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Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: Daithi on 30.11. 2018 22:29

Title: Crankcase restoration
Post by: Daithi on 30.11. 2018 22:29
Good evening all,

 As you can see below my crankcases are in pretty bad condition and need some tlc to return them to their former glory.
I have been reading a lot of mumbo jumbo on d'interweb about the best way to tackle the job.
I dont have the resources to outsource so vapour blasting ect is not an option.
I have concluded that some sort of mild acid wash, rinse (dishwasher... ye/nea??), a mechanical clean using wire brushes and finally some way to seal using anti corrosion is the way to go.

Wondering if anyone has any tips/tricks they would like to share?
I reckon the sump ball valve spring assembly might *eek* need a new spring and a clean out. How do you remove this?
Dave
Title: Re: Crankcase restoration
Post by: Peter in Aus on 01.12. 2018 01:03
If it was me I would be sand blaster it (using glass beads) to clean it up, but looking at crankcases they look pretty bad, but with a bit of patience they could be brought back to life.
Use heat to remove the sump ball valve assemble, looking at it I think that it is beyond redemption.
Good luck
Peter   
Title: Re: Crankcase restoration
Post by: BSA_54A10 on 01.12. 2018 05:13
If you have a compressor then you can make a soda blaster with a plastic sot drink bottle & an air duster.
It is slow but breathing in the soda will not hurt you and it washes off with cold water.
Truck wash will go a long way to getting most of the flakey corrosion off.
Works better still if soaked for 1/2 hour, NOT OVER NIGHT and you work it with some STAINLESS STEEL , wool , not Brillo pads.
If you have a dishwasher the double up on the detergent and give it several washes, don't get caught or it will cost you big time.
Title: Re: Crankcase restoration
Post by: RichardL on 01.12. 2018 05:30
At the risk of being seen as self-promoting and exposing myself to some deserved chiding, here is a video I made about removing the "retainging" ball.

https://youtu.be/5IaZnt5WHeI

Richard L.
Title: Re: Crankcase restoration
Post by: KiwiGF on 01.12. 2018 06:59

I reckon the sump ball valve spring assembly might *eek* need a new spring and a clean out. How do you remove this?
Dave

The sump pickup assembly will probably come out of the crankcase with a bit of heat, as they are usually glued in place (I used loctite retainer, which softens with heat). Only use a little force eg twisting as they can be snapped off.

I’m not sure how the ball inside the pickup is removed but hopefully once removed you can get it really clean and removal won’t be necessary  *dunno*

With cleaning jobs like those cases I’d just get some beers out, find a bluntish knife, and start scraping! (not a sharp enough knife to harm the metal underneath).
Title: Re: Crankcase restoration
Post by: Greybeard on 01.12. 2018 08:37
If you have a dishwasher the double up on the detergent and give it several washes, don't get caught or it will cost you big time.
Eh? Dishwasher stuff turns alli grey.
Title: Re: Crankcase restoration
Post by: duTch on 01.12. 2018 09:59

 I bought a soda-blast unit about a year ago to do stuff like this (~AU$90 + media 25kg/AU$60)- only used it briefly a couple of times thus far, need to be diligent where it's used though, as is a bit 'dusty'....even if you took it to a car-wash place and give them a high pressure blast you may be surprised
Title: Re: Crankcase restoration
Post by: Sluggo on 01.12. 2018 11:41
I believe I can help *ex*  I have repeated much of this on many forums so might appear a broken record however here it is for what its worth.

First, DO NOT SANDBLAST AND DONT GLASS BEAD * (*More on GB below)

Castings have a skin to them (Epidermis?) And depending on sand cast, Die cast and quality, the finish may be rough, but its got a hard skin to it.  Once you sandblast you remove that top layer and its now semi porous,

## Porosity is variable, Im chiefly referencing the outer side of the cases, meaning every time you touch the cases with oily/dirty hands it leaves a stain,  Its hard to keep clean and it will be more prone to corrode easily, (Whitish powder).  However SOME castings regardless ARE Truly porous and will weep oil but thats a separate issue and the solutions.

You CAN polish the cases and that seems to skin it back over, and myself, I *LOVE* to polish my alloy.
(Some in the UK are challenged when pronouncing Aluminum, My Yorkshire neighbor runs a machine shop and his staff put it on his "To-Do" list of learn to say it properly)
I have a 65 Triumph with excessively polished cases, head and covers, You need sunglasses.

