Vapour Blast sent my engine grey - New Pics added 08/01/2012

[kev edwards]

I,m not sure but am wondering if they have had a bath in a caustic type degreaser which would leave them grey and could also leave the whitish deposits (chemical salts) on them.

[coldsummer]

I,m not sure but am wondering if they have had a bath in a caustic type degreaser which would leave them grey and could also leave the whitish deposits (chemical salts) on them.

You may be on to something there Kev. A year or so ago I left an engine sprocket cover overnight in a bucket of degreaser thinking it would save me some time. The next morning the case had turned a dark grey, almost like it had been chemically burnt. I thought it would have to be scrapped but Mikey managed to polish it back to a mirror finish.

[mikey]

I,m not sure but am wondering if they have had a bath in a caustic type degreaser which would leave them grey and could also leave the whitish deposits (chemical salts) on them.

You may be on to something there Kev. A year or so ago I left an engine sprocket cover overnight in a bucket of degreaser thinking it would save me some time. The next morning the case had turned a dark grey, almost like it had been chemically burnt. I thought it would have to be scrapped but Mikey managed to polish it back to a mirror finish.

Yes that right simon forgot about that but it was a dark greyish color wasnt it
and badly scarred to as i remember by the caustic effect of the solution

[Z1B]

In my oppinion the media that they have used is filthy, we filter it all the time & you need shades on when the jobs finished ! to do this aqua blasting properly it doesnt just take 5 minutes iv done dozens of "z" motors

Yea just about to add the above, had experience of such likein many processes Eg Chrome plating can give bad results if the medium is not kept clean, lots of cowboy companies really dont take the time to recycle the media or Chemicals properly, or like our local Chinese they use the same oil over and over and over again and everything tastes the same, blastings no different if the beads have turned to mush with all the old carbon, oil, paint and everything else added the results will be shit,
the lads have also mentioned grit ans sand these open up the pores and cause quicker Oxidation, whereas beads, close the pores and polish and strenghten the material thats why racing components are bead or similar blasted NOT sand,grit or otherwise
Remember back in the 70's a friend got his Tiger Cub engine blasted by the local boys who were doing the walls, Laugh I nearly wet myself when I saw it, all the fins were gone it was SCRAP LOL.

[kennym]

Thank you everyone for all your suggestions, I believe that it was due to the chemical additive that was being put into the water, it was aquablast ? some salt mix which I think was causing the aluminium to oxidise virtually on contact, It would appear that the operator may have doubled up on the mix anyway I requested that we try again without the additive just the glass beads and clean water, I was allowed to do the blasting myself so completely hands on the results are much more as to what I was expecting thank goodness. I guess you must e dilligent and keep a eye on everything now on with the rebuild must go lap some valves

Kennym

[Z1B]

Did you get it blasted as it is shown or are the parts sitting together to show us the finished product ??? this is quite important as those beads need cleaned out of the cyl head threads etc if absolutly everything was not blanked off, you will need to put grease on a M6 tap and run it in to each threaded hole to remove ALL beads, and absolutly blow and wash out every oil passage through the head, if the blaster is not absolutly switched on with engine parts you will end up with a wrecked engine, I am only playing the devils advocate here, but you mentioned dilligence so thats something to kick off with. let us know what blanking was carried out.

[Z1B]

Just had a quick look at your parts at first, looking back now over them it is fairly obvious that you have sat them together to take the pics, initial concerns were based on years of experience of other folks having done similar and myself having to rebuild the poor bastards Zeds etc hope alls well

[kennym]

thanks Z1B you are correct the parts are just sitting there, I have started the task of making sure tht they are 100% clean, bloodey hell I never relised that there were so many bolt / screw holes lol

[Rich]

pay particular attention to cleaning the oil galleries as well

[Garn 1]

My opinion is, that most of these Vapour-blasters have a few tricks and methods up their sleeve. They keep them secret, with regards to their blasting media, technique and cleanliness.
RegardZ.

[DDZ900]

garn ! im saying nowt ???

[Garn 1]

DDZ900, Think about this, your jobs are good and shiny, because you constantly filter your medium solution, perhaps that is your secret!
RegardZ.

[Big Fluff]

Engine parts sure do look bloody brilliant after aqua blasting that's for sure.
But as Z1B says, you reallydo need to make sure that all glass media is removed 100% guarunteed.

On a personal note, I would never have the faith required after I thought I'd cleaned my little Z500 engine parts enough, only for it to wreck the crank upon start-up. Admittedly they run plain shells on both the crank and cams, but that stuff hides bloody everywhere.

Anyway, I hope it's all well and you have no nasty surprises.

[Dodgy Z1B]

I wrecked a gs750 engine many years ago by not getting the blasting media completely out I washed the head the cases etc for days in a parts washer and also blew through all the oilways with an air gun but still missed a bit. So you really need to be very very carefull.

[DDZ900]

yeh a mate of mine wrecked hes z650 that way, he got the topend back & just build the thing, 15mins later after start up just started knocking (i did tell him) he drained the oil & it was like grinding paste Every head i do i slide hammer the little alloy plugs in the end of cylinder head so you can get direct into the gallery with an attatchment i have on my airline.