Author Topic: Crankcase restoration  (Read 929 times)

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Re: Crankcase restoration
« Reply #15 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.
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Re: Crankcase restoration
« Reply #16 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.
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Offline Sluggo

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Re: Crankcase restoration
« Reply #17 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.
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Offline Sluggo

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Re: Crankcase restoration
« Reply #18 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!)
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Offline Joolstacho

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Re: Crankcase restoration
« Reply #19 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!
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Offline Peter in Aus

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Re: Crankcase restoration
« Reply #20 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
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Re: Crankcase restoration
« Reply #21 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.
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Re: Crankcase restoration
« Reply #22 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.
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