Tuesday, March 31, 2020

Hand clamps


Stupid curved locomotive body. Those panels need to be held very firmly in place, even after many hours bathing in water to make them a little flexible.

Holding the things is a nightmare. In the end, I put the PVA glue (after trying Super 'phatic and even superglue) on and just sat holding the panel in place for half an hour while watching the TV. Eventually,
the glue did its thing and the panel stayed put. I still put a fillet in the back of the joint afterwards though.


One panel incorporated the windscreen and curve, but that didn't make it much easier. Another long bath (overnight) followed by bending around a pen while drying followed by lots of clamps sort of did the job. I'll admit I seriously considered swapping wood for plastic.

Are there any special clamps out there I'm not aware of?

6 comments:

  1. I know this problem well Phil, and not just with curved wooden components:

    https://workbike.wordpress.com/2015/01/26/finals-08/

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  2. There's a lovely period photo of Sea Lion on Ebay at the moment - ridiculously expensive, but worth a 'window shop' to inspire you to complete what seems to be a rather troublesome project
    https://www.ebay.co.uk/itm/303523372237

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  3. Jim - It's a nice card, but not an uncommon image. Not worth a tenner to me. It shows the loco in the original 2-4-2 form. Eventually the pony wheels were removed and turned in to a truck for more batteries.

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  4. Buy it? Crikey,me neither - I screenshot it and added it to my never share folder!

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  5. Weren't they 0-4-0 to begin with, then pony wheels added, then batteries removed?

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  6. I don't know about any specialist clamps - but there are dodges that can sometimes help with clamping curved surfaces.

    One that I can remember from when I needed to fit strain gauges to round steel bars involved placing soft padsb the bars and the clamp faces.

    Typically, these pads would be something like nitrile rubber (not much stuck to it) - with the pads resting on top of a thin layer of polythene which, in turn, also rested on top of a layer of sellotape (or thin PVC insulation tape, if the bars were "high tensile", which often had ribs around it) - the tape was used to position the gauges and hold them in place whilst the adhesive cured.

    For modelmaking purposes, I'd probably use soft plastic pencil erasers for the pressure pads.

    Of course, if scratch building in wood, there might also be the possibility of making some curved panels using "flexible MDF" (think double sided hardboard, with slots every few millimetres) - or, perhaps, even matchsticks or coffee stirrers fitted "edge to edge".

    In case you're wondering why I've given any thought to this stuff, I'm in the middle of working on actual size computer drawings for a "Corona lockdown" build project which is likely to require curved panels.

    Don't worry about me wasting loads of data on the RMweb server - I'm only planning on posting photos if I can make certain key aspects of my build to work.

    I've also got to make some decisions about materials.

    In other words, I could imagine this taking some time. Unfortunately, I'm not expecting any shortage of time during the current lockdown.

    Still, I'm not aware of any compelling reason for me to rush with my build, or post detailed updates.

    Obviously, if the position were to change, I might step up the pace. Otherwise, it's not even a private challenge - just a hobby - and I'll use the build to help me relax.


    Anyway, whilst on the subject of builds, it'll be interesting to see how you get / got on with your build.

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