Author Topic: CONWAY 0-4-0 3 1/2" GAUGE LOCO  (Read 174296 times)

Offline Firebird

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #930 on: August 31, 2019, 08:11:37 PM »
Hi

I have signed up to Imgur image hosting. It looks ok

The first image was exactly as I uploaded it. The second image has been rezized to 600 x 800

Cheers

Rich

Offline doubletop

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #931 on: September 01, 2019, 01:09:20 AM »


Rich

A late arrival at your party.

If its just weeping from the outside stays thats not a big problem and doesn't warrant silver solder. Use this

https://www.harrisproductsgroup.com/en/Products/Alloys/Soldering/Lead-Free-Solders/Bridgit.aspx#technical

Pete
?To achieve anything in this game, you must be prepared to dabble on the boundary of disaster.? - Stirling Moss

Offline Kim

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #932 on: September 01, 2019, 05:59:33 AM »
Rich, that's got to hurt to have to re-do the boiler yet again!   :wallbang:

You'll get it licked though, I know you will!

Kim

Offline Firebird

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #933 on: September 01, 2019, 08:07:34 AM »
Hi

Thanks for the tip Pete. Not sure if our boiler inspector will allow soft solder, I'll check with him.

Thanks Kim  :ThumbsUp: I still work 3 days a week so it will be later next week before I can get back on it. A bit frustrating at times  ::)

Cheers

Rich

Offline Jo

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #934 on: September 01, 2019, 10:16:41 AM »
 :headscratch: Has that boiler passed its double working pressure test?

Boiler inspectors like to do that totally bare off the model..

Jo
Enjoyment is more important than achievement.

Offline Stuart

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #935 on: September 01, 2019, 10:33:42 AM »
Bet that will make up when you steam it up , yes we all like a dry boiler but after a bit of service small weeps around the stays are common but only leak when cold

But it’s your boiler so do it to your standards   It likely to have been a flux inclusion that now has dissolved first test it held but that was before you kept getting it wet  :pinkelephant:

Stuart
My aim is for a accurate part with a good finish

Offline Firebird

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #936 on: September 01, 2019, 10:48:52 AM »
Hi

Jo, yes the boiler has had and passed its initial twice working pressure test.

It now has to have a 1 1/2 times working pressure test ie 120psi with all its fittings in place.

When I first tried to pump it up I couldn't get any pressure at all but noticed it was dripping out of the cylinder auto drain cocks. It could only be getting past the regulator. Reading up on regulators it is apparently quite common for them to leak and can be difficult to seal. So I capped off the main steam pipe and snifting valve and plugged the drain cocks. Its now I noticed the leak from the stay :facepalm:

Hence the strip down

Stuart, yes I would like to get it as dry as possible. This is my first loco boiler so a bit of a challenge. I'm assuming that the 1 1/2 times test it has to hold pressure?

Cheers

Rich

Offline Stuart

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #937 on: September 01, 2019, 11:09:01 AM »
Rich

Know what you mean , if your boiler inspector will allow soft solder that’s the way but once you have soft solder on the boiler no more silver soldering


Try a light caulking with a blunt centre pop first

The difficulty is getting any penetration of any type of solder into a stay joint let alone cleaning it , there is going to be contamination , at best you will only be able to put a blob on , but remember every reheating to silver solder temps may stress and open nearby joints so you end up chasing your tail , been there done that on my first loco boiler , things can get ugly fast when reworking boilers


But please be advised by your inspector they all follow the code but all interpret it differently



after five locos up to 5 inch you get to know what’s ok and what’s not , boiler inspector is person ( got to be pc ) to give the final say so
My aim is for a accurate part with a good finish

Offline Firebird

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #938 on: September 05, 2019, 03:03:45 PM »
Hi

Thanks Stuart  :ThumbsUp:

After re soldering the stay I got everything bunged up and did a test







Thankfully all went well. It held 120psi for about 15 minutes

But, theres always a but isn't there. When I removed the blanking plug from the end of the steam pipe I couldn't get any pressure up at all. The regulator must be leaking like a sieve

<a href="https://www.youtube.com/watch?v=gOjyZw-w5mo" target="_blank">http://www.youtube.com/watch?v=gOjyZw-w5mo</a>

Cheers

Rich

Offline crueby

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #939 on: September 05, 2019, 03:22:47 PM »
Great result on the boiler itself, hopefully the regulator is an easy fix, something in the mechanism rather than in the piping to it inside.
 :popcorn:

Offline Firebird

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #940 on: September 05, 2019, 11:01:39 PM »
Hi

It looks like the regulator has to come out :'(

That means the wet head, super heater, internal steam pipe etc.

I can't think of any way to test the regulator before its fitted

Cheers

Rich

Offline Admiral_dk

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #941 on: September 06, 2019, 11:13:01 AM »
Oh man - I feel your pain and fustration - this is absolutely no fun ....

I wish I  could help you, but I do not have any useful ideas.

Offline cnr6400

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #942 on: September 06, 2019, 01:14:34 PM »
If you are taking out the regulator, I'd suggest getting rid of the Martin Evans twin disk twin link gizmo. A screw down regulator or a Swagelok high temp ball valve regulator in the smokebox (if there is room) would both be easier to make and far more likely to shut off reliably for a very long time.

The screw down type was made popular by LBSC in England. Very simple to make, really just a tube with internal threads and a cone-ended rod with external threads, and some tubing, as well as seals between cone end rod and tube, and between operating rod and boiler backhead. The tube with internal threads and seat for the cone goes toward the smokebox and the cone end thread rod goes toward the firebox via a rod like your existing regulator.

Just food for thought. There are so many things that could go wrong to make the twin disk regulator fail I just can't believe Evans promoted them. (like a lot of things in his designs). I know you had trials and tribulations to build your regulator Rich, and its' a shame you had to go through that.
« Last Edit: September 06, 2019, 04:29:50 PM by cnr6400 »
"I've cut that stock three times, and it's still too short!"

Offline Firebird

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #943 on: September 06, 2019, 05:53:49 PM »
Hi

Thanks Admiral  :ThumbsUp:

cnr6400, could you give a little more info please

Swagelok ball valves in the smoke box?

The front tube plate bush and the bush in the backhead are both tapped 1/2" x 32 tpi so I could just about get 7/16" through the tapped hole

Cheers

Rich


Offline Roger B

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #944 on: September 06, 2019, 06:39:17 PM »
Looking Good  :ThumbsUp:  :ThumbsUp: at least until the regulator  :(  :toilet_claw: like Per I can't really offer an solutions but hopefully some of the steam people on here can  :headscratch:
Best regards

Roger

 

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