Prior to widespread use of Soda blasters and vapor blasting, the old school method was called "Bright beading" (or at least thats what everyone I know called it.  I bet in Australia they have their own name)

Bright beading is a 2 step process and time & labor intensive.   You practice with a glass bead machine with BRAND NEW glass beads, the good quality ones. Take a scrap piece of Alloy and crank down the PSI of the machine, Start at 20-25 PSI and build upl  Typically 40-45 PSI but is variable on the cabinet and gun.  What you want is just AT the point the glass bead shatters, then drop it a notch so less than 10-15% of the beads shatter.  It can take a long time to clean cases... Then follow with 2 steps in a solvent tank, Diesel & Stoddard Solvent makes a good mix although toxic, (Use LOTS of ventilation & respirator)  We use 3M Scotchbrite pads, 2 colors, Green & Red, so translate whatever grit that is.   The diesel has a lot of oil in it and acts not only a solvent but a bit of lube.
Cases with lots of elbow grease come out sparkly and show ready.

Much easier with Soda blasting or Vapor blasting is my #1 choice.  Some positive bennies and comparison.

The soda blasting became the std in aviation as, when done a hot water bath and air nozzle does a good job of removing friction material as it dissolves.  (ANY Cleaning you can never be TOO clean, repeat 3x more than you think you need on cleaning)  But the soda is the safest method.   Soda can be purchased from industrial suppliers and can vary in abrasive # so shop around,  The Grocery store stuff works but is too powdery.  With soda blast you can blast inside and outside a engine case, all others have to be masked off.

I have been experimenting and found a Harbor freight regular pressure sandblaster works better than their dedicated soda blaster, But you have to convert the gun to a soda model or modify the sand type gun. (Trigger clogs and the nozzle orifice needs to be smaller)  I run 120 PSI with a 2 stage compressor with 2 60 gallon tanks and a 90 gallon piggy back tank.  Volume matters, (Pressure vs Volume)

I dont care what anyone says, use a respirator, not just a dust mask.  I can write a book on the health issues.  Sand, baking soda, walnut shells, glass bead,,, ALL of them.

I dont have a vapor blaster but I would like one, Was going to partner up with a friend and build a commercial one, but not on the front burner.  We have several places that do the vapor blasting and some guys do ship their cases.

I Prefer vapor blasting if i do case repairs, welding or had to go grinding or other work.  A lot of my stuff seems to have holes, nicks and scratches so its rare I dont have to do surgery on a engine case or parts.
    "  Ye olde junque pile

My old job and my wifes machine shop DO have a texturizing set up. (Blanking on the tech term)  But those can vary but they have 2 one runs solvent and one runs water.  But its a big hopper about 4' across and cone shaped with a rotator, a spray wand that rotates and spray nozzles on the sides.  It has a humongous vibrator table under it, and filled with sandstones and some sort of rubbery cones,,They have different grades of the stuff, just depends on what materials they run thru as the shop runs copper-brass, steel & Stainless as well as alloys so they have different media.

You turn the machine on the bed of stones and other bits shake and you drop your parts in and watch it get swarmed like ants.  Stainless takes a while but alloy bits need only 3-4 passes and done.   If you do an engine case ALL holes and internals have to be securely sealed off.  If you left alloy in there 2 long (overstayed the coffee break)  Every sharp edge and feature will be smoothed off.  But if you are going to polish the cases,, thats a big time saver!   I prep and then have Mrs Sluggo do all my bolts and hardware before I send to plating. Deburs and shines up the metal so it plates beautiful.  (its ALL in the prep!)

I dont do it for others except REALLY good friends who gift me lots of beer  *smiley4*  But I used to do a lot of polishing and have a backlog of stuff to do.  I have multiple buffers and polishers, "Buff-Zilla" is my main machine.  Runs a 1" solid billet steel hardened shaft and a monster motor.  I can lean into stainless and it wont stall.  (Dont get hung up on HP,, its ALL in armature size! Bigger is better. Mass, I got a big industrial motor and its a beast)  Ive got stepper pulleys to dial in shaft speed for the material.  Buffing and polishing is a whole different art.  Im only adequate with a lot of swearing and cursing and occasionally launching a part across the room, But I used to work with and still know some real artists with a buffer.  Its truly an art form between a hack like me and a really skilled guy.  Nobody lasts long in the polishing business. Carpal tunnel wrist and arthritis is not an *IF but when....

