Oil catch can/oil return

[Popcorn]

I've made a oil catch can/ oil return for my engine out of off cuts 304 stainless tubing, I didn't purge it I used flux for stainless instead.
Yes I know I should have done it properly, but unfortunately I don't have the gear to purge it correctly and the flux was a lot cheaper.
It worked quite well, but I can still see some sugaring inside that I cant get at to clean with a wire brush and Dremel.
Im worried about bit of this coming off and contaminating my engine oil and destroying bearings etc
So what I want to know is can I use some pickling paste to remove it ? Would that work or is it just from removing the colour/oxides in super hygienic/critical jobs.

 

[Cheesie]

Pickle past just removes burn marks not the coking/sugaring

 

[Popcorn]

Cheers @Cheesie that's what I suspected, do you know of anything else I can use ?

 

[Cheesie]

It's not the sort of stuff that falls off unless it's real bad, for your own peace of mind you could do it again but purge it, personally if it's not to bad leave it as is

 

[500e]

How about some steel shot and knock up a tumbler
Wonderful what you can make with an old wiper motor

 

[MetalMonkey]

No idea if it will work for that, but sharp gravel, water and a good shake often shifts a lot of sludge out of inaccessible containers.

 

[Popcorn]

Yep thinking the tumbler ideas a good one, probably put some gravel in it and stick it in the pillar drill for a while.

 

[Jelly_Sheffield]

Cheers @Cheesie that's what I suspected, do you know of anything else I can use ?

On a chemical level pickling paste is capable of removing it, but suffers from both localised the exhaustion of the reagent when trying to consume a larger amount oxides, and a lack of heat.

The classic methods for chemical descaling of oxides on SS are the same (or slightly more concentrated versions) as the solutions used for immersion pickling:

• 20% Nitric Acid, 5% Hydrofluoric Acid, at 60°C
Or
• 10-12% Sulphuric Acid, 2% Sodium Chloride, at 75°C

Both would require gentle agitation of the solution or part during the bath, followed by a dip in a neutralising solution (Sodium Carbonate is a good choice), and a thorough rinse.

I don't know that I'd want the Nitric/Hydrofluoric around as a liquid (even though it's the same material as picking paste), but the Sulphuric mix isn't too scary.

 

[500e]

Yep thinking the tumbler ideas a good one, probably put some gravel in it and stick it in the pillar drill for a while.

Wants to be able to rotate fairly slowly and also be able to move the rotation point to get coverage

Hydrofluoric really nasty stuff

 

[Agroshield]

Is there any way to make a micro-bead blasting setup that you can poke into the tank and blast the seams?

You know where the seams are, so can localise the blasting to those places. The tumbler will abrade everything uniformly, including the parts that do not need abrading.

 

[Popcorn]

Just thinking a mate of mine has got a small ultrasonic cleaner, wonder if that would shift it.

 

[Jelly_Sheffield]

Hydrofluoric really nasty stuff

Oh yeah, it certainly deserves serious respect, although is not nearly as bad as the reputation it's picked up.

Which is to say that in dilute form, you'd need to be bathed in the stuff to experience the tissue necrosis and contact poison effects.

A small to medium splash at 5% would probably "only" results an extremely painful and permanently disfiguring burn developing the next day if the splash was not immediately treated with Calcium Glucose gel followed by A&E.

At least mixed with the nitric it would dye your skin yellow so you can clearly see where you need to put the gel on.

Maybe I have spent too long around the chemicals...

 

[Anguz]

We use 20%, and the fumes will etch glass