I would appreciate hearing
about it.

Frank Kerfoot
[email-masked]

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From: [email-masked] (Mark Kinsler )
Date: Fri, 14 Apr 1995 01:06:38 GMT

One post on this subject made reference to a product used to coat the 
insides of gas tanks.  It's pretty good stuff and I think it's the only 
product of an outfit called the Creem company, somewhere in California.  
I used it to leakproof the horribly rusted gas tank of The Beloved 1964 
Econoline Van.  Of course, I first had to remove the rust by shaking 20 
feet of tow chain around inside the tank and then applying hydrochloric 
acid.  But on a new tank you wouldn't have to do this.
                                  M Kinsler