"As cast" finishes are nice, and for a concours show bike, its a standard to uphold, But I love polished old vintage alloy and tend to over do it.  Its a special level of OCD because once you start polishing a cyl head or cases,, its either all or none.  Half polished looks like S**t.
Title: Re: Crankcase restoration
Post by: RichardL on 01.12. 2018 17:24
Uhh, I suppose I gltched and read the "ball" question as referring to the retaining ball. Nevertheless you need to replace that, as well, and improve the ball seat.

Richard L.
Title: Re: Crankcase restoration
Post by: duTch on 01.12. 2018 20:03

 
Quote
......I reckon the sump ball valve spring assembly might *eek* need a new spring and a clean out. How do you remove this?.

 Possible the end of the tube is a sweat braze fit over the main tube- may be removable with heat  *dunno*
Title: Re: Crankcase restoration
Post by: Peter in Aus on 02.12. 2018 01:26
I believe I can help *ex*  I have repeated much of this on many forums so might appear a broken record however here it is for what its worth.

First, DO NOT SANDBLAST AND DONT GLASS BEAD *

Shot down in flames again *dunno*
But I have been using sand blasting with glass beads for years with no problems, inside and out. and then use a high pressure water cleaner with detergent.
I am not a purist, I like to ride it, not polish it *beer*
Peter

Title: Re: Crankcase restoration
Post by: Joolstacho on 02.12. 2018 02:36
Plenty of useful info in these posts, but I want to say just ONE thing about finishing AFTER you've cleaned it all up:
DO NOT try to seal the aluminium with any type of clearcoat or anything like that.
It ALWAYS peels off, oxide blisters underneath and will look disgusting, and it's then a nightmare to refinish.
I reckon (once the big cleanup is done): Polish (not shine)* the aluminium thoroughly, going through wet & dry papers to at least 800 grade.
Then polish.
The finer you polish it with the wet 'n dry, the more it will resist oxide and dirt, because there will be fewer/less miniscule pits and scratches for the dirt to reside.
Hit it with much pressure cleaning and detergent before the final polish (with Brasso or similar).

Good luck, hope you have lots of elbow-grease.

*Polish is what Jewellers and Silversmiths do... Shine is what you get on cheap Xmas decorations
Title: Re: Crankcase restoration
Post by: Daithi on 02.12. 2018 02:46
Thanks for the input fellas and Richards vid up the other end of the pitch, Some good info there
I'm going to have a route under the sink and see what class of chemical delights await.
Having a look at the condition of the oxadiseation and how thick it's caked on I think a wire brush head on a battery drill is the best way to start. Then see what shape there in.
Dave
Title: Re: Crankcase restoration
Post by: duTch on 02.12. 2018 06:34

 
Quote
.....I'm going to have a route under the sink and see what class of chemical delights await...

 That's scary.... what ever you do don't put caustic soda ( sodium hydroxide-NaOH if I recall correctly)... anywhere near it plutonium and indium, Imodium, regular uranium and Osmidium may be Oll-Korrect, but NaOh will turn it to hydrogen and sludge *eek*

 Yes also I didn't mention sand or bead blasting because sand is too abrasive and acidic, and beads get in everywhere and are a pain in the butt to clean out....water blast is probably the best... now where was I... *conf2*


Title: Re: Crankcase restoration
Post by: BSA_54A10 on 02.12. 2018 09:11
If you have a dishwasher the double up on the detergent and give it several washes, don't get caught or it will cost you big time.
Eh? Dishwasher stuff turns alli grey.
Prior to the ultrasonic cleaner, I boiled my amals in dishwasher detergent for decades.
If they get hydroxyl staining ( grey to black colour ) then rinse in hot water with a touch of vinegar in it then into boiling clean water.
Otherwise it s a boiling water rinse and a blow dry.
Title: Re: Crankcase restoration
Post by: BSA_54A10 on 02.12. 2018 09:17

