Europa #435 G-RODO Build Journal - 2007 09

index sitemap advanced
search engine by freefind
tickgo to list of milestonestick Navigation & Acknowledgements
day notes hours
3 Take peel-ply etc off clip and sleeve layups. Trim rough edges off both with hacksaw blade. Mark up clip layup into 10 lengths. First piece cut off looks much too big when I offer it up to the stall warner tube, so cut it in half and that looks much better. In fact the flanges could be reduced as well, but leave that for later. Mark and cut 10 clips to half the original length. Mark conduit sleeve into 20mm lengths. One of 40mm is needed at the angled rib, so cut that off first, and then 9 other 20mm. Smooth ends of all sleeves with 240 grade wet-and-dry paper. Start to smooth ends of tube clips with smooth round Perma-Grit file, but that is a bit coarse, so instead use a piece of 240 wet-and-dry wrapped around it. 802.7
5 Smooth ends of inboard conduit piece with 240 wet-and-dry. Slide into position with sleeves adjacent to ribs. Mix 2 strokes resin & paint onto each sleeve and the adjacent rib hole. Slide into position and brush resin around joint. Mop up drips & leave to cure. 803.5
6 Find some small gaps between sleeves and ribs - should have thickened the resin with flox. Make a blue-foam pad to support the inboard end of the outboard section of conduit near the outboard end of the inboard section. Cut BID pieces for 2-layer straps over the foam block (150mm x 20mm), and for 3 off 2-layer straps near the the spar tip (2 off 100mm x 20mm, 1 off 100mm x 50mm). Bend outboard conduit using pipe spring. Takes several tries to get it right, and I find that the conduit is slowly springing back after each bend. Over-bend it slightly and leave for a while to see how near it comes to the desired angle. Don't want it springing off the foam pad while the layup is curing. Shorten tip end of conduit to just beyond the end of the spar, leaving plenty of room for any recessed light fittings that may come later. Find a bit of nylon rod that's a good fit in the conduit so that I can use it as connector to an offcut piece positioned in the tip to ensure alignment during the layup and cure. Bend up a couple of thin pieces of aluminium offcut into saddles to carry weights that will keep the conduit on the foam pad during layup and curing. Shorten tabs of tube clips to about 10mm. Mark all places on spar and bottom skin where resin or flox is to go and roughen those areas with a small piece of fine Perma-Grit sheet. Mix 2 strokes resin and add 4 doses flox to make a pretty dry, stiff mixture. Mix 3 strokes resin, wet out all BID strips on polyethylene sheet. Brush resin lightly on stall-warner tube clips and on corresponding areas of bottom skin. Position them and weigh down. During this hear an odd noise and it turns out to be the flox mixture exotherming! Toss out the main hot hard lump and try to rescue some uncured bits by puttying them onto rib-sleeve gaps, but not very successfully. Finish fitting tube clips. Brush with resin the foam pad, and the areas of the bottom skin and spar where the layups will go. Still plenty of resin left, so add 2 doses flox and build pads on the spar for the outboard end of the conduit. Coat the one sleeve for this section with flox and slide it into place in the rib, buttering last of flox around it. Weigh down the inboard end onto the foam pad, and apply 2-layer BID strap layups to the spar and foam pad. Peel off polyethylene, apply peel-ply. Scrape off various bits of excess flox & resin and leave to cure. 807.2
7 tickPhone Martin Carolan to check that he's OK for the wing pre-close inspection today. Remove weighted peel-ply from clips and BID straps. All looks good. File off a few sharp glass whiskers around foam pad supporting conduit. Fit roof bars to car and get help from Robert next door to move starboard wing out and on top of car. Put rudder in car so Martin can have a look at that too. Find some pieces of wood to restrain wing at sides of bars and provide support for tie-down ropes (so that the flexible TE will not get pulled out of shape). Bandsaw an L-shaped piece for root end TE to support against the bottom corner and keep rope clear of TE. Screw wood blocks to roof rails and tie down with ropes. Journey to Severn Valley Sailplanes uneventful except that the turbulence from large lorries in front causes intermittent downforce at the front (tip), making the rear (root) end rise slightly against the ropes. Although it's the first XS wing he's seen in the flesh, Martin is happy with all the internals and clears it for closing up. He's also happy with the rudder finish, and thinks I've achieved a satisfactory standard. He points out the need to ensure that the Redux doesn't squidge out and drip to places it shouldn't be when fitting the top wing skin. He recommends doing it upside-down so the Redux doesn't have anywhere to go except to form fillets around the joints. We discuss various clamping methods. Martin suggests toggle-clamps mounted on industrial-strength suckers attached to the skin forward of the spar. That sounds a bit complex and I suggest just having a straight piece of wood for the wing to lie upside down on, using the weight of the wing itself as clamping pressure (could add weights near the tip as it's pretty light). At the TE, could use bulldog clips or similar. Back home, Robert helps get the wing off the car and back onto the building table. Put rudder, roof bars and side support blocks in the trailer. 807.4
