Fournier Res­ur­rec­tion Part 5

Fournier Res­ur­rec­tion Part 5: putting it back to­gether again

Pilot - - CONTENTS - Words: Bob Grim­stead Pho­tos: Bob & Karen Grim­stead

Now it's time to put it all back to­gether

Wagon’s fuse­lage is re-cov­ered, its wing is re­cov­ered, so now all I have to do is bolt it to­gether, right? Sadly, as I dis­cov­ered, no. I guessed there was still quite a lot of work to get my Fournier back into the air. What I hadn’t re­alised was just how much there was. Some­body had ripped off the fire­wall

and pulled apart its three sand­wiched el­e­ments. I don’t know why, but it had ru­ined my fire­wall and un­cov­ered the raw as­bestos pre­vi­ously safely sand­wiched be­tween the two outer metal sheets. So now I have to fab­ri­cate a new one. That shouldn’t be too hard. It’s not made of stain­less steel, only softer and more mal­leable alu­minium, and I have the RF4D draw­ings with ma­te­rial spec­i­fi­ca­tions.

I ask my local metal sup­plier for the spec­i­fied AG3, 530mm by 450mm and 0.8mm thick. “That’s a French spec­i­fi­ca­tion, but 5754 is the same, only we don’t have any.” Okay. I make a quick call to LAA Engi­neer­ing, “Don’t worry, 2024-T3 Al­clad is an ac­cept­able al­ter­na­tive.” Back to Rudg­wick Met­als. Yes,

they can sup­ply 2024-T3 but I’d have to buy a full eight-foot by four-foot sheet. This was not the first in­stance of what I came to call the ‘Fournier Fox­trot’, a dance with which I have be­come very fa­mil­iar over the years. It goes: one step for­ward, two steps back! Luck­ily they had an of­f­cut more than big enough but in slightly thicker 3/64-inch thick­ness which they sold me for a very rea­son­able price. Good.

Now, how can I pre­vent heat trans­fer to the wooden air­frame, since as­bestos is banned nowa­days and mine is ru­ined? I search through the Air­craft Spruce and Spe­cialty cat­a­logue. Aha, this mod­ern Fiber­frax washed ce­ramic fi­bre stuff looks good. Both bet­ter at tem­per­a­ture re­sis­tance and lighter than the orig­i­nal, it comes in 24-inch widths and two thick­nesses. I or­der three feet of the thicker, 1/8-inch va­ri­ety from their Bri­tish stock­ist, LAS Aero.

While wait­ing for that to ar­rive I made a start on the two alu­minium sheets, by first cut­ting a tem­plate from MDF iden­ti­cal to the fuse­lage Sta­tion One (the very front, wooden fire­wall bulk­head) with my grandpa’s old jig­saw. Get­ting the 21.5° ta­per around the edges was tricky, but when I of­fered it up against the fuse­lage it matched very well. Now I could mark and cut the first, in­ner sheet to shape around that, again us­ing the jig­saw, but this time with a metal-cut­ting blade.

Next I clamped the outer alu­minium sheet in place with my tem­plate, al­low­ing enough ex­tra ma­te­rial around the edges for the flange that would over­lap the for­ward fuse­lage sides. I used the old, dam­aged outer fire­wall to mark out the many re­quired holes in both sheets. In the cen­tre was a big one for the mag­neto hous­ing, while there were also five more quite large ones for var­i­ous wire and tube con­duits, plus six­teen for the en­gine mount­ing bolts, eight for the cowl­ing fas­tener brack­ets and a hand­ful of others. I had to be care­ful, be­cause some of those holes were now re­dun­dant and a cou­ple were over-large, and of course no­body wants any more or big­ger holes in their fire­wall than they can pos­si­bly help. By drilling them all through my MDF for­mer I en­sured there were no burrs.

With ev­ery­thing clamped to­gether on the for­ward fuse­lage I started ham­mer­ing over the front sheet’s flanged cir­cum­fer­ence−as learned in met­al­work evening classes many years ago. Of course met­als suf­fer from hys­tere­sis, so when the flange was fin­ished it still wasn’t flush with the fuse­lage sides. But it was easy enough to un-clamp my MDF tem­plate and the outer alu­minium layer, turn them around so the ta­per was re­versed and keep ham­mer­ing un­til the flange was the re­quired shape. In fact I had to cut away more of the MDF’S cham­fer to get it per­fect.

