Stripping black finish off of 2017 engine case and cylinders

[Greaseball_imp]

I'm thinking of launching into a retro project (using Whitehouse parts) on a 2017 CB1100ex model.

In order to get the retro look that I'm after, the engine cases and cylinders would need to be silver, or natural aluminum, in color. The 2017 ex model has black engine cases and cylinders.

Does anyone here have experience in stripping the black finish off of these engines? As a last resort, I could paint a silver finish over the black finish, but I'd probably be setting myself up for paint flaking issues as the bike ages.

Any help from the forum would be appreciated.

[Cormanus]

Welcome to the forum, Greaseball. One member did take the black finish off the fins, but I don’t recall anyone here stripping the whole engine. See http://cb1100forum.com/forum/showthread.php?tid=10329

[pekingduck]

Stripping the black paint off the engine is a tremendously painstaking and time consuming task. A proper job would mean taking the engine out of the frame, whether you do it chemically or by blasting. There are hundreds of little nooks and crannies, and then you have a bare surface that will corrode without coating it. I see a potential disaster.

Painting it silver would be the easier solution, but again, so hard to mask it off everywhere, it's much easier done out of the bike.

[GoldOxide_imp]

Welcome to the Forum Greaseball. Sounds like a significant project, if done to get the expected finish performance. Sandblast the engine and then anodize it silver? Maybe a service exists to powder coat a clear finish. Still sounds very significant. Possibly less significantly, when not elsewhere, you will be here.

[Greaseball_imp]

Thanks for all of your help so far guys!

I'm not shook up about pulling the engine off of the bike. I'm thinking that will be the best way to go in order to get the results that I'm looking for in the finished product. But once it's out, what will the next steps be.

Looks like chemically stripping the engine will be very labor intensive. And even IF I could get all of the black paint off of the intricate areas then I'd still be left with raw aluminum that would have to get protected to stave off corrosion.

Maybe my best bet is to take the engine out of the bike and then take the bike to a powdercoater. They can bead blast the engine AFTER it gets sealed up. After bead blasting, the engine could get a heat resistant clear coat. I've never had something powder coated but something tells me that my thought process could be workable.

Has anyone else here had parts clear powder coated with a heat resistant finish?

[Greaseball_imp]

id never powder-coat an assembly that is together. the minute you pull a part off (if you can) the powdercoat will fail at that seam. bad idea there. if anything, get it painted clear. but def not powdercoated. also, its needs to be oven baked to an even temperature for the coating to work. Any good shop wouldn't go near an assembled motor with a 10 foot pole.

Thank you for reminding me of a few critical things. Powder coating an assembled engine would NOT be advisable for the very reasons listed above.

I've done some research on vapor blasting. It's an interesting process and there is a vapor blasting shop not too far from me. I'll have to pick their brains about this project. I'll let you all know what I find out.

[Bazbro_imp]

Annoyingly, my aluminium engine covers are silver PAINTED... The cylinder heads too!
Why? Satin polishing would be SO much better.

The barrel fins are also black-painted, much to my annoyance. Be interesting to hear how you sort this, Greaseball.

[Greaseball_imp]

I talked with the owner of a local vapor blasting service. He uses a mixture of approximately 80% water and 20% glass bead media. He thinks that should be able to get the black finish off of the engine, including the cylinders. The tricky part would be sealing off the engine completely. He's done it before but does not guarantee that the plugged and tapped off items wouldn't get dislodged in the process. It's my risk. Some of his customers have kept their aluminum pieces looking food with wipe-on protective coatings. Or, he could use more blast media in his mixture to give the final surface more tooth for painting. He estimated approximately $200 to $250 for his service.

Bottom line, it looks like I have this process as an option with some risks involved.

[peterbaron]

If you have auto wreckers nearby, go and get variety of soft plastic plugs and insert'em into ports, behind tape. Home Depot and Lowe's have them as well but variety may not meet your needs.
Good luck with your project and remember to post some pics before and after:



....or you may lose 6 demerit points

[pekingduck]

I would be very leery of any liquid/vapor or air blasting on any assembly. While vapor blasting glass beads supposedly does not impregnate in the surface like air-driven glass beads, I still wouldn't trust it. I have had many things bead blasted, sand blasted, soda blasted, where I put bolts to seal the threads, and there still has been grit inside the bolt holes.

People usually sandblast at 80-100 psi, and no tape will withstand that. Even making block-off plates and installing them with gaskets and sealant is risky. It doesn't take much grit to score a cylinder wall. Or to get past an oil seal, the grommets for the alternator/signal generator wires, or the rubber on the valve cover.

And curing powdercoat will require baking at about 375-400 degrees F., at the upper end of what some of the rubber and plastic parts may tolerate.

An alternative might be to simply paint the engine cases/cylinder/head silver, and maybe just powdercoat the engine covers (or replace with polished parts).