Anyone successfully grit blasted a gearbox without stripping it first? I plan to block up the vent hole on top and bag the shifter seal area first, and just not aim directly at the output shaft seal area (not really visible anyway). Who else worries that this will end in a crunch nightmare? The box was recently rebuilt by a specialist but they didn't clean the outer casing so I don't want to wreck the internals for the sake of appearance but in my car it'll be on show all the time.
What is wrong with the gearbox currently? is it just flaking existing paint, or is it oxidisation? i personally wouldnt want to risk blasting a gearbox. Id try using a chemical cleaner, and maybe a wire wheel to get the worst bits, then paint it.
I'd not like to blast it either. Bag and seal the openings/seals and get to work with a degreaser and stiff brush. Once its fitted its going to get grubby again anyway.
Why not just wire brush the worst of the corrosion/dirt off the gbox and dust lightly with some silver paint? always worked for me. much less risk than fillng the gbox with grit!?
The most extreem way I would clean a box would be with a pressure washer.
I'd seal it up good and blast the flip out of it. Can't beat a blasted finish for painting
I might blast a box before a rebuild but I would NEVER do it to a rebuilt box
Never
Never
Never
A bit of hard work with brush and cleaning fluid
Another one for "don't even think about it!" Just asking for trouble.
Cheers
Fred W B
I've done it and had to strip and rebuild (the gearbox, not me)!
It was a second hand box that had been rebuilt but came covered in dusty rust. I took ages wrapping any points of ingress with duct tape/tin
foil/cling film/insulating tape etc and I was sure it would be OK. I used a bodywork 'Spot blast gun' but the pesky stuff still managed to
get in!!
Bah, see I knew the answer but didn't want to listen to my common sense!
It's a very very complex alloy casting with nooks and crannies and there's no way in hell I can get any usable mechanical brushing in there,
and hand-wire-brushing doesn't seem to scrape the surface. It's well and truly oxidised but not white and powdery. I might just wash and
paint over the corrosion to save heart ache and replacing it in 0.3 miles when the grit eats it.
I used a dozen different chemicals on my alloy block and it's still fluffing white oxides everywhere so I'm wary of anything chemical.
[Edited on 9/11/12 by coyoteboy]
What about soda blasting? Would that not be OK.
Adrian
I blasted mine but with the media suspended in water so no dust. Wrong or not its done now, well eight or ten years ago...
quote:
Originally posted by AdrianH
What about soda blasting? Would that not be OK.
Adrian
I tried calling all the local soda blasting folk, no-one would do it. IDeally I'd like dry ice blasting so I've no mess to tidy up but alas I only have a cabinet and al oxide.