When that was done I could clean off the white plas­tic pro­tec­tive coat­ing. Meths should do that OK. No? Well then, how about ace­tone? Nope, that didn’t work ei­ther. What is this stuff? Right, I’ll bring out the big guns. Hor­ri­ble, stinky MEK will dis­solve any­thing so I’ll use that. Well I’ll be blowed, the MEK made it nice and clean, but doesn’t show the slight­est sign of dis­solv­ing it, no mat­ter how long it soaks.

Fournier Fo­rum ad­vice sug­gested paint-strip­per, so I tod­dled off to our local hard­ware store and dis­cover two things about mod­ern Nitro­mors: nowa­days it is green, pre­sum­ably as a sop to the en­vi­ron­men­tal­ists, and it is noth­ing like as strong as for­merly. More Fournier fox­trot­ting: a whole af­ter­noon and two cans of that fee­ble stuff later, by scrap­ing away with an old credit card I even­tu­ally had two clean and thor­oughly washed sheets of alu­minium. Now I could prime and spray th­ese fire­wall sheets with Smooth Ham­merite, which I have been us­ing for decades. It doesn’t need a primer on steel (although you have to use a wa­ter-based primer on

alu­minium), it makes a thick coat with a high-gloss fin­ish, is re­sis­tant to scuffs and chips and, most im­por­tantly, it stays flex­i­ble for years. I have used it on all my aero­planes. Yes, there is a lim­ited range of colours, but they are all bright and cheery−although I mostly use black, sil­ver and white, as on this fire­wall.

When the Fiber­frax ar­rived I was fas­ci­nated to see how clean, soft and light it was. Cut­ting around its out­line with scis­sors was sim­plic­ity it­self. Next I marked out the po­si­tion of its re­quired holes with my MDF tem­plate to make them with an or­di­nary punch, but then I had a re­al­i­sa­tion. Clearly this ma­te­rial’s heat in­su­lat­ing prop­er­ties came from the mi­nus­cule air pock­ets trapped within its ce­ramic ma­trix. Un­for­tu­nately it is eas­ily squashed, so if I sim­ply glued it into place be­tween the two alu­minium sheets and then tight­ened all the bolts it would be­come com­pressed. That would spoil its heat-re­sis­tance, and my en­gine mount­ings and ev­ery­thing else would soon be­come less than firm. So I or­dered a pack of stain­less steel wash­ers from LAS to use as spac­ers. But how to punch out those big­ger holes? Brain­wave! Ta­per a foot of tough air­craftqual­ity 4130 steel tub­ing of the re­quired di­am­e­ter to make my own punch. That worked a treat. Now I could glue in place the in­ner alu­minium sheet, stick the Fiber­frax onto that, and clamp them both with my MDF for­mer un­til the ad­he­sive set.

I was fas­ci­nated to see how clean, soft and light the Fiber­frax was, and easy to cut

Although the fi­bre­glass mag­neto box had never pre­vi­ously been in­su­lated against an en­gine com­part­ment fire I de­cided this was im­per­a­tive, so I lined it first with Fiber­frax and then with a layer of ad­he­sive alu­minium tape to re­flect heat. Mean­while I sim­i­larly lined the new cowl­ings I had ear­lier bought from Ital­ian Fournier spe­cial­ist Eu­ge­nio Lanza di Casalanza. Then I fit­ted the en­gine com­part­ment’s un­der­belly exit scoop and made new alu­minium heat-shield pan­els for the fuse­lage sides where the ex­haust pipes leave the cowl­ings. It soon be­came clear that fill­ing, paint­ing and fit­ting th­ese new cowl­ings would take sev­eral days, and pos­si­bly weeks at my nor­mal work rate. So while I did weigh ‘Wagon’ with th­ese new, larger cowl­ings, I sim­ply re-fit­ted the old ones for the test fly­ing, leav­ing the new set un­til af­ter I had got back into the air−my driv­ing im­per­a­tive since I had been forcibly grounded for 22 months.

