Mike Trice's 4mm Workbench

Discussion in 'Workbenches, including workshop techniques.' started by Mike Trice, 1 March 2020.

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  1. Mike Trice

    Mike Trice Western Thunderer

    As mentioned earlier I am cross kitting Comet D186 Gresley Sides with MJT Floorpan. The MJT Floorpan looks like this:
    IMG_1817.JPG

    When I developed the MJT range my concept was to assemble the sides, ends and floor as one unit with the roof being fitted separately. For this build I wanted to try building the sides, ends and roof as one component and have the floor removable.

    Taking the basic floor pan the centre line was scribed and a centre point pop marked:
    IMG_1818.JPG

    The resulting pop-mark was opened out by drilling up to 2.5mm IMG_1822.JPG

    The etched ends were snapped off and the tabs cleaned up: IMG_1825.JPG

    At this point I asked my previous question regarding the folding of the side lips to 90 degrees. I more or less followed the method outlined then starting by scribing the etched fold lines with a knife blade until the result could be seen from the other side:
    IMG_1826.JPG

    A folding jig was made up from 2 lengths of scrap timber and screwed together. The outside lip was then clamped in the jig. Somewhere I have a set of Blacksmith bending bars which would need finding and getting the vice out etc and it was actually easier to knock the wooden version together: IMG_1827.JPG

    The centre section was then bent against the work surface: IMG_1829.JPG

    A full 90 degrees was not really possible and I would guess I only managed about 85 degrees in the jig: IMG_1831.JPG

    The last 5 degrees were tweaked using a steel ruler and engineer's square. New fixings to attach the ends to the floorpan were made up from K&S 1/4" angle cut to length then centre popped and drilled 2.5mm: IMG_1837.JPG

    Using a cocktail stick to align the items a brass M2 nut was soldered to the angle bracket: IMG_1838.JPG

    The angle bracket was now soldered to the end leaving a 12thou rebate at the bottom so it would sit against the floorpan: IMG_1843.JPG

    With a little opening out of the holes in the floorpan (elongating with a rat tail needle file) the ends could now be bolted to the floorpan: IMG_1847.JPG
     
  2. Mike Trice

    Mike Trice Western Thunderer

    And that is the problem. The quality of the work on WT is so good and solder clean up first class so I am trying to match, as much as possible, those standards.
     
    Rob Pulham, iak63, P A D and 2 others like this.
  3. LarryG

    LarryG Western Thunderer

    Imagine this is a fold-up on a coach floor or indeed anywhere. I press it against a flat surface and it gives a perfect fold....

    WEB Fold 0.jpg
    With hundreds of coaches to build (well over a 1000), I designed things from the outset to be quick without the need for special tools...
    WEB fold 1.jpg WEB Fold 2.jpg
    WEB Fold 3.jpg
     
  4. Mike Trice

    Mike Trice Western Thunderer

    Note taken.
     
  5. Mike Trice

    Mike Trice Western Thunderer

    A quick recap. The way Comet reproduce the 3 layer panelling is by having an overlap joint between the upper and lower panels:
    IMG_1850.JPG
    The MJT sides on the other hand do things a different way resulting in no "step" on the back. This means that the Comet sides do not lay against the false ends correctly:
    IMG_1849.JPG
    To resolve the ends were removed and marked where metal had to be removed:
    IMG_1851.JPG
    And after filing:
    IMG_1853.JPG
    Checking all is square the sides were tack soldered in each corner resting the whole floorpan on a piece of melamine chipboard so that the screw mountings hung over the edge.

    One of the strengthening strips along the top was a little short and you can just see where I have put a piece of scrap to space it out and bridge the gap:
    IMG_1855.JPG
    Finally the end seams were soldered, in all cases by snipping off very small lengths of solder, applying flux, then a piece of solder and running the iron along it:
    IMG_1857.JPG
     
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  6. Mike Trice

    Mike Trice Western Thunderer

    The MJT Floorpan includes etches for the headstocks which need folding up into a "U" section. As before the half etched lines have been scored to ease folding:
    IMG_1863.JPG

    Some time ago I made a folding tool based on an idea found on YouTube. It comproses a hinge bolted to a piece of brass "L" section. Note the top edge has been bevelled:
    IMG_1864.JPG

    The item to be folded is clamped in place using a couple of small G Clamps:
    IMG_1875.JPG

    Something is then pushed against the back of the etch to effectively fold the etch through 90 degrees. In this case a small engineer's square is ideal:
    IMG_1877.JPG

    On removal from the tool and the second edge folded I now have a perfect "U" section:
    IMG_1879.JPG

    For a more detailed description of how I made the tool check out this post on RMWeb: Photo Etch Folding
     
    jonte and Dog Star like this.
  7. Mike Trice

    Mike Trice Western Thunderer

    No doubt everyone has their favourite clean up technique. In the old days I used to scrub models with VIM scouring powder but you don't tend to see it nowadays.

    During a wander through our local Wilco I spotted a tub of "The Pink Stuff" for £1 which looked interesting. A subsequent visit to Poundland resulted in the aquisition of a Wisdom Smoker's Extra Hard toothbush:
    IMG_1881.JPG

    The ends of my coach were already reasonably clean with some small hint of solder:
    IMG_1884.JPG

    Opening the tub of cleaning paste it was applied to the coach end and scrubbed with the toothbrush. After a short while the pink turned dirty with cthe muck being removed:
    IMG_1885.JPG
    After scrubbing again in plain water the end is now a nice matt finish which hopefully will be a good basis for priming:
    IMG_1887.JPG
    These products look promising and I will continue to use them and report back on how I get on with them.
     
