Topic: Steam Tube Lagging (Read 17437 times)

derekwarner · « **on:** June 11, 2013, 03:04:12 am »

After finally modifying those problematic SAITO 4.06 mm OD steam tube sizes & funny sized thread form fittings to 5/32"OD tube size..........I though it was time to re-read our achieves from Mick & Jerry C on their methods of steam tube lagging
I was pleased with the soldering results as it is the first time I have used Cup Alloys low temperature silver solder
However I was using Chinese "Tipex" and the result was disastrous

...so much so this morning I am removing the lagging & will think more............

......Derek

Circlip · « **Reply #1 on:** June 11, 2013, 09:21:56 am »

Many wrap the pipes with close wound cotton string and then tightly wrap with plumbers PTFE tape.

Regards Ian.

derekwarner · « **Reply #2 on:** June 11, 2013, 09:46:13 am »

Thanks Circlip........ my previous attempts naturally included 100% Australian cotton twine... the Chinese "Tipex" ... produced more white hair strings than the bearded lady

I will wait 24 hours & see if any other suggestions come forward...& then

will trial a sample piece on 5/32"OD brass tube ....the PTFE tape sounds like it will fill the natural voids in the twine.....not sure how tough it will be after painting with water based paint?...........
Each successive removal of the cotton twine & superglue is damaging the surface of the tubing...& whilst only cosmetic....

.........is gross ......Derek

Jerry C · « **Reply #3 on:** June 11, 2013, 10:47:51 am »

PTFE ? Teflon? and paint? Suggest you try it out on the frying pan first. Prepare a good excuse before you do just in case it sticks! To save you searching for hours, two layers best Australian white cotton parcel string, no glue, do like whipping. Paint or trowel on several coats of (in UK) polyfilla. Or whatever you use in Oz to fill cracks in plaster (not decorators caulk) or can use plaster of Paris. Dries quick. Then file or sand to shape and smooth. Then paint with two coats of white outdoor masonry paint smooth. Probably only available in south Tasmania. Easy to keep clean but can be a bit brittle(I just chipped a bit off the end of pipe the other day). However your work that I saw left on, at first sight looked as if you had sewn on an outer canvas cover and I was a teeny bit jealous. Thought I saw a seam. That was my initial plan but realised it was a job too far. It has taken me a long time to learn to stop trying to do things as full scale but in miniature. I think the term artists use is impressionist. I'm getting there slowly. Should go without saying but lag the pipes off the engine.
Best wishes.
Jerry.

Circlip · « **Reply #4 on:** June 11, 2013, 03:15:27 pm »

No paint, close wind the string tightly onto the pipe and then flat wind the PTFE tape on top so yes, it does show depressions between the string ribs, and as it's white, why do you need to paint it?

No need for superglue either, as everything is done dry, there's still flexibility.

Regards Ian.

derekwarner · « **Reply #5 on:** June 21, 2013, 01:01:26 am »

Thanks kno3......I do appreciate critical questioning :nono

.....as this is my first steam installation

I am sort of stuck between the rock & the proverbial here......with the proposed installation into a new hull of PS Adelaide @ 1:20.......I find

1. The engine cylinders on Adelaide were in the horizontal plane with the engine crankshaft closest to the boiler chimney
2. For me to achieve a similar scaled installation dictates that a live steam run of 215 linear mm [which include the 42 mm for the lubricator] from the discharge isolation valve on top of the boiler to the inlet of the steam regulator just underneath the steam inlet port tube on the engine
3. I do understand the need to minimise condensation in the live steam line & hence my removal of the initial steam lagging until I can better understand a method of providing functional lagging over just the visual string wraps
4. I have looked at many French model vessel steam WEB sites and found many examples of similar sized horizontal boilers with lagged live steam lines estimated at greater than 200 mm

Naturally if any PD has any comments.......please let them be known.......