While I waited for things to be de­liv­ered, there were plenty of other jobs. Rather than un­der­tak­ing tasks in a log­i­cal, suc­ces­sive or­der, I was of­ten do­ing half-a-dozen things con­cur­rently, such as clean­ing, paint­ing and re-as­sem­bling my dis­man­tled tail­wheel unit on an­other bench be­fore fit­ting it into its new block on the up­turned rear fuse­lage. I also stripped and re-painted the steel tailplane fit­tings and sev­eral other com­po­nents−all with white Ham­merite of course.

When the fuse­lage was up­right on its tres­tles I tried fit­ting its tailplane and fin to make sure noth­ing had shifted dur­ing those wood­work re­pairs. I also added re­in­forc­ing fab­ric patches around the rud­der ca­ble exit holes, static vents, rear fuse­lage

lift­ing han­dle, where the wing root fair­ings and cowl­ings fit­ted, and around the in­stru­ment panel sur­round and the rear of the cock­pit, where the Leather­man tool on my belt had scuffed off paint in the past. I then dou­bled that cock­pit pro­tec­tion with au­to­mo­tive stone-chip tape bought from Mer­lin Mo­tor Sports. Mean­while the divers com­po­nents of my re­tractable main­wheel glow­ered at me from the din­ing room floor where I’d laid them out for re­assem­bly. The wheel lever lock latch arm was miss­ing, so I’d have to make a new one. I wasn’t sure whether that had to be done in situ, which would be awk­ward, so I kept putting it off. Even­tu­ally I cut one out of 4130 steel and it worked per­fectly.

While be­ing busy ei­ther in my garage or at Dunsfold, I also had to up­date Wagon’s doc­u­men­ta­tion. I mostly did that in the evenings. Re­sent­ing hav­ing to pay the LAA fees for mod­i­fi­ca­tions some­body else had pre­vi­ously in­cor­po­rated, I just had to bite the bul­let to make my aero­plane le­gal. On top of that I wanted new mods of my own, in­clud­ing cam­era mounts, im­proved con­trols, drag re­duc­tion mea­sures, and un­lim­ited aer­o­batic ap­proval. Af­ter com­plet­ing lots of pa­per­work and a few prac­ti­cal demon­stra­tions, they were all ap­proved.

I also made a new wiring loom in the evenings. The RF4D’S orig­i­nal elec­tri­cal sys­tem was simple: just a gel-cell bat­tery sup­ply­ing the red stall light, plus an­other yel­low light and a horn to warn the wheel wasn’t down when the throt­tle was closed or the spoil­ers ex­tended. This bat­tery should live in a holder on the back of the hinged in­spec­tion panel at the rear of the bag­gage shelf, but Wagon’s had been in the left footwell, an un­ap­proved mod­i­fi­ca­tion that must have al­tered the cen­tre of grav­ity, so I re­lo­cated it where it should be.

Nowa­days a ra­dio has vir­tu­ally be­come a ne­ces­sity, es­pe­cially for dis­play fly­ing, plus of course I had wires out to my wingtip smoke pods. I wanted a warn­ing horn in par­al­lel with my stall-warn­ing light, and an­other, louder one just be­hind my head for an un­locked main­wheel. I also needed pro­vi­sion for a pos­si­ble transpon­der and an ipad charg­ing socket. All of this needed wiring, so I searched around for the cor­rect Du­minivyn, find­ing the last known spool in cap­tiv­ity at nearby K Lacey, Rust­ing­ton. Then I made a pur­pose-de­signed loom, sheath­ing it in many lay­ers of heat-shrink tub­ing for pro­tec­tion against abra­sion in Wagon’s snug cock­pit. Fit­ting this loom was an­other mat­ter. It took time and trou­ble, and I didn’t yet have an in­stru­ment panel, so con­nect­ing that would have to wait un­til later.

