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Hi Folks,I have an M16 that is 2 years old with corrosion developing on the right side base plate. This plate is the structural interface between the mast and undercarriage leaf spring (pictures attached). It is made from 4130 Chrome Molly (along with airframe).The aircraft has been maintained meticulously & hangared well since day, so this one"s a puzzle.As I need to address this ASAP, can anyone advise whether if this has happened to you? and if so, what repair method/technique did you use?Your thoughts would be greatly appreciated.Andrew
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Maybe send an email and pics to Magni and see what they recommend? It would be easy just to hit it with some rust converter, but you never know how bad the rust is under the plate..... so I would be asking the manufacturer for their advice on proper repair before doing anything, thats for sure.
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Thanks Mate & good idea!i"ll be doing that.
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It certainly appears that the powder coating didn"t adhere properly for some reason? How close to the coast are you? or where was the machine when you bought it? Didn"t you have some issues with corrosion of the prerotator starter bendix too?
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Machine is approx 30kms from coast in a fully enclosed hangar, it was also in a good quality hangar in Newcastle prior to me buying it. I don"t believe the environment is a factor here.Pre-rotator failed 6 months ago however that was an unrelated issue (seized bendix gear) due to ingress of sand, dust, dirt etc.. between gear & shaft (not by rust) - this was evident during petrol bath. My bendix does not have a top umbrella as is fitted on newer versions now.
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No worries, I am not blaming you in any way, I was just looking for any possible connection. It looks to me like there might have been some water get under that plate and sit, causing the rust.... especially if the powder coat/paint has lifted off the steel? It will be interesting to see what the factory has to say about it and their suggested fix for the issue?
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Thanks MadMuzz, yes you could be right there!I"ll be in touch with Magni and see what they recommendCheersAndrew
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the C.R.C. company that makes all those wonderful spray cans and other products stuff have lots of truely amazing new
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Andrew that looks like the type of fault you get when the paint fails on a sharp edge - usually due to poor preparation during the cleaning cycle or also the gun angle and subsequent spray pattern. The sharp edge has possible had some contaminant (handling oil from a finger print?) and the paint has failed to correctly attach to the base metal. The bubbling looks like further moisture has crept in by capillary action from that initial paint imperfection. Structurally it appears as though you have caught it in time.Regards......Chook.
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Hello Andrew, Looking at your pictures the main reason for this is paint or powdercoat doesn"t like sticking to sharp 90* corners and also has a reduced film build because of this. What you are seeing is actually not as bad as it looks. It would definitely pay to remove the main landing gear spar and check the underside for pitting. I reckon that if you were to remove that bubbled up coating all you would see is dark rust stains and it would be extremely unlucky to see any pitting on that top surface.The best way to repair that would be to sand out the dark stains with sand paper. I would not use sandblasting as the grit gets into places that you don"t really want it. ( ie. magneto housing, control system etc ) If you have any minor pitting you can use the corner a small drill bit ( 3mm or less ). Put the drill in at approx 20-30* from the horizontal and slowly use the corner of the cutting edge to remove the dark stains. Once you have no dark rust stains left apply a good quality etch primer and two pack paint. ( Killrust and White Knight etc ARE NOT good quality :
) You to be looking in the automotive paint section or at least industrial paint. Don"t get sucked into paint that doesn"t need primer, they are two different things.Machine is approx 30kms from coast in a fully enclosed hangar, it was also in a good quality hangar in Newcastle prior to me buying it. I don"t believe the environment is a factor here. You better believe it that enviroment has had something to do with this. You very rarely see these paint flaws in areas right away from the coast.Chook you beat me to it while I was typing. ;D Regards Matthew.
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Yes it is good he caught it now, however I still suggest he contacts the factory with pics of the issue and asks for their advice, rather than just fix it himself without letting them know. They might want to replace the part for him to be sure it is safe, they might tell him how they require he fixes it (to protect any further claims down the line)
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Thanks Guys for your input, I appreciate your advice.i"ll let you know what Magni have to say.Big thanks!
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Magni have replied and stated problem was caused by calamine of the laser cut that impeded a correct contact with the primer.They suggested to sand the corrosion off and repaint.
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