Mediablasing an engine?

Hey all,

I've got two more bolts to take off my '75 Honda CL360 engine, and I've been thinking about how I'm going to clean the thing. A wire brush/degreaser set up is still an option, but I wanted to see what to possibility of just getting it sandblasted. I'm mostly worried about the flanges as I'm not sure I'd be able to clean them well. I've read all the threads I could find, but I still have some questions.

1. What media should I use(leaning towards glass)?

2. What do I need to do to prep the motor for blasting(Plugging holes, etc)?

3. What parts can I and can't I get blasted?

4. Is it going to be any easier than just doing it by hand?

Thanks in advance.

I'm working with the same thing on my gt380. I'm thinking of glass blasting it. i took the engine completely apart and masked it up with ducked-tape.
and I'm thinking of leaving all of the nuts and bolt halfway in place just to cover all the holes and getting them blasted as well..

I guess newspaper would do the trick in the holes too.

i tried to do it by hand, and even ran i trough a parts cleaner with really hot water for two hours, but the corrosion is a sucker.. And now that I'm starting with the glass blasting, I'm doing everything that's going to be painted. nuts, bolts, engine cases, cylinders, oil pump... EVERYTHING.

Consensus is largely soda-blasting, NOT sand. Soda won't cause you issues with oil passages etc - easier to clean out.

For a super fine finish, you go with vapor blasting. Not common but there is a shop in the US doing the work for good rates.

http://www.vaporblasting.biz/

vain said:

I'm working with the same thing on my gt380. I'm thinking of glass blasting it. i took the engine completely apart and masked it up with ducked-tape.

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Vain,
Glad to hear that I'm not the only one. Yeah, glass beading was what I'd thought would be best as well. From the videos/pictures I saw, it gives a pretty good finish. Once I get new gaskets on my engine(sometime next week if the come in), I'm going to do to the same with the masking tape. Great idea on the nuts and bolts too. Hadn't thought of that.

I'd heard parts cleaners just can't get the oxidation/corrosion, you just confirmed it for me. Yeah, now that I'm gonna get something sandblasted, I think I'm just gonna do it all. There's a whole bunch of rust in hard to reach places, and as much as I love spending hours hunched over parts with a wire brush, I figured I'd take the easy route and get it all blasted. Are you going to get it blasted cracked open, or sealed?

As far as plastics go. Does it all have to come off?

Tim,
I've read about soda blasting but found that cleaning the parts is a total pain. Have you used soda? If so, how'd you clean it?

That vapor blasting looks FANTASTIC, but probably over my budget. I know a metal worker in town and he was going to help me out. I'll leave it as an option though. Those engines look amazing.

Walnut shells or glass bead, NOT SAND! Sand will actually take good metal away, shells and glass bead will only take corroded or weak metal away, and leave a much nicer finish than straight sand. There is a sand out there that will still give you a very fine finish. It's reddish/pinkish color and feels like sugar. It's super tiny particles, and you would still have to soak and wash and blow out and soak and wash and blow out times about 5, but it will be faster than shells or bead.

The vapor blasting isn't that expensive from what I've read on that site. $35 for a big part and down from there. So yeah, you'd be into $200 or so to have your entire engine done, but if I was doing it I wouldn't be painting after so there's money not being spent.

I'm going to be having my lower cases soda blasted. I don't have the air compressor to do it at home and don't need it done enough to warrant spending the money (and I don't have the room in my garage for a large compressor).

Jewbacca,
That's what I've heard. I'm gonna ask the guy who's going to be doing the work which he thinks I need, but I'm in favor of Glass beads right now.

Tim,
Yeah, that's a bit on the high side. It's really tempting because the finish you get is the finish I'm going for, but, again, it's just costly. Maybe if I didn't have to pay $100 in shipping, I'd be more inclined to do it. Thanks for the tip though.

I gotcha. How much is it gonna run you? And what does your prep look like? Oh, and what bike is this on?! I've never seen any of your bikes!

