Cast Iron Manhole Rusted to Frame

You wouldn’t heat the cast iron plate as it could crack , but you could heat the outside ring that it fits into , it would expand faster and loosen then be prised off.

i see his WD 40 has worked anyway so nuff sed :)

Aren't "blow torches" sorta obsolete now? Anyway, a "hot wrench" of some sort. But it probably is cast iron or steel, so you would probably have to be careful of differential heating because of brittleness. Try to heat evenly if that is possible.

IIRC there was a thread on CR4 some years ago which described - sometimes in graphic detail - various methods of manipulating a cast-iron object. Unfortunately, A) most of them were destructive to the object, 2) many were destructive to the manipulator* and γ) the thread is no longer accessible on CR4.

Sorry I can't be of more help.

* Oxford comma not required.

White vinegar eats rust, and it's cheap.....or hydrochloric or muriatic acid if you're in a hurry...

Naval jelly or Iron Out if available.

I used Iron Out on a lawnmower wheel hub that had rusted to the shaft. Took a while but it eventually worked.

On steel yes but not cast iron as it turns to powder or the carbon leaches out of it , depending on the grade and quality of cast iron.

on steel my favourite is the hydrochloric acid in a 30 - 50 % concentration (also known as pool cleaner or concrete cleaner acid)

phosphoric acid works great too but it’s a nasty wench best left alone.

white vinegar for household use is usually 4% conc , it can also be purchased from industrial chemical suppliers commonly up to 16% except its then called acetic acid not vinegar but also works nicely on rusted steel.

if you want to get fancy there is a more environmentally happy blend called methyldiaminetetracetic acid (my spelling could be wrong) , it’s biodegradable and you can stick your fingers in that without harm but it’s very expensive .

or good old fashioned fermenting molasses - but I don’t know if that affects cast iron.

:)

It's more commonly known as MDTA; most people use ethylenediaminetetraacetic acid (EDTA) instead- including for foods (do you ever read the ingredients on a cereal box??). Problem with both of them is getting any less than a 45 gallon drum from a chemical supplier!

Ah! Signs of movement . A good soak with WD40 and a good smacking all round the frame with a 4 pound club hammer has loosened some of the rust and mud from the join, I can see the WD is penetrating through.
Just needs some patience now and keep going round.
What's best to grease round the frame to prevent it rusting up again?Wax, tallow, grease?
Del

Melt some lead to use as a gasket....

Elbow grease of course.

To prevent re-rusting I would suggest a heavy (viscous) grease, the idea being to form a long-lasting "barrier" coating and prevent electrical contact. But first a sand-blasting of both pieces to give better surfaces would be appropriate.

For penetrants I have used Kroil with good results. But there are many that each user will swear by!

But your smacking and patience is where I would start. Use a compressed air blow gun to get debris out of the joint.

There's an implied detail (CR4 images become such poor quality) that might be fasteners at the four corners. Some kind of a fastener would be typical of a non-circular cover. Often to deter theft or vandalism an atypical tool removes the fasteners.

Agreed, it does sort of look like mechanical fasteners at the corners.

Absent are the expected pick holes; how does one remove the cover or replace without a finger pinch?

Is this going back in the ground, or can you use this as a trivet on your dining table?

Or maybe a BBQ grill plate
Del

Can you give us a closeup shot of that logo in the middle? I'd be interested to see it.

Your wish is my command

I notice it's "GRADE C" damn cheapskates
Del

It appears that the rusted cover problem is solved, however count me in as one who would purchase that print...or heck, the cover itself. It's really something!

Trying to wrap my head around the symbology here. Took me a moment to notice that man is standing on a beautiful woman. What does it mean? Is this an image of enlightened man conquering sewage? What do the lions represent? What is he holding in his right hand? I think it might be time for a new thread devoted to the beauty and basic utility of the hole covers we call man.

You could grab an upgrade

on ebay

for £35 (pick up in Blackburn...... Wasn't there a Beatles song.........?)

