Phil Cooke Posted July 22, 2014 Share Posted July 22, 2014 You don't need to add much water at all really, you wan't it 'creamy', just add enough to enable it to 'flow' on a 1/2" brush. One thing worth mentioning, it shrinks whilst drying, so if you do the top side of a wing, for example, make sure you do the bottom side in the same session so it doesn't pull itself all out of shape. All but the very thickest of structures will be warped by the powerful shrinkage effect... Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted July 22, 2014 Author Share Posted July 22, 2014 Ok cheers Phil for the tips - I'll pre cut all the panels with a little overlap and finish in one - I'll attach something (pins) a way of keeping off the bench while working on it - then hang it up to dry without it touching anything. Quote Link to comment Share on other sites More sharing options...
Depron Daz Posted July 22, 2014 Share Posted July 22, 2014 Cheers Phil Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted July 22, 2014 Author Share Posted July 22, 2014 Daz does wood chip sand flat or do I have to use that skim-filler to get it flat and smooth? LOL. Edited By Mark Kettle 1 on 22/07/2014 22:37:55 Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted July 22, 2014 Share Posted July 22, 2014 Sorry, another tip I remember - before you apply the paper its best to paint the model thinly in undiluted PVA all over and let it dry. Once dry if you sand it back with a medium paper to take any nobbles off then its ready to receive the paper/diluted pva. Gives a great bond. Also, an iron can be used to heat down any flaps or edges around wing tips etc to get an immediate grab! Edited By Phil Cooke on 22/07/2014 22:42:51 Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted July 22, 2014 Author Share Posted July 22, 2014 Well that's the way to go - I'll enjoy doing that process to get a good finish, thanks Phil for adding these finishing details to this build thread. In our club the Melton Lancaster was finished off with brown paper on foam - also Arthur Askew one of the part owners / build team also told me that they also used pre-gummed brown paper in strips ( supplied on rolls) the type that was used to seal boxes and put on box edges years ago. By the way I think and believe the Melton Lancaster was over 300 lbs in weigh. Edited By Mark Kettle 1 on 22/07/2014 22:50:37 Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted July 24, 2014 Author Share Posted July 24, 2014 Just back tracking a little whilst I was doing the assembly of second wing, I thought I would show you how and a method I used to choose where the main spar was put - keeping in mind the main spar would be a good point to balance the model with, and also show how the main spar is put in. It Involves a 'Plumb Bob'. Basically set up some kit, as in photo - then hang up by the wing tip and put the plumb bob from the same point, with masking tape on the wing centre line mark where the cotton used crosses the centre line. The trick is to check it by doing the same from the other wing tip. The funny thing is at any point that you check either along the LE or TE of the wing this method confirms the balance point, once the plumb bob stops swinging it always passes through the original mark. I then put it in this jig after marking up a line where I will cut in half to enable the main to go inside the wing, The position is referenced by the use of 2 mm wire control rods pushed like skewers top to bottom of the wing then push to up the metal edge of this throat cutter. picture below then Hot-wire bow is used to cut it off. Main spar is 10 mm square wood - inset a little from the bottom in this wing with only the outer tips needing sanding a blending to wing shape. Better glue in back together now. Edited By Mark Kettle 1 on 24/07/2014 19:54:59 Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted July 24, 2014 Author Share Posted July 24, 2014 While I'm at it - I'll show the rear trailing edge -drag spars- 6 mm square wood and 6 mm deep wood central spar support all glued in with contact adhesive. Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted July 24, 2014 Author Share Posted July 24, 2014 Back to the 1st build one now...... As advice form Phil ( earlier on in this thread ) on preparation before covering in brown paper, applied PVA and once PVA put on wing was dry I sanded it with a Car Perp fine grit - it was either side of this sponge foam pad. Well smooooth now....lovely egg shell finish. ready for the PVA solution and brown paper. Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted July 24, 2014 Author Share Posted July 24, 2014 Can you guess what this is? Clue - Made this today a tool for the Model Vulcan..... used for what? Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted July 24, 2014 Author Share Posted July 24, 2014 ........................ Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted July 24, 2014 Share Posted July 24, 2014 is it a bomb bay hand launch rail system???? (like the 'Well Smooth' motivational poster by the way - very good!) Quote Link to comment Share on other sites More sharing options...