    Len Cattley, michl080, P A D and 5 others like this.
  8. GrahameH

    GrahameH Western Thunderer

    Mike,

    Have you tried using Viakal for cleaning up the brass ?

    Since I was informed about it I tend to use it on all of my work.
     
  9. Mike Trice

    Mike Trice Western Thunderer

    I have not tried Viakal. I was after something abrasive which I did not think Viakal was.
     
  10. LarryG

    LarryG Western Thunderer

    I mix my own liquid flux. Brushing it liberally on brass will also clean it up. For final cleaning prior to priming, I have always used what we used to call 'panshine' in olden days, ie: Ajax scouring powder. It is non-greasy. Finding somewhere that sells it is another matter. ;)
     
    P A D likes this.
  11. jonte

    jonte Western Thunderer

    Many thanks for sharing all this, Mike.

    Jonte
     
  12. P A D

    P A D Western Thunderer

    You can find both Ajax and Vim scouring powders on line, although they both now contain bleach. Vim original is still available though. I used to use them a lot in the past but moved on to things like hob bright or shiny sinks, then Viakal and Cilit Bang. Recently, having found a tin at the back of the kitchen cupboard, I've been using Ajax followed by Cilit Bang. Bar Keeper's Freind is another scouring powder but I've never used that and have only seen it online. Several options, so choose your poison. :D
     
  13. Mike Trice

    Mike Trice Western Thunderer

    I managed to find both Shiny Sinks and Bar Keeper's Friend, at least one of which was in Wilko. I used Shiny Sinks applied with a normal toothbrush when cleaning up the sides. The Pink paste mentioned above seems to be more abrasive than Shiny Sinks and at only £1 for a huge tub is probably cheaper as well. Another item bought but not yet tested is Eucryl Smoker's Tooth Powder.
     
  14. P A D

    P A D Western Thunderer

    I'm guessing Shiny sinks is some sort of fine particle abrasive dispersed into a paste. It's pretty effective but tends to leave a white deposit that can be a sod to rinse away. It tends to adhere to solder and fine seams that add otherwise not noticable show up as white lines. The main drawback with chemical cleaners is rinsing them away from nooks and crannies as the model progresses.
     
  15. Mike Trice

    Mike Trice Western Thunderer

    Onwards and upwards, or in this case downwards. The floorpan has been unscrewed from the body, the headstocks and solebars soldered in place:
    IMG_1891.JPG

    Now the solebar overlays containing all the rivet detail are sweated on: IMG_1895.JPG

    With the solebars added the underframe is reunited with the body and the whole lot scrubbed up: IMG_1900.JPG

    Something I had forgotten to mention previously is for the fun of it I soldered one of the droplights in a partially open position: IMG_1901.JPG
    IMG_1902.JPG

    The ends and roof domes are going to be 3D printed resin. Something I suspected but my usual ends confirmed, is the Comet sides are not full height. Fortunately with 3D printing it is easy to modify the model and reprint. These were done on an Anycubic Photon: IMG_1903.JPG

    The concept is both ends are fixed in place then a section of MJT Aluminium roof fixed between them. So my next task is to decide what glue to use to fix them and the aluminium roof in place? At the moment I will probably go for Evo Stick as it has a little give rather than epoxy or superglue which goes brittle. IMG_1904.JPG
     
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  16. Mike Trice

    Mike Trice Western Thunderer

    A quick experiment using a spare resin moulding and some brass indicated that Evo-Stik Impact Adhesive would work to the carriage inner end and 3D print have Evo-Stik applied:
    IMG_1910.JPG

    I did not wait for the Evo-Stik to fully go off before joining the two parts as I wanted to have a small opportunity to adjust. When happy the moulding was clamped in place and allowed to cure: IMG_1913.JPG

    With the second end also applied a length of MJT roof was cut to fit between the two ends and Evo-Stik used to fix to the roof ends and sides. Filling of the joints has started with Humbrol filler: IMG_1915.JPG

    Looking more like a Gresley: IMG_1917.JPG
     
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  17. Heather Kay

    Heather Kay Western Thunderer

    I wonder if I could save time by just saying I "like" this whole thread, rather than clicking the like button on each post! :))
     
  18. Mike Trice

    Mike Trice Western Thunderer

    Thank you Heather.

    One problem I face, and I doubt I am alone, is knowing when to spray the first primer coat especially for a model like this which is made up of composite materials. I have filled a few seams and cleaned up as best I can but of course in the process I am covering some elements of the brass sides and aluminum roof.

    So I have taken the brave decision to remove the floorpan and have sprayed the body in Halford's Etch Primer in the hope it will highlight any further remedial work necessary. No pictures at present, sorry.
     
  19. LarryG

    LarryG Western Thunderer

    Mike, the beauty of Halfords Acid 8 etch primer is it will do for everything including 'modern' bare plastics. However, it is not meant to be sprayed on top of paint.

    The longer the primer is wet, the more it will do its work etching into the surface. So I warm my sprayshop up to rid the air of any dampness then turn the heat off and allow the shed to cool off a bit before applying Halfords Acid 8 primer.
     
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  20. Mike Trice

    Mike Trice Western Thunderer

    After first coat of Etch Primer. Seams along the roof join quite obvious:
    IMG_1921.JPG

    Deluxe Perfect Plastic Putty applied with the help of a paintbrush and diluted with some water: IMG_1922.JPG

    After a few minutes to harden a cotton bud dipped in water is used to clean off the excess filler: IMG_1925.JPG

    Top seam sorted: IMG_1927.JPG

    And after second coat of primer: IMG_1929.JPG
     
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