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Bandsaw Steve

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    Mig 15 Scratchbuild

    in Work in Progress - Aircraft

    Posted

    Hello,

     

    It's Christmas eve and time for an update.

     

    A few posts back I asserted that my woodwork was dreadful.  On this post you will see exactly what I mean. This one is all about bodging and filling and sanding away mistakes in full confidence that all of this wood-butchery will be hidden under primer and paint.  I've said it before - you don't really need any special skills to build models this way - you certainly do not need to be an expert woodworker. So if you feel inclined to have a go - just have a go - it's actually all fairly straightforward.

     

    IMG_3182

     

    Those of you that have been following along might remember that when I was carving out the hollow for the cockpit a fairly large chunk of wood snapped off from the port side just beside the pilot. This hole needs filling - otherwise the pilot will be able to climb in and out of the cockpit without opening the canopy.

     

    Here's what I've done to alleviate the situation.

     

    IMG_3194

     

    Using a set of dividers to measure a few of the hole's key dimensions (length - width etc) I reproduced the offending hole's shape on an appropriately thin sheet of wood.  In this case it's New Zealand White Pine (re-cycled Kahikatea). I only mention that it's Kahikatea to distinguish it from 'Pinus Radiata' the white plantation pine that is found almost everywhere but is not IMHO really suitable for this kind of work because it is too fibrous and tends to 'chip out' when carved.  

     

    You can see what I've done in the photo above, I've just cut out the wood to the right shape and stuck it in the hole. I used a variety of glues in this case - two part epoxy for rigidity, some liquid nails for strength and then a generous amount of PVA to fill most of the remaining gaps.

     

    Once the glue had set hard I just took to the Kahikatea with a number 11 hobby knife and whittled it to match the fuselage's cross section.

     

    IMG_3207

     

    This wood carves and whittles beautifully. Where-ever you are in the world the woodworkers will know the right type of local wood for carving so have a chat to them and get something that's suitable for the work you have in mind.

     

    IMG_3213

     

    With the majority of the hole plugged I just smeared plastic wood all over the plug to fill the numerous small gaps and cracks. I also filled over the joints between the fuselage and cockpit rebate and worked a tonne of the stuff into the wing roots. The wing roots on a Mig 15 have a small blending fillet between the wing and the fuselage and I'm going to use the wood-filler to sculpt this shape. a plywood insert that I put on top of the wings (see a couple of posts earlier) helps to fill out this volume and gives something for the plastic wood to grip onto.

     

    IMG_3212

    On the starboard side there was another gap, but as it was a smaller and simpler shape I just filled it with plastic wood.  In fact - while I was working with the filler I went a bit mental and gave the entire airframe a close inspection and just plastered any surface imperfections that I saw.  Now you can see why my woodwork teacher was never too impressed with my approach! Just look at the state of the tail in the photo below.

     

    IMG_3231

     

    And so, after letting the wood-filler set for 24 hours in the 40 degree Western Australian summer sun it had cured and was ready to be sanded.

     

    IMG_3236

     

    Nothing surprising here; start with a coarse sandpaper - sand everything. Select a finer sandpaper - sand everything again. Select a very fine finishing paper - sand everything yet again...

    For some reason I really enjoy this - it's therapeutic and as time passes the mess diminishes and the model 'emerges'.

     

    IMG_3251

     

     

     

    IMG_3269

     

    IMG_3351

     

     

    IMG_3355

    And here she is - all filled and smoothed out.  To get to this point I actually went through a second, more detailed sequence of 'inspect, fill, sand' but it's just repetition and If you have ever built a model you probably know about it anyway so I won't labour the point further. By the way - if you are wondering about the tailplane - it's made but I'm not sticking it on until as late as possible as I fear at the moment it will just get in the way and / or get damaged. A few posts ago I showed the model with the tailplane (sort-of) attached. But it was just stuck on with blue-tack 'for illustrative purposes only'.

