Engine lift/setback brackets

[Jon Fuller]

diplomatic skills my arse!!! I should publish some of the 'bollocking' emails you send me!

[Dan]

Oh well. All I`ll say then is anything we manufacture for the marine industry (and also all of our marine based customers)would never use 304 then. Next time any of you take a trip to Plymouth (Mount batten area) have a look at the lovely waterfront town houses whose balconies were made from 304. Lovely apart from rusty balconies that is!
aaaawell that engough about work!!

[Dan]

Originally posted by Jonny
not always.

if the surface is polished, it appears to be ok, in this pic, all the steering system, rams, brackets, tie bar etc, and the C/S bollts holding the lifting eyes on, are 304, and 4 years old.(actual lifting eyes are 316)

Hey Jonny,
When they do rust let me know. I`ll do you some 316L ones!!

[Jono]

[Rant mode on]

Aaah feck!! I was not gonna rise to the bait... but you couldn't leave it alone could you?

Alrighty... let battle commence, .... explain this statement then?


"304 is cheaper as it has a higher carbon steel content?"

What the feck are you on about?
Nothing to do with the fact that 316 has a higher nickel content and Moly added then? No... why would adding two very expensive components such as Nickel and Moly have anything to do with the price?

It's the Moly content that increases 316's resistance to "pitting"
So 304 has higher carbon steel content? Wow... It sure does lead a double life considering it's an austenitic steel....


So, no ships propellers have ever been cast in CF-4 then? That's the wrought equivalent of 304L, which you undoubtedly know....or perhaps sonar domes on some Yank warships? They've only been in service since the mid '50s.. I'll be sure to tell 'em of your concerns... [/Rant mode off]

Originally posted by Dan
Any form of marine application you should always use 316 or 316L (L stands for lower carbon). 304 is a fair bit cheaper as it has a higher carbon steel content.

[jw.]

Mrs Jono, feed him a pill, quick!

...found it. If it's a S/steel to a BS spec it is NOT 316. The colour for that is green. If it's red it's likely to be 303s31...

Cool, dissimilar stainless. I'll weld on me nuts later.

Cheers Jono.

[Dan]

WOW chill out. Didn`t mean top touch a nerve. If you use 304 fine, all I`m saying is that no one I deal with at work inc RNLI, Devonport Managment limited etc etc never ever ask for anything other than 316 thats all (not even on fastner, nuts bolts etc etc). Yeh ok fair game on the cost. As for material make up 316 can include from 10% nickel & 304 upto 10.5 so a little (ok yeh a little) bit of a cross over here. And again I stand corrected both material have 0.08% Carbon.

[Jono]

Okay, Okay.... laffin@ "Give him a pill"... I might have over reacted slightly.......

However as my business is s/steel based, I kinda get upset when people genaralise... I can't help it... if I wasn't bald I'd be a Ginga.......

...and as a point of order....max allowable nickel in ASTM 304 is 10% and ASTM 316 is 14%... those percents add up to $$$$ especially when you buy it in 100 tonne plus casts.... the reason for the corrosion showing on things like architectural steel work is normaly down to poor workmanship such as contamination from tooling or poor finishing.. like Jonny says..polish it....

[Jon Fuller]

I know the accepted thing seems to be 304 will rust, or at least leave rusty stains running down ya boat from fittings made of it.
I have to confess that when I was ordering the steering system, and noted that it was made from 304, I was a little concerned, even made a call looking for reasurance that I wouldn't suffer any such aggro.

All the stuff I've ever made for external use on boats (such as my lifting eyes and control levers) I've always used 316.

But I have to say, the IMCO steering stuff, which is now 4 years old, and made from 304, used in the sea etc, has no signs whatsoever of corrosion, pitting, disscolouration, or dirty streaks running down the transom.

My observations now are:

If you mop/polish the 304 component, (such as the heads of the C/S bolts holding my lifting eyes on) it doesn't suffer the usual traits.
one theory is that when you polish, removing a thin layer of material in the process, you also get rid of all the impurities/shitty bits, that get embedded in the surface during machining/forming, and it's these shittybits that cause the streaks and pitting on un-polished stuff.

it works for me anyway, try a test with two identical bolts, polish one and expose them boath to the same elements, it's amazing.

Something that bears this theory out, is that where I cut the holes in the 100x10 316 bar to make my lifting points, and it's difficult to polish inside these holes, those areas that were a machined surface disscoloured when exposed to salt, which I had to polish back to a shine quite a few times, before presumably all the contamination from drilling on the radial drill had rusted away, or been polished away, anyway, it stays shiney now.

[Dan]

OK well call its quits then!! (although I stand by the upto 10.5% nickel). What line of work are you in then is if stainless steel based, dont suppose you a steel supllier are you?

[Matt]

So that time you PM'd me and asked me about stainless steel fuel tanks cracking, you were just being a nobba?

Originally posted by Jono
However as my business is s/steel based, I kinda get upset when people genaralise... I can't help it... if I wasn't bald I'd be a Ginga.......

[Jon Fuller]

Originally posted by Jono
if I wasn't bald I'd be a Ginga.......

How do think I feel, I'm both!

[Dan]

Something that bears this theory out, is that where I cut the holes in the 100x10 316 bar to make my lifting points, and it's difficult to polish inside these holes, those areas that were a machined surface disscoloured when exposed to salt, which I had to polish back to a shine quite a few times, before presumably all the contamination from drilling on the radial drill had rusted away, or been polished away, anyway, it stays shiney now.

Hey Jonny,
What we do with the trim tabs etc etc is send them for electropolishing. You may already know but I think its like the opposite to plating. Instead it takes the top layer way back to the clean metal (ie getting rid of all the shite on the surface). Not as good as normal polishing but still a good finish on it and a dam site quicker to. Rather than you making your bits by hand you should come to me and I`ll laser cut em for you instead!!

[Matt]

He needs some exercise in his life.

Originally posted by Dan
Rather than you making your bits by hand you should come to me and I`ll laser cut em for you instead!!

[Jono]

Originally posted by Matt
... you were just being a nobba?

Feck right off... or I'll tell Rob ya trashed his mota....

[Jono]

Originally posted by Jonny
....one theory is that when you polish, removing a thin layer of material in the process, you also get rid of all the impurities/shitty bits, that get embedded in the surface during machining/forming, and it's these shittybits that cause the streaks and pitting on un-polished stuff.

...It's called *snigger* "Crevice corrosion"..*snigger*...

[Gav]

stainless shmainless! wtf is all this rantin about? just use the fkin best! simple....... dont they use pig iron on rhibs?

me and lobbers(trumpton) are having ss ski frames made for our boats out of old bog pipe!

hey jono, i didnt realise there was anyone as clever as you in kiddy well ,apart from me

[Gav]

got some practice in for st patricks day talk about peir pressure

[Jono]

Originally posted by Gav
got some practice in for st patricks day talk about peir pressure

...Piss 'ead.!!. me too ..*hic*.....

[Cookee]

Originally posted by Dan



What we do with the trim tabs etc etc

You do trim tabs? Still thinking about a set for the race boat - still havn't decided what to do about it yet - what sort of thing do you do?