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Discussion Starter · #1 ·
Hey guys, this would be my first post, I'm a reasonably new cx500 owner. Putting some work on my 1980 custom. Was just wondering if someone knew the best method for cleaning up the engine block, mine has a fair bit of corrosion and doesnt look great. I would like to keep it semi close to the original look. I've already done the cylinder heads with alot of hand sanding and buffer wheeling but thats not really the finish I'm looking for. Any advice really appreciated, Included some photos as well. I'm a bit of a neophyte so I'm not sure if wire wheel and sand paper is even an option, preferably something I can do my self.
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I haven't tried it yet, but my father has been saying glass beading it instead of sand blasting...

I guess that's not too useful, but when I do try it I'll tell you if it worked or not! :big smile:
 

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What are you looking to do?

Polishing the block will be difficult due to the shape with all the raised ribs and pockets.
 

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Discussion Starter · #4 ·
What are you looking to do?

Polishing the block will be difficult due to the shape with all the raised ribs and pockets.

I'm just looking to get some kind of uniform finish on it, all the patchiness is pretty unsightly. I know that sand or bead blasting is an option, but I was kind of hoping maybe a dremel and some flapper wheels might work. I just wanted to see if anyone had any experience, or what people usually do to clean up an engine block
 

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I think Many have done the dremel and scotch brite pad thing and a thorough solvent and acetone cleaning and then one of the Duplicolor silver spray paint. to dress this issue. Someone will chime in with better information.
 

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My build had a fair bit of hard corrosion deposits on the engine. A wire wheel on a drill and lots of emery paper and elbow grease (and some heavy degreasers) got it ready for paint - I used VHT engine paint - turned out very satisfactory.

John
 

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I would think 'sandblasting' would be the methode of choice, but for that the engine should come out of the frame, anyhow . I am sure you know , hellster : the right back top engine bolt is missing on the photo ? do not ride the bike like that , please ...
 
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I used the sandblasting on mine.
I had to change the pistons and do the famous triple bypass...so here's the pic when it was all opened. But look at the color of the engine.
This week will be finished, I'll post another picture

IMG_2893.JPG
 

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This looks very very good, Axelsoul !
 

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I haven't tried it yet, but my father has been saying glass beading it instead of sand blasting...
That is absolutely correct.

Looking at a sandblasted surface with a microscope, you will see many many small crater. The surface is clean but very rough.
Good to collect dust, oil, dirt, greasy fingerprints etc.

The same with fresh glass beads: We see fine round impacts. Glass blasting "hardens" the surface. The optical effect is slightly shimmering.
Glass beads break after some use, then the surface is rough when they are used again/ to often.
Use less pressure when working glass bead blasting

For both work/methods the engine should be removed.

Sometimes I use nutshell granule. It is not abrasive like sand and glass. Jewelers use it to clean jewelry.

At least this method
https://en.wikipedia.org/wiki/Dry-ice_blasting.
If I would have theese machines my advertising slogan would be:

Drive in, blasting, pay the bill, drive out.


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Izak please do not send your any inflationary used likes. It's a very normal posting without any special characteristics. Thanks ;-)
 

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That is absolutely correct.

Looking at a sandblasted surface with a microscope, you will see many many small crater. The surface is clean but very rough.
Good to collect dust, oil, dirt, greasy fingerprints etc.

The same with fresh glass beads: We see fine round impacts. Glass blasting "hardens" the surface. The optical effect is slightly shimmering.
Glass beads break after some use, then the surface is rough when they are used again/ to often.
Use less pressure when working glass bead blasting

For both work/methods the engine should be removed.

Sometimes I use nutshell granule. It is not abrasive like sand and glass. Jewelers use it to clean jewelry.

At least this method
https://en.wikipedia.org/wiki/Dry-ice_blasting.
If I would have theese machines my advertising slogan would be:

Drive in, blasting, pay the bill, drive out.


________________________________________

PS
Izak please do not send your any inflationary used likes. It's a very normal posting without any special characteristics. Thanks ;-)
;-) ( wink ) & I took ( off the air ) off the air .
 

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Discussion Starter · #12 ·
I would think 'sandblasting' would be the methode of choice, but for that the engine should come out of the frame, anyhow . I am sure you know , hellster : the right back top engine bolt is missing on the photo ? do not ride the bike like that , please ...
appreciate the concern :) hah I just took the crash bar and bolts off to get a better photo, will be sure to throw them back in before I jump on it. Yeah I'm starting to think getting it blasted is my best option. Thanks for the advice , everyone's so helpful on this forum
 

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My engine looked worse than that when I got it. I just dropped the engine and used paint stripper and a brass wire wheel to clean it up then painted it with 1200 degree grill paint. Been holding up pretty well after 2yrs and 12k+miles. It's not that difficult at all to drop the engine out. You drop it with the radiator attached, and you can leave the carbs in the bike attached to the airbox. Takes an hour or so to get it out using just regular tools. Only thing you may need is a M12 bolt to pop the cooling fan off.
 