I will post this same massage on Model Mayhem.........there are some very experienced steamers there......... Derek

southsteyne2 · « **Reply #6 on:** June 21, 2013, 03:34:46 am »

Hi Derek very nice steam plant you have there ,I have used the string and teflon tape for years works fine but must be painted as it stains from the steam oil just curious why do you have so many pressure gauges?

and also 2 bucks fifty a schooner at the cabbage patch Tuesdays and Thursdays

John

derekwarner · « **Reply #7 on:** June 21, 2013, 04:08:13 am »

Hullo John.......
Here is a note I posted on Paddleducks explaining the gauges......
For reference, what is the approx. linear length of lagged steam tubing on your South Steyne? .....Derek
____________________________________________________________________________________________________________________
Hi PD's...........kno3

1. The lagging....I will wait until I finish all tubing ...should be this week I hope & the resolve the lagging....possibly just cotton string & a few coats of whitish flat paint
2. The 3 gauges..... they each sense the same pressure at the cylinders....but being different sizes & pressure ranges I expect to see varying pressure fluctuations....& not just a semi constant boiler pressure.......most paddle engines [if not all OZ paddlers] had 2 x pressure gauges & 1 x vacuum gauge ....so with the engine being visible I thought I would just copy the visual aspect.....
U syphons have been installed & one isolation valve .
4. For the past year or so I had been concerned that the Niggle lubricator would not be adequately supported by the #22 gauge 5/32" OD tube..........[75 mm on the inlet & 125 mm on the outlet]....so asked Winfried if he could produce over length 2.5mm diameter tie rods........at the time he was too busy so yesterday soldered M5 AF hexagon brass extensions which are internally tapped M3 .....all other components are to be secured with M3 stainless screws from under the base.....Derek

steamboatmodel · « **Reply #8 on:** June 24, 2013, 05:18:03 pm »

Derek I am confussed over your statement
"3. I do understand the need to minimise condensation in the live steam line & hence my removal of the initial steam lagging until I can better understand a method of providing functional lagging over just the visual string wraps"
as I have always found the string wraps functional as long as like any insulation you keep it dry.
Regards,
Gerald.

Jerry C · « **Reply #9 on:** June 24, 2013, 07:40:02 pm »

It's not whether the insulation gets hot, it's how quickly. String/plaster/paint really do work. My boiler lagging is made from a plumbers soldering mat plus 1/8" mahogany strips. It gets hot , of course, but takes a bit to burn me. It's a hell of a lot better than stuff all!
Jerry.

derekwarner · « **Reply #10 on:** June 24, 2013, 11:32:50 pm »

The 1:20 scale copper smiths have been working on night shift & ripped the 3 gauges, isolation valve block & tube work out

for fear of being a condensation issue
They have been replaced with a single gauge & minimal fittings which should be easier to lag/insulate..........
Gerald....the reason I removed the initial lagging was simply that it was a botched application.......very untidy at each end

.......I think I have a fix for this now.......Derek

hammer · « **Reply #11 on:** June 25, 2013, 05:14:44 pm »

Derek, remember the silver foil method. Geoff.

Yes I am watching you now.

derekwarner · « **Reply #12 on:** June 29, 2013, 03:20:26 am »

That little steam regulator ...3/4" cube was a glaring heat loss

so have lagged it [in 2 1/2 layers] in the same material as the other components......... Derek

vnkiwi · « **Reply #13 on:** June 29, 2013, 03:33:55 am »

very neat Derek,
like it. Your dressing up your engine/boiler very nicely.
Keep up the good work, can't wait to see the whole boat, if your work on the engine is anything to go by, she will be well worth waiting for
cheers
vnkiwi

derekwarner · « **Reply #14 on:** June 29, 2013, 04:58:35 am »

...& hammer says.......

yes I am watching you now.... Geoff..........thankyou RGY.....I need your support & experience.......

.....Derek

southsteyne2 · « **Reply #15 on:** June 29, 2013, 07:10:17 am »

Derek length of lagged tubing straight from boiler to superheater = 150mm boiler to lubricator = 180mm exhaust = 200 mm

John

KNO3 · « **Reply #16 on:** June 30, 2013, 01:18:23 pm »

That looks nice!

derekwarner · « **Reply #17 on:** August 14, 2013, 02:57:57 am »

Question for Jerry C.......

