Author Topic: Vapour blasting  (Read 2189 times)

Offline Dazza215

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Vapour blasting
« on: April 19, 2017, 11:46:45 AM »
I sent my head, barrels, rocker cover etc to the vapour blaster. Currently waiting for the call to collect them.
I feel like an expectant father. Surely this is not right!!!

Ive never gone to this level of restoration before, So chaps, when I get them back, what do I need to ensure before putting the engine back together?
Thanks in advance
I dont ride a bike to add days to my life. I ride to add life to my days.

Offline Nurse Julie

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Re: Vapour blasting
« Reply #1 on: April 19, 2017, 12:03:24 PM »
Make sure every single grain of glass bead is removed from all the oil ways you can find, and the oil ways you can't find and ensure no engineered surfaces have been damaged during the process.
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Offline mike the bike

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Re: Vapour blasting
« Reply #2 on: April 19, 2017, 12:06:21 PM »
After having my engine cases vapour blasted I was careful to remove every scap of glass beads from the oilways, I run a tap down every tapped hole, in short, I was paranoid about glass bits damaging the internals so I was scrupulously clean when reassembling it.
Fast forward seven years.   I went to replace the camshaft with one that wasn't worn and the first thing I noticed was loads of swarf and glass bits.   The head, rocker cover, crankshaft, shells, oilpump are all now scrap.  My theory is that the glass beads were lurking up a dead end oil path in the bottom crankcase, like the one that's got the plug in behind the alternator.
Luckily I had a spare dismantled engine which is now not far off ready. 
Hope you fare better than I did.
Where's that 10mm socket got to?

Offline Nurse Julie

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Re: Vapour blasting
« Reply #3 on: April 19, 2017, 12:10:38 PM »
Lucky you did have a spare Mike  ;D. Just one piece of glass bead can wreck a beautifully restored engine  :'( :'( :'(
LINK TO MY EBAY PAGE. As many of you know already, I give 10% discount and do post at cost to forum members if you PM me direct.
https://www.ebay.co.uk/sch/julies9731/m.html?item=165142672569&rt=nc&_trksid=p2047675.m3561.l2562

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline Dazza215

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Re: Vapour blasting
« Reply #4 on: April 19, 2017, 12:14:25 PM »
Thanks both. I was going to go over the oil ways with a maginfying glass and carb cleaner and compressed air and, and, and.......
I'm just praying that the guy does a good job and he knows about these things.
I will check everything but i am still neurotic about ruining my engine. lol.  :-[
I dont ride a bike to add days to my life. I ride to add life to my days.

Offline Nurse Julie

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Re: Vapour blasting
« Reply #5 on: April 19, 2017, 12:17:24 PM »
I hope all goes well for you. Does your magnifying glass go round cornets and is it so minute you need another magnifying glass to see it ?
LINK TO MY EBAY PAGE. As many of you know already, I give 10% discount and do post at cost to forum members if you PM me direct.
https://www.ebay.co.uk/sch/julies9731/m.html?item=165142672569&rt=nc&_trksid=p2047675.m3561.l2562

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline mike the bike

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Re: Vapour blasting
« Reply #6 on: April 19, 2017, 04:41:39 PM »
Just to hijack the thread..
The replacement head has two sheared off M6 bolts.  Drilling them out and tapping them didn't work out accurately enough with my crappy £50 piller drill and the rocker cover bolts don't kgo in.
I've had to get an engineering bod to spark erode the bolts out and replace the threads.  Only tenner a hole; could have been worse.
Where's that 10mm socket got to?

Offline Moorey

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Re: Vapour blasting
« Reply #7 on: April 20, 2017, 02:23:15 PM »
These sort of jobs make compressors such a great piece of kit to have, and they have never been cheaper to buy.

Offline Dazza215

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Re: Vapour blasting
« Reply #8 on: April 20, 2017, 03:08:38 PM »
[ Guests cannot view attachments ]
This is how they turned out.
« Last Edit: April 20, 2017, 03:10:51 PM by Dazza215 »
I dont ride a bike to add days to my life. I ride to add life to my days.

Offline mike the bike

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Re: Vapour blasting
« Reply #9 on: April 20, 2017, 03:27:45 PM »
I've got a compressor,  didn't help.
Where's that 10mm socket got to?

Offline Trigger

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Re: Vapour blasting
« Reply #10 on: April 20, 2017, 04:39:57 PM »
O dear, I hope you never had the head basted with the valves in ?

Offline Dazza215

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Re: Vapour blasting
« Reply #11 on: April 20, 2017, 04:43:15 PM »
I am replacing the valves but didnt want the seats ruined.
I dont ride a bike to add days to my life. I ride to add life to my days.

Offline Trigger

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Re: Vapour blasting
« Reply #12 on: April 20, 2017, 04:53:55 PM »
Cheaper to reface the valves and regrind the seats than new valves, what is wrong with the valves ?

Offline Dazza215

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Re: Vapour blasting
« Reply #13 on: April 20, 2017, 05:02:42 PM »
They were covered in sandstone from the American desert i think.
I thought thats what you were referencing with your last comment.
Why would you not have the head blasted with the valves in? Surely with the valves in it will protect the guides and the seats etc?
I dont ride a bike to add days to my life. I ride to add life to my days.

Offline Trigger

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Re: Vapour blasting
« Reply #14 on: April 20, 2017, 05:05:48 PM »
They were covered in sandstone from the American desert i think.
I thought thats what you were referencing with your last comment.
Why would you not have the head blasted with the valves in? Surely with the valves in it will protect the guides and the seats etc?

If the blaster knew what he was doing, they would have put bungs in to protect any machined surfaces

 

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