 I bought a soda-blast unit about a year ago to do stuff like this (~AU$90 + media 25kg/AU$60)- only used it briefly a couple of times thus far, need to be diligent where it's used though, as is a bit 'dusty'....even if you took it to a car-wash place and give them a high pressure blast you may be surprised
A dip in boiling water will clean them up.
Much better than spraying.
Bi-carb is water soluible so 10 minutes in a rolling boil then blow dry & it is clean.
Have yet to try blasting soda , same stuff just bigger crystals . I am still using the 20kg bag of animal feed soda ( $22 ) that I bought to test it out to see if it was worthwhile.
Saved a fortune in degreaser & carb cleaner . Outsides get a soda blast followed by inside the bowl then 10 minutes in the ultra sound $ 40 please sir for carb clean.
Title: Re: Crankcase restoration
Post by: BSA_54A10 on 02.12. 2018 09:26
Plenty of useful info in these posts, but I want to say just ONE thing about finishing AFTER you've cleaned it all up:
DO NOT try to seal the aluminium with any type of clearcoat or anything like that.
It ALWAYS peels off, oxide blisters underneath and will look disgusting, and it's then a nightmare to refinish.
I reckon (once the big cleanup is done): Polish (not shine)* the aluminium thoroughly, going through wet & dry papers to at least 800 grade.
Then polish.
The finer you polish it with the wet 'n dry, the more it will resist oxide and dirt, because there will be fewer/less miniscule pits and scratches for the dirt to reside.
Hit it with much pressure cleaning and detergent before the final polish (with Brasso or similar).

Good luck, hope you have lots of elbow-grease.

*Polish is what Jewellers and Silversmiths do... Shine is what you get on cheap Xmas decorations

Avaition aluminium cear caot is what you use on motorcycles.Does not yellow, peel or blister IF THE ALLOY IS CLEAN.
Most polishes leave a waxy surface behind and it is this wax that causes the finish to blister.
As for polishing, yes there is decorative polishing and metallurgical polishing.
he latter is what you do prior to plating using high pressure and abrasive soaps.
What actually happens here is the very surface flows and combines with the soap to form a semi-metallic glass.
That is why a professional buffed polished surface looks so deep and stays shinny for so long.
Then you get decorative polishing, the type of finish you get with Autosol, Mothers etc etc.
In this case the micro pits are filled with wax which is what you buff to get a shine and why it goes dull so quickly.
Title: Re: Crankcase restoration
Post by: Sluggo on 02.12. 2018 09:31

A dip in boiling water will clean them up.
Much better than spraying.
Bi-carb is water soluible so 10 minutes in a rolling boil then blow dry & it is clean.
Have yet to try blasting soda , same stuff just bigger crystals . I am still using the 20kg bag of animal feed soda ( $22 ) that I bought to test it out to see if it was worthwhile.
Saved a fortune in degreaser & carb cleaner . Outsides get a soda blast followed by inside the bowl then 10 minutes in the ultra sound $ 40 please sir for carb clean.
[/quote]

Yep, I agree, Like a Doctor, Do no harm if possible. For most cases the Blasting soda or other non invasive processes are the safest.   Used to be in aviation we used walnut shell, The thought was if a little chunk got in the engine by failed cleaning it would do less harm than sand or glass bead.

You know what abrasive walnut shell does to bearings?  Pretty much the same as glass bead and sand.  Its abrasive.

I Love a good ultra sound cleaner.  Started using them for fuel systems in jets and can clean all the nooks and crannies you cant reach.  So I  had a steady side business rebuilding auto carbs and especially 4 cyl MC Carb racks (IE Honda-Kaw-Suzi etc)  and Mrs Sluggo would take them to work partially stripped and run thru the commercial sonic cleaner at her work.   US Chem cleaner "Simple Green" partially diluted did a great job in the sonic cleaners.  They had other commercial/industrial cleaners at her work, But no one would say anything if you used the machine but supplied your own chemicals.   Simple Green worked well for that.

At one point 2 yrs back with 5S and some other stupid corporate ideas they were going to get rid of their big monster sonic cleaner.  We had dibs on buying it.  It was a money maker and I wanted it badly.
Not to be..... Someone stole it out of the warehouse.

But I will say, One can earn some nice $$$$ for very little effort if you have one of these machines, An enterprising lad can line up all kinds of creative income streams with some initiative.
Title: Re: Crankcase restoration
Post by: Sluggo on 02.12. 2018 10:20
Boy, this topic is a one of those proverbial box of spiders isnt it???  (I love that metaphor much better than the US "Can of worms")

As to clear coats, I again agree with Trev for the most part.   I have experimented with them and have yet to find one that looked good, lasted a long time and didnt yellow.

There must be some that work, The vintage "Patina" crowd really loves painting over rust and bare metal, I Dont know how they get the clear coatings to stick, but clearly some manage. So it IS possible,, But I have enough problems without going down that route.

