7mm Jan's 7mm Workbench

Discussion in 'Area 51' started by Lyndhurstman, 1 May 2017.

  1. simond

    simond Western Thunderer

    I use my (home brewed) RSU lots, mainly, but not exclusively for adding details, including adding whitemetal to brass by tinning the brass first with "normal" solder, then a drop of lowmelt, loads of flux and a quick blat of heat from behind, it melts, joins & refreezes very quickly - similar approach to Raymond.

    I do use solder paint with it, but I'm equally likely to use ordinary cored solder wire, possibly cut into tiny pieces, along with a drop of flux.

    I think there was an article about building RSUs, possibly 20 years ago in the Gazette or MRJ?. I bought a Maplin transformer kit, which provides a 240V primary, plus iron cores. This is connected to the mains via a suitable push button, with a neon indicator, and a 2A fuse in the plug. I wrapped my own secondary from approx 2mm varnished copper wire, and it works fine. I only ever use it on "max". The whole thing is mounted in a steel box, and sits on the floor under the bench. I slip my slipper off, and press the button with my left big toe.. other digits are available. It is fully isolated, and the case & ground pin is earthed - this is important!

    I did use an ally ground plate, it's ok, but gets dirty and is an effective heat sink. I now have a brass plate on top of a bit of MDF on which my smaller bench vice is mounted. This is used occasionally (thus the vice is also an earth), and is also an effective heat sink, but the simplest & best approach IMO is to fix the ground wire to the model, somewhere inconspicuous.

    I also use a 25W Antex, and a ruddy great 80W Weller thing. The latter is my normal tool of choice for any heavy soldering, but the mains lead is irritatingly short.

    I guess it's down to taste, but I find it to be a useful weapon in the armoury. (And I'm building in 7mm)
    Best
    Simon
     
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  2. adrian

    adrian Flying Squad

    Thanks - to be honest I've found them less likely to buckle with the larger iron. I use solder cream and so using the 80W I can be in and out in a fraction of a second so it never has time to heat up the rest of the etch. With the smaller iron it takes longer to get the joint up to temperature meanwhile the heat is dissipating throughout the etches.
     
  3. oldravendale

    oldravendale Western Thunderer

    It just goes to show - different techniques suit different people.

    I've heard of - in fact knew until his recent demise - someone who built an etched brass wagon using the RSU and no other means of soldering. He was a good builder and it was just to prove a point, but it can be done. Nevertheless he continued with his traditional method most of the time, using a hot stick.

    For myself, building 7mm kits, (and it's a very personal thing) I use an Antex 50W soldering station for almost everything, but I have an RSU which has it's uses from time to time. I'd rather not be without it. I normally attach the wire directly to the model, or occasionally may use a crocodile clip, although the contact is not as good or reliable. Very occasionally I use baking foil which gets rid of the heat sink problem. I use it quite often for white metal as it's sometimes easier to get in from behind, and if that's the case do exactly as described by simond. The trick with that, to my mind, (and it's counter intuitive when handling white metal) is to use the RSU on maximum output. A "blip" on the foot pedal is usually all that's needed, but with experience (make sure you practice this first!) you can actually see the solder flash but your reactions have to be perfect. In fact any problems I've had with white metal have usually occurred because I've forgotten to adjust the temperature of the Antex, although even there a large hot bit and quick in and out is often better than a low temperature over time approach.

    However, I reckon this is another of those threads which proves how different techniques can be used to create fundamentally similar items. I'll bet that we could put our finished models side by side and not be able to tell the difference, so is there truly a "best" way? I think not. I started by using a small iron and 70 degree solder, and despite the warnings of the gurus it's still stuck together and no-one has looked at the van concerned and said "well, you should have used a higher temperature solder". Discussing techniques with different people over time has lead to my current preference for high heat and short dwell time, and that does it for me apart from making (usually) perfectly strong joins.

    And right now I'll admit that I can't show you any examples because house move has meant time in the workshop is very limited. But normal service will be resumed at some time in the future.

    B
     
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  4. Dikitriki

    Dikitriki Flying Squad

    I've always thought that you were either in the microflame or RSU camp. Me, I'm in the microflame camp. I periodically find my RSU and think I ought to give it another go....then I reach for the soldering iron:)

    Richard
     
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  5. oldravendale

    oldravendale Western Thunderer

    Oh yes, forgot about microflame. I use mine about as often as the RSU, which doesn't tell you how often but is a reminder that it's another useful tool/technique within the arsenal.

    B
     
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  6. simond

    simond Western Thunderer

    Ah yes, a selection of Naked Flame Devices from "micro" to "macro" are ranged within easy reach of the SimonD workbench. Very useful for unsticking the bits I stuck on wrong...

    (And occasionally for sorting something that needs a serious bit of heat input, like the boiler and 3-lamination smokebox of my Dukedog)

    Not usually my first choice for assembly. I'd probably grab the RSU...
    Best
    Simon
     
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  7. Lyndhurstman

    Lyndhurstman Western Thunderer

    Hi Adrian

    I'm very grateful for your input here. It's true that we look at the experience of others as gospel, and act accordingly. I know I'm guilty of this. Which is why I always work under the umbrella of "personal enlightenment" .

    It seems to me - as someone who can get solder all over the place - that an RSU would help to produce better work for me. But having spent a fair few years wielding a Weller for The Government, I'm pretty good with the smaller stuff, it's just the larger irons seem to amplify my inadequacies!