The fuel tank had been re­fit­ted be­fore the fuse­lage was re-cov­ered, which is wrong. The fab­ric ought to have gone on first, and then the tank would be sealed into place over it. Hav­ing seen the dam­age pre­vi­ously suf­fered here I had used three lay­ers of Ora­tex, two on the up­per for­ward fuse­lage plus a re­in­forc­ing cir­cle around the filler. So now three lay­ers of nice new fab­ric came right up to the edge of the filler’s cut-out, but I couldn’t tuck it down in­side to glue it for se­cu­rity as I should. I just knew the mo­ment a drop of fuel got spilled or over­flowed it would seep be­tween those fab­ric lay­ers and ei­ther sep­a­rate them or soak the ply­wood. This would not be good, so I hunted for a sealant that would ad­here to both the alu­minium filler neck and the fab­ric, and be im­per­vi­ous to av­gas and mo­gas, even if it should con­tain al­co­hol. And I found just what I wanted: Dow Corn­ing 730 RTV sol­vent-re­sis­tant sealant. It was avail­able in white, so (at great ex­pense) I or­dered a tube. It was easy to ap­ply and smooth off, so for once some­thing worked out. As a fin­ish­ing touch I ap­plied av­gas stick­ers of match­ing red.

For the fuse­lage trim and wing sun­burst I de­cided it would be quicker and eas­ier to use red Ora­tex be­cause it would prob­a­bly be lighter and cer­tainly smoother than brushed paint, would en­sure the colours matched, and should re­sult in cleaner lines with no need for la­bo­ri­ous mask­ing and paint­ing. The sub­tle shape of Wagon’s for­ward fuse­lage curve hadn’t been right since a big re­pair in the early seven­ties so I traced this shape from an­other Fournier which still had its

I made a pur­posedesign­ed wiring loom in the evenings

orig­i­nal paint­work, re-traced that on to the back of a length of red Ora­tex and cut it to shape be­fore trans­fer­ring that shape onto the fuse­lage and paint­ing ad­he­sive onto both ar­eas. Iron­ing the fab­ric into place was sim­plic­ity it­self−one of my few time-sav­ing ideas that ac­tu­ally worked out!

The regis­tra­tion would have to be painted be­cause cut­ting such an in­tri­cate shape into fab­ric was go­ing to be be­yond my skill-set. I now made the most won­der­ful dis­cov­ery. Red Smooth Ham­merite is pre­cisely the same shade as Ora­tex’s ‘Fokker Red’. With a can of that and a pre-cut mask­ing sheet from local stick­er­mak­ers I was in busi­ness.

At this point my wife Karen joined me from family and busi­ness com­mit­ments in Aus­tralia. With that, and the ar­rival of spring, things looked up. Karen is a pro­fes­sional artist, so with a sweet smile I pointed to the regis­tra­tion mask and handed her paint and brush. Of course we wanted it to spread nice and evenly with­out runs, so first we had to turn the fuse­lage on to its side. Then, when one side was dry, we had to turn it on to the other side. In our cramped garage, and strug­gling un­der its weight and awk­ward curved shape, I was thank­ful we didn’t cause any dam­age.

Mean­while I screwed on the ‘cheek cowls’−fi­bre­glass fair­ings ei­ther side of the sprung wheel­well doors−and re-as­sem­bled the main un­der­car­riage. I had al­ready cleaned ev­ery­thing, in­spected the three big alu­minium al­loy cast­ings for

The regis­tra­tion would have to be painted on

cor­ro­sion and checked them for cracks with Ar­drox dye pen­e­trant, and re-greased the wheel bear­ings. Un­sur­pris­ingly, the ne­glected brake drum had a light patina of rust, so I cleaned that off. The tyre had also gone soft, so I checked it and its in­ner tube for leaks be­fore re­in­flat­ing and fit­ting them, and re-at­tach­ing the whole wheel and brake as­sem­bly into their cast­ings. With the fuse­lage on its side I bolted the lot back in place be­fore car­ry­ing out a cou­ple of side­ways retraction and ex­ten­sion tests.

With great dif­fi­culty I reached into the rear fuse­lage to re-fit the twin static lines and ports be­fore screw­ing into place that in­ner in­spec­tion panel with its in­te­gral bat­tery holder. Next I fit­ted to the cock­pit floor the big, black fi­bre­glass wheel well fair­ing known as ‘the snail’ be­cause of its shape. Fi­nally, I re-fit­ted the re-painted canopy hinge pins and made a trial fit of the canopy. This had been mis­shapen ever since the Per­spex bub­ble had been re­placed by a so-called ex­pert, but there was lit­tle I could do about that. Then, like a dolt, I re­alised I hadn’t fit­ted the exCitröen hand­brake or ca­ble, so I had to remove the canopy and snail again to crawl in­side and con­nect this all up to its re­painted han­dle (Ham­merite sil­ver, of course). More fox­trot­ting, but af­ter mi­nor read­just­ment it all seemed to work.

