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Discussion Starter #21
Hi Postie.

Good read.

I considered zinc plate over stainless for my rebuild but was swayed to the latter due to the corrosion free properties of stainless.

Pitting can occur with stainless, but this would require severe environments which might include the presence of corrosive chemicals such as chloride.

The problem with zinc plating is that corrosion will take place once the zinc coating is damaged.
Such damage can easily take place simply by the pressures brought upon the respective surfaces of fasteners when tightening takes place.

On the other hand, zinc plating is ideal for those who require fully original restorations in which original fasteners are valued in a rebuild.

Cheers

R R
Thanks for the kind words, Rod. I'm not going for originality as the bike is already a real Trigger's Broom (I am thinking of naming it "Trigger" :) ), and it's never going to be a show winner. I must confess to choosing zinc mostly for cost reasons. A quid a bolt isn't a lot, but added up over the whole bike, that's the fork refresh paid for, or a good chunk towards the engine rebuild costs.

There isn't a single part I've taken off it that isn't going to have to be reconditioned or replaced, so I'm trying to keep the budget sensible where I have the option to. In this case, given the bike is only going to be ridden for pleasure (nice days, basically), and will be cleaned carefully after use, I thought I'd take the chance on zinc.

Having run modern(ish) Jap bikes previously, I had a good lesson paying attention to fasteners, which really do not cope with British weather and road salt at all. My old Kawasaki ZZR600 used to corrode fasteners almost in front of my eyes, particularly around the forks and front brakes. Regular washing, and wiping a rag soaked in 3 in 1 over the bolt heads every so often seemed to keep the worst of it at bay, although that was ridden all year round and used for commuting occasionally, so it had a pretty hard life. I'll have time to tinker and fettle the old girl once she's running, so I'm happy to add fastener care to the list. :)
 

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And, you can always replace any that do corrode but as long as you get good quality Zinc Plated fasteners (i.e. British or German), I doubt you will have any issues. I have a Lotus Seven rebuild, completed 23 years ago, and the ZP fasteners still look great, even the exhaust manifold nuts. Admittedly apart from occasional Summer showers, the only moisture it has seen in that time was soapy....

Grove Components are my ZP fastenings supplier. Not the cheapest but the quality is excellent.
 

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Discussion Starter #23
And, you can always replace any that do corrode
My thinking exactly, Boggie. :)

I have managed to clean up the swingarm pivot bolt, nut and washers, plus the metal dust caps to a point where I'm happy to refit them (plus they're quite well hidden anyway). Being caked in oil and grease seems to have preserved them quite nicely. Even the o-rings on the dust caps are still pliable and undamaged. A small win! :grin2:
 

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Thanks for the kind words, Rod. I'm not going for originality as the bike is already a real Trigger's Broom (I am thinking of naming it "Trigger" :) ), and it's never going to be a show winner. I must confess to choosing zinc mostly for cost reasons. A quid a bolt isn't a lot, but added up over the whole bike, that's the fork refresh paid for, or a good chunk towards the engine rebuild costs.

There isn't a single part I've taken off it that isn't going to have to be reconditioned or replaced, so I'm trying to keep the budget sensible where I have the option to. In this case, given the bike is only going to be ridden for pleasure (nice days, basically), and will be cleaned carefully after use, I thought I'd take the chance on zinc.

Having run modern(ish) Jap bikes previously, I had a good lesson paying attention to fasteners, which really do not cope with British weather and road salt at all. My old Kawasaki ZZR600 used to corrode fasteners almost in front of my eyes, particularly around the forks and front brakes. Regular washing, and wiping a rag soaked in 3 in 1 over the bolt heads every so often seemed to keep the worst of it at bay, although that was ridden all year round and used for commuting occasionally, so it had a pretty hard life. I'll have time to tinker and fettle the old girl once she's running, so I'm happy to add fastener care to the list. :)
I can understand your need to keep a lid on cost.

These machines can be a money pit.
I'm too scared to add up my receipts and its not over yet.

The big problem with corrosion isn't from the visible external areas.
It's from the hidden threaded areas, particularly contact between fasteners and casings.
This is where catalytic processes occur causing the surfaces to fuse with each other. :frown2:


R R
 

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I can understand your need to keep a lid on cost.

These machines can be a money pit.
I'm too scared to add up my receipts and its not over yet.

The big problem with corrosion isn't from the visible external areas.
It's from the hidden threaded areas, particularly contact between fasteners and casings.
This is where catalytic processes occur causing the surfaces to fuse with each other. :frown2:


R R
Also: Whatever you do, don't include labour! My '59 Triumph roadster took over 2000h to complete (although it was a basket case that arrived in boxes). I dread to think how much time I have spent restoring stuff over the last 35 years but I never count the hours spent on a hobby... :)

Absolutely agreed on the dissimilar metal issues; My picture earlier in this thread illustrates / proves there is a real problem but it is the hidden stuff that causes the most problems. Fit a dissimilar metal nut to an existing stud and this WILL be a problem eventuality. Admittedly for some people this is not a concern as they will no longer own the vehicle when this is the case but as I said earlier; I treat all my restorations as "keepers". I wish all of the previous owners of the various bikes/cars I have restored cared as much about the next restorer.... :)

Cheers,
Ian
 

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Ian,

My picture earlier in this thread illustrates / proves there is a real problem
Curiously, despite following several of the links, I couldn't find any details of the grade of "stainless" used nor of the environment in which the pictured components were used; can you enlighten the Forum?

