OzVMX Forum
Clubroom => Tech Talk => Topic started by: evo550 on November 16, 2016, 04:58:54 pm
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Is this do'able with normal paint stripper or blasting without damaging it?
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Non-caustic paint stripper (methylene chloride) is fine with metals, but will wreck many plastics
Caustic paint stripper (sodium hydroxide) will dissolve magnesium and aluminium
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Yep i have done this plenty of times. Just paint stripper out a tin, that clear paste sort of stuff from Mitre 10. I would not sand blast it though, at least anything thats not really thick because its too aggressive. Normal glass beads are fine but if the parts are really rotted and getting thin it is possible for the beads to errode the mag or even blast holes in it but you need to be holding the gun really close to the part for minutes at a time to really do that so just use common sense. Dont hold it in one spot for really long time and have a decent gap an give it more of a light 'dust' instead. Just experiment a but and you will soon work out what the part can handle. I have had some suzuki magnesium covers that have caused me some headaches as they have been in really bad condition. Pretty much throwaway items that i have wanted to 'save', with really bad rotting and it gets to the point that you cant blast all the corrosion out with out erroding the material away or blasting holes in it. Have had the same problems with XL250 motosport clutch covers which are known for rotting where the clutch actuatator shaft is.
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Thanks gents, does it become less durable if it remains unpainted?
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You need to keep it covered if bare metal, as it will corrode very quickly. I always paint the item as quickly as possible and touch up any chips when in use.
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If it's a magneto cover and made of magnesium, it's a good idea to paint the inside as well as the outside, for protection from corrosion
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Its a complete 2t bottom end, I kind of like the bare magnesium look, maybe clear anodising?
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From the home of vapour / vapor / wet / aqua / hydra / hydro blasting. So many variations of a title for the same basic process lol !!!
When I do magnesium for customers parts the paint is removed in a methylene chloride dip tank then vapour blasted at a reasonably high pressure for paint prep, along with another little trick which gives a little more 'key' for paint to latch onto unless it is going to be left unpainted and then it's done with a different approach for a more durable and dressy finish.
Magnesium should generally be painted for maximum protection as it can be more unstable and vulnerable to corrosion.
Same process applies for aluminium but for a dollar reason. Why spend your dollars for me to chase a shiny finish that paint is less likely to want to attach too.
Hope this helps.
Dave Mac :)
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Powdercoat like rotax and you have no problems!! leave it open to the air at your peril!!
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Don.t use the oxy blow torch.....