8 Bring starboard upper wing skin in from trailer. It is marked S315 on the 3D Mouldings label. (NB the wing root label is marked S316.) Find a piece of 5/8" drawn aluminium tube that is a loose fit in the wing conduit. Can't immediately see any piece of wood that is the required 3.5m long to act as a support against the spar while bonding on the top skin.
10 Sort through long pieces of wood stored outside. Longest softwood piece is 3.2m and longest mahogany is 2.9m. Settle for two well-matched and straight-edged pieces of mahogany about 2.1m long, 80mm x 46mm with a rebate on one corner reducing the adjacent faces to about 70mm and 30mm.
11 Cut the 5/8" aluminium tube to length, and tap one end M14x1.5 to fit a spare wheel-bolt I have in stock. Fit it into wingtip, attach ropes and hoist wing well clear of table. Try the pieces of mahogany on the table; they seem to line up well. Clean up the wood with the hot-air gun, old chisel and sandpaper. Lower wing and leave wood under it on table. Hold top skin in place with small spring clamps to stop it sliding off onto the floor.
12 Get some more clamps from Screwfix.
18 Get more cleats from Lynall Boats and more pulleys from B&Q.
19 Fit new pulleys and cleats near centre of work area. Start to whip rope ends. Order on eBay a 40kg suspension scale for weighing components. (Should have got it and used it on the rudder before and after profiling & painting!)
20 Cut ropes to length and finish whipping ends.
21 Fit ropes to pulleys and cleats and check for satisfactory operation. Notice that there are some lumpy areas on the underside of the top skin, near the horn-box recesses. It looks as if they are just lines of resin rather than that the underlying cloth is rippled. They would certainly interfere with a good fit against the TE if left as they are.
24 Mix up 11g + 4.4g of the already-opened batch of Redux and make a test piece using a couple of offcuts of the 6-ply BID layup. Note Neville's advice on the e-mail list 2006-09-24 about putting a 2-layer BID donut 2" around the conduit holes in the ribs. Could still do it, overlapping & offsetting the joins.
25 Phone factory; only John there - will have to phone in the morning to get Roger. Send e-mail to Neville about the BID donuts and the wing skin bonding method. Check cleco stock, and try one on the BID layup make sure it holds OK on glass.
26 Digital suspension scales delivered at last (longer wait than for any previous eBay item, and they turn out to be 20kg not 40kg). Phone factory. Roger says to ask Neville about the various detailed queries I have on the wing. He does say the line of resin shouldn't be on the top skin, it's probably an artifact of the vacuum-bagging. The amount of flox added to the Redux should be just enough to stop it dripping off. He says as the Redux is several years out of date it's too big a risk to take; recommends that I shouldn't even bother to make test pieces, but buy new stock. Because it's deemed hazardous, the carriage is about half the cost of the Redux itself, so defer purchase decision for now. Fit hook in suitable garage roof joist and hang scales. Weigh rudder; can't be bothered to unwrap it at present - with bubble-wrap it's 2.905kg. Turn top skin over and file off lines of resin. Blue lines in glass layer underneath remain intact, proving it was only resin. 808.1
27 Phone Neville and get lots of advice about bonding the wing top skin. He says the BID donuts were a response by Andy Draper & Barry Mellors to the fact that the wings were tested without holes in the ribs for conduit. The reinforcement was intended to prevent initiation of fractures from the hole.

left-arrowgo to previous page of journal listgo to list of narrative pages list go to next page of journalright-arrow
Return to Rowland's home page

This page last updated 2013-08-24 22:17. I try to make this page as accessible as possible, by adhering to HTML 4 standards. Valid HTML 4.01! Valid CSS!
I welcome comments on this website. However, because of the amount of spam it attracts, I no longer post a direct e-mail address on any page. Instead, please click here to contact me. You will have to confirm that you are human before the message will be sent on to me.