David's Mallard

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David's Mallard

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David's Mallard

Postby bird_d00 » Mon Apr 01, 2019 11:31 am

My Mallard stalled over a year back, as my soldering iron couldn't cope with the brass chassis as more and more parts were added to it. It just sucked the heat from the iron without getting hot enough to melt the solder. Now maybe time to continue as I have a much bigger/better iron, and with an enforced holiday as my car failed it's MOT (badly) and there is a lack of mechanics at the garage to fix it quickly.

I decided to solder mine together, as I don't trust superglue for permanent joints. The lacquer on the brass was removed with Wilco paint stripper which seems to work best, after unsuccessful attempts with Nitromors and cellulose thinners (not at the same time!). Soldering worked fine for the cab, and initially OK for the tender and loco chassis, but my iron rapidly ran out of oomph as the chassis had more bits added to it. I had the seemingly common problem folding up the cab, with the fold line near the cab window not being deep enough, and not using bending bars, I got a kink. After many attempts to straighten it, I wasn't happy with the result and ended up adjusting it with a large lump hammer. A second attempt with a spare issue 1 was much more successful.

I left off the lamp irons, as they are way too fragile made from whitemetal, and didn't fold down the cab window armrests as these would end up getting snapped off also. It doesn't mention in the instructions that the upper holes for the rear cab handrails need to be drilled, and that there are no location marks for this as not all A4s had handrails in the same positions.

Like everyone else it seems I had trouble drilling holes in the mazak boiler, breaking several drills in the process, but got there in the end. The real trouble was fixing the boiler and cab together. The instructions tell you to drill 1.9mm holes into the boiler and use the supplied self tapping screws. I did this and was rewarded with the heads of the screws snapping clean off as they were tightened. Seems that 1.9mm is the correct hole size for SHEET materials only. Had to drill out the screw remains and then drill the holes 2.1mm for this to work, and even then it was a struggle. I went a bit mad with epoxy resin as a belt and braces fixing, and still need to rub this down at the joints where it has oozed out.

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Now to try to complete all the bits I've so far left out and we start at issue 11 with the backhead - again with the drilling holes in mazak castings. I searched forward to get all the hole sizes and drill them all at once. This revealed an extra washout plug which suddenly appears in issue 53 without even being mentioned, so I drilled that also. By this point my hands were sore from using the pin chuck for many hours! (yes I do have a mini drill, but it can't cope with these mazak castings and just stalls if not set to silly speeds where you can't control it) There is also an extra hole for the slacking pipe, with no locating dimple. The measurements they give don't seem correct for this, so I'll leave this one till later. Trying to fit the pieces of 1mm square bar for the washout plugs into the 1.2mm holes revealed that the holes aren't big enough. After re-drilling to 1.3mm it was just possible to force the bar in place
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David Bird
Built: Eaglemoss Vector3
Building: Hachette Mallard, Eaglemoss Endeavour X section, Altaya Bretagne, DeAgostini Wasa
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Re: David's Mallard

Postby casper » Mon Apr 01, 2019 11:51 am

Great start David, looks a great kit :mrgreen:
sorry to hear your issue one was "adjusting with a large lump hammer" :laughing-rolling: :shifty:
glad your back on track :)
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Re: David's Mallard

Postby bird_d00 » Mon Apr 01, 2019 3:17 pm

I wouldn't say it was a great kit by any means. Some of the castings in whitemetal should have been provided in lost wax cast brass, as they are way too fragile. It's cost cutting taken to extremes. Some bits are quite good, but others not so. The lamp irons are a case in point, if I had fitted the whitemetal ones provided, they would be broken by now. They will be replaced by brass ones from Laurie Griffin, whenever I see him next. Currently trying to make something of the backhead castings, which are absolutely appalling. Take a look at these :-
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The valves on the sight glasses are terrible, and oh so delicate. Can I refine them sufficiently to make them useable - not sure yet, but trying to clean them up is playing havoc with my eyes - have to keep stopping as I'm going cross eyed. I would have had no trouble 20 years ago - but now euck!

David Bird
Built: Eaglemoss Vector3
Building: Hachette Mallard, Eaglemoss Endeavour X section, Altaya Bretagne, DeAgostini Wasa
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Re: David's Mallard

Postby Mustang » Mon Apr 01, 2019 7:37 pm

Hi,

I built the Flying Scotsman by Hachette some years ago, so understand about the solder issues.

Just wanted to ask the soldering issues.

Are you using a flux and are you solder coating the parts before trying to solder them together.

And if your finding the heat is disappearing to quick try placing a clamp either side of the parts so the heat doesn't travel all the way down the parts, this way the clamps keep the heat closer to the parts. But be careful as the clamps will get really hot.

I found the best solder iron was one which had a control base so you could change the heat depending on what you was working on.

Hope this helps.

Also if you need to drill small holes in the mazak, cheat by drilling a bigger hole with a drill piece that won't snap i.e need a 0.5mm hole use a 1 or 1.5mm drill which hopefully won't snap then fill the hole in with some p38 and then re-drill the 0.5mm hole just remember to use glue and not solder.
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Re: David's Mallard

Postby bird_d00 » Mon Apr 01, 2019 9:08 pm

Should have no troubles soldering with the new beasty - Katsu 31280 - 70W temperature controlled iron & 750W heat gun (other than a lack of hands to hold iron, air gun & solder). It was just the sheer mass of the components causing problems - I have over the years soldered up dozens of locos, so I know most of the tricks, but the largest were a Slaters 7mm scale LSWR A12 (an 0-4-2 tender loco) and a Gladiator 7mm scale LBSCR I3 (4-4-2 Tank loco), never anything of this size.

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I find the opposite way easier when drilling holes in the mazak - start small , then enlarge them. Large bits just jam solid in the mazak and ruin the jaws of the pin chuck if forced. I've blunted so many drills on this I had to buy a new set (and a new pin chuck).

David Bird
Built: Eaglemoss Vector3
Building: Hachette Mallard, Eaglemoss Endeavour X section, Altaya Bretagne, DeAgostini Wasa
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Re: David's Mallard

Postby bird_d00 » Wed Apr 03, 2019 6:05 pm

OK, Issue 12 is now complete. The whitemetal castings use a rather better alloy than the usual "margarine metal" beloved of Keyser and many other cast model railway kits (thank goodness), so the water gauges survived the attention with numerous files and fine saw blades, and now don't look too bad if you don't look too closely.

The brake valve though was a mare. Apparently the instructions were written (and photographed) from the prototype parts, which were then altered for the production versions - but the instructions weren't.

The instructions stated to drill a 1.9mm hole in the lug on the left of the backhead to locate the brake valve and insert the peg on the back of the valve into it. Trouble is the "lug" or "ear" has been changed to a large D shaped pillar, and the valve now has a similar pillar on the back of the valve to locate onto the end of the backhead one. Not realizing this I drilled the hole, found the peg on the valve wouldn't fit, so filed it down till it did. This then locates the valve in the wrong position, so had to sleeve the peg back out again with some brass tube, and file down one side to produce the D shape.

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David Bird
Built: Eaglemoss Vector3
Building: Hachette Mallard, Eaglemoss Endeavour X section, Altaya Bretagne, DeAgostini Wasa
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Re: David's Mallard

Postby Mark » Thu Apr 04, 2019 7:05 pm

This is a good read David. I admire your tenacity, and I'm sure it will let one to be proud of in the end.
Those sight glass castings look like they are white metal (zamac?) versions of the original lost wax castings.

Watching this with interest!
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Mark

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