Andy P.

Last Sunday was a great and yet not so great day of flying for a really good friend of mine in our club (Howard Murphy). Howard is our flying site manager and it has to be said that he puts and enormous amount of time and hard work in to keeping our flying site in the glorious condition we all enjoy.

A couple of month's ago Howard lost his CARF Impact on a take off, the cause was a little embarassing so we'll leave that there but this meant a search for a new airframe ensued and was found quite quickly through another well known forum which I care not to mention and purchased from a fellow F3a guy for a very reasonable price.

Howard has taken his time to rig out his newest aquisition namely a PL "Partner" and in usual "H" style, applied himself to ensuring that everything was in great shape ready for it's first flight. Well that first flight took place last Sunday and after an uncertain take off by "H" the Partner soon settled in to a really graceful looking few circuits. The responses were a little lively in FM.0 so he sitched in to FM.1 which I had set with less movements and different expo's, using 20% less on all surfaces, this he said felt much better but still wanted a few tweaks so "H" landed the model.

An hour or so later, after some tweaking of the flight modes "H" took the Partner back up for another flight to assess the changes we had made, at this time the sun had moved around and was now lower due to the time of day, this made "H" feel uncomfortable flying the model due to silloueting so decided to land the model, on the approach which was dictated by the wind direction, there is a tree which is difficult to gauge in the best light let alone nearing late afternoon, we were both convinced that the model was airside of the tree but we were both wrong [&o] the model was just the other side from us and subsequently clipped the branches making a really sickening crunch as it did so. The model struck quite a few branches and was tumbling down through them as it finally rested about half way up the tree. Anyone who has witnessed this sickening luck will know how it made us both feel, especially after "H" losing his trusted Impact only weeks before.

So the low head walk over to the incident site started and "H" was obviously down in the dumps at the thought of losing his new model and I have to admit the sickening crunch made me think that it was a "bin job", but not quite so........................

Upon viewing the model from the ground up, the fuse was undamaged (albeit a few minor scratches) but the left wing panel had a chunk missing and the left stab was pushed back (bent stab joiner) also a few minor flying surface dents and scratches were evident but nothing that couldn't be sorted (according to me anyway) but "H" wasn't convinced.

We retreaved the model and returned to our clubhouse to de-rig and assess the full extent of the damage, as thought, no major damage at all to the fuse, not even the prop was damaged!

As "H" has very little repair experience coupled with the lack of a suitable shop to work in, I offered to do the repairs for him and decided this might be a good "repair thread" for those who may have faced this situation themselves but didn't know where to start with the repair, please don't get me wrong, I'm not pro at this kinda stuff but have carried out this kind of repair before for myself [].

So, I'll let the pics tell the story as best they can, anyone want any other details just chime in and I'll do my best to reply.

Regards,

Andy.

Andy P.

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Andy P.

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Andy P.

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Andy P.

So, with the marking out and removal of the damaged area completed it's time to mark up some old styrofoam I had laying around which is really quite light. No rocket science applied here, just a good square edge and a bread knife will do nicely, keep the knife nice and square to the foam edge tho, it really is easy and much less fuss than getting the hot bow out for such a small task!

Andy P.

A nice snug fit on the 3 faces of the new plug of foam and oversized in depth, were ready to do some sanding!

Andy P.

with the edges of the repair area protected with some masking tape I sanded the foam plug flush to both sides then fitted a couple of 3/32" balsa strips to one side, this pushes the plug proud to one side, I then sanded the exposed side again flush to the wing surface.

Andy P.

now we have a new foam plug ready to glue in that is recessed to take the new balsa sheet faces which will be 1/8" each so there will be a small amount of surface each side to sand flush with the wing when inserted, that's today's job!

Off to the workshop...........

rcflyer4fun

How bad did your friend crunch his impact? I have a set of wings and stabs available. I am currently building my Impact with a focas wing and stab.

Evan

Jetdesign

My Feedback: (8)

Andy,
It's really nice to see you help your friend with a quality repair. Personally, I always have that feeling of 'it will never be the same,' however it looks like you are going to get it pretty darn close.

Thanks for the pics. My next project will most likely be second hand, so these threads help build the database I will need to keep things up and running nicely.

dreadnaut

My Feedback: (5)

Good Job. I once had a tree attack one of my planes. Wasn't so lucky myself.

Andy P.

Hey Evan,

It was a total loss, even blitzed the rear of the engine on that one but I had enough spares to get him going again

gaRCfield,

thanks for the words, I like to help where and when I can, especially with people who give so much to the hobby and "H" is right up there on that one.....................

Glad this thread is going some way to helping others on here as well, never had the true incentive to photoshop any of my work before but it's a synch really, just keeping the dust of the camera is proving tricky at times

Anyway's, on with the show. Here's where I'm at right now after around 3 1/2 hrs of playing in my pen :

I started by making the balsa blanking sheets, I laid these in to the wing skins and marked off the leading edge of the foam blank then cut the leading edge of the new sheeting back.

Andy P.

next up was repeating the process for both sides and finally getting the new skins glued in. I used Bob Smith's "Foam Safe" CA and Kicker for this, speed and weight control being the two critical issues for me here, I'd like to see this model go again this coming Sunday!

Andy P.

and after around 3/4 hr I was ready for a quick sand and start to replace the leading edge. I cut back beyond the repair skin seams with the original wing skins by around 4" and added a complete new section of L/E. I also cross cut a small section where the new met the old and inserted a cross grain piece, this is so that when I carried out the final sand of the new L/E section it would sand back slower to avoid over sanding in to the original section and creating a dip, in practice I'm glad I did as the L/E of this wing is very soft!

