122 Dmu

[Simon]

There isn't a discrepancy, the gutter along the bodysides (the original of which I removed if you look back through the thread) has yet to be applied to match that on the resin ends.

The brass is there simply to strengthen the top of the bodyside and as noted above needs filing back to be flush with the side, so it won't be visible.

Simon

 

[Martin Field]

Ah, that's OK then! Although brass and ally hate each other but if there's a good bit of JB Weld holding it on you should be OK. Even ambient dampness can cause a reaction twixt the twain.
BTW, I started that Derby Lightweight in G1 and already have a cab front and a pair of styrene bogie side masters for later resin casting.

 

[Simon]

I have started deploying knife filler between body sides and cab castings and along the roof.

It doesn't photograph very well, but…..



The lower corner of the roof could do with a tiny bit of building out with epoxy filler, but apart from this I have now finished using it.

Really, the next nettle that needs grasping is filing the brass strip ahead of forming the new rainstrip.

Simon

 

[Simon]

I put a bit more knife stopper on this morning before the shop and then on my return rubbed it down. With dinner in the oven I decided to throw caution to the winds and give the whole shebang a witness coat of primer. I just managed it in the approaching dusk and have just fetched it from the greenhouse.

It shows that there is more work to do, and down one side there has been a very slight "sinking" along a glue line (see earlier in the thread), but I reckon that's just the result of some poor shunting at Launceston Road in the "back siding". More filling and rubbing down but nothing too bad.

Apologies for the volume of pictures but I'm pretty chuffed with it
Of course now would be the perfect moment to put it down for a few more years

Simon

 

[Martin Field]

No, now would be the perfect moment to get some Milliput yellow/green and whack a coat on to find what a great material it is, Simon. Really, you could fix all that in one hit and use some car shop cellulose putty for the less deep scratches and dints, but if you dig them out with a chisel you can bang Milli in those, too and do it ALL in one hit. Trust me!

 

[Steph Dale]

Simon,

I'd watch that sink mark on the side of the body. It's almost certainly caused by trapped solvent. I've had problems with a couple of my scratchbuilt carriages, which was sorted by drilling through the affected area and leaving the sides for a while for the excess solvent to evaporate out; a test with a thumbnail pressed firmly into the area soon showed when I'd given it long enough. When it's hard, plastic rod can then be glued into the holes; use superglue or similar so you don't end up with trapped solvent again.

Oh, and make sure the side is stable before you try and fill it or paint it otherwise it can only get worse. Epoxy fillers won't allow the solvent to migrate through them and solvent based filler like 'green' or Humbrol will only introduce more solvent - however temporarily.

Steph

 

[Simon]

Steph, I take your point, but don't forget this was all done three years ago - I'm pretty sure the bodyside has done all the shrinking it's going to do!

As regards Miliput, I'm sure its great and may get some to try and improve the roof to roof joint as it will be easier to manipulate than the JB Weld, although I'd worry a bit that it would adhere properly given the really small amounts of filling that I now need.

Pretty much everything else is already being subjected to car cellulose putty, that's what I'm calling knife stopper and jolly good stuff it is too

As I said, I'm inclined to leave the sunken area as its very slight and does look like shunting damage, but then again….

Simon

 

[Yorkshire Dave]

As I said, I'm inclined to leave the sunken area as its very slight and does look like shunting damage, but then again….

I'm sure if you pointed a camera at a shallow angle along the prototype body you'd see more ripples than you've eaten raspberry ones.

 

[Martin Field]

Simon, in Milliput terms those dips, dints and gaps are not small at all. I have just filled areas I hadn't seen in a 1/32nd scale Tecno F2 car pattern because I'm short of cellulose putty in a tube and want to keep that for really fine dips. Milliput has a slightly changed formula which makes it even stickier than before and even if it does let go, a quick touch of superglue to it will ensure it stays put permanently. It also now sticks to you better so keep that thumb well spit-soaked when pushing it down on the filler.
Just to act as Devil's advocate.....how would the side of a DMU get damaged in "shunting" at that level?

 

[Peter Insole]

Simon, it looks as if BR had similar trouble with solvent and filler back in the late fifties...?!



Pete.

 

[Simon]

Simon, in Milliput terms those dips, dints and gaps are not small at all. I have just filled areas I hadn't seen in a 1/32nd scale Tecno F2 car pattern because I'm short of cellulose putty in a tube and want to keep that for really fine dips. Milliput has a slightly changed formula which makes it even stickier than before and even if it does let go, a quick touch of superglue to it will ensure it stays put permanently. It also now sticks to you better so keep that thumb well spit-soaked when pushing it down on the filler.
Just to act as Devil's advocate.....how would the side of a DMU get damaged in "shunting" at that level?

