(DIR) Return Create A Forum - Home
---------------------------------------------------------
Office of Steam Forum for Model &amp
;amp;amp;amp;amp;amp; Toy Steam Gas &amp
;amp;amp;amp;amp;amp;amp; Hot Air Engines
(HTM) https://officeofsteamforum.createaforum.com
---------------------------------------------------------
*****************************************************
(DIR) Return to: Restorations
*****************************************************
#Post#: 11605--------------------------------------------------
Carette 677/13 a big one
By: Nuvolari Date: July 11, 2019, 7:49 pm
---------------------------------------------------------
I recently bought a big Carette 677/13
Here as seen in the catalog of 1911
(HTM) https://live.staticflickr.com/65535/48136738851_465d9ffaac_c.jpg
(HTM) https://flic.kr/p/2gkFnpi
It was sold with the remark of a leaking water gauge…
This is how it arrived…
(HTM) https://live.staticflickr.com/65535/48136847692_30f6e7b641_c.jpg
(HTM) https://flic.kr/p/2gkFVKS
(HTM) https://live.staticflickr.com/65535/48136785228_bb9b213f11_c.jpg
(HTM) https://flic.kr/p/2gkFBbU
(HTM) https://live.staticflickr.com/65535/48136751921_498c4252cc_c.jpg
(HTM) https://flic.kr/p/2gkFrhDhttps://live.staticflickr.com/65535/48136751921_498c4252cc_c.jpg
(HTM) https://flic.kr/p/2gkFrhD
The machine was still in a very good patina, but still someone
did try to repair it in the past, using some crude methods.
The whistle and outgoing steam tap where soldered to the boiler.
And a crack in the nickel boiler / burner house ring, was
repaired by soldering a thin brass plater on the inside of the
ring.
After some consideration, I decided to leave it as it is as
part of it's history
Big issue was the water gauge.
Even before I took it off, you could see that the original
screws where replaced.
Screws on water gauges are always a big issue.
Since I had my first antique steam engine, I had to deal with
that.
For a beginning collector this can be a real nightmare, as a
repair like that require some skill.
Problem with most of these, is that they are made of soft brass,
that is nickeled.
They tend to break, this due that they can't stand pressure and
heat changes, so not idle for holding a water gauge.
What makes it even worse is, that when the closing washer around
the glas it self doesn't seal off, people tend to put even more
pressure to these screws.
And that is fatal of course.
I will come back to the washers later, but first the screws.
Sometimes a big issue can be, what kind of tread they used for
the original screws.
This can be metric, but also withworth or some other od tread
size.
So If you want to replace a screw, keeping the original size,
sometimes asks for real tradesmen knowledge.
That's, why often, you see such bad repairs, where someone just
wacked a non fitting entirely differed size screw in.
Let me tell you, that this never ever will work, and that it
will end up in disaster.
Even danger, as these screws can become lethal projectiles under
steam pressure.
I'm all in, for if it comes to replacements, to find or make an
original fitting screw.
But If the tread in the boiler, is damaged you have 2 choices.
Most difficult, and time consuming, are special made screw
inserts.
These must be custom made on a lathe.
And to fit them in, the old hole must be drilled out, and the
inserts soldered in.
It is a specialist job, but it allows you to keep the original
screws if they are still good.
The easiest way is to retap in a slightly different bigger size.
Let say the original was M2, you retap to M2,5.
I also advice, to keep the extra bigger size, to a minimum.
By this I mean, If the original is a M2, not to go for a M4
replacement.
A 0,5mm increase is more than enough
Downside is, you need new screw.
Also the original screws of that time, had a sharp edge, giving
them a cylindrical look, like this one, of a other engine…
(HTM) https://live.staticflickr.com/65535/48136751561_40a0dd643c_c.jpg
(HTM) https://flic.kr/p/2gkFrbr
Modern screws however have rounded edges giving them more the
shape of a balloon, as where replaced on this engine…
(HTM) https://live.staticflickr.com/65535/48261468917_db00633c33_c.jpg
(HTM) https://flic.kr/p/2gwGDiF
And I really don't like that, to me it gives the appearance of a
cheap repair.
So what I usually do, is cut off that edge on my lathe, turning
them looking like the original screws.
Coming back to my restoration It seems that they taped a M3 hole
to fit in the new screws, a bid big if you ask me.
Anyway after reshaping the heads of the screws.
I reassembled it.
Coming to the issue of the washers…
(HTM) https://live.staticflickr.com/65535/48137108988_34e6e37228_c.jpg
(HTM) https://flic.kr/p/2gkHgqY
The black washer on the left was used.
Now, out of experience those aren't any good, because they seal
off bad.
This makes people, put more pressure to the spanner screws,
with a breaking result.
The washer on the right is what I use, they fit very tight to
the glass, and being flat, fits tight to the boiler.
And with little pressure the spanner screw close everything
off.
An other thing I also use, in combination, is Loctite SI 5990.
It's liquid sealer, that when dry, tuns into a very heat
resistant rubber.
And I have a strong feeling that Loctite SI 5990 is almost the
same recipe the manufacturers used.
I also apply Loctite SI 5990 on the screws, as the screw tread
hole is an opening into the boiler.
This being done I immediately noticed that the M3 holes tread
was gone on my engine.
Even cold water poured out on them.
So disassembling it again, I went for the only sensible thing to
do.
Drop the screws into a spear box, and make incerts and use new
M2.5 stainless screws.
The screws heads where adapted to look like old ones, and
stainless steel is much harder to break.
The incerts where closed incerts, by this mean, once soldered
in, there is no direct opening anymore to the boiler.
So this way you avoid the chance of water leakage over the
screws.
Anyway with everything cleaned this was the result…
(HTM) https://live.staticflickr.com/65535/48136686606_00a2379e46_c.jpg
(HTM) https://flic.kr/p/2gkF6Sw
(HTM) https://live.staticflickr.com/65535/48136686601_80f78d2e29_c.jpg
(HTM) https://flic.kr/p/2gkF6Sr
(HTM) https://live.staticflickr.com/65535/48136718853_4155fb335f_c.jpg
(HTM) https://flic.kr/p/2gkFgsv
(HTM) https://live.staticflickr.com/65535/48136718918_5abf96a37e_c.jpg
(HTM) https://flic.kr/p/2gkFgtC
Only thing left do was to put it under steam pressure…
(HTM) https://youtu.be/gwYOrEzYhTE
Cheers,
Danny
#Post#: 11643--------------------------------------------------
Re: Carette 677/13 a big one
By: txlabman Date: July 12, 2019, 7:02 am
---------------------------------------------------------
Thanks for the detailed explanation of the sight glass repair
Danny.
I just love this one! 🤠
👏👏👏👏
#Post#: 11644--------------------------------------------------
Re: Carette 677/13 a big one
By: txlabman Date: July 12, 2019, 7:03 am
---------------------------------------------------------
Where did you source your flat washers?
#Post#: 11659--------------------------------------------------
Re: Carette 677/13 a big one
By: Nuvolari Date: July 12, 2019, 8:54 am
---------------------------------------------------------
A Guy in Germany that I now and than meet.
I think hè cuts them from a soft thick rubber tube.
*****************************************************