Andy P.

and on the final stage now of block planing and a final sand. A little fine surface filler and another finishing sand and were almost done!

Andy P.

all shaped up and now to think about the covering, erm yep, he's getting it covered too [X(]

Andy P.

thought I'd spend a little time filling out the small dents to the L/E near the root, a little cosmetic surgery is all that's needed here, the 300ft finish I call it

apereira

Hello Andy,

Also try water on the dented balsa, it comes right out, of course, it will need so minor filler anyway.

Great job on the repair and best supporting your friend!!

Andy P.

Top tip there apereira!

thanks I'll give that a try on the other small dents [8D]

Off to go and prepare for the covering now, I'll post more pics on this later.

Regards,

Andy.

Ryan Smith

My Feedback: (25)

If we were closer, I would have just sent your friend the wings off of my Partner. I've got both of Quique's airplanes, and I'm putting new wings on them. Great job on the repair, I think the Partner is a fantastic airplane!

dreadnaut

My Feedback: (5)

Good Job so far. I have a couple of questions and comments. You did not mention what that filler you were using was, but it looks like some stuff I have used. It comes from the home improvements store. The stuff I get locally is called Patch'n Paint Lightweight Spackle. I am sure it goes by a different name where you are. I swear, the first time I picked this stuff up from the shelf in the store, I had to open the tub to see if anything was in it. It is probably less than an half pound/cubic foot. Is this the same stuff you are using?

Also, the technique I use when gluing with CA in this situation is to first spray one surface with accelerator, then put CA on the other surface then stick them together. In this case, I would have sprayed the foam, then put a thin film of thick CA on the wood. Usually I would make a few practice runs placing the wood before actually gluing. Where I have done this has not been in this exact situation. I use it, for example, on sheeting built up wings. I spray the sheet with accelerator, then run a bead of thick CA along the tops of the ribs, and spar. I use pins stuck into the spar as "stops" to place the sheet against, then use a long aluminum angle to "roll" the sheet toward the L.E.

I don't think this would work (or even be desirable) for sheeting an entire foam wing. It should work for a patch job like this though.

Andy P.

Guy's thanks for the replies, I'm really enjoying this repair as I've not done any proper modelling for around 18 month's (well I have designed a couple of foamies and put them together but that's not real modelling is it ) pretty much since I finished my ZN Twister, in fact I STILL have another Twister kit sitting in it's box ready to put together, maybe a build thread?............................

I've pulled off the project for the evening and will resume first thing in the morning after taking the wife to work at 6am, I really like getting in the shop early and getting down to it, I'm also really down with a tough cold/flu thing at the moment and the evenings seem to be the worst time for getting all bunged up again (why is that?). So tommorow it is, finish the final filling and sanding, then get the covering on, no big deal with that!

Dave, just to answer your couple of points, yeah the filler is just the type you mention, it's marketed as "Red Devil" over here as well as other names but it's the same stuff you mention, almost as light as microballoons. It sands real easy and I always give it a shot of thinned pva after just to seal the dusty surface ready for covering, I apply this using a small piece of tight cell foam, the kind you'd find in your TX carry case, used as a squeegy almost. I'll post up some pics of that when I get to it tommorow. I then use my covering heat gun to quick dry the pva coating being careful to keep the heat far enough away from the surface of the wing so not to cause the pva from bubbling up but close enough to rapid dry and prevent any swelling, hope that makes sense . Your right on the money with the CA/Kicker method of application, however, I run a piece of masking tape along the inner most edge (parrallel to the span) of the piece of balsa that I inserted in the wing skin as a hinge tape kind of affair, then run the CA over the foam surface and shot the kicker on to the balsa skin inner, the skin is then layed down immediatley in to place and within seconds it's bonded and good to go!

Ryan,

That would have been so cool [8D], it's amazing how us modellers all think the same way when our fellow fliers need some support, great jesture there my friend, great jesture!

Regards,

Andy.

dreadnaut

My Feedback: (5)

Andy,

Thanks for the tip on PVA on the Red Devil. I have used Finishing Resin, but the weird thing is that when you combine these two (which are easy to sand by themselves) the result is a real b!@# to sand.

rwlewis

My Feedback: (4)

For the balsa repair tip that suggested water to remove balsa dents....

One further step to add to this is to iron the wet balsa with a covering iron set to "sizzle' the moisture out. This steam swells the wetted balsa area and which can be sanded back flush and may require zero filler!

Careful with a hot iron over wet sheeting on foam, the water conducts the heat though easier and risks melting the foam.

Atlanta 60

My Feedback: (18)

Exactly...Just a drop of water or even just wet your finger and use that to dab the water onto the bare balsa and watch it wick into the wood...Then run the covering iron over the area moderatly quick and walla!! If the balsa is just compressed into the dent this works really nice...As stated you will normally have excess to sand off and no filler required...If the balsa is actually chunked out and missing then you will probably have to fill...I just learned this tip a year or so ago but have been impressed with what hanger rash I have "fixed" using this technique...

I've even experimented a little on covered areas...I'll first take a #11 exacto or small pin and poke a hole or two in the covering...Then a drop of water and try to let it seep in...Then the iron...I've only tried it a couple of times with 50/50 success so far...I have one "challenge" type of repair I will tackle when I get my technique down...

Nice job on your repair and thanks for sharing!!

Oh BTW what a good looking plane the Partner is...

Chuck