sandblasting engine without stripping it?

[kinkajou]

Hi, Im planning to sandblast my Eldo's engine....somebody did that before without stripping the engine? just plugging every holes should be fine right? or do I really have to stip it....dont really want to , It runs just perfec like that.... Any help apreciated...Thanks

 

[Penis Rotor]

Don't even think about it.

 

[ghezzi]

Do you want it to look like new again instead of that dark grey tarnished/corroded ancient alloy look?
1. Scrub the crap out of it with wire brush, tooth brush or whatever to get all road grime off.
2. Paint it with aluminium heat proof engine paint.
3. After paint is dry and hard, remove old bolts one at a time and replace with stainless steel cap screws & acorn nuts.
Keep it clean and it will look new forever.

Even glass bead blasting of individual components (when diss-assembled) is fraught with danger. You need to scrub the life out of it after because any tiny particles left inside, will dislodge, suspend in oil and grind your motor to death.

 

[Brian UK]

You can use soda for a blasting medium, the coarse version. This is water soluable so can be washed off afterwards.
But be warned, it's very messy, that white powder gets everywhere. You'll be cleaning it out from places you can't reach for weeks afterwards.

 

[Phang]

If you have the access to dry ice blasting, it will be the perfect solution.

Phang

 

[Mi_ka]

Dry ice sand blasting! Whoah! :shock: Never heard of that before!

 

[Phang]

Wikepedia on Dry ice blasting

Youtube on Auto Paint Removal With Dry Ice Blasting

I reckoned it may not as effective as other blast media in cleaning up the oxidation off a bare aluminium engine.

Phang

 

[fastfreddy]

A friend had his Harley engine bead blasted with plastic beads. Years ago and engine still runs, so it didn't hurt anything. He removed carbs and stuff and duct-taped openings. Said if any plastic got in that it wouldn't hurt the engine. After it was blasted I sprayed the HD crinkle paint on it. This was almost 20 years ago and it still looks good.

 

[Tonerjockey]

Hey Kinkajou,

So ya wanna make it look "new" eh?

Blasting engine components (and entire, assembled engines) is fraught with potential disasters. I have experience with sucessfull and not so sucessful cleanings.

You might get lucky and only spend hour upon hour:

cleaning (to get the tape to hold on to greasy rails etc.)
removing (chrome pieces, carbs, etc etc)
prepping (tapeing, masking, covering)
acquiring blasting tool$$ media etc
cleaning up the blasted media, blasted parts, blasted unprotected parts
reassembling
cleaning
and then-> repairing the destroyed stuff.

One difficuly that won't be immediately apparent is if ANY media gets into the engine. The self destruction will take a while... but it sure will be costly! AND potentially dangerous ( accelerating onto the expressway, far from home, and getting an engine failure).

Here's what I would recommend:

Start trying cleaners (my latest find is Purple Power) and clean the thing. Put money away regularly. Save until you can afford a couple thousand to blow on the bike. Get the manuals (parts and service). Make friends with a local machine shop. Get in good with She Who Must Be Obeyed ( ). Finish off your tool collection... and go for it! Remove the engine/trans. Dissasemble the engine and clean each part (NO BLASTING). Clean the trans and everything else you have removed or can now easily get to.
Replace all questionable components and reassemble bike.

You'll wind up with a machine that is cleaner and more reliable than by any other process I have found.

AND you will have the knowlege and tools to do it again in 40 or 50 thousand miles. The added plus of spousal harmony is not to be discounted.

This process works for me. I repeat it every month (May -> November) on my race bike. After a while one can get the job done fairly effeciently and with minimum grief.

You might just drive it the way it is and accept that as "patina." B)

Good luck.

Alex

 

[Amboman]

This was done without blasting of any kind:

It was cleaned with Gunk degreaser, then Berkebile 2+2 Gum Cutter in spots, then E-Z Brite Aluminum Cleaner (an acid concentrate meant for cleaning aluminum trailers) mixed 50/50 with water, lots of scrubbing, more E-Z Brite and scrubbing, lots of rinsing, a baking soda solution bath (to neutralize and residual acid) and yet more rinsing.

 

[Tonerjockey]

Hey Ambo,

Nice. Very clean look.

Al

 

[Chris R]

Here is my two cents worth.

1. Sand is definitely the wrong media - it cleans off the corrosion but opens up the grain in the aluminum making it look even worse as the aluminum soaks up any oil or grease.