Mean­while the en­gine had been lan­guish­ing on the floor in a cor­ner, await­ing the re­turn of its mag­neto which I had re­moved for over­haul by my old friends at Deltair. Karen and I strug­gled out of the garage with the fuse­lage to turn it around so I could fit the en­gine by the

light of day. Then we put my Work­mate in front of it. We tried hoist­ing up the 56kg en­gine on to that in one go but were de­feated, so we did it in two stages, first on to an old milk crate, and then−af­ter a breather−up from there on to the Work­mate.

By chock­ing it up with var­i­ous bits of wood (rather pre­car­i­ously, now I look back on it) I was able to line up the en­gine mounts, so it was sim­ply a mat­ter of push­ing it back­wards and in­sert­ing the bolts. Then I re-con­nected all the en­gine wiring, fuel lines and con­trols. Karen fol­lowed me, touch­ing up any in­evitable chips and scratches in my nice

The orig­i­nal throt­tle ca­ble had mul­ti­ple kinks

new fire­wall while I re-fit­ted the car­bu­ret­tor.

This is when I re­mem­bered the orig­i­nal throt­tle ca­ble had mul­ti­ple kinks at its en­gine end, caus­ing ex­cess fric­tion and mak­ing it dif­fi­cult to make the tiny mod­u­la­tions needed for for­ma­tion aer­o­bat­ics. So I re­placed that with a new one, also from LAS Aero. Need­less to say I was danc­ing the Fournier Fox­trot again: this ten-minute job turned out to take a cou­ple of days, be­cause while the orig­i­nal knob and bracket fit­ted nicely at the cock­pit end, the en­gine end had to be length­ened by adding an ex­ten­sion piece or­dered from Amer­ica. Even then I had to make up a new bracket and ac­tu­at­ing arm to en­sure full and free move­ment of the car­bu­ret­tor’s but­ter­fly.

Fi­nally I bolted on the lovely Her­cules pro­pel­ler and spin­ner, checked the track­ing and wire­locked the bolts. At last we had some­thing that looked like a real fuse­lage. Time for a cel­e­bra­tory cuppa. Look­ing back on it all now, it’s hard to re­mem­ber just how many lit­tle jobs had to be done. The thing is, it’s a thou­sand times eas­ier to pull an aero­plane apart than to put it all back to­gether again. If you use Ora­tex, re­plac­ing the whole fab­ric cov­er­ing shouldn’t take more than a month or cost much more than £5,000; do­ing all the rest takes longer and costs more.

THIS PAGE TOP TO BOT­TOM: the old fire­wall split apart, re­veal­ing the as­bestos core; us­ing the orig­i­nal to mark out a tem­plate in MDF and form­ing the edge of the outer sheet

THIS PAGE TOP TO BOT­TOM: the bare Al­clad-fiber­frax fire­wall in place; Bob’s im­pro­vised hole punch; and the fin­ished job, with en­gine mount brack­ets etc all fit­ted

There was a wide ari­ety of po­ten­tial tail­wheels to choose from - which would be best?

Wheel retraction/ex­ten­sion was tested hor­i­zon­tally

Tail­wheel cho­sen, as­sem­bled and back in place

BE­LOW: fuel filler sealed with sol­ven­tre­sis­tant sealant and la­belled, ready for fuel. Note clas­sic brass float fuel gauge!

RIGHT: the en­gine bal­anced and chocked - some­what pre­car­i­ously - on Bob's Work­mate, ready to con­nect

Karen touch­ing up any dam­age to the fire­wall af­ter the en­gine went back in

BE­LOW: the Per­spex canopy bub­ble, mis­shapen by the same pre­vi­ous 'ex­pert', fit­ted back in place

BE­LOW: fire­wall done, en­gine at­tached, pro­pel­ler on, nearly there... time for a cel­e­bra­tory cuppa. Cheers!

Newspapers in English

Newspapers from UK

© PressReader. All rights reserved.