Depron Daz Posted July 24, 2014 Share Posted July 24, 2014 Posted by Mark Kettle 1 on 22/07/2014 22:34:31: Daz does wood chip sand flat or do I have to use that skim-filler to get it flat and smooth? LOL. Edited By Mark Kettle 1 on 22/07/2014 22:37:55 Or self levelling cement Mark....... Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted July 24, 2014 Author Share Posted July 24, 2014 The cement evenly spread could be ballast Daz - I'll make it a jacket. Good guess Phil - its the other side of the model ..... Jig to cut a hatch.... Angled slots 1.5 mm wide width of a knife - allow constant and straight cut. Angled edge should help with keeping the hatch to the top. To retain hatch, peg at front magnets at the back. May have the put some 4 mm carbon rod in it to keep it in shape. Will cut out after covered in brown paper, then recover the bare edges. Edited By Mark Kettle 1 on 24/07/2014 22:47:52 Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted July 24, 2014 Share Posted July 24, 2014 Very clever that. Lovely job. More work in the tooling than there is in the bit that eventually will fly!! Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted July 24, 2014 Author Share Posted July 24, 2014 Tooling Always time - however makes the second onwards really quick to build, for instance today cut a little off the -wing plan form- patterns because of a little overlap at the leading edge I kept having to sanding off the LE epp foam, only needed 3 mm off middle and second out pattern, and a lot better now. Edited By Mark Kettle 1 on 24/07/2014 23:03:15 Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted July 24, 2014 Author Share Posted July 24, 2014 Glued in spars and glue front of wing back on second wing build. weighted down over night on a flat bench to keep straight and true. Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted July 25, 2014 Author Share Posted July 25, 2014 Second body going on wing via this opening on the bottom of the fuselage. 30 mm back from wing / fuse opening and slice through the bottom Edited By Mark Kettle 1 on 25/07/2014 21:18:14 Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted July 25, 2014 Author Share Posted July 25, 2014 ....after a bit of trimming and fitting the wing fits nice a snug. and a little trim off the bottom fuse and it will be good to glue on. Edited By Mark Kettle 1 on 25/07/2014 21:19:15 Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted July 25, 2014 Author Share Posted July 25, 2014 Front wing slots cut for fuse / wing support exactly correct width for ply to make contact with fuse sides inside when slid in. Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted July 25, 2014 Author Share Posted July 25, 2014 Right fuse is on.....made the fin earlier with its 3 spar supports, the angle on the fin spars could be a problem to fit into the fuselage.....but guess what I made another ( dam ) jig. Made a jig to poke holes in the fuselage for fin insertion into the fuselage. Made from MDF sandwich - spacings as slots inside it the same width and angle as spar supports. A Poking rod made from 6 mm carbon with brass screw glued inside - flattened on one side to help with boring - right through to the bottom of the fuse. Notice middle spar shorter because it goes to the drag spar support and not through it, outer two fin spars go through to bottom of fuselage. The rear fin spar happens to be at a point where if I wanted I could put a rudder into the edge. Fro correct placement put a TE level mark. All I have to do is hold it upright and down the centre line, I'll hold the wing still with weights so it doesn't move on the bench. ...... running out of wood to make jigs, that better be the last jig to make . Edited By Mark Kettle 1 on 25/07/2014 21:51:37 Edited By Mark Kettle 1 on 25/07/2014 21:52:42 Edited By Mark Kettle 1 on 25/07/2014 21:53:55 Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted July 25, 2014 Author Share Posted July 25, 2014 Time for bed, hope i can sleep with all the noise coming from the workshop, from the 'God of Fire Twins' 44 inch span Avro Vulcans epp models. Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted July 26, 2014 Share Posted July 26, 2014 Awesome job Mark... brilliant work! Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted July 26, 2014 Author Share Posted July 26, 2014 Cheers Phil - lots of covering and painting to do now.Edited By Mark Kettle 1 on 26/07/2014 06:27:09 Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted July 26, 2014 Author Share Posted July 26, 2014 Back in the workshop and weighed the two only 40 grams difference between the two current finished state. - the one on the left includes two standard servos in - has had two coats of neat P.V.A and rubbed down smooth and weighs 640 grams - the second one on the right also two standard servos in - no PVA on and weighs 600 grams So over the whole area of the model the PVA coating only adds 40 grams so for nice finish its worth doing, I can afford the extra weigh in the big picture of things. Edited By Mark Kettle 1 on 26/07/2014 08:16:14 Edited By Mark Kettle 1 on 26/07/2014 08:17:07 Quote Link to comment Share on other sites More sharing options...
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