It sideswiped a bogie bolster that was foul of the points

Milliputwise, I am going to get some and give it a go anyway. In the past I found it too "solid" but guess I didn't knead it enough - the impatience of youth I expect..

Simon

 

[Martin Field]

OK, that's a plausible excuse<G>
Milliput can't be spread conventionally, no, but it can be pressed on/in the damage or on the areas needing building up with a wet thumb, or a wet craft knife. If you put little bits on, you can pretty much spread it, but never as softly as knifing putty of course, but I have genuinely never found that a problem. Just moderate the size of lump you press on the job. You can always build it up in layers, but I'm an impatient sod, so I bang it all on at once. Keep what's inevitably left over and roll it up into a ball the size of a person's head so as not to waste it, or roll it into arms and legs and leave it in a pot to use for something different later. I never waste it. But PLEASE, use Yellow/green. The white stuff never sets properly and goes chalky and is no finer than the normal stuff. As to curing it, you'll have to be patient as with a styrene body you can hardly put it in the oven as I usually do when putting it on resin or brass.
Let us know how you get on.

 

[Simon]

Well after a thoroughly distracting weekend, Saturday involving a visit to see this:



And Sunday afternoon spent being entertained by Bill Smarme and the Bizness:



I have today bitten a medium sized bullet and successfully filed down the brass angle along both bodysides. In the end I made a corrugated cardboard inner in an "L" shape and with a double edge to file against and used a large file, followed by wet and dry and a quick blow over with the trusty Halfords primer.



Job's a good 'un I reckon. Although there is a slight line where the roof joins the bodyside, when the rainstrip/gutter is put on it will pretty effectively mask it.

A really useful discovery is that the reason for the cast gutter on the left hand cab not matching that on the right hand one, on both sides, is that I have cast the gutter such that it falls away toward the bodyside on the right hand side of the cab when viewed from the front. So by cutting away the cast gutter to about the top of the drivers door I will be able to replace it with a Plastikard one and all will be hunky dory.

Don't worry if you can't follow that, it confuses me too, but I might just try sorting it out shortly. The joy of this is that it effectively lifts the gutter line to exactly where I want it.

Actually, it lifts it to exactly where I had it before I laboriously removed it(!) Why oh why didn't I pay more attention to the reasons for there being a mismatch when my gutter ran parallel to the bodyside

No matter, I guess what I ought to be worrying about is the next stupid mistake I'm about to make

Simon

 

[D6356]

The fine dent in the photo - post 410 is due to the leather pouch of a token holder belting the side when exchanged a bit too fast - some 111 lightweights had a buffing plate fitted and on the class 26s doors without windows to save on glass. Fun to have it on a model ! and a good weekend as well...
Robert

 

[daifly]

I don't recall DMUs having a copilot so I'm intrigued to know how the exchange was made by the driver at speed without the brakes coming on in a hurry when he released the go lever.
Dave

 

[mickoo]

There's a seven or ten second (can't recall the exact timing) delay between the deadmans handle being released and the brakes coming on. To enable tablet collection (the joys of traveling on the Felixstowe DMU's) there's a push button on the right hand side of the cab on the corner pillar linked to the deadmans handle, driver pushes and holds said button whilst collecting the token.

The only rolling token pick up was Westerfield, at Derby Road and Trimley the bobby came out of the box which was on the platforms for the change over.

 

[Neil]

Have seen the drivers bag hung off the deadmans handle once the unit had left the main line and was heading off to Blaenau.

 

[Simon]

A distracting week, but I have this weekend cobbled together the rainstrips on both sides of the vehicle.



A tiny bit more fine surface filling and it'll be time for another witness coat of primer.

Simon

 

[Heather Kay]

At this rate you're going to have to make a chassis for this!

(Of course, you may already have one stashed away that I've missed earlier in the thread…)

 

[Simon]

Well that's it I reckon, bar a bit more filling and finessing and rubbing down around the body before spraying in body colour.



I am going to introduce a roof rib along the back edge of the cast cab roof to mask the join. Although it's true that the joint could be better, I think we are into diminishing returns and it is bound to show no matter how good I make it. Hence the rib subterfuge. Subterfuge in the sense that I'm putting a rib where there isn't one on the prototype and will adjust those adjacent to mask the fact.

For any future build, the thing to do will be to cut the back roof edge of the cast cabs in line with an actual rib on the prototype, easy enough to arrange with the benefit of hindsight

As Heather says, what it really needs now are some wheels etc. I intend to use Steph's "blines" kit for the propulsion etc so look out for incoming questions in due course Steph….

I will be drilling the holes for ventilators and putting ribs along the roof section fairly soon though and am also likely to tackle the underbody gubbins before returning to the interior details.

Then I'll have to decide on a sound chip - I'm looking forward to lots of reverberating farting and rattling noises next year!

Simon