drive tube lugs

[Geoff Uphill]

I've been attacking a very rusty short shaft drive tube casing - and I see the lug is braised on. I always presumed they were welded.
Are all the lugs braised ? Or just the older ones ?

If so, they should knock off fairly easily at red heat - an would slip back on to suitable stainless polished tube.

1" 1/8th OD polished 304 stainless in a wall thickness of 2 - 2.5mm is available - and at approx £60 - 70 for a 20 foot length !
I found it listed at 1.5mm wall thickness - and on enquiry was told it was no problem to supply heavier gauge.

Just a thought.

Geoff

[woodbutchergraham]

Not bad Geoff that works out about just over a tenner each, you could have a sideline on your hands ! Keep up the posts and PM me if you have some spare. My intention was to machine out the old tube and re weld new pipe.

[Geoff Uphill]

Of course the problem with this stuff is how it gets delivered. The place is up north somewhere.
I'm thinking to get back to him again - to double check on what gauge he could supply. Seagulls seem to be 2.5mm thick which is an swg size I think. I've looked a lot online for 1 1/8 tube and this is the first I have found in polished stainless. 304 is fairly low grade of course.

If they could do a price for cut lengths - the carriage would be easier. Depends on how many to keep the cost down.
That price was for the 1.5mm at a 20' stock length.

I'm still not sure of course, whether they are all braised. I suppose a way to check is to grind away a bit of the top flange face.
It would also only be good for standard shafts - not the big ones that reduce at the crankcase.
You don't need a great deal of heat to split a braze - especially if you chop the old leg off and just heat the lug.

I've no idea whether stainless can be welded to steel - but they could be epoxied and and pinned easily.

It was just that all the posts I have read have always talked about machining out the old bar - so I presumed they must be welded.
Seeing this re-awakened my search for stainless tube ! As I say - just a thought, for now...

Geoff

[StephenRT]

I have at least 4 legs that are too rust pitted to re-chrome.The cast ends are all reasonable and I’ve been thinking of trying to substitute stainless steel tube but have been unable to find a source of inch and one eighth diameter with a thick enough wall.

If you have a source I would be very interested in knowing the name of the supplier.

As mentioned, the chrome on the cast ends is still good and rather than risk destroying this by heating I intended to bore them in my lathe to suit the size of the new tube.My idea for joining the new tube to the original end was to use one of the many Loctite retaining compounds with perhaps a grubscrew or pin for additional security.

I know that the thought of effectively gluing the parts together may raise a few eyebrows but I’ve used it for fitting main bearings in motorcycle engines with success.

[Charles uk]

Here's a very poor copy of a report Seagull did in 86 on this subject, you will have to rotate your head to read it.

[Charles uk]

I've just thought about the previous posts talking about retaining Stainless tube in the top castings.

If the drive shaft tube came loose this is what probably would happen,
First the drive shaft tube would start to slide out of the casting, this you wouldn't notice, until the drive shaft parted company with the crankshaft, or the whole lower end disapeared into the deep, at this point the engine revs will go into terminal overdrive, now the captain will take his hand off the tiller arm & make a grab for the throttle to stop it screaming, if the bottom end had not allready taken the plunge it would now, due to all the vibration, at this point there is nothing holding the powerhead to the transom bracket so bye bye seagull.
If it hadn't thrown it's toys out of the pram, due to over reving, immersion whilst running would cause it to hydrolic, so a scruffy drive shaft tube would be the least of your problems.

Please could you film this & post on youtube, I'm sure it will get heaps of hits.

P.s. don't forget to take your paddle.

[40TPI]

Here's a very poor copy of a report Seagull did in 86 on this subject, you will have to rotate your head to read it.

Sod the debate on polyester vs epoxy, or what is the best design for your next bath tub design with Ikea fitted furniture on some hull software package ..... that was amply worth the bandwidth in terms of furthering a technical debate on SS casings and what and how it was originally being presented and where....... and to who.

Note for instance the circulation............

In terms of something new I'd say that rates post of the month. Thank you Charles.
I just wish I/(we collectively) could book a few hours in front of the filing cabinet this originally came out of.............

Peter

ps I do hope you will follow up with a sequel on the Indian kiagrade pistons and also Hydralon?

[Geoff Uphill]

Thanks Charles - interesting read,

as I said, just a thought.
Now, where's that silver paint - lets keep things simple !

Geoff