MM2 chimney

Atticman · MM2 chimney

Hi, I have a nice oldish MM2, looks like an early vap burner type, has the same holder as my SE3, ie a steel thick wire rather that the metal strap. Also the fly is Mazak but the other part of the crank is copper.

Sadly there is no chimney, just the brass stud and dents suggesting the old chimney was forced off.

Firstly is the vap burner the same as in the TE1s, I have used this but the flame leaps over the boiler. ie is the vap burner for the MM2 a lower height or is the flame part of the fun

Second, where do I get a replacement chimney- do Forest Steam do them, I think they do chimneys for SE3s

Thirdly how do I refit the chimney if/ when I get one Looks like the stud may need to come off

.

It runs great till the fly came off, landed in Mrs Attics soupbowl. I guess superglue will sort this slight problem

OK here are the pics,
Firstly the boiler, still needs a bit more wet and dry, but nearly there- not dezincified I hope

The nobble and dent

of an old chimney- as well as copper crank

Needs some green paint one day... and I need an electric polisher

Side on

And showing the vap burner slot

bessytractor

I too need to know how to sort chimneys on a MM2, mine leaks!

I think Mamod man will help here!

Atticman

Does that mean you have a rare MM2 that has smoke coming from its chimney

8_10 Brass Cleaner

Minor1PJG

The best offer is certainly a SE2 Chimney I don't think you'll get a new one from a supplier. The chimney for the SE3 was always 'demountable'.

The early chimneys were fitted (I believe) by passing them over the pround brass 'rivet' or stud and then rounding it over the head slightly (probablly with a special tool). The later MM1's and probably MM2 chimneys were secured by a blind copper rivet and this might be an option if you can get the 'nose' of your rivet gun down the chimney!!

The burner you have is correct for that engine. Contaminated or old Meths might make the flame lap up around the boiler as you describe. Sometimes cleaning the underside of the boiler to remove sooty deposits helps a little.

Good luck.

CCairns

The blind copper rivet would be your best option for fitting that Chimney. If that does not produce a steam tight seal then you would need to look at taking the end cap of the boiler and soldering a screw on the inside of the boiler and fixing the chimney with a nut from the top. See my posting on an SE1A restoration for more on this option - http://modelsteam.myfreeforum.org/about6857.html

The marks on your boiler would seem to indicate that this boiler has fallen at some time and the chimney has been pulled off in the fall, but nowhere as bad as my SE1A suffered.

Chris Cairns.

Atticman

Thanks for the replies so far, agree my meths is a bit old well spotted

The fall certainly fits as the dents are pretty much where the old chimney was- the marks are worse on Chrises SE1a I guess as its heavier than the MM2.

As for fitting the chimney, suggestions are v helpful, will ponder for a bit, not relishing an end cap removal as Ive got a lot on at the moment

flywheel61

Try MF, he has made a few different types, i think, and was tooling up for the prewar ones at some stage,

Cheers

Chris

Wallace

Nice engine Atticman

Can't really add about the chimney

But just be careful with Wet and Dry use on that spot on the boiler.

A good thing is that it doesn't look like dezincification to me.

But I have a brass wheeled MM2 with a similar coloured spot. I thought it was solder, or even metal filler.
Whatever it is, polishing it didn't make it go away or change colour.

Dezincification can be a copper colour, sometimes with white powder deposits. It will polish out, but comes back

Good luck

Atticman

Nick

How do you get the nose of your rivot gun far enough in the chimney for the rivoted chimneys. Is there an easier way to re-rivot them?

CCairns

When I was looking at my SE1A restoration I was lucky that the pop rivet gun that I bought would fit right down inside the SE1A chimney, although with little clearance. I did try it with a copper rivet held in the gun and it certainly would have worked OK.

However I decided to solder a 6BA screw up from the inside instead, thus allowing me to remove the chimney when I get around to repainting that engine.

Not sure if the diameter of the MM2 chimney is the same, as my MM2 is currently boxed up in storage at present.

Mamodman123

When fixing a chimney on ive always taken off the end cap (usually the front one on the MM2) and soldering a nut and bolt through the top! Holds it well and will never leak!

Atticman

Havent sorted this yet, the nut is a nice brass bit. I will try to get a chimney at STIA.

I have had a thought though

If I make a circular flat piece of copper/ brass that will fit inside at the bottom of the chimney.

Then make a tiny hole so it can just push over the brass bit.

Then solder this small piece underneath the chimney at the bottom

Then tighten the small hole with a centre punch down the chimney.

I think this will sort it and wont fall off

Nick

I would really prefer the rivot as it looks the easiest.

Nick

I guess my rivot gun does fit down the chimney and is long enough.

Minor1PJG

Just need a chimney now then

Nick

The one I am redoing is still on the engine. It is just very loose.

johnreid

One would probably have to remove the end cap to punch it firmly and flatten the rivet better. You might try carefully trying to bend the rivet and I do mean carefully.

Nick

It's just a pop rivet. I can drill it out and put a new one in the chimney. Then use my rivet gun by sticking it down the chimney. If I press it tight to the boiler it will be fine. I'm thinking about using gaskets on the rivet.

johnreid

They do make sealed pop rivets

Nick

I know, but I am talking about the outside edge of the rivet.