Treating Ally and Mag cases/parts

[Gippslander]

Building up a Husky CR450 engine and rebuilding a KTM wheel.

Had the usual parts soda blased, Gippsland Soda Blast here in Sale (0428 598 778 Dave) did a great job.

Then I wanted to treat the alloy properly, I remember when I visited Jiri Starec in the Czech Republic and was asking heaps of Q's he mentioned that when he gets raw castings he always does the proper factory treatment (he showed me how he does the CZ mag hubs that he makes brand new).

So I asked around over here and a friend who is into Aircraft told me about what the Aircraft Industry do with Alloy and Magnesiumn parts when they are rebuilding engines, and he said, bring your parts out to the workshop and we will do them for you.

Photos...

Chemical that is mixed with water to get the ally treatment, it is a gold coloured powder, the colour of shelac before it is mixed


Chemical that is used neat on Magnesiumn parts


The data sheet for the Mag chemical


Removing a case half, it had been dunked for 3-4 min.


Rinsing the case half, the other parts are being scrubbed with scotchbrite n' water before being dunked


Before and after case halves, easy to sse the difference


Some Ally parts done, some mag parts awaiting treatment


Mag part being treated


KTM mag hub with the treatment, takes a min or so for it to go grey


Treated Mag parts, the colour goes a bit more even when they are dry


Now, to assemble, and the instructions are that the parts are painted normally, and because of the treatment they should not breakdown as can happen with Ally subjected to a lot of weathering and the same for Mag but a lot faster.

[Davey Crocket]

Awesome stuff Gibbsy, those aircraft boys only have the BEST shit, anybody with mag stuff should be getting that done.

[Lozza]

Nice stuff Gipps, where did you get and how much?

[firko]

Good stuff Gippy...This is the type of post that sets this forum above the rest. It's much better than watching Viper implode elsewhere on the forum.

Does this process produce the proper goldish tinge on magnesium? One of my pet hates is CZ hubs painted bright gold when in fact it should be a sort of metallic beige colour. Is it a permanent finish like anodizing or does it have to be occasionally redone? Can the chemicals be readily purchased (without a Hazmat permit or whatever)? Could I do the process at home in my parts washer?......questions, questions, questions

[tony27]

Looks to me that the alloy goes yellowish & the mag dark grey Firko, unfortunately my CZ hubs will be painted when I can afford to replace the steel rims, $660 each is the stumbling block

[oldfart]

Mark , The mag procees in done in 2 parts    1-  using  dow # 1 to remove oxides and then part 2  - dow # 19  which provides a protective coating  prior to painting
You can call them direct @     EZY Spray   03 5977 4088
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Alodine is brilliant on Alloy  but i don't like the goldish finish (a  personal thing )       
                                                                                                             

[Gippslander]

To try and answer Q's

The cost was nil

I asked a lot of Q's, the mech said:

Re the ally...
1.  He did not know what it would cost, he said it is part of reconditioning an Aero engine and is required to stop the breakdown of the alloy.
2.  The chemicals are big $, the 20 L drum is about $2K but has been there since he has been there - 2 years - and is only half used and maybe 3-4 aero engines a week.
3.  You can buy in much smaller quantities.
4.  Keeps really well, in his training it was said that you had to have a fresh mix every few engines, but nobody does that.
5.  The finish lasts for a "few years" if left unpainted and is to protect a part if the paint gets chipped or if moisture gets under the paint.
6.  You can get a much darker gold (sort of) colour on ally parts by leaving them in far longer, and the extra time is cosmetic only, he recalls being told that 3 mins is enough to give corrosion protection.

Re the mag...

7.  He has not done much of that.
8.  Did not know a lot about it.
9.  Recalls that in training was told that if mag parts are left in too long they go mucky black, was told not to do that, can't recall if it degrades the mag.
10. Recalls being told that the process must be done for every mag part because mag degrades comparativly quickly.

Also,  when I asked Jiri Starec about the process he showed me the  20 L pail of powder chemical that he uses for the mix (don't recall if he said water), he said the parts simply get left in there to pickle, do not recall any mention of heat or current. 

[Lozza]

Good stuff Gippy...This is the type of post that sets this forum above the rest. It's much better than watching Viper implode elsewhere on the forum.

Does this process produce the proper goldish tinge on magnesium? One of my pet hates is CZ hubs painted bright gold when in fact it should be a sort of metallic beige colour. Is it a permanent finish like anodizing or does it have to be occasionally redone? Can the chemicals be readily purchased (without a Hazmat permit or whatever)? Could I do the process at home in my parts washer?......questions, questions, questions

Chromate is the corrosion protection magnesium needs.

[Montynut]

Lozza is correct although Chromate is only the first step in protecting magnesium (Dow No1 solution). It in itself does not protect the metal but prepares it for some other coating by pickling the surface rendering it neutral for painting etc.

http://www.mb-racingwheels.com/magnesium_protection.htm

I can not read what the Dow No 19 solution is'

I would really like to know how Marzocchi get the sort of dirty gold effect on their fork legs from the ’70 & ‘80s.  You cannot replicate it with paint. I have tried time and again but it is alway off

[firko]

I'd like to get a cylinder and head done...I wonder how the process reacts to the steel liner of the barrel? Is it  harmless? Does anybody know where I can get this done in Sydney? 

[Gippslander]

The steel liner and the thread inserts in the top of the cylinder look completely untouched by the process, it's now about 30 hours later and I have not even rubbed an oily rag in the cylinder and no spot rusting which is what you would expect, it's going to get a light hone anyway

[rocketfrog]

Alodine is used to achieve the chromate conversion as Lozza says. This Product works extremely well to protect the base metal and provide excellent primer and or paint adhesion. Alodine is basically hexavalent chromium solution or chrome 6. If you have seen the film Erin Brockovich you may have heard how toxic Chrome 6 is. Be warned that this process is not a DIY for most folks, as the chemical is expensive to buy and even more expendsive to dispose of according to law. RAAF Surface finishers use Alodine 1200 every day, they tell me that the stuff will cause cancer and will likely kill you if not handled with all precautions. This job is best out sourced to the pro's.

[Lozza]

This job is best out sourced to the pro's.

Jason that is VMX code for go "It'll cost way too much so might as well do it at home, how hard can it be?"