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Well, if you wanted to tear the engine completely down I would recommend Vapor Blasting by a fellow in Tucson, Nils, who started his business last year. He does primo work and isn't too expensive...but tearing down the motor is pretty extreme for a respray.
The nice thing about the vapor blasting is that the finish has a bit of textured look to it and is a pale grey on some parts and brighter on others. It peens the surface and forms an oxide that is very durable and doesn't need any top coating. You can have it clear powdercoated for a much longer lasting finish though. The SOHC/4 forums has a thread on it...He is in the services section I believe and he does great work. Lots of pictures of before and after work he has done. The clear powder coating isn't required but it will transform the life of the finish looks from 3 years or so (provided you are subjecting the bike to salt or other corrosives without rinsing it off before it starts its nasty work...
The problem with salts is that the motor being warm they start to work almost immediately...so, keeping them clean in winter like conditions is very hard unless you are cleaning the bike often. Most don't ride in winter where road salts would present themselves...but sea salt/salt air in coastal conditions are a problem.
Then the PC route is recommended, either in clear, silver, etc.

David
 

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I go along with that: vapour blasting gives the best finish and abolute cleanliness. Oh, the term is occasionally misused, because it isn't actually vapour... The better term is 'Hydro blasting'. It is high pressure water with glass beads (very fine ones) and compressed air, and is a 'cold' process. That means there is no localised heat created at particle impact and the glass beads are not broken. They also don't embed in the surface. The water removes all the dirt and grime in the process. It gives a perfect 'factory' finish - but it is not cheap. I had a complete 1971 Honda engine done and it looked like it was just remoived form the moulds. I was very happy indeed.
I've also tried the 'sand' blasting path on a CX500 engine. It looked great but VERY rough surface. I two-pack clear coated it to seal it and it looks OK, ust a little greyer than original. Wouldn;t do that again.
Cheers,
Joe
 

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Well, the vapor blasting is as you mentioned a cold water blasting technique with glass beads used most commonly, but, the exact contents of that media mix are normally a trade secret...they don't reveal the exact contents. The results are similar but there will be differences in the results. I don't think it is as expensive as you might imagine, but, I haven't asked the costs. I will have to post the details of Nils' business particulars and with some photos he can give you quotes. I will post the link to the thread over on SOHC4 forum to see the results he has shared. He asks that you degrease parts sent to him. He also can do motor teardown for a fee if you want him to do the disassembly.
 

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If you want to see what Vapor Blasting can do...check this out over on the SOHC/4 Forums...
http://forums.sohc4.net/index.php/topic,150819.0.html

Nils started his business in Tucson last year and is turning out some really nice stuff for all makes of bikes and a few other parts as well.
It would be a nice finish for parts when going for a nice custom bike but, that said... I think I recall the CX500 and CX650 block isn't easily disassembled and reassembled...but, that may no longer be true. I know Murray in NC does full motor rebuilds and he would have to tear down the motor pretty far to do bottom end work...

Nils has an example of a 750 top end cover that was heavily bead blasted and the vapor blasted part really restored a lot of bright luster to a previously dull part. It isn't the smooth(ish) surface of the stock cover...but it is far better than its previous state. As Nils stated, the original bead blasted surface would have been extremely time consuming to try and restore to original look.

But, for our bikes, generally a good cleaning and etching primer when you have it down to bare metal is advisable and a good spray paint suffices for most. I recall Blindstich having redone a 650 motor in bike with it masked off and then sprayed with some good spray bombs and it looked pretty good. That particular motor was a black finish instead of the earlier silver...

If you are going to try polishing the valve covers you will need some buffing wheels that are smaller than the typical 1/2" width to do it well. Disassembly and resewing the wheels layers are the easiest way to do this. Might need someone with a commercial machine to do it. My aunt is into quilting and has several machines and she did some for me a few months ago. I just ripped out the existing stitching of a loose cotton wheel then separated it into 3 sections to give me the narrow widths to fit the grooves of the valve cover of a CX500. I haven't done it yet. Sanding between the grooves is a royal pain and the clear coat is tough. When it starts breaking down the oxidation isn't pretty. My bike saw plenty of outside storage apparently.

David

David
 

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honestly dude i think u should polish up that CX500 logo plate there and call it a day! the patina matches the rest of the bike. Maybe polish up some of those rusty bolts.

you should be more worried about not having that engine mounting bolt, and rerouting your clutch cable
 

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I'm just looking to get some kind of uniform finish on it, all the patchiness is pretty unsightly. I know that sand or bead blasting is an option, but I was kind of hoping maybe a dremel and some flapper wheels might work. I just wanted to see if anyone had any experience, or what people usually do to clean up an engine block
Here's a good article in the wiki on polishing by LRCXed (Larry of Larry's Carb book): How to Polish Aluminum by LRCXed - CXGL (remember to close your mouth when looking at the pictures to keep the drool in). He's working with the parts off but some other members have done it without dropping the engine. I recall a post somewhere about using brass wire wheel dremel attachments and then moving up to buffing attachment/compound. I'm in more or less the same spot and want to begin polishing in the next week or so. If you have time to wait I'll post some notes from my experience on my conversion thread (http://cx500forum.com/forum/cx-cust...-scrambler-conversion-project-cdn-1979-a.html).

Also check out these older threads:
http://cx500forum.com/forum/technical-help-forum/16470-how-clean-engine-block.html
http://cx500forum.com/forum/general-discussion/7934-polishing-aluminum.html
 
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