The English translation of the German caption to the picture is, "Stainless steel screws and nuts with corroded washers on a galvanized steel base". Absent more factual information, ime that picture could show nothing more than poorly-plated steel washers left without attention for some time, that period depending on the environment? Absent more real actual facts, 'fraid I don't see it "proves" anything.

As I posted earlier in the thread, understanding different types of corrosion and their different causes was once part of one of my past jobs, which I was paid handsomely to get right because, when people got it wrong (and others did), companies had to spend very large sums of money replacing or renovating equipment.

So the extrapolation of a certain type of corrosion that occurs in reality only in very limited circumstances into some sort of magic that affects only "stainless" as a collective noun is laughable. If nothing else, it ignores that the major components of these old heaps are two "different metals" - iron and aluminium - alloyed with several other "different metals", the iron alloy plated with yet more "different metals" to slow down (note not stop) corrosion by at least one other cause. But somehow just "stainless" is the modern opposite to the Philospher's Stone? Mmmm ...

Different pov and experience - yours included - have been posted in this thread already. More to the point, Dan The OP has had his question answered and has made his decision. Extending the thread simply by persistent repetition of one particular pov, without additional factual information, is therefore pointless.

Regards,
 

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Hi Rod,

not over yet.
The big problem with corrosion isn't from the visible external areas.
It's from the hidden threaded areas, particularly contact between fasteners and casings.
This is where catalytic processes occur causing the surfaces to fuse with each other. :frown2:
:thumb Good to know you're still carrying on with your bike's restoration, although a pita to read it still isn't finished. :(

:confused: Given our previous discussions about stainless, and particularly fasteners, what corrosion issues have you experienced?

Regards,
 

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Hi All.

I am going to leave now. I see no value in debating proven science here. I just present the facts and let people decide. Here is some real information from the stainless steel industry and a metallurgist.

https://www.bssa.org.uk/topics.php?article=95

http://www.ssina.com/corrosion/galvanic.html

http://www.ssina.com/corrosion/galvanic.html

There is lots more if you search Google and Google Scholar. Bottom line: Bimetallic galvanic reaction will occur between steel and stainless. That is a well known, documented scientific fact. How fast the reaction occurs and how much damage is done is influenced by a number of factors, moisture, grade of metals etc. I prefer to play it safe but you all can decide what is right for you and your project. This is all that needs to be said really.

Good luck with your restorations! Whatever you choose, it is great that so many of these fabulous old bikes are being rebuilt. Long may we hear the thump of big Brit Bikes on the open road.

Cheers,
Ian
 

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Hi Rod,


:thumb Good to know you're still carrying on with your bike's restoration, although a pita to read it still isn't finished. :(

:confused: Given our previous discussions about stainless, and particularly fasteners, what corrosion issues have you experienced?

Regards,
Thanks Stu.

Sadly needy dependants are stealing my resources (time and money).

Next stage is the engine rebuild.

Items completed include:
Rebore and hone.
Barrels painted.
Head already reworked (valves and guides).
Many parts collected including full gasket kit, special tools, pistons and rings, Motao Oil Filter Kit, bottom end and gearbox bearings, new clutch plates, 6 volt coils, Pazon EI, Alternator, NOS 3 Phase Stator, Rec/Reg, seals, and other parts too numerous to mention.

Engine pull down is next. :frown2:

Until I find time, I'm just collecting tips to make sure I'm well prepared.

In terms of the stainless steel fasteners, I'm more than happy with the results.

R R
 

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Discussion Starter #30
Also: Whatever you do, don't include labour! My '59 Triumph roadster took over 2000h to complete (although it was a basket case that arrived in boxes). I dread to think how much time I have spent restoring stuff over the last 35 years but I never count the hours spent on a hobby... :)
I reckon I’m about 50 hours in so far, and all I have so far to show for it is a bike in kit form, with boxes and bags of of rusty and knackered stuff, albeit with an almost painted frame :grin2:

I’ve thoroughly enjoyed 49 of those 50 hours. The remaining hour did involve a bit of swearing :wink2:
 

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I have had stainless on my bike since 84 and never had an issue

So long ago that Middleton & Son was just dave Middleton
I also have stuff from acme stainless, a guy on eBay, and andy molnar

Incidentally I found this while looking for something else
https://www.wrightsautosupplies.co.uk/product-category/motorcycle/triumph/

While there are many scientific facts and theories about galvanic effects, they just don't happen on a bike that gets ridden
 
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