You're 'avin' me on incha? Aye fule can see that's a grade C too .
Having been left overnight the soil and rust is coming off a bit easier now, I'll try a wire brush in the eclectic drill next
Del

I'll have to sue my optician, I'd've sworn that was a B.

It's funny whenever I play pool, I wonder if a cr4p pool player has ever murdered their optician.

At least it isn’t one of ours. I worked for Stanton & Staveley.

Thanks!

Good idea to reserve an old screwdriver for non-screwing tasks that they are so good for! Try welder's needles for getting rust and crap loose.

I guess you and many others have not noticed that five and a half years ago Del separated the Manhole from the frame. He even provided a picture of the cover and frame.

AAAAAGGGGGHHHHHHHHHHHHHHHH!!!!!!!!!!!!!!!!!!

You may think that... I couldn't possibly comment.

Del

Unfortunately, you have taken a rare objet d'art and desecrated it by removing all the years of patina and turning it in back to a damn manhole cover.

Where is your pride, man?

Ya know, there may be something to this.

Tomorrow I will snap a pic of the MH in our parking lot - as many are, custom cast per customer order. I would agree, to an extent these are pieces of art.

I like it (and SE in #15) GA vote for you both from me.

And I’m throwing a bunch of stars on here too.

Some ice on the inside piece and some gentle heat on the outside. Don't let the temperature difference be too great. A gentle bang bang around the edge should loosen the two.

Some say use fire

Some say ice

What I know of results

Using both should suffice.

(with thanks to Robert Frost)

You should try whatever method was used a few years ago for breaking the cast iron bathtub.

Is their any history to this ? Why and wherefor was it found...why dig an unknown cover up. I'm fascinated because FIL has a sealed off WW11 bunker in his garden (white cliffs of dover). So far, I have not got there with Mr Sledge.

One of my habitats has two odd manholes in the garden. Local Council have lost all records of what they do. Tempting to smash open, but they are clearly hermatically sealed. Both constructs have been heaving up and down due to a clay based subsoill. Mr Sledge is very itchy to get going.

I'm with you on bust it open and see. What did you see underneath. I promise not to tell your local council.

4lb hammer ? yer 'avin a laugh. Man it up !

Why are they hermetically sealed? Makes me wonder.

Be careful what you open up, you never know what might come out...

My wife and I had a little fun after the shock of finding a 20 ft deep well under our house when we started some renovations. She called it the "pit from hell" on facebook and immediately had people respond with pics from the movie "The Ring" and other creepy well references.

If you use HEAT you will destroy the seal if it has one..SO.. Try full fat Coca- Cola.. that will clean any rust from it.. you have top and bottom so make a polythene lined depression cover in Coke and let it soak..24-48 hrs.. when the rust rubs off you will find the prise points..on the edges

Don't know about manhole covers (Never seen a rectangular one, btw), but old farm implements and most anything else with rusty threaded parts I've messed with respond well to a 50-50 mix of automatic transmission fluid and acetone. Do some googling; there are lab tests where that concoction worked as well as any of the high dollar rust cutters. Soak it well, wait a few hours/overnight. If it doesn't come loose on 1st try, repeat.

We are now moving towards the refit.
I chiselled most of the rust out of the frame, pressure washed it, wire brushed it, even got Mrs Cat to give it one of her hard stares .
I then warmed it up with a blow torch and melted a couple of candles into the "U" channel, that soaked in and should hopefully give it some protection.
Del

If you only want the rust gone (bye-bye patina as well), consider electrolysis. The steel frame will suffer, but cast iron cleans nicely.

Can you clean the groove with an angle-grinder using a thin blade abrasive disk.

If it is an economic thing then scrap it and buy a new one... but first have a go by hitting it really hard - you risk breaking it, but nothing to lose.

If it is a 'save the cover' thing then use various acid/oil solutions already suggested, and also I would try a set of pulley-draws on each corner to gently prize the cover out.

