Michael Edge's workbench

[Michael Edge]

On 02/06/2021 at 10:23, Barry O said:

any photos of the Tiny yet?

 

 

Baz

pictures on Wentworth Junction thread today

[Michael Edge]

Back to work last week with the next job, an LMS 2P from Gibson and Comet parts - plus a fair bit of scratchbuilding to compensate for what was missing.

This is mostly the Gibson etch but the frames were missing so I've cut new ones from .020" steel, the ashpan sides are used as compensating beams connecting the driving axles. The incorrect outside frame round the vertical windows has been filed off - these frames are on the inside of the cab.

These brass etches have obviously been stored for many years and are very tarnished - however no attempt was made to clean them and they solder together perfectly well with phosphoric acid flux.

[Michael Edge]

With my one time apprentice over from Jersey this week the big lathe gets some more unusual use.

One of four Hillman Imp brake drums being machined on a hub fitted in the 4 jaw chuck - this is only a medium sized job for the venerable Milnes lathe. Makes a change from its usual work of machining gauge 1 boiler fittings.

David has also been busy back home with a 7mm loco, pictures on the Judith Edge kit thread.

[doilum]

3 hours ago, Michael Edge said:

Back to work last week with the next job, an LMS 2P from Gibson and Comet parts - plus a fair bit of scratchbuilding to compensate for what was missing.

This is mostly the Gibson etch but the frames were missing so I've cut new ones from .020" steel, the ashpan sides are used as compensating beams connecting the driving axles. The incorrect outside frame round the vertical windows has been filed off - these frames are on the inside of the cab.

These brass etches have obviously been stored for many years and are very tarnished - however no attempt was made to clean them and they solder together perfectly well with phosphoric acid flux.

Any particular reason for not cleaning them up whilst nice and flat on the etch?

Edited June 7, 2021 by doilum

[Barry O]

2 hours ago, doilum said:

Any particular reason for not cleaning them up whilst nice and flat on the etch?

Not required for soldering, mike gives locos a quick sand blast before painting (or a similar technique)

Baz

[Michael Edge]

12 hours ago, doilum said:

Any particular reason for not cleaning them up whilst nice and flat on the etch?

It's a waste of time - that was my point here, I do this for a living as well as for fun. It will get scrubbed and grit blasted before painting but there's no need to polish the surface.

[doilum]

20 minutes ago, Michael Edge said:

It's a waste of time - that was my point here, I do this for a living as well as for fun. It will get scrubbed and grit blasted before painting but there's no need to polish the surface.

Another reason I should have bought a blast cabinet years ago. Brake calipers, inlet manifolds..............

[Jack P]

Mike, how big is your sandblasting cabinet? It's certainly something i'd like to add to the repertoire one day soon.

[Michael Edge]

I don't have one, just use it in the garage against some shelving - I have thought about getting a proper cabinet but not got round to it.

[Gordon A]

Mike,

 

What gauge(?) grit do you use.

 

Gordon A

[Michael Edge]

I don't know but I'm running out and not sure what to replace it with - any suggestions from anyone else?

[innocentman]

1 hour ago, Michael Edge said:

I don't know but I'm running out and not sure what to replace it with - any suggestions from anyone else?

 

I hear baking soda is a possible alternative

[Gordon A]

Looking for grit I got some results under "Air Eraser".

 

Gordon A

[Michael Edge]

Thanks Gordon.

[SP Steve]

Try searching online using the terms "bead blast media" or "blasting media" and it should reveal a multitude of options.

 

[Enterprisingwestern]

 

https://www.azom.com/article.aspx?ArticleID=10431

 

From my (limited) experience of blasting, a company I worked for used this to clean delicate components in gas and water equipment.

 

Mike.

[Guest Jack Benson]

I may be wrong but WS ballast is crushed walnut shells.
 

StaySafe

 

[Michael Edge]

The loco part of the 2P is more or less finished now.

It's had a quick wash to get the flux residue off but it still looks fairly scabby, gritblast before painting will see to that though. Sandboxes and guard irons to fit then the frames can be painted.

[Michael Edge]

The 2P is finished ready to paint now.

Tender footplate and frames were missing as well, quicker to cut some out from steel, the steps are from one of my own etches.

Frames painted for the first test run, this is a Mabuchi motor (usually about £1.20 on Ebay) on a High Level 68:1 Loadhauler. These motors are extremely powerful but do need a fairly high gear ratio.

Seen from underneath, the driving axles are linked by a compensating beam which forms the ashpan sides, this is made from thick brass, jig drilled with the frames from the coupling rods. The bogie is not sprung, just able to move sideways, plenty of room in the boiler and firebox to add enough weight to use some of the power - nothing like all of it though, I've got this combination in a 4F and it still spins the wheels after loading up to 750g with V blocks placed on top of the boiler.

[JeffP]

OK, this is probably a daft question, but surely leaving the etches tarnished will help the paint stick?

[Daddyman]

14 minutes ago, JeffP said:

OK, this is probably a daft question, but surely leaving the etches tarnished will help the paint stick?

I've often wondered that. And wasn't there something in Model Rail years ago by a bloke who prepared his loco for painting by deliberately tarnishing it as much as possible - albeit chemically rather finger-printically. The model was a J94 if I remember. 

 

[Enterprisingwestern]

 

39 minutes ago, JeffP said:

OK, this is probably a daft question, but surely leaving the etches tarnished will help the paint stick?

 

22 minutes ago, Daddyman said:

I've often wondered that. And wasn't there something in Model Rail years ago by a bloke who prepared his loco for painting by deliberately tarnishing it as much as possible - albeit chemically rather finger-printically. The model was a J94 if I remember. 

 

 

Tarnishing is like a scab, so you are spraying onto a loose surface, and chemically tarnishing is another word for etch primer I would have thought?

 

Mike.

[Michael Edge]

I wouldn't say that tarnish on brass is a loose surface - it would be a lot easier to get off if it was.

Most painters will tell you that shiny polished brass is much harder to paint on, according to Larry Goddard the most difficult of all were the gold plated Jubilees which came from Hong Kong in the 1980s.

[Nicktoix]

I believe Beeson preferred painting onto a tarnished surface. Seems like a good recommendation to me.

Also I find no need to polish surfaces up before soldering unless excessively tarnished. Your flux is acid and does a great job of cleaning. That's what it's for.

Nick

[Michael Edge]

This is the 2P after a first coat of Upol primer.

No trace of the tarnish but some areas of filler need attention and I can see that I forgot to put the additional rainstrips on the cab - nothing in the "kit" for these of course.

Meanwhile here is the start of the next job, something different this week.

A 60ft turntable for an EM layout from the Metalsmith kit. This is a very comprehensive kit with a lot of carefully packed components, I've even had to resort to reading the instructions which are mercifully short. The MDF and plywood components of the well are very accurately cut and fit together easily, next job is to fit the circular rail which will be located by the brass channel radius guide seen on the left.