Engine blasting - tear down or assembled?

[Sci85]

I'm in the process of an engine tear down to replace a bunch of leaking seals. Engine runs great otherwise. Anyway, on this build I want to paint the engine so I was thinking I would soda blast or glass media blast the engine to prep it before painting.

My question is do you guys blast the cylinders, head and cases as individual pieces or do you reassemble the engine first then have it blasted? Would like to hear from those that have actually been through the process and can provide tips and gotcha's.

Thanks,
Sci85

 

[Paulrxs650]

Hi. I strip the engine to the bare cases, get them blasted, coated / painted, meticulously clean them to remove any blast media, then reassemble.

 

[member3480]

I have done it both ways. The down side of completely apart is you really have to clean very good so you get all of the blast material out. I have done them together and closed off all the openings and it was faster but still had to clean very good.

 

[Sci85]

I think I'll rebuild it and put it all back together then blast it since it sounds like that's ok to do. That way I don't have to tear apart the bottom end.

Is plastic or glass media ok for blasting? I can't find anyone in my area that does soda blasting.

 

[Paulrxs650]

Plastic or fine glass will work but bear in mind the cleaning that needs to be done to ensure no media is left in the engine. Soda blasting is often preferred as any small remnants of media dissolves in water (if you wash it) or in oil. Personally, if you have it to bits completely, blast it all then. You can then be 100% sure that all the nasties are out of the internals prior to rebuilding. If you're not splitting cases etc pop it back together and mask off the relevant holes and go for it

 

[Sci85]

Well I finally lucked out and found someone who does Soda blasting. He said he would do the engine for $50 bucks. Does that sounds reasonable?

 

[angus67]

Yes, if its a real soda blaster.

 

[abyssmaltailgate]

Is there any particular way one should mask the top and bottom crank cases when glass media blasting? I was initially thinking about assembling the two halves to protect the mating surfaces of the cases, and then I would apply tape to any oil gallery holes and all the bearing seats, but unless I cover the openings for the connecting rods and bearings, glass will still get in the case... Should I just blast them separately and mask a different way?