Prepping engine for paint

Doc.

Doc.

Been Around the Block
Hey guys,

What is the best and cheapest way to prep the head and cylinder jug for paint, with all the fins, and crap and grease inside the fins? It's for a CB450 K6 btw. What is the method most use? All the internals are out.

What do you guys think of soda blasting?
 
I'm no expert on paint, but soda blasting is great. Vapor blasting is even better. You won't even want to paint your engine if you get that done.

Very hard to find places to do it - here's one of the only ones in North America that has been mentioned.

http://www.vaporblasting.biz/
 
Soda is the best way that most people can do. But Tim is right, the most amazing this is this Vapor Blasting thing and that's the only place I have ever seen.
 
I am buying a large blasting cabinet to to do this. I did a test run on my bike and couldn't believe how good it looked after just a little bit of soda blasting.
 
I do agree with Tim - soda is the way to go. Vapor blasting leaves the aluminum looking great, but costs some cash. Besides, you'll be painting over top of the finish anyway.

One thing that might be worth looking into is boiling the parts before paint. I've read from a couple different misc. sources that oil soaks into the aluminum, and can make it tough for paint to truly hold onto it. Just wanted to mention it......
 
Soda blasting is great but be sure to rinse the parts with vinegar before you paint to get all the little particles of soda off the metal the soda will keep the paint from sticking to the metal. I personally bead blast then powder coat or polish.
 
Vapor isn't too expensive now, at least not at that link I put up there. $35 for a 'big' part, which includes an engine case 1/2 for example.

So, 2 engine cases + 1 cylinder block + 1 head = 4 big pieces. Then rocker cover and couple other covers make say 3 smaller pieces, and they do the smallest stuff for free, assuming you send in a bunch of stuff.

4 x $35 = $140
3 x $10 = $30

So $170 + shipping to vapor blast your entire engine, more or less. They don't suggest doing the side case covers as they're made differently from the engine cases and don't finish as nicely, plus they're easy to clean up/polish yourself.

I wouldn't paint after vapor blasting, so $170 to me makes sense given it's all done at that point. It's the shipping that kills it for me up here in Canada, but I'm still considering it for my XS engine build. Only reason I might not is the cylinders are brand new from the factory (750 kit), the head and rocker cover have just been blasted by Ryan at 707 Racing as part of the work he's doing, so that only leaves the bottom end. Don't want everything to look different so I might just soda blast the bottom cases here in Toronto and leave it at that.
 
Thanks for all the replies guys.

I'm leaning toward soda blasting. I'm aware of vapor blasting and the mentioned link above, but after shipping both ways and insurance, and cost of cleaning, we're talking about close to $200+ for maybe two parts. If I wasn't painting the parts, I can see doing that.

I like the vinegar suggestion, and also the boiling water thing. I will go ahead and purchase a compressor and maybe the HF soda blaster, and give that a shot. I'll probably then use vinegar to clean after the blasting, then follow by boiling the parts. I'll probably heat the parts in the oven pre paint as well.

Thanks again. If you guys have any other suggestions or advise, please let me know.
 
Let's save you some money and substitute it with some time and labor. Start of with a strong detergent, something like Simple Green will do just fine. Use it full strength or slightly diluted and whatever kind of stiff brush it takes to get between the cylinders and into all the crooks and crannies. You can find both the strong cleaner and the brushes of every sort at your local Lowe's or Home Depot. After you've scrubbed the hell out of it and got all the grease and crud off then hit it with some of that spray-can paint stripper that is available at all the big-box-style auto parts places. I think they usually call it "aircraft"stripper or some advertising-nonsense like that. Anyway it will blister off the paint and anything else that is left on it, so then hit it with high pressure water. That will clean out all of the rest of the crud. Now put the parts in the dishwasher and pray to god that they get done before the old lady gets back home. Seriously, a dishwasher can do a serious job of finishing up the cleaning job just before you repaint the parts. The thing is you have to be ready to lubricate any steel parts, cylinder lines and that sort of thing but at the same time make sure you get absolutely no oil on the part to be painted. If the parts to be painted are aluminum make sure you use an etch primer on them - that is the only place an "etch" primer should be used. Follow the paint manufacturer's instructions on application and curing. If you can get the old lady out of the house long enough the oven will work very nicely to cure VHT paints.
 
Thanks Kong.

I actually haven't had any luck finding brushes to fit in between the fins. I ordered some tube brushes from HF and they ended up being nylon (wasn't thinking and just ordered). They won't be strong enough to get the grime off.

I used DAP degreaser on the other parts, and I really didn't like the mess. Used paint stripper on the upper case, didn't really do a damn thing, so I ended up sanding it down anyway. I like to sand things down to bare metal.

Soda blasting has gotten some really good reviews. I need a compressor for the garage anyway, and soda is super cheap, so I'll give that a shot. It should be much easier and less labor. I also need to clean all the carbon off the ports and the head, and soda is the best option since media can be harmful.
 
Also I was told not to use primer on the engine due to the heat, and that VHT should be good enough on bare metal. I hope that's true because I just got done spraying the first coat on the side covers :eek:.
 
I'm trying out a new method. Oven cleaner. Heard it works great. I'll let you know how it goes.


Sent from my iPad using Tapatalk, bitches.
 
Degrease with brake cleaner....aircraft stripper if necessary. Wax and grease remover. Lots of air. You can prime with 2k urethane primer before VHT.

Cb 650 I just finished

e455fa3f.jpg
 
djelliot - check that your oven cleaner doesn't contain sodium hydroxide (caustic soda).

Sodium hydroxide attacks aluminium vigorously with the release of hydrogen.

Crazy
 
Gonna agree with Kong and evolutionfab. These inexpensive simple routes work great and are the way to go. My engine paint is still holding up just fine using these methods. Been doing it this way for years.
 
Thanks guys. I'll keep that as an option. Like I said I went the degreaser route with the upper case and it's a bitch. Plus it's cold as hell out. Haha.
 
Yeah, in the end blasting will probably work better for you. It will force you to buy a compressor with a good sized tank, and that is always a good thing. I'd imagine you'll want at least 50 gallon, which is a pretty common size; I see them come up for sale at auctions all the time. I don't recall where I saw Soda for blasting for sale but it was in fact dirt cheap, and of course the nice thing is you can blast with it outdoors so there is no cleanup to deal with and still not feel like you've polluted the entire earth after you're done.
 
Another cheap alternative is to go to Harbor Freight and buy one of those cheap portable sandblasters, of course you still need a compressor, a smaller one will work, and Harbor also sells glass bead or sand for the blasting media or you can use play sand. Degrease first with gasoline, blast all the corrosion off with the media blaster then final degrease with acetone. Then paint with VHT.
 
Media blasting is not good for engines. The media eats in the metal and most times stays in which causes problems later down the road. Soda is the best bet because it devolves in water.
 
bead blasting is pretty typical in shops, but you don't want to do a final cleaning with acetone, unless you're washing the parts in a tub of it. final washing after bead blasting needs to be done in a tub sink of hot soapy water with all manner of brushes and pipe cleaners (twice at least, with new water and soap), glass is far harder than the hardest bearing surface in an engine, and will easily destroy an engine if it's not properly cleaned out. you should also wash the parts in soapy water after washing in solvent, as solvent will leave a sticky residue and collect bead, making your work even more difficult
 
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