I hve some vintage Asian bikes and used to read some crazy ideas on stripping the coatings on vintage Honda SOHC/4 Hondas..   One idea is a oven cleaner foaming cleanser and soak the engine down inside a plastic trash bag and let it sit. Then wipe the coating away or brush it off and then polish.  I dont recomend doing that, as it most often attacks the alloy chemically and no polishing will restore it. The alloy will be discolored black-gray ish.  Even sanding it down you have to take a lot off to remove the discoloring.

Same with dishwashers... Bad idea in my experience,, but It is possible some variable might work.

What I have used with success on HD and Asian bikes with the deteriorating clear coatings is a mild furniture paint stripper.  Something for restoring and refinishing wood.  Test it on something you dont care about, But I found a few that will take off the clear coatings and wont attack the alloy,   But its a messy job.

I did read some UK Bike magazines like "Bike mechanics" and maybe "Classic Bike" where they took asian engines to a specialist who masked off the engines and baking soda blasted them to remove oxidation and clear coat.   Seemed they listed a lot of shops offering the service in the UK.  Being the popularity of vintage Asian there...... Ive seen a lot of references to it.

One other option I didnt mention, But will here just to be pedantic...  I know a local shop offering plastic media blasting.   Instead of glass  bead or soda, its tiny plastic balls or chips.  Cars with fiberglass or painted plastic you can strip off all the paint, coatings or dirt/oxidation and wont harm the base material.

IE:Corvettes, or other plastic fantastic cars.   But it works on sensitive alloy as well.  Not cheap but it works really well.   Well beyond the home workshop but useful to know about.

See: http://plasticmediablasting.com/html/automotive.php#prettyPhoto

" AUTOMOTIVE

Today there is an alternative to both sandblasting and chemical stripping your automobile. Plastic Media Blasting has quickly become the most popular and excepted method.

Plastic Media is mainly used for thin gauge sheet metals. This method uses plastic granules which are harder than paint but softer than the base material. Using a high-volume, low pressure application, the media will cut, shear and lift the paint without affecting the substrate.

Since it is a dry process, there is no flash rust after stripping and most importantly the plastic won't warp or pit the metal. It's non-corrosive and safe for all metal, stainless steel, fiberglass, plastics, aluminum and moving parts. The only short fall is it won't remove rust... hence may require other blasting methods."

We have a large commercial stripping company in Portland, They can dip entire car and truck bodies in their largest tanks.   I have used them for OIF Triumph & BSA Frames (1971-1983)  as the one should NEVER EVER Sand blast, bead blast, or any other abrasive blast an oil vessel.     I also used them when people used coatings inside fuel tanks.  They can strip out any coating.

See:

However use extreme caution when chem dipping alloy bits, same as dishwashers and other chemicals.   I liquidated a big Ariel Sq4 collection and one of the bikes, the owner had sent in some greasy old Ariel cases to the machine shop and they dipped them but used the wrong tank.  melted the cases.  I have pictures of the results.............  this happened in the 1970s and they were able to source some extra engine cases from Nicholson Brothers in Canada with no numbers,  But good luck finding replacements today!

This place is who I use locally for chemical dipping and stripping.   Mrs Sluggo has her dream car project, Its a 1969 Chevelle muscle car and the whole body will get dipped there next spring. When its stripped to bare metal, they then chem dip it with an acid etch to prevent flash rust on the steel.  We can then proceed with body and paint with a totally clean virgin canvas.

This place does not have much of a website, but they do have a lot of pictures on FB.. See: https://www.facebook.com/AmericanMetalCleaning/

My point here is, Dont cut corners, and test your ideas first and do your research.

(Cant find the ariel pix at the moment but here is one polisher/buffer we have here.... What a beasty!)
Title: Re: Crankcase restoration
Post by: Joolstacho on 02.12. 2018 22:47
"Avaition aluminium cear caot is what you use on motorcycles." (sic)

The big difference is that the aluminium sheet used in aircraft fuselages is not porous. Whereas our alloy castings ARE porous, so when clearcoated, minute pools of oxide and other potential impurities are trapped in there, which later can and will bubble. In addition, clearcoats on aluminium tend to look too thick and glitzy. Then there's the scratching problem. If the bike is a 'user', inevitably the clearcoat will get scratched, -the oxidation will then have it's evil way!
Maybe it's a matter of taste though.
What brands of clearcoat have you found to be successful Trev?

