Here's a picture of Johns dull chrome combination levers...He sent a few images so I'll post another when I've been through them in more detail...Any problems with service etc. John?....Ian
I've had lots of dull plating done to my satisfaction for years by a firm local to me, but it seems they didn't do such a good job for Ian. So I'm reluctant to pass on any contact details.
Of course it's a lot easier when you are friends with the firm and collecting staff by hand where imperfections can be rejected on the spot to be reprocessed.
Here are the Docherty levers on my Big4 and 16H. Ron
Thanks John (and Ron). The finish looks good from the photo. I'll give them a go with a spare set of levers. And Coventry's on the way to my parents, too.
Mark it's referred to "Dull Chrome" or "Dull Nickel" in the parts lists. It's not actually called Mat Chrome. So I guess a slight sheen is acceptable. But the duller the better to my mind. I wouldn't actually ask for Satin Chrome, which is what the previous owner of my G3 must have got, which does bug me a bit. Ron
It's certainly not what most platers refer to as 'satin chrome' which seems to be generally bright chrome over a brushed surface.
I'm not actually sure that it's possible to replicate the original extremely protective dull-grey with a bluish tinge finish in any country which has forbidden the use of hexavalent chrome.
Fine sand blast the item , don't go overboard with it , then a quick pickle.
This eliminates actual flat surfaces so when you plate over it , the plating grows every which way so it is not refective
Same optically as sand blasted glass or non reflective glass used to frame painting with .
Polishing for plating actually turns the surface oxide into a semi metallic glass with no grain orientation so the plating deposits in a uniform rate and in a uniform direction so becomes glassy
If allowed to plate out in random directions it no longer reflects for the same reason as galvanised iron is not overly reflective .
Platers are reluctant to do this for fear of getting blasting sand into the vats and contaminating them as it costs a fortune to send out a vat of chromic acid for cleaning & restoration .
Those of you with a home plating kit might like to try it .
And because you are plating over a very rough surface it takes a lot longer in the bath & deposits a lot thicker layer by the time the entire surface is properly plated
Plating currents ( and to a lesser extent voltages ) are determined by the surface area being plated
An easy calculations on a smooth flat surface but difficult to do on a rough surface .
Even harder in a jobbing shop where each rack is different .
Too much current & you burn the plating effectivly turning all into scrap metal and not enough current you get incomplete coverage which is very hard to rectify.
Easy in the wartime because they were doing racks & racks of the same items so a little wiggle room for trial & error but no such luxiary when doing one offs for picky restorers .
Dull nickle is a treatment in itself, used for example, on Lucas dynamo bodies (you can see that on the dynamo body in the picture below)...A reasonable substitute for that is tin plating, which benefits from having a copper layer first before the tin is applied and is thus reasobaly durable whilst having a good visual appearance for the application...
Dull chrome is applied over dull nickel to give the dull finish...The problem these days is that dull chrome is not a commonly applied finish and many platers (including my local one) don't even have a dull nickel tank...
IMO there is no way to replicate the finish that provides the right finish and is durable and believe me I've tried a few ways...
I believe BZP for fasteners (as a substitute for cadmium) is a complete waste of time for anyone that intends to use a bike in any type of 'aggressive' environmemt..For example when the roads are salted in the winter or for playing on the beaches of Normandy in the summer..Visually it also looks awful...I think tin plate would be a better option but blasted stainless steel is the better and permanent solution....My problem is that I can't practically replicate some parts in stainless so dull chrome is still required...These parts aside all fasteners and fittings on my M20 are now stainless...Visually it looks good and I don't have to go through the drama of getting a good plated finish...All the fasteners you can see in the image of my WB30 below are blasted stainless as a substitute for cadmium...Ian
Ian, I love the attention to detail on your BSA, it looks amazing. Can I ask what treatment you use on your alloy components; engine, gearbox & carb? I'd like to get the same finish on my G3WO. Also, what type of paint do you use?
Thanks for the positive comment....All the various alloy components are prepared by hand to remove obvious damage and then bead blasted using a medium aluminim oxide grit (80 grit) followed by finishing glass bead...
The oxide I run at about 85 psi and the finishing glass bead (which I recall is a 60 grit) I run at about 60-65 psi...I do a lot of preparation before blasting and getting the right finish on the castings prior to blasting is the 'trick'...Contact me off forum if you want more information on that subject...
I've always mixed my own paint to achieve the 'KGP No3' type shade I like....I use late war British Dark Olive Drab and mix with red oxide primer to move the colour towards the brown/green colour of KGP....All the paints are synthetic...I spray it myself using a Devilbiss spray gun...I've achieved pretty good results with the 'bottom of the range' 'Finishline' gun...I worked on the theory that even the base line Devilbiss gun has good nozzle technology and the baseline part is just a less fancy finish and construction...I use one gun for primer applications and another for top coat...One other gun I keep for 'civvy' jobs to apply laquer coats....Ian
Thanks Ian, I always like looking at bikes that you and Ron post on here, it gives me something to aim for! Do you do anything the stop the alloy components oxidising after you've cleaned them? The alloy still looks nice and bright on your carb and cases.
Tom what year/contract is your G3? my 1940 panel tank had all painted cases. Fortunately I have the parts list for my contract, which lists all the finishes. Ron
After blasting and washing/cleaning the parts thoroughly to remove any blasting media I just apply some WD40 and wipe off with a clean rag/paper towel....Ian
Easy way to "dull" stainless is to use a domestic chemical stainless steel saucepan cleaner .
The trick is to do one and time it so that you get the finish you find appealing
The longer the solutions are on the duller and darker the parts get
I haven't had a chance to compare with vapour blasting, but have used brick cleaner (hydrochloric acid) with good results. As WM20 says, parts get darker with longer exposure.
Hi Ron, my G3WO is frame number is 13596, which I think is 1940. I don't have the Orchard/Madden book to hand to check what contract it is. I've seen an ex-works photo of a non-panel tank and all the alloy is bare unpainted.
Hi Tom 13596 is the 597th bike from 3000 under contract C8078 supplied in 1941. 256 of them had panel in tank (I guess the first 256?)
Apart from the parts list for my earlier contract, I have these factory pictures of a later non panel bike, which shows the gearbox is painted but not the engine. It also shows a different silencer. But I've no idea of the contract that this bike comes from. Ron
An add on to a wavering thread...
Does anyone know the original finish of early front brake rods? Were all parts plated or some painted? I'm sorting out a list for plating, while the UK still has an economy.🙄
Hi Craig
I have the colours & finish for the rods & by part
It was a mix of plate & paint
I can check tomorrow- the book is not here with me in the house
Br
John
Here's another picture (I'm sure there are clearer ones) The only plated parts look like the sliding part at the top. Divert your eyes to the right of the bare metal speedo drive in the brake plate. Ron