How to unplug sticky wings?

[Dave Elam]

It's quite a problem you have there.

Can you get a steel ruler in the gap between the wing and fuselage? If so then you have a vertical face to apply a force to. By force I mean the shock of a hammer blow. Start with soft blows and work up in severity stopping at the point before some severe damage may be done!

I'd also put some protective covering around the areas where the hammerhead may accidentally come into contact with the moulded components.

Regarding penetrating oil. From experience with nuts and bolts I've always found PlusGas to be better at penetrating.

 

 

[oipigface]

47 minutes ago, satinet said:

Hows big is the gap, if you can get a piece of wood in either side you could create a kind of reverse press with threaded bar.

That's exactly what I have been doing, using 1/2mm aluminium angle from the edge of greenhouse staging. 

50 minutes ago, satinet said:

Although the big questions is how did it go in the car?

It just fitted, nose down, wings diagonal, one up,  one down in the back of my Vauxhall Vivaro van!

[SilentPilot]

There you go then. If the servos work just leave the wing on!!!!

[Les]

Use some of that dirty curry from the Indian in Bridgend, the last time I ate there it unplugged me the following morning

[Skip]

pop it in a small room with a dehumidifier and heater for a couple of days. Any liquid in the joiner box will make it nearly impossible to get out (Hydrolock). As the moisture is drawn out of the plane, hopefully swollen bits will reduce and you can continue along your merry route.

Wedges made of Polypropylene used to relieve fibreglass parts from their moulds would come in handy.

I'm with Mike once all avenues are exhausted 

Dry her out John  

[Redbird]

I think I would dangle it spanwise with a decent weight on the lower tip, taped on, and shock/clout the joiner area regularly. Have cushions to collect it in case it separates overnight.

[Nigel_W]

I'm with Skip.  Most plastics expand when damp.  It is likely the joiner resin has absorbed damp - which will take a lot of time to dry.   Whenever pondering your next move overnight, consider placing it in a warm dry place like over a radiator.  (Maybe then get it really cold to try extract as others have suggested - leave it out on a frosty night?).

[oipigface]

This is turning into a real talking point, isn't it? Pity we're not in the pub!

[Skip]

Dehumidifiers are the dogs danglies!  Takes the moisture out of damp bricks in my garage (and causes cracks in your house if you're not careful  ) 

I think the pub would be great! Bloody nightshifts. ...

 

[Redbird]

1 hour ago, oipigface said:

His is turning into a real talking point, isn't it? Pity we're not in the pub!

Pity we're not in your workshop getting the job done!

See you Sat.

[isoaritfirst]

Time gentlemen please!

and time waits for no man.

Power up the Dremel. 

[Phil.Taylor]

Theres one sure fire tried-and-tested method of getting F3F wings to slide off...

go fly it WITHOUT taping the wings on - works a treat (ask Joel?) 

Phil.

[oipigface]

4 hours ago, pete beadle said:

When the airframe was returned to you, was it covered in dirt and grime? but particularly were there any GREEN marks indicating plant growth, mould etc?

Did you clean it up first, to be better able to inspect the damage?

I'm trying to account for this stickiness by thinking that perhaps there is some sort of vegetation growth starting in the cracks activated by the soap and water(?) used to clean it?

I have only cleaned the tailplanes, to see if they would ever fly again. I think they would, but I think the plane would be better with new ones.

I haven't tried cleaning off what dirt there is on it, and I don't know what the finder cleaned off it. This is mostly sort of muddy dust, and pine needles. I suspect it might have spent most of its time under the mulch that you see on a forest floor. There is no obvious sign of algal growth or mould, but then such things are very often microscopic.

I've looked out some threaded rod, and I'm going to buy some iron angle and a couple of steel rules, to make a more robust version of my wooden device. In the meantime the plane is in a spare bedroom near a radiator, and the Dremel is waiting....

[isoaritfirst]

Calm down Pete! 

John knows what he is doing - he's done enough repairs to know whats involved if he does slice and dice.

Its not an Extreme measure at all , its not irreversible, (with the exception of needing a new joiner) its just a simple repair. I've done more as a field repair.

The model has a hole in the wing that needs a repair as well, and this will not phase John at all.

Sometimes cutting out can give you a simple quick repair, with significantly less hassle and without the risk of doing unknown damage by poking and pushing for days with a less structure plan.

Which will give first with a push/pull on the wing root?

The joiner loosening, or the wing root collapsing, or possibly damage to the joiner box. As well as dents in the wing skins.

If this was a wood fuselage would you not cut it out and get  on with the job,

To those of us used to working with epoxies - its no different, splicing in, is easy and successful. 

Its not sacrilege it not against any engineering principals its just a day to day repair, that once completed will be invisible and as strong as the original. 

 

 

[Phil.Taylor]

hacksaw through the incidence pins first, before the joiner - then you'll know if it really is the joiner that's stuck

Phil.

[isoaritfirst]

Not offended Pete - your experiences differ.

[Bobbyr]

If its hydro locked , as said it wont come off ,

                      so drill a small hole through the wing at the end of the joiner box , 4 mm Diameter will do ,  this will allow any water trapped inside to come out and Air in to allow separation at the end of the joiner , and a small hole will be easily filled , just an idea Mate , not very destructive either . Incidence pins are usually ST/ST or Tool steel , doubt they would rust to be honest

 

                                     Bob

 

[isoaritfirst]

wing joiner is hollow so hydro lock would seem less likely. but could be released by drilling into joiner at the centre.

[isoaritfirst]

I recall when I had my Jaro Muller Elita, I was convinced that Muller quality would not require the joiner to be fettled so I pushed it harder into the wing than I should. 

I could not pull it back out.

Eventually as it was just one panel I clamped the joiner into my wood vice and pulled/tapped.

No hydro lock just good old friction, can be tuff.

 

Pulling may well be imparting a degree of sticktion as the pull is unlikley to be square. again I have experience pulling hard to no avail then a lighter but more controlled square pull releasing items like this. 

Tapping is a far better way. it will not suffer from the same side loads, or cause gather in the materials. 

Not sure if "gather"  would be a problem with a carbon joiner but thinking about rubber handlebar grips, trying to pull them off is hopeless but tapping a spanner on the inner edge will remove them effortlessly.

[oipigface]

Meanwhile, I am in a pub recalling today’s visit to B&Q, where I bought 1m each of steel I-beam and  20mm square section tube and two steel rules. 

From these and some bits of threaded rod I hope to devise a machine that will deliver a straight and controlled pull on the wing. Before I use it though I’m going to see if I can’t drill a hole in the joiner tube through the servo cavity. That way, I don’t need to damage any visible surfaces.