MooseMan
Progress, progress....
Resurrecting a Bowman M101
The Bowman M101 currently gracing my collection rose like Lazarus from two incomplete engines:
Engine 1 was a complete-ish E101 that I bought about three years ago, with a badly restored boiler (you know the kind, bad soldering etc). This engine surrendered it's false cylinder cover, flywheel, oiler and chimney. Using parts from engine two it was then reassembled as a "runner"
Engine 2 was a fairly incomplete M101, repatriated from the US. From this engine I used the base, boiler, firebox and most of the engine.
Engine 1 was a complete-ish E101 that I bought about three years ago, with a badly restored boiler (you know the kind, bad soldering etc). This engine surrendered it's false cylinder cover, flywheel, oiler and chimney. Using parts from engine two it was then reassembled as a "runner"
Engine 2 was a fairly incomplete M101, repatriated from the US. From this engine I used the base, boiler, firebox and most of the engine.
Cleaning
Perhaps the most time-consuming job on this
engine. I began with thorougly degreasing, using white spirit followed
by normal detergent. The brass parts were then cleaned by all the
methods known to me. Most of the parts came up well with just
SimiChrome and Brasso and copious amounts of elbow grease, but for
other parts, most notably the boiler endcaps, I had to resort to
mechanical polishing with the Dremel - in a few places I actually had
to resort to light sanding or grinding. This leaves marks of course,
but these can be got rid off by repeated polishing using ever finer
methods, e.g: sand with fine grit, polish with copper bruss, vinyl
brush and simichrome, buff wheel and simichrome, hand polish with
simichrome and brasso - repeat as necessary!
Restoring the Boiler Stay Rod
The Bowman 101 engine was originally
equipped with a boiler stay rod, running right through the boiler and
held in place with solder and nuts. One threaded end extrudes and is
used to hold the chimney in place.
Unfortunately, this rod's made of iron, and invariably either perished or badly corroded, leaving the owner with two holes in the endcaps and a boiler full of rust. And so it was with the otherwise very good boiler from the US engine - stainless screw in one end, rusty bolthead in the other, lots of rust and bits of iron in the boiler.
After the boiler had been cleaned externally, my main concern was to get the fragments out. The powdery rust washed out easily, but the bigger fragments had to be broken up and extracted. This I achieved by with a selection of dental picks (highly recommended), and a magnetic pickup tool.
The screw and nut at either end were then unsoldered and the remaining solder scraped off, leaving me with a nice clean hole in both endcaps. I used a length of 5/32" copper pipe as a replacment for the stay rod - this was soldered into place, with a (purely cosmetic) brass nut soldered onto the front. I used high melting point lead-free solder with a high silver content
I then turned an M4 size slotted screw down to fit in the pipe, soldered this in and cut off the head - this gave me a threaded end rod to hold the chimney. After I'd cleaned up the joins, this repair looked, to all intents and purposes, like a factory fit.
Unfortunately, this rod's made of iron, and invariably either perished or badly corroded, leaving the owner with two holes in the endcaps and a boiler full of rust. And so it was with the otherwise very good boiler from the US engine - stainless screw in one end, rusty bolthead in the other, lots of rust and bits of iron in the boiler.
After the boiler had been cleaned externally, my main concern was to get the fragments out. The powdery rust washed out easily, but the bigger fragments had to be broken up and extracted. This I achieved by with a selection of dental picks (highly recommended), and a magnetic pickup tool.
The screw and nut at either end were then unsoldered and the remaining solder scraped off, leaving me with a nice clean hole in both endcaps. I used a length of 5/32" copper pipe as a replacment for the stay rod - this was soldered into place, with a (purely cosmetic) brass nut soldered onto the front. I used high melting point lead-free solder with a high silver content
I then turned an M4 size slotted screw down to fit in the pipe, soldered this in and cut off the head - this gave me a threaded end rod to hold the chimney. After I'd cleaned up the joins, this repair looked, to all intents and purposes, like a factory fit.
Burner Issues
The firetube on the burner I decided to use
was badly weakened, but easily replaced with a 5/16" tube, slotted and
cut with my trusty dremel. I used a shell casing (provided by
IndianaRog) for an end fitting.
One of the slight flaws in Bowman engines is that the burner tends to move due to vibration when the engine is running fast, and you can end up with the firetube resting against one side of the firebox, with flames and soot shooting up one side of the boiler. I remedied this by taking another (.38) shell case, and grinding this down to admit the firetube - this was then mounted on the baseplate for the firetube to rest on and be gently held in place.
One of the slight flaws in Bowman engines is that the burner tends to move due to vibration when the engine is running fast, and you can end up with the firetube resting against one side of the firebox, with flames and soot shooting up one side of the boiler. I remedied this by taking another (.38) shell case, and grinding this down to admit the firetube - this was then mounted on the baseplate for the firetube to rest on and be gently held in place.
Painting
This engine was a full stripdown and
repaint. For the stripping I used the "all's fair" method - from
chemical paint stripper to sanding via scraping with my thumbnail! The
base and engine stand were painted using automotive spray paint - the
base had about 6 coats, followed by a rubbing down and three coats of
clear lacquer after I'd fitted the replica decal. This was left to
dry for two weeks.
The firebox was painted with Plasticote "Hot Paint" spraypaint, and cured in a very hot oven for nearly three hours. After that it was buffed gently, and came up with a very authentic-looking half-matte finish
The firebox was painted with Plasticote "Hot Paint" spraypaint, and cured in a very hot oven for nearly three hours. After that it was buffed gently, and came up with a very authentic-looking half-matte finish
Other Issues:
After IndianaRog's experiences with his 101,
I fitted two small angle brackets to prevent firebox movement. A also
fitted some non-asbestos insulating material to prevent burning of the
base. Finally, the engine was mounted on little rubber feet to prevent
vibration. For some reason, the L-support bracket on the engine stand
is in a different place on the M101 and E101, leaving me with a minor
compatibility problem - I solved this by cutting a small rubber disc to
go under it. Not original, but looks good - may even damp vibration a
bit.
