Wet blasted casings

[BrianC500]

I had my CB400F engine casings wet blasted by someone that came highly recommended. Instead of using glass bead he used ground glass which was far too abrasive. Would getting them re-blasted with glass bead help to smooth them over? Or, am I destined to spend the next 10 years polishing them up?

[Trigger]

It is down to the grade of bead they are using. The finer the bead = a smoother finish. What cases did you have vapour blasted ?

[BrianC500]

The whole engine was blasted.

[Trigger]

I would not like to clean that mess up.
I don't understand why people go down he vapour blasting route. I have been building Honda engines for more than 26 years and this way of cleaning has many dangers.

[BrianC500]

The engine was in a very poor state. It had been kept in a damp leaking lock up for 26 years and was very corroded. Unfortunately I wasn't able to be there when it was done. One massive lesson!

[Laverda Dave]

I had my castings vapour blasted for the same reason, i couldn't clean them up even by soaking in paraffin and when that failed, using a dishwasher tablet in boiling hot water for a couple of days (someone told me it would work....!).
After I got the blasted cases back I cleaned them three times   with gunk and boiling hot water and then a final 80psi air blast.

[Trigger]

The problems I face with getting a 40+ year old engine clean is a long process, some painted and some just fir balls of corrosion. First the engines go into a jet steam cleaner to remove all the years of dirt, then they sit in acid for two days (the acid will remove any oil that is soaked in to the alloy, this can be a problem later as it will lift the paint once heated). Then they go into a hot wash and left to dry off, into a oven at 200c (just to check that there is no oil still in the cases) then soda blasted to remove any corrosion, hand finished and all oil ways blasted and checked.
Painted with 2-3 coats of VHT paint, left for two days to dry before being cured in a oven.

[Laverda Dave]

Lovely finish there Trigger.
My next project after 'project 400' is the restoration of my Rickman CR750 and it's festering engine. I'll try your method to clean it up.
Dave

[AshimotoK0]

Lovely finish there Trigger.
My next project after 'project 400' is the restoration of my Rickman CR750 and it's festering engine. I'll try your method to clean it up.
Dave

Yes lovely finish .. were the cases off a Russian Import

[Trigger]

Lovely finish there Trigger.
My next project after 'project 400' is the restoration of my Rickman CR750 and it's festering engine. I'll try your method to clean it up.
Dave

Yes lovely finish .. were the cases off a Russian Import

I did have one in once, painted in bright yellow

Dave this sort of case cleaning is done on a industrial level. It costs £2000 to fill the tank with acid and £375 to get rid of the old waste.

[Laverda Dave]

  £2k to fill the tank with acid! Maybe I could try a washing up bowl full of coke!!
Back in the day when I worked in a train overhaul works I had access to that sort of cleaning kit, and blasters, stove enamelling, zinc and chrome plating, not anymore, those days have well and truly passed 

[Clem2112]

Yes... back in the late 70s I could get chrome, polishing, welding, enamelling done at a well known aero engine maker!
 My 400/4 was nearly up to aircraft standard ..... Nickel plated the swing arm and centre stand then painted over when the novelty wore off.

[Trigger]

£2k to fill the tank with acid! Maybe I could try a washing up bowl full of coke!!
Back in the day when I worked in a train overhaul works I had access to that sort of cleaning kit, and blasters, stove enamelling, zinc and chrome plating, not anymore, those days have well and truly passed 

Did you work at Wolverton works ?

[Laverda Dave]

No Trigger, not Wolverton,  it was in London.

[BrianC500]

If ever a decision was regretted it was not being there to double check what media was being used to blast the engine with.