    Cheers

    Jan
     
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  8. Lyndhurstman

    Lyndhurstman Western Thunderer

    Hello Chaps
    All this is wonderful stuff, and the variety of means and methods gives me a lot of food for thought; I must admit that a microflame tool holds appeal - anything that doesn't have a lead to irk gets a boost to the rankings!

    I've looked at upping the bit size on the 40W, but there doesn't seem to be anything meatier than the one I have, so an upgrade in wattage is looking likely. When funds permit...

    Thanks again

    Cheers

    Jan
     
  9. Lyndhurstman

    Lyndhurstman Western Thunderer

    Personal (de)Vices

    Side 1 (Double-A Side) suitably restricted, and awaiting a fatigue-free solderer.
    IMG_3415.JPG
    Just the courage needed now. Or London Pride...

    Cheers

    Jan
     
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  10. jonte

    jonte Western Thunderer

    'Bottoms up, Jan!'
     
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  11. farnetti

    farnetti Western Thunderer

    I'm a fan of the 'lots of heat very quickly' school of soldering. So tend to use flame and RSU with an Ersa as back up.

    Occasionally resort to 24 hour Araldite or Loctite 480 when parts are too small (and they haven't pinged off into the ether first).

    Probably the best soldering method is the one you feel comfortable with. I am quite keen to try out some silver soldering but always found it a bit of a dark art, but maybe with the flame?

    Ken
     
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  12. Lyndhurstman

    Lyndhurstman Western Thunderer

    Hi Ken,

    Thanks. After making a mid-range Horlicks of the fix of solebar to body with the Antex 40W last night, I'm probably going down the flame route too . If for no other reason than to take it apart and start again!

    Cheers

    Jan
     
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  13. Rob Pulham

    Rob Pulham Western Thunderer

    HI Jan,

    I pretty much use the flame for as much as I can get away with. I only resort to the iron if I can't use the flame for any reason. - You just need lot's of clips and self locking tweezers to act as heat sinks to stop bit's already added from falling off.
     
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  14. adrian

    adrian Flying Squad

    For silver soldering I use binding wire, Binding Wire . There's no reason why it shouldn't work for soft soldering as well.
     
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  15. Scale7JB

    Scale7JB Western Thunderer

    Hi Jan,

    I had a thought whilst I was building last night, and recalled the photos you had posted.

    Having a look again now, the brass that you seem to be soldering looks awfully yellow and tarnished. Are you cleaning up the area that you are soldering with some glass paper or a scratch brush. In all honesty and without doubt a 40w will be more than enough for what you're doing, but the metal does need to be clean..

    JB.
     
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  16. Lyndhurstman

    Lyndhurstman Western Thunderer

    Hi JB

    Thanks for your input. I agree - the brass does look tarnished. I did pretreat the area with a fibreglass brush before applying both flux and solder, but I'll do double on the other side.

    As a newbie to this size of working, I'm erring toward thinking that part of the problem is that the expanse of the body - basically a 100mm x 60mm sheet of brass) is taking the heat away from the seam too quickly. And if i recall (I'm in Shropshire on a weeks holiday at the minute...) the Antex doesn't have anything more than an 1/8" screwdriver bit to it.

    Cheers

    Jan
     
  17. Lyndhurstman

    Lyndhurstman Western Thunderer

    .. But It's Watt You Do With It That's Important

    Shropshire is a-fixed firmly in the Rearviewmirror. I have come back to work to find the Draper 60W waiting for me. Having girded my loins (other junctions are available...) I took the plunge:
    IMG_3797.JPG
    Smooooth.... lots of heat at the tip, and a nice flexibility to the lead made short work of my fear, and served to render the previous effort (more reminiscent of a pigeon with a bad case of Montezuma's Revenge) into something s bit more pleasing to the eye - and a darn sight more structurally useful!

    I still have doubts about whether there's enough room left between the back of the solebar and the bufferbeam hole to be able to fit the whitemetal boss of the buffer housing in without modification of the later, but Doubt Dispelled is a Step Forward - and A Moment For Pleasure.

    Thanks to you all for your support.

    Peace

    Jan
     
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  18. Lyndhurstman

    Lyndhurstman Western Thunderer

    A Short-lived Warm Spell
    The euphoria of previous posts was extremely brief. After no more than two evenings radiance, a brief flare of activity is over: the Draper is cold and dead. Forensic footling (that probably rendered the guarantee invalid) has identified the expiration of the element. To say I'm hacked off is STBO. It was all going so well..

    I've tried to restore some kind of progress via the 40W Antex, but - despite switching to solder paste and introducing blocking efforts to try and restrict the thermal diaspora - I'm back to looking for portable oomph.
    IMG_3821.JPG
    Above: Evidence of Ex-Lax utilised in affixing the corner and bracing plates.
     
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  19. jonte

    jonte Western Thunderer

    'Thermal diaspora' ......This is well over my head, Jan, but all looks very neat.

    May I wish you more power to your ......Antex-y thingy!

    Jonte.
     
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  20. Lyndhurstman

    Lyndhurstman Western Thunderer

    Hi Jonte

    Thanks. I think my increased verbiage is inversely corellated to my progress! Basically, using the smaller iron, I'm trying to corral the heat into the area that needs it, which would result in a better environment for joint and joiner.

    Cheers

    Jan
     
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