Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Builds, Repairs, Show Your Machines! => Restorations => Topic started by: Loosenut51 on March 21, 2019, 12:54:17 pm

Title: Re: Marklin Donkey Engine Restoration
Post by: txlabman on April 15, 2019, 01:17:15 pm
Thanks Karl.

A nice job on this restoration.

Looking forward to seeing it running again.
Title: Re: Marklin Donkey Engine Restoration
Post by: Nick on April 14, 2019, 08:48:45 pm
I wish I was the lucky owner of this Beauty!  8)
Title: Re: Marklin Donkey Engine Restoration
Post by: Jim on April 14, 2019, 07:30:19 pm
I'm enjoying this thread Karl.
Title: Re: Marklin Donkey Engine Restoration
Post by: Stoker on April 14, 2019, 07:04:39 pm
A true professional grade restoration ... for certain and for sure!!!
Title: Re: Marklin Donkey Engine Restoration
Post by: Loosenut51 on April 14, 2019, 06:07:50 pm
As the previous post will show. The boiler has been mounted back on it's base and secured with 5Ba cheese head slotted screws.
The steampipe is a complex affair as it loops out from the steam valve, drops vertically and enters into the firebox via a vent hole and to the steam inlet on the rear of the slide valve engine.
A slide over spring coil pipe bender earns it's money on this.
[attachimg=1]

[attachimg=2]

[attachimg=3]
Title: Re: Marklin Donkey Engine Restoration
Post by: Loosenut51 on April 14, 2019, 05:58:28 pm
Two enamel paint jobs on the flywheel. The reverse face matches the base whilst the outer face is red. The drive shaft polished up bright on the myford and reunited with the flywheel.
[attachimg=1]

[attachimg=2]

Next stop... Pipework
Title: Re: Marklin Donkey Engine Restoration
Post by: Loosenut51 on April 14, 2019, 05:46:53 pm
So two coats of etch primer, and three coats of enamel paint and the base is done.
[attachimg=1]

The same treatment to the flywheel. An unusual type made from a cast lead alloy, with a brass hub and brass outer casing.
[attachimg=2]
Title: Re: Marklin Donkey Engine Restoration
Post by: Loosenut51 on April 14, 2019, 05:12:10 pm
What brand of etch primer do you use?

I will check tomorrow and let you know. It a very good all rounder.
Title: Re: Marklin Donkey Engine Restoration
Post by: KNO3 on April 14, 2019, 04:42:07 pm
What brand of etch primer do you use?
Title: Re: Marklin Donkey Engine Restoration
Post by: Nick on April 14, 2019, 10:07:30 am
Very nice progress  8)
Title: Re: Marklin Donkey Engine Restoration
Post by: St Paul Steam on April 14, 2019, 06:26:08 am
beautiful work Karl, a joy to see the transformation.
Title: Re: Marklin Donkey Engine Restoration
Post by: Loosenut51 on April 14, 2019, 05:17:32 am
Yes indeed

The drain cock sourced from German eBay is fitted.

[attachimg=1]

The cast metal base has been in my new sandblaster and given an etch primer coat.

[attachimg=2][attachimg=3]

Further updates later today hopefully
Title: Re: Marklin Donkey Engine Restoration
Post by: KNO3 on April 13, 2019, 02:30:31 pm
Very nice work! Any progress?
Title: Re: Marklin Donkey Engine Restoration
Post by: SeeSteam on March 22, 2019, 06:58:30 pm
Reminds me of a retro Dalek
Title: Re: Marklin Donkey Engine Restoration
Post by: classixs on March 22, 2019, 04:27:38 pm
Been missing the opportunity to follow your restoration-threads Karl, it´s such a treat to follow your work.


