Rusty muck in Reciever... how to treat???

[GRW]

I managed to remove the large 2" fitting to access the 50-year-old Reciever tonight.
What a mess!
I've spent the last 2.5 hours scraping around and picking rusty flakes and gunk out of the bottom of the tank on my Type 30 using a telescopic magnet.
Despite a growing pile of orangey nastiness, the Reciever does sound, well sound when tapped firmly all along the underside, with a healthy ting-ring.
It's also been taken up to full pressure several times already with no issues.

My question is.... After I've got out as much gunk and rusty bits as I can manually (it'll never properly dry util I do, but there's a practical limit to how clean I can get it).....
... can I spray some kind of rust converter or similar inside the tank to try to protect it going forward?
TIA
G.

 

[brightspark]

just power wash it out they go rusty anyhow

 

[wyn]

With the tank on mine, i welded a tube on each end, sat it on axle stands. I then filled it with bits of scrap metal and sat there turning it to knock the rust off inside.
I think i gave up pretty quickly though.

 

[GRW]

just power wash it out they go rusty anyhow

I'd considered that but wasn't sure. I can try to get the flakes etc out so the grit etc can flush out of the drain?
I do have some very watery "rust stuff" (can't recall what it's called, but I got 5 Litres of it) that seemed like it worked well on a car subframe.... so I could spray (carefully with goggles and mask on, cos it's nasty stuff) some inside the Reciever afterwards? Can't hurt, right?

 

[GRW]

With the tank on mine, i welded a tube on each end, sat it on axle stands. I then filled it with bits of scrap metal and sat there turning it to knock the rust off inside.
I think i gave up pretty quickly though.

I think poking around with a jemmy bar, an led torch and a telescopic magnet for an evening (so far) is about as far as I want to go)

 

[daleyd]

I'd considered that but wasn't sure. I can try to get the flakes etc out so the grit etc can flush out of the drain?
I do have some very watery "rust stuff" (can't recall what it's called, but I got 5 Litres of it) that seemed like it worked well on a car subframe.... so I could spray (carefully with goggles and mask on, cos it's nasty stuff) some inside the Reciever afterwards? Can't hurt, right?

Might do if it starts flaking off and making its way down your airlines at a later date…I’d do as @brightspark says and leave it as it is

 

[GRW]

Might do if it starts flaking off and making its way down your airlines at a later date…I’d do as @brightspark says and leave it as it is

There's (wet) rust fakes there now - so I was thinking "what's the difference" tbh

 

[daleyd]

There's (wet) rust fakes there now - so I was thinking "what's the difference" tbh

Yeah, but give it a wash/blow out and they’ll be gone. Any coating might end up coming off in big flaky chunks (might not of course but I don’t think I’ve ever known the inside of one to be painted).

 

[roofman]

The rust flakes wont fall off the inside as they have upto 150psi pushing them back into the steel

 

[GRW]

Yeah, but give it a wash/blow out and they’ll be gone. Any coating might end up coming off in big flaky chunks (might not of course but I don’t think I’ve ever known the inside of one to be painted).

It's not a paint. It's the sort of stuff you can soak spanners or other metal in to remove corrosion.
On the subframe, I sprayed it on using a paraffin gun (how I found out its pretty acidic and you do not want any of it airborne coming back at you), and like phosphoric rust killer stuff, it sees to react with the ferrous and turn dark.
(I sprayed 50/50 Underseal/Waxoyl mix over the subframe afterwards, and it seems to be good so far).
So, if it reacts with and converts to get part of the structure then I was thinking it might be good.... but its an idea and unproven of course

 

[GRW]

The rust flakes wont fall off the inside as they have upto 150psi pushing them back into the steel

Excellent point

 

[brightspark]

The rust flakes wont fall off the inside as they have upto 150psi pushing them back into the steel

yea rito gravity takes over if there a hole in the tank the pressure will push it through

 

[daleyd]

It's not a paint. It's the sort of stuff you can soak spanners or other metal in to remove corrosion.
On the subframe, I sprayed it on using a paraffin gun (how I found out its pretty acidic and you do not want any of it airborne coming back at you), and like phosphoric rust killer stuff, it sees to react with the ferrous and turn dark.
(I sprayed 50/50 Underseal/Waxoyl mix over the subframe afterwards, and it seems to be good so far).
So, if it reacts with and converts to get part of the structure then I was thinking it might be good.... but its an idea and unproven of course

Ah ok - but from that description it makes it sound even less appealing to be putting in there!! Do you really want an acidic chemical being pushed at high pressure down your airlines and into pressure switches etc with rubber seals etc??

 

[GRW]

Ah ok - but from that description it makes it sound even less appealing to be putting in there!! Do you really want an acidic chemical being pushed at high pressure down your airlines and into pressure switches etc with rubber seals etc??

An excellent point indeed! I hadn't thought of that!
I had thought I'd pressurise and then remove the drain bung a few times - (outside and well clear of anything and anyone) to clear any residue.... but that I can see doesn't ensure that any future moisture wouldn't cause it to do just as you say.
Maybe I need to rethink

 

[GRW]

yea rito gravity takes over if there a hole in the tank the pressure will push it through

If there's ever a hole in the tank then all of it becomes all rather moot I think

 

[daleyd]

I’m guessing you would spray it and let it react etc before pressurising it so it would “probably” be neutralised by that point but I think you may just be overthinking it - clean it as best you can and that’s good enough I would think

 

[Ubique]

You could (somehow) remove all the loose rust from the surface and spray with Dinitrol 900 or similar, it bonds to the rust and forms an epoxy-like surface. That won't migrate once 'set'.

 

[GRW]

You could (somehow) remove all the loose rust from the surface and spray with Dinitrol 900 or similar, it bonds to the rust and forms an epoxy-like surface. That won't migrate once 'set'.

I've seen Dinitrol mentioned here a few times...I'll have to research it and see if I can get some.
(It's undoubtedly expensive no doubt... but good stuff always is)

 

[Ubique]

I've only used the spray cans, about £40 for a 400ml can, which should be more than enough for inside a receiver, however, spraying through a 50mm inspection port may be an issue...

 

[MetalMonkey]

Not sure how well it would work, but if you had it dismantled and the receiver on its own, you could fill it with water and some gravel and swirl it about to shift the worst of the scale.

For treating it, you could fill it up some phosphoric acid and then drain it off.