Here's the stuff I read. Might be a help to someone else.
Great source to see/learn about different finishes.-->http://www.dansmc.com/sandblasting.htm
Other threads I found...
http://www.dotheton.com/forum/index.php?topic=32815.0
http://www.dotheton.com/forum/index.php?topic=30538.msg329298#msg329298

Blasting the bottom cases is likely going to cost me $30 or so. Having 4 rims done too so maybe another $10 each.

I'm going to clean up the cases as much as I can before taking them to the blaster so they don't laugh at me. Not really sure what they will expect or want in terms of them being 'clean'.

These are for my XS650. I'm building it a new engine. http://www.dotheton.com/forum/index.php?topic=448

Fox said:

Are you going to get it blasted cracked open, or sealed?

As far as plastics go. Does it all have to come off?

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Fox,

I'm doing open, and took away all the seals... and just taped shut all holes and gasket areas.
I trying this tomorrow hopefully and I'll take a few pictures along the way.. I'll post them when i get home late Monday for you too look at.

Fox said:

Hey all,

I've got two more bolts to take off my '75 Honda CL360 engine, and I've been thinking about how I'm going to clean the thing. A wire brush/degreaser set up is still an option, but I wanted to see what to possibility of just getting it sandblasted. I'm mostly worried about the flanges as I'm not sure I'd be able to clean them well. I've read all the threads I could find, but I still have some questions.

1. What media should I use(leaning towards glass)?

2. What do I need to do to prep the motor for blasting(Plugging holes, etc)?

3. What parts can I and can't I get blasted?

4. Is it going to be any easier than just doing it by hand?

Thanks in advance.

Click to expand...

Fox,

I have experience with glass beading, wire wheeling, soda, walnut shell and vapor blasting motor parts (BSA, Norton, Triumph, Honda and Suzuki).

In order to answer your questions, we need to know what is your goal, Do you want to restore your motor to original appearance, paint it a new color, polish it, ceramic coat or ?

There are no shortcuts and you must break down your engine, remove all seals, bearings, gaskets, residue etc. Everything must be completely and thoroughly cleaned and degreased.


To answer your questions if you are repainting your motor:

1. Use glass, walnut or soda but NOT sand.
2. Plugging holes and taping areas off is useless. The pressure from the blasted media will blow right through your tape or plugs.
3. Anything can be blasted, but not everything need to be (oil pumps, valves, gears etc)
4. If your paint is just dull and has little areas of corrosion, peeling etc, hand sanding will work well. Leave the factory primer and paint on if it still sticks and paint over it.

Clean, clean, clean and clean everything when you are done blasting or sanding. ONE SINGLE bead will cycle through you motor's oilways again and again, scoring you cylinder, camshafts etc. Use compressed air to blow out all passages followed by brake cleaner. Use the correct sized greased taps to clean threads. Wash everything in hot soapy water. DO NOT use Purple Power, oven cleaner, toilet bowl cleaner or any other cleaner with sodium hydroxide on alloy parts. Dry, tack, spray with high heat etching primer, dry, light sand and finish with several light coats VHT engine paint. You must heat cure your parts in an oven to get any durability and gas resistance from your paint.

NO shortcuts.

If you want unpainted and/or polish cases and covers then blast or vapor blast and polish away. Vapor blasting is simply the best (before and after)



Good luck and post your results.

Tim, Thanks for that info. Dude. Your bike is freaking incredible. Your attention to the details is inspiring! Great job.

Vain, I'll be keeping an eye out for your posts. By what swan said, you might want to reinforce that tape.

Swan,
Wow. That is an awesome post. Thanks for going into such detail. That is a really great help.

I do actually want to paint some of my engine so it looks like I'm gonna be going the hard way.

As far as cleaning and degreasing goes, what do you use? I took my engine out today and put in some work on it using engine degreaser/carb cleaner and a toothbrush/dishbrush. There's still some pockets that I don't think would pass through sand blasting, but I either couldn't get at them with my brushes, or the solvents didn't do anything. Can anyone tell me their process for deep cleaning their engine?

Oh, how mandatory is cleaning all the threads with taps? The cheapest set I could find is for $50 and I'm very reluctant to drop that much money on something I wont use very often. Is it really worth it?

Here's a few shots to give you an idea of where I'm at.

Fox - Swan:

I'll keep these thing in mind. the places i have taped are places that are not going to be blasted, the tape is there just to help me from getting too much glass in there. so i hope it will be good enough.

