Author Topic: adding a bronze liner to an aluminum steam engine cylinder  (Read 2952 times)

Offline sierrasmith71

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adding a bronze liner to an aluminum steam engine cylinder
« on: February 14, 2018, 05:27:21 PM »
Quick question . I have been looking at plans for several two cylinder steam engines, with aluminum cylinders, that specify a bronze cylinder liner with a wall thickness of 1mm.  The liner is, say 32 mm OD with an ID of 30 mm. My question is how does one do that? Bore a 32 mm hole and press fit a 32 mm bronze rod , then drill and bore the bronze to 30 mm? I did a quick search for 32 mm bronze tubing but didn't find anything. 
Bronze ain't cheap and boring  that much away seems like a big waste!

Any ideas  would be appreciated!

David G.
Gaithersburg MD

Offline Roger B

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Re: adding a bronze liner to an aluminum steam engine cylinder
« Reply #1 on: February 14, 2018, 05:44:41 PM »
I have used hole saws to cut a core out solid sections which leaves you a blank that can be used for something else in the future rather than a pile of swarf.
Best regards

Roger

Offline stevehuckss396

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Re: adding a bronze liner to an aluminum steam engine cylinder
« Reply #2 on: February 14, 2018, 05:57:30 PM »
A cheaper way to go is to use cast iron or 12L14 steel to line the aluminum bore. If your piston is aluminum I would use steel. If the piston is cast irin you can use cast a liner.
Do not be like the cat who wanted a fish but was afraid to get his paws wet.

Offline steam guy willy

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Re: adding a bronze liner to an aluminum steam engine cylinder
« Reply #3 on: February 14, 2018, 06:12:22 PM »
You could also use a Rotabroach in the lathe or drill/mill ...quite expensive but you will get a sizeable slug out of the middle...Also good to make curved parts on stock...
« Last Edit: February 14, 2018, 06:16:53 PM by steam guy willy »

Offline Bluechip

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Re: adding a bronze liner to an aluminum steam engine cylinder
« Reply #4 on: February 14, 2018, 06:24:38 PM »
Brass is not as durable as PB but drawn brass tube is readily available.

If the engine is not going to be used heavily would it be OK?

1 1/8" x 16g tube is available from Livesteammodels @ Little Eaton, about a couple of miles from me. ( 16g is circa 1.6mm )

http://www.livesteammodels.co.uk/suppliescat.html

Don't have to buy a metre. They will sell in shorter lengths. At least they have to me at the works  :)

Dave

PS Prices ex-vat  ... why do they do that for predominately retail sales    :headscratch:  ????

EDIT Ooops    Sorry 32 mm is circa 1 1/4"   :facepalm:  :old:

PB stuff att.
« Last Edit: February 14, 2018, 06:37:10 PM by Bluechip »

Online Jo

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Re: adding a bronze liner to an aluminum steam engine cylinder
« Reply #5 on: February 14, 2018, 06:30:04 PM »
Bronze is available in thick wall tubular sections (bronze cored round bar) for making bearings.

You do not want Oillite i.e. sintered bronze  :hellno:

Jo

Edit: A USA supplier: http://www.bronzebushings.com/bar-stock/c93200-sae660-bar-stock.html?find=cored-bar-1-1-5-29076
« Last Edit: February 14, 2018, 06:35:36 PM by Jo »
Enjoyment is more important than achievement.

Offline Jasonb

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Re: adding a bronze liner to an aluminum steam engine cylinder
« Reply #6 on: February 14, 2018, 07:59:45 PM »
What Jo says, I've been machining a bit of the very stuff this evening why pay for the bit in the middle that you don't need.

Other option is to make the whole cylinder out of bronze or cast iron block, I'm not keen on having aluminium as the surface for the valve to slide on as quite a few of these designs do.

Offline sierrasmith71

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Re: adding a bronze liner to an aluminum steam engine cylinder
« Reply #7 on: February 15, 2018, 01:21:38 AM »
Thanks to everyone that responded!

You all have given me much food for thought. I get as much, perhaps more, pleasure thinking about and planning as project as I do in actually doing it!   

This forum is a gold mine of information and appears to be frequented by a lot of friendly and knowledgeable  model engineers.

Thanks again!

David G.
Gaithersburg, Maryland USA

Offline stevehuckss396

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Re: adding a bronze liner to an aluminum steam engine cylinder
« Reply #8 on: February 15, 2018, 02:19:09 AM »

This forum appears to be frequented by a lot of friendly and knowledgeable  model engineers.

And me!
Do not be like the cat who wanted a fish but was afraid to get his paws wet.

Offline Ian S C

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Re: adding a bronze liner to an aluminum steam engine cylinder
« Reply #9 on: February 15, 2018, 11:45:26 AM »
I use the hollow cast bar, and if I have any left over the company I get my metal from will take it back, so I always just take the uncut bar, can't remember how long maybe 500 mm, It costs me more to go to town than to have to go back and get more if I stuff up. Last time it worked well, the price of bronze went up.
Ian S C

Offline Allen Smithee

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Re: adding a bronze liner to an aluminum steam engine cylinder
« Reply #10 on: February 15, 2018, 06:14:17 PM »
Brass is not as durable as PB but drawn brass tube is readily available.

If the engine is not going to be used heavily would it be OK?

I've always understood that using brass parts near high-pressure steam is a bad idea because the steam de-zincs the brass, leaving very brittle copper behind.

But I don't do steam (except when I see the price of diesel) and could have completely the wrong end of the stick, so if others say it's not a problem I would trust their views more than mine!

AS
Quidquid latine dictum sit altum sonatur

Offline Jasonb

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Re: adding a bronze liner to an aluminum steam engine cylinder
« Reply #11 on: February 15, 2018, 06:55:50 PM »
No problem with steam on brass, its the boiling water and the impurities in it that will eat the zinc

Offline Bluechip

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Re: adding a bronze liner to an aluminum steam engine cylinder
« Reply #12 on: February 15, 2018, 07:37:55 PM »
Off Topic ..
AS:
'Price of diesel' ?  At least you're probably getting a decent MPG  :headscratch:  Last time I went home from Jo's in my diesel Forester: 175m, 3h20m. 60.2 mpg. The new petrol one: 175m. 3h40m 38.8 mpg. I feel I'm propping up the world petrol industry at my own expense. Woe is me   ...   :'(

Back on:

We don't know if the engine is actually going to be used on steam, lots aren't.  And if it is, approx. how many hours per annum. If it's of the sort that powers a small boat or such like then PB

Back to my  :DrinkPint:   ;D

Dave
« Last Edit: February 15, 2018, 07:44:43 PM by Bluechip »

Offline Allen Smithee

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Re: adding a bronze liner to an aluminum steam engine cylinder
« Reply #13 on: February 15, 2018, 09:02:13 PM »
Off Topic ..
AS:
'Price of diesel' ?  At least you're probably getting a decent MPG  :headscratch:  Last time I went home from Jo's in my diesel Forester: 175m, 3h20m. 60.2 mpg. The new petrol one: 175m. 3h40m 38.8 mpg. I feel I'm propping up the world petrol industry at my own expense. Woe is me   ...   :'(

Ah. Last time I went back from Jo's it was ~8miles, 20 mins and around 40mpg in my diesel Accord...

 :LittleDevil:

AS
Quidquid latine dictum sit altum sonatur

 

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