Thanks for sharing ! (https://emoji.tapatalk-cdn.com/emoji482.png)
Title: Re: Marklin Donkey Engine Restoration
Post by: Mi Steam on March 22, 2019, 02:38:45 pm
Karl you are doing a great job restoring this Marklin.
Title: Re: Marklin Donkey Engine Restoration
Post by: Kevin68 on March 22, 2019, 02:25:26 pm
Karl splendid work on the boiler and fittings. Looking forward to seeing more.
Title: Re: Marklin Donkey Engine Restoration
Post by: Loosenut51 on March 22, 2019, 12:08:37 pm
A quick dip in a solution to neutralise the flux and a cold water rinse & dry and then a polish up on the buffer wheel & test fit all the fittings

[attachimg=1]
[attachimg=2]

Next we will turn our attention the engine and heavy cast metal base.
Title: Re: Marklin Donkey Engine Restoration
Post by: Loosenut51 on March 22, 2019, 12:05:10 pm
Next to clean all parts to bright finish ready for assembly.

A generous application of flux to all parts and then the process of soldering it all together got under way both inside and out, including two more newly made threaded brass inserts for the drain cock and whistle.

[attachimg=1]
[attachimg=2]
Title: Re: Marklin Donkey Engine Restoration
Post by: Loosenut51 on March 22, 2019, 11:41:16 am
I needed to source a replacement Marklin drain cock (missing when it came in) and a Marklin whistle with a 90deg elbow fitting (also missing).

weeks of trawling Ebay.de came up trumps with these rarities albeit not cheap.

[attachimg=1]

[attachimg=2]

Title: Re: Marklin Donkey Engine Restoration
Post by: Nick on March 22, 2019, 09:32:29 am
Some very impressive work so far Karl, and that new boiler is beautiful  8)
Title: Re: Marklin Donkey Engine Restoration
Post by: Loosenut51 on March 22, 2019, 09:04:13 am
The only correct fittings on the Marklin was the Safety valve & the steam Regulator. The SV was missing the spring so a new spring was trial fitted plus an o ring and the valve set to the required blow pressure.

[attachimg=1]

[attachimg=2]

The regulator was given a clean and polish likewise the SV and set aside.

Next was to make and solder in new brass threaded inserts into the dome for the regulator and SV.

[attachimg=3]

The next part will cover the boiler reassembly.

Title: Re: Marklin Donkey Engine Restoration
Post by: Kevin68 on March 22, 2019, 05:59:33 am
Karl it’s a shame to see an engine in such a state. It’s great to see a fellow member restore this engine to its original condition. Will be watching with interest Karl.
Title: Re: Marklin Donkey Engine Restoration
Post by: Loosenut51 on March 22, 2019, 02:38:00 am
Now the old copper boiler casing is opened out and flattened to be used as a template.

[attachimg=1]

Then using new 1.2mm copper sheet the new casing is marked out paying attention to the position of the firebox vent holes and the base fixing locations.


[attachimg=2]

The holes are drilled to the required size , de-burred and the plate passed twice through my sheet metal rollers to achieve the required diameter.
 
[attachimg=3]

Title: Re: Marklin Donkey Engine Restoration
Post by: Nick on March 21, 2019, 07:10:30 pm
A favorite engine of mine that I have yet to add to the collection. Keep the pictures coming Karl!  8)
Title: Re: Marklin Donkey Engine Restoration
Post by: Jim on March 21, 2019, 05:28:55 pm
Love following threads like this.
Title: Re: Marklin Donkey Engine Restoration
Post by: Loosenut51 on March 21, 2019, 02:25:47 pm
As you can see the boiler casing is toast ( or Swiss cheese)

[attachimg=1]


So now to make a new one.
Title: Re: Marklin Donkey Engine Restoration
Post by: Loosenut51 on March 21, 2019, 02:20:00 pm
Next step see what can be salvaged, give them a clean and good look over.

Chimney ok
Flue pipe ok
Boiler base ok
Copper dome ok
Boiler wall- scrap

[attachimg=1]
Title: Re: Marklin Donkey Engine Restoration
Post by: Loosenut51 on March 21, 2019, 02:15:50 pm
Step one strip down and see what's what.

[attachimg=1]
Title: Marklin Donkey Engine Restoration
Post by: Loosenut51 on March 21, 2019, 12:54:17 pm
This rare little chap came in to me in a bit of a state. Heavily modified (for the worse) too many holes for incorrect fitting and covered in cover patches. General quality of soldering poor.

[attachimg=1]

The only solution was a new boiler
More to follow on this extensive restoration 😉