2. Bead blasting with glass beads will peen the grain shut so oil does not get absorbed and improves the fatigue strength of stressed parts but it is fraught with danger! Firstly most people don't do it correctly - the beads can only be used once and not recycled as once they hit the aluminum they shatter and become razors that have exactly the opposite effect - they leave the aluminum a ragged mess and actually open up the grain - so no blast cabinet here. Secondly as everyone has pointed out, they become lodged in the aluminum and all it takes is a small number of them to wreck your engine. Yes if you bead them properly, only do the outside and then clean with high pressure water and then scrub the crap out of it with a green scrubby but there is a risk.

3. Soda blasting/plastic beads/high pressure water are no doubt safer but I don't know how effective they are in actually removing corrosion. I have soda blasted sheet metal and it is great for removing paint but you have to use sand to remove rust. I don't think either really peens the aluminum like glass beads but I don't really know.

4. If you go the chemical way and paint you need to find fuel/oil proof heat tolerant paint - Eastwood's carburetor paint is the right colour and fuel/oil proof but I don't know about its heat tolerance. I would do some experiments before I sprayed the whole thing. No doubt others have some experience out there. However painted my motor used some nasty varnish which is peeling so beware!

Ta,

 

[kinkajou]

Thanks everybody for the advises....

Ambo man, I think Im gonna try your method....looks like the kind of results I want....the bike is already decent and I dont want a trailler queen....just a reliable dailly driver....

Heres a picture...the bike is still in chicago...just bought it....and still waiting....with a bit of love and yes I already have a new LAPD solo seat from cycle garden...I should look great....and loud....

 

[T Bill]

I've had really good luck with Simple Green and an assortment of brushes. Scrape and pick as much of the thick crud off as possible. Then with the engine dry, spray it with full strength SG, and get to work with the brushes. Gun bore brushes work pretty well between fins. It works kinda like hand cleaner, where you want to let it get the grot emulsified before you rinse it off with water. I've had several people ask who did the bead blasting after this treatment. All this was done without removing the engine, with the bike standing in the driveway.

 

[geodoc]

I happen to have an Eldo engine in for overhaul. It's got heavy corrosion so soda is not going to bring it back to a nice finish, it will have to be glass bead blasted. I prefer soda since it's water soluble so it's easy to completely remove residue. With glass beads I blank off all the holes to reduce the amount of bead that enters the case interior and oil passages. You still have to clean the living hell out of it to be absolutely sure its all out. Very time consuming.

I 1st blast with the beads that are in the cabinet that have been used for a while. After the surfaces are cleaned up I completely clean out the cabinet to remove the old, smashed-up beads and load with new #6 beads. Keep the nozzle a ways from the surface and go over the whole thing to "peen" the surface with the new glass beads. You end up with a nice smooth finish that looks fresh-cast and is much less prone to let dirt & grime stick to it.

As a last step, after completely cleaning with warm water and soap (in a dish washer if possible), I lightly etch the outside surface with "alumaprep", wash and dry, then spray on "Alodine 1001" "clear" alodine, let it soak for a few minutes then wash with warm water. The alodine is a "conversion coating" that creates a corrosion resistant finish, but is invisible - the surface looks like bare aluminum.

GD

 

[kinkajou]

Finally decided to go for Soda Blast! A shop close to my place is offering you blast! So for around 75$ and 1 hour of my time, the guy said the engine and the tranny will be done.....Just waiting for easter week end to take the engine out....its still a bit to cold here to work outside :shock:
Will post picture for sure!!!

 

[rbm]

Although you've decided to go with soda blasting to restore your engine cases to their original patina, I thought I'd mention another process called hydroblasting. The soda blasting will work well and you should be very pleased with the results.

A person who is restoring a BMW recently posted pictures on another forum of the results he got by having a firm hydroblast the engine casings for his ride. They ended up looking better than factory parts. Unfortunately, I would have posted the link to the pictures but that link appears to be broken. I can assure you that the parts looked absolutely amazing. The process employs very high pressure water to remove undesirable grime, dirt or paint and clean the parts. There are Youtube videos available on the hydroblasting process so that you can be familiar with its capabilites. It is a process that requires specialized equipment and possibly skill so it will be harder to locate a vendor to do the work. The major advantage with hydroblasting over any other media blasting is that is does not use any media which could change the structural properties or impact the structure of the material or threaten the operation of the engine afterwards.