     

    And that's about it for this post. I'm hoping I'll get one more in before the end of 2016. Once again thanks for the interest and the comments, I am really enjoying keeping this log of the build and appreciate each and every reply.

     

    Have a very merry and safe Christmas.

     

    Best wishes,

    Reconcilor.

     

    • Like 11

    Mig 15 Scratchbuild

    in Work in Progress - Aircraft

    Posted

    As promised, in this post the tail goes on and the jet-pipe and air intake get drilled out.

     

    Attaching the tail is fairly easy.  Prepare the fin exactly as per the wing - cut out and stick on a paper outline and then cut the plywood to shape with a bandsaw or some manual equivalent. Its up to you whether you contour the fin into a streamlined shape before or after it's attached - but in this case I did it after.

     

    Now I apologise for this post as I did not take sufficient photographs of the process to fully illustrate it - but it's not rocket science so I'm sure you will follow along easily enough.

    IMG_3149

     

    When you cut out the tail-fin ensure that you leave a large 'root' at it's base. This is what will provide the attachment to the fuselage. Now cut two parallel cuts in the correct location for the fin to slot into and at the correct location so that when the wood between the cuts is removed you have a single slot at exactly the width of the plywood (or just a fraction less to make a tight fit). I used a coping saw for the parallel cuts as it gives better control than a bandsaw and it worked well in this case giving me exactly the width slot that I was after - just tight enough so that the fin's root would slide into the slot but be held by friction.
    Remove the wood remaining between the two cuts with a chisel (or a fret saw if you prefer) leaving a single slot into which the root of the tail can fit.

     

    The fin was then simply glued into place using PVA and held with clamps for 24 hours. In this photo you can see that I've also done most of the contouring to give it a streamlined leading edge and a sharp (ish) trailing edge.

     

    IMG_3150

     

    Once the tail was secured I drilled out the tailpipe. Start by marking out the exact centre of where the hole will sit - then make an indentation on that spot with a braddel, a woodworking tool that looks a bit like a screwdriver but has a sharp point on the end. Use the indentation to provide the starting point for a fine guide drill-hole - say 2mm maximum. I use an electric drill because it's quicker and tends to wobble less than a hand held 'eggbeater' drill.  Once you have confirmed that your first hole is in the right spot and is nice and straight then stick in a larger drill - say 4mm and repeat. The accuracy of the first hole should guide the second into the right place. Once you finish the second hole once again check that it is straight and true and continue enlarging the drill and repeating the process until you reach the diameter you need.

     

    IMG_3199

     

    Obviously I didn't want to drill to the full length of the tail-fin's root as this would reduce the strength of the tail's connection. In this case I went a bit more than half way along the tailfin root. Once I had achieved the target diameter I rolled up a bit of sandpaper and tried to smooth the cavity as best I could - one day I will buy a dremmell tool. At this stage the cavity looks very basic but  latter on I'll add some detail to make it a bit more realistic.

     

    IMG_3198

     

    The process for then nose intake is exactly the same except once finished I had to cut out and carve an airflow splitter and glue it into place with PVA.  There's also a bit of whittling / sanding / shaping required to get the rounded appearance of the leading edge of the intake correct.

     

    IMG_3075

    And that's about it for now.

     

    Next time I will show how I made the mess in the photo below - and will now leave you wondering if the entire project is doomed...

     

    IMG_3213

     

    Merry Christmas to you all...

     

    Reconcilor

    • Like 2

    Mig 15 Scratchbuild

    in Work in Progress - Aircraft

    Posted

    Actually my woodworking is dreadful. I gave up woodwork at school because I hated the subject. I didn't exactly fail it but no-one complained when I dropped out and took up cooking.  The difference between this and 'real' woodwork is that when is finished it will be painted not varnished, so just about any mistake, can be concealed with bodgy work and wood filler. Also because it's just a model it doesn't have to be that strong so there's no fancy joinery involved. I really think anyone with an interest and a few basic tools could do this. Thanks for the comments though, they are greatly appreciated.

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