EW 350 HANDLEBAR REBUILD

[LATDOUGNUT]

Hi All,

I have recently tried metal flame spraying on the Douglas EW 350 handlebar lug which was terribly corroded and would not replate. The lug walls, especially around the handlebar tube, were too thin to file down, so I sprayed Nickel powder and literally added metal where it was due. The result after brazing onto the handlebar tube is quite good and should replate well. All brazing was carefully filed and sanded away as it usually shows up after initial acid dip. This is just to show what can be achieved with modern technologies and know-how in cases which otherwise might seem desperate...
Please see the photos attached.

LATDOUGNUT

Old handlebar before rebuild






The lug is cut out -- the rust pitting can be seen



The tube remains are machined out





After nickel metal flame spray the lug is brazed on the new handlebar






Plated result

[graeme]

What a fabulous result! Your engineering skills never cease to amaze me. I had never heard of nickel powder before - and have certainly had numerous occasions where this technique could have been put to good use. I'll know what to do now!
Cheers, Graeme

[classicbike99]

Hi looks great can you give me more info on this process, and where to get the relevent parts required.

[LATDOUGNUT]

Hello,

Basically flame powder spray is an old technique and there are many newer technologies around nowadays, but these require expensive equipment and the powders used are very specific. I bought my MWA International MAC flame powder spray oxyacetylene torch 7 years ago at an industrial exhibition in Riga from a Rostherne based UK company. The torch can cost around GBP 1000 nowadays. There are many other torch manufacturers on the market, but you must remember that it is "flame powder spray" and any other term may mean an other technology which requires a different powder too. These powders have round particles and they fuse ideally without making pores or bubbles, hence it is an ideal material for building up hopeless parts for plating. MWA International were also selling Nickel powders -- they can be different hardness from HRC 15 to HRC 60 and different composition. For building up parts you only need HRC 15 powder. Since then I have been using UTP powders, e.g UTP HA-6315G (Ni, Cu,Si,B,C) -- it is 170 -- 240 HV (Vicker's Hardness) and is easily machinable and flowing well. You need to sandblast the part clean shortly before flame powder spraying. The trick is to heat the part and start applying a thin coat of powder (it goes through the oxygen channel from a little cup on the torch) before your steel or cast iron part gets blue -- if you overheat, the coating will not adhere. Likewise if the part will be too cold the process will not go properly. It takes some experience and patience. Sometimes if intricate parts need joining you can build up each part, machine them and then put together and spray build up like they have always been -- one part. For building up worn shafts I use UTP HA-5, it is Ni, Cr, B, Si, Fe, C and is around HRC 40 - 45 with good antiseize properties. I have been building up worn steel brake drums, shafts, welding cast iron cylinders, frame lugs, worn brake pedals, etc. This technology is a real restorer's Godsend if you use your imagination and practice the skills.
Good luck.

Before repair 1



Before repair 2



After repair 1



After repair 2

[LATDOUGNUT]

Here is the plated result of the handlebar in the first post above.

[Edin]

Hej Juris
What an exelent result,- I am impressed.
After rebuilding,- before nickelplating,- do you then cover the rebuild area with copper (electrolyse),- before it is
polishd and nickelplatet or nickelplatet/cromecovered?
Regards Edin DK

[LATDOUGNUT]

Hello Edin,

I have all my work plated in Germany and Britain by platers who use cyanide copper before anything else. I plate exhaust pipes(except first 15 cm from the cylinder head where copper peels off from heat!) and silencers, nuts and bolts and general items in Germany and petrol and oil tanks in Britain because there are small businesses working together with platers -- they can mend your tank if a problem occurs during palting. This is not possible in Germany though.

Why so much bother sending precious parts so far away? - I hear you ask. Because cyanide copper is no longer available in Latvia. There are a few plating places here, but they will first nickel plate your steel part -- just a little flash nickel and then they will acid copper plate it, 2nd time nickel plate and if necessary -- chrome plate as well. The problem is that nickel plating does not hold well enough on steel and the whole triple or quadruple plating can peel off! If you cyanide copper plate underneath nickel and chrome your parts can be scratched in use, rust still will not creep under nickel! Imagine the hassle of having to replate your built up wheelrims or painted tank after 2 or 3 years use on the street!

One precaution -- you must warn your plater that your item is nickel powder sprayed, otherwise he will keep it in reverse nickel bath and try to remove nickel from the repaired area by reverse electrolysis! Sometimes if it is a simple part you can get away by nickel powder spraying it all over and then file it and use several grades of abrasive paper and polish it in the end -- it will be like nickel palted!


With best wishes,

LATDOUGNUT