My point about polishing was that it's all too easy to get a quick shiny finish using the polishing mop, but when you look closely you'll see that the polish compound has 'dragged' the aluminium surface. Looks cheap 'n nasty, plus, polishing compound can get buried in there.
There is no substitute for elbow-grease!
Title: Re: Crankcase restoration
Post by: Peter in Aus on 03.12. 2018 02:59

 I bought a soda-blast unit about a year ago to do stuff like this (~AU$90 + media 25kg/AU$60)- only used it briefly a couple of times thus far, need to be diligent where it's used though, as is a bit 'dusty'....even if you took it to a car-wash place and give them a high pressure blast you may be surprised
A dip in boiling water will clean them up.
Much better than spraying.
Bi-carb is water soluible so 10 minutes in a rolling boil then blow dry & it is clean.
Have yet to try blasting soda , same stuff just bigger crystals . I am still using the 20kg bag of animal feed soda ( $22 ) that I bought to test it out to see if it was worthwhile.
Saved a fortune in degreaser & carb cleaner . Outsides get a soda blast followed by inside the bowl then 10 minutes in the ultra sound $ 40 please sir for carb clean.


Sounds good Trev, next one I do I will give it a go, How much Bi-carb to the Lt. of water do you use?
Peter
Title: Re: Crankcase restoration
Post by: BSA_54A10 on 04.12. 2018 09:57
"Avaition aluminium cear caot is what you use on motorcycles." (sic)

What brands of clearcoat have you found to be successful Trev?

My point about polishing was that it's all too easy to get a quick shiny finish using the polishing mop, but when you look closely you'll see that the polish compound has 'dragged' the aluminium surface. Looks cheap 'n nasty, plus, polishing compound can get buried in there.
There is no substitute for elbow-grease!
It came from Aircraft Spruce in the USA.
Heaven only knows what it was .
Went onto an early Honda 4, well actually several early Honda 4's.
Single pack volatile solvent paint took about a full day to dry & the cases got 3 coats
Was on the bike for 15 years & looked just as good when my mate got wiped out as it did the day we painted it.
Ideal came from Brit Iron .
As for crud in pores, it is just a case of getting the cases hot enough to drive off the moisture.
No moisture in the pores = no corrosion.
No oxygen or hydroxyls = no oxidation
And the stuff is designed to be resist dust at 300mph so it does not abrade nor chip off.
Title: Re: Crankcase restoration
Post by: BSA_54A10 on 04.12. 2018 10:07

 I bought a soda-blast unit about a year ago to do stuff like this (~AU$90 + media 25kg/AU$60)- only used it briefly a couple of times thus far, need to be diligent where it's used though, as is a bit 'dusty'....even if you took it to a car-wash place and give them a high pressure blast you may be surprised
A dip in boiling water will clean them up.
Much better than spraying.
Bi-carb is water soluible so 10 minutes in a rolling boil then blow dry & it is clean.
Have yet to try blasting soda , same stuff just bigger crystals . I am still using the 20kg bag of animal feed soda ( $22 ) that I bought to test it out to see if it was worthwhile.
Saved a fortune in degreaser & carb cleaner . Outsides get a soda blast followed by inside the bowl then 10 minutes in the ultra sound $ 40 please sir for carb clean.


Sounds good Trev, next one I do I will give it a go, How much Bi-carb to the Lt. of water do you use?
Peter

Done dry.
Google "Soda blasted" on U tube and you will find dozens of them there.
The only difference is I try to use wide mouth drink bottles and then runs some hot glue around the hole where the air duster goes through.
Narrow ones tend to cake.
Really and old coke bottle + a $ 10 air duster, drill a hole through the neck, poke the duster through the hole , fill it with dry soda & you are in business.
Looks a bit like a gravity fed spray gun.
Only trick is you have to turn it upside down when you let the trigger off because the bottle pressurizes a little and that way you let the air out, not bulk soda.
If I get excited I might do a video but really there are thousands of them out there.
Shane bought an expensive soda blasting kit using a supply tube from a pressurised  tanks but the $ 10 jobie works much better.

Big downside is it is like scrubbing the dunny floor with a tooth brush, a slow process in you are removing heavy rust. Useless on wet grease, can take bad paint off but needs a vinegar wash after or the paint won't take.