...did you use any additive with the cellulose filler when you coated the string insulation?
I have made 3 attempts now.....

& each time I seem to file more filler off than I apply!!!!

I have used 4 mm ID white nylon washers at either end of each individual spool piece to help maintain tidiness ....straight runs are not too difficult........but the bends are causing issues........Derek

Jerry C · « **Reply #18 on:** August 14, 2013, 08:56:08 am »

Hi Derek, whatalotapipeyougot! First off I didn't use cellulose filler. The stuff I used didn't smell of cellulose anyway. In this country it's called "polyfilla". My first choice was "plaster of Paris" which we used to get from the local chemist when we were kids to make casts of animal tracks. Nowadays it comes not in powder form but as p. o. p. bandages for broken legs etc. I did find some in powder form however but it cost me an arm and a leg! The next time I came to use it for pipework Mk2 it had gone off and was unusable. That's why I used polyfilla. .

As to using it, from what I see in the pictures you've just taken too much off is all. You need to "see" the finished lagging inside the blobby job you end up with after applying the filler and file/sand until it appears, rather like a sculptor does. You have to stop sanding before the string appears. I do see some potential for those washers though. If you put a lot more on, say every inch, filled in over the lot then sand down until the washers show, indicator like, you'd end up with a perfect job. Probably too good! Finish off after a few days drying with white radiator paint which I know you can get in Bunnings. When it's dry cook it off in the oven at about 140°C. Start off at 70° and work up slowly to avoid blisters. Best of luck.
Jerry.

derekwarner · « **Reply #19 on:** August 14, 2013, 10:08:57 am »

...thanks Jerry........when I say cellulose filler .....it is identical to the "polyfilla" product you mention
More haste....less speed on my part? ..............& I will also bake the next application of cellulose filler prior to the next filing ...........

Thanks Derek

Jerry C · « **Reply #20 on:** August 14, 2013, 10:17:02 am »

Not sure about baking the filler. I baked after painting because the paint stays sticky until heated. Radiator paint here is for painting domestic radiators in central heating systems. Bake em before fitting then if ok you'll know they won't blister in use. Softly softly catchee monkey.
Jerry.

Circlip · « **Reply #21 on:** August 14, 2013, 10:28:27 am »

Plumbers White PTFE tape don't crack.

Regards Ian

ooyah/2 · « **Reply #22 on:** August 14, 2013, 02:10:54 pm »

Derek,
In your No 17 post you show a pic of your pipe runs, why do you have flanged joins in 4- off them when they are not needed as your pipes have loose connections on each end and can be dismantled without the need for flanged joints.

These flanged joints will negate your efforts to insulate the pipe runs to keep your steam temps as high as possible as there will be some heat loss thro' the flanged joints, unless you insulate them as well.

Is it that you just like flanged joints, or am I missing something?

George.

southsteyne2 · « **Reply #23 on:** August 14, 2013, 10:55:23 pm »

I have to agree with George on this one, one should strive to keep the installation as short and simple as possible as too many joins will eventually cause a headache down the track

John

derekwarner · « **Reply #24 on:** August 14, 2013, 11:12:56 pm »

Morning George....
Mr SAITO produces engines with problematic tube sizing 4.06mm OD......this has been a point of contention with a number of SAITO engine owners over the years.........and the port tapping's are even more obnoxious or bar###rd sizing
The standard 5/32" OD [3.968mm] tube cone for nut & cone connection does not have sufficient wall thickness to leave sufficient parent material for enlarging to accept the 4.06mm tubing
The flange sets as produced by Winfried Niggle whilst are nominated as to suit 4mm, do in fact accept the 4.06mm tubing
In reality, there are two flange set in the steam supply that could have been eliminated & I accept your comment that these flange set will be a heat loss
The other flange sets are on steam discharge [4.06mm OD] or around the de-oiler so are of less concern........Derek

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Author Topic: Steam Tube Lagging (Read 17437 times)