Or improvise with some like a large G-clamp with suitable chocks

Get some help & use couple of torches to heat the frame whilst keeping the cover as cool as you can, It needs to be done quickly so as not to transfer too much heat to the cover. If possible place the whole thing on a drum of water under the cover so it dissipates the heat but leaves the frame to fall away.

Heat usually helps I have found out over many years. Big gas torch!!

Best of luck.

Update.

I see you got it off/open....Well done!

Please don't hit the cover with a lump hammer; it will shatter and might injure someone.

A ductile iron road-grade access cover and frame is about £60. Why are you bothering?

Build up the chamber underneath with a couple of courses of engineering brick and fix a new cover on top.

I have and it didn't.
The brittleness of cast iron (and my stupidity) is often greatly overstated. This may well be a ductile grade anyway as it is made to the appropriate British Standard.
I'm bothering because I enjoy using my skills and the physical work is keeping my 66yr old body in a reasonable state of fitness, it also helps conserve the worlds resources and lets me feel that the money saved can be spent on stuff I want... I recently bought and refurbished a little milling machine
I believe in making and mending rather than throwing money at things.
I already have built up the chamber with 3 courses of engineering bricks and this morning I cemented in the frame.

Del

Well, I'm glad you are enjoying it: One man's pleasure is another's root canal treatment!

How about some pictures of the milling machine as well?

I did already!
https://cr4.globalspec.com/thread/122233/Del-Gets-Burnt
Del

Nice one!!! Thanks.

Got it done at last, I painted the cover with some "Drive Revive" tarmac restorer that I had left over.
I think the drainage function is a fluid logic OR gate

I think it looks better than a modern galvanised replacement one.
Del

The way you wrote your original post, I thought that you just found it buried, not that it was an access to your drains still, so some idiot simply concreted it over!!!!

(Not you, I can guess that much!!)

Maybe some of the posts were also not understanding that "small" point!!

By the way, you did a great job and I would l would have re-used it too.....

Any idea how old it might be (same age as the house possibly?)

Yeah, prob' same age as house which is about 1960.
Del

That looks like a valve at the bottom. Then again it might be a Y coupling for a branch line. Do you have any idea what kind of fluid is in those pipes? Domestic sewage or roof runoff comes to my mind but neither seem likely to have a valve. I'm thinking this might be abandoned infrastructure like water or gas supply.

That's not a valve it's a steel staple which act as a step so you can climb in and out, there's 2 of them... this pic shows them better.

It's "foul water" (sewage), I think it may have some rainwater run off in it too.
Del

I saw the rusty staple(s) earlier. I was commenting on the black pipes at the bottom. I know I have a warped mind but it now wonders why bother to provide brick lined access to a pipe junction? A cap for cleaning things out or a valve to manipulate makes sense for access but a hole in the ground to do nothing at the bottom makes no sense to me.

Then again, it doesn't have to make sense. It's an old utility line.

I have the impression it is a half pipe and you are seeing the wet lower "half"!

A half pipe? Nobody will be using a skateboard, snowboard, or skis in that hole.

Just the lower half of the pipe like a U so they can be accessed and rodded out if there is a blockage.
presumably that's where the half pipe got it's name.
Del

Thanks for the confirmation.

The chamber acts as an expansion vessel/ buffer tank, so it takes a lot of back-up before it gets into the (cast iron?) bath.

They can be self cleaning as the pressure when full can be enough to dislodge offending matter.

Yup, nailed it
Del

I'm gonna hire youi. That looks really good!

A blowlamp?

You said it completely wrongly! Not "A blowlamp? "

"e blew limp!"

Pardonnez moi!!

As you did but with a bit of low frequency vibration, just enough to see some movement at the joint should do the trick. Mind you, the CR4 should do the job when combined with patience.

In my line of work (Civil Engineer), our first effort is always to bang the lid several times with a sledge hammer and see if we can knock it loose. If that doesn't work, sometimes soaking the joint space in vinegar might help. But, if the seldge hammer does not work, be prepared for a wrestling match. If its really bad, nothing may work.