This is my first try at mediablasting, and i'm a bit scared


And fox: your engine looks more or less like mine does. We're in the same boat here.

I use Simple Green and a 3M brand red scrub pad for metal to clean and degrease. You may not need to media blast after you clean it and degrease. If the underlying paint is just dull, touch any rough spots with 400 grit sandpaper, tack with acetone, prime, paint, etc. Your motor looks good and I would paint over what is there. The factory paint is very good on Hondas and we cannot buy equivalent paint today due to EPA regulations. I suspect it has lead and or zinc in it. Try small pipe cleaners or gun cleaning rods and wads to clean the hard to reach areas.

Are you going to paint or polish your outer covers?

You can but individual taps for a few bucks each or simply use a the correct sized greased bolt

Vain,
Gotcha gotcha. Even if it does get blasted through you can always clean it. No worries really. At least you'll have a nice shiny engine!
Haha! I know that feeling!! You'll do fine. Tons of people have done it before us, so how hard can it really be? I'm excited to see how yours turns out! Best of luck!

Swan,
Really?! Only Simple Green? Geez, must be on steroids or something! I may decide not to blast once it's all said and done, but the issue is that I'm only painting the cylinder heads, and they have some nasty oxidation in between the fins. That won't flare up a few years down the road and starting bubbling my paint? The rest I was going for a brushed aluminum finish. Can I do that with my 400 grit paper? I'm gonna do a test spot with some sandpaper to see how it looks. Will post later today.

Hehe I'll probably use a greased bolt. College makes you cheap. Oh, and thanks for all your help. Really appreciate your input.

Here is a 50 year unpainted alloy case after straight Simple Green, 3M scrub pad and elbow grease (before and after)

my recommendation is to stick with the vapor blasting unless you want that nice matte look.

I glass beaded my indian vertical cases and they came out very very nice. Even the bearing areas that I masked off with tape didnt have issues if you are careful. The only issues to note is the metal will be very porous and even hand oil will show up. There was a prior post on here on a sealant that is clear to help with this issue. The other is on impact sometimes some of the glass bead can imbed and not be easily removed or seen which can cause issues down the road. Just have to be extremely careful cleaning the item out.

good luck either way.

If you are going to media blast, the motor MUST be completely stripped and degreased first and washed after. Glass balls get into everything and it only takes one to ruin a crank. Buy Taps one at a time as you need them and use lots of Q tips and sometime you need to take an 1/8 or 3/16 drill bit and use that to clear the bottom of a tapped hole (between your fingers - not in a drill).

I have tried glass, walnut and wet blasting and there's no comparison. Vapor (wet) is the best look, but not cheap. I usually use the old fashioned way with simple green or something similar and a series of small screwdrivers and picks to scratch that garbage out of there. It takes time and there's always a balance to be struck between time and cost. I never have enough time and I always have other things to spend what little cash I have on, so for me its easy - get to work.

Got the engine blasted today, BUT when i took the damn thing apart i didn't get the one gear drum out due to sucky bolts. so i blasted the engine case with this thing still inside... the masking i did was good enough but some got inside anyway. i used about twice the time to clean it than blasting.

The result was beautiful!! :-*

Tomorrow i will take another hour to get all the glass out with brake cleaner and compressed air.
Pictures will come then..

peace out from the glass blasting conquer

Here's the result.





And i started painting :

vain said:

Got the engine blasted today, BUT when i took the damn thing apart i didn't get the one gear drum out due to sucky bolts. so i blasted the engine case with this thing still inside... the masking i did was good enough but some got inside anyway. i used about twice the time to clean it than blasting.

The result was beautiful!! :-*

Tomorrow i will take another hour to get all the glass out with brake cleaner and compressed air.
Pictures will come then..

peace out from the glass blasting conquer

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Damn. That thing looks BEAUTIFUL! Very well done!
Tell me more about cleaning it. How long did that actually take you?
And what's the color scheme of your bike? I'd love to see some pictures of the whole thing. Do you have a build thread?

Oh, and a question to the other participants of this forum. If I vapor blast my engine, would I still have to clean it?