Engine paint removal on 1978 cb550k

[sweet_baby_james]

Hi guys,

I have all but finished stripping down my 78 cb550k motor (due to a broken came chain guide) and I am wondering what the best way to have all the paint stripped off the motor.

The previous owner rattle canned it black but I would like to bring it back to the stock bare aluminum. The upper and lower crank case, block, cylinder head, head cover and all other covers are painted in black! As I see it there are a couple of options:

1. Paint stripper such as aircraft, would be incredibly tedious and difficult to get in between all the fins but would remove the risk of damaging any threads or precision parts of the motor.

2. Bead blasting, would provide a better finish but would need to cover all threads, cylinder bores, bearing housings etc.

Could I reassemble the motor and then have it media blaster??

Any assistance would be appreciated!

Thanks

 

[AlphaDogChoppers]

Bead blasting requires intense and thorough cleaning afterward, no matter how carefully you mask things off. It's especially effective for the cylinders, as they are simpler to clean afterwards. The cases are more problematic, as you don't want to have a single bead of glass remain in the engine. No joke. Soda blasting is safer. The soda is water soluble, and easy to wash off. The outer case covers are good to bead blast, because they are simple and easy to clean. Bead blasting leaves a pretty good surface to work with if you want to polish.

The original finish on the cases is not bare aluminum, it is gray paint, BTW. The side cases were originally somewhat polished aluminum with a clear coat. That's why bead blasting is good for the side cases. It will take that original clear coat off.

 

[sweet_baby_james]

Thanks for the response. Im not familiar with soda blasting; how diligent do I have to be in cover all tapped holes and threads etc? Is it aggressive enough to damage these? In the case of the block, can soda blasting damage to bores? Since I would most likely be having a paint shop do the blasting, should I leave the masking to them?

Thanks

 

[AlphaDogChoppers]

You don't have to mask off anything for soda blasting. The person doing the blasting will simply not direct blast media at inappropriate areas. Soda blasting will not damage your bores or tapped holes.

Soda blasting can cost a little more because the media is not reuseable, whereas glass bead can be used almost indefinitely. I haven't done any soda blasting myself, but a soda blaster is on my short list of equipment that I must get very soon.

Even with bead blasting, I don't do a lot of masking off. Media blasting is quite focused, so it's a simple matter to avoid directing the blast where you don't want it.