Pouring lead into the rudder??

22 posts in this topic

Posted

Hi, I have hit a stumbling block on my Magnum build.  I am at the point where I need to pour melted lead into the elevator and rudder.  The manual is very vague to say the least on how to do this and where exactly to put the lead, it only states to pour it in front of the hinge center line? I can assume that the elevator lead goes in the outer front tips of the elevator where the flat plate gussets are.  But I am at a loss as where to put the lead on the rudder because there are no openings at all on it?

 

Thanks in advance on any suggestions!

 

Barry

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Posted (edited)

Barry, I don't have my MAGNUM manual since I sold it.  One possible thing on the rudder is to drill a hole in the top forward large tube and put the lead into it - another better way to get more weight is to rivet or weld some flat metal plates, or sandwich some fiberglass plates on the front sides and put the lead in between them and seal it on with an enclosure.  Fiberlass or metal plates will also work on the elevator horns too -

NOW, before you think I am crazy enough to pour hot lead into fiberglass - Let me explain - The easiest use of lead that I have found is NOT TO MELT IT - I use lead shot like you get in shotgun pellets, buying it by the bag, or even lead bullets or balls for cap & ball pistols, or BBs - The small shot works better to form into a cavity - You mix it with some 9460 or some silicone caulk like GE Silicone II and push it firmly into the area until your part, only supported at the hinges, gets a forward overbalance - make the overbalance a little extra because you are going to add fabric and paint to the parts later.  You may have to hang your rudder on a couple of horizontal nails or a wire stretched in the hinges to do this.   HOPE this helps.   EDMO

Edited by EDMO
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Posted

Ed,

Thanks for the reply, I actually read a post on here earlier today about using 9460 and lead shot. That seems way easier than melting lead and trying to pour it in a small hole etc....

And the tip on how to balance the rudder and elevator is good too, I was wondering how to get the right amount of lead in there!

Thanks again,

Barry

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Posted

Ed,

Thanks for the reply, I actually read a post on here earlier today about using 9460 and lead shot. That seems way easier than melting lead and trying to pour it in a small hole etc....

And the tip on how to balance the rudder and elevator is good too, I was wondering how to get the right amount of lead in there!

Thanks again,

Barry

Barry, That might have been one of my old posts - I seem to be forever repeating what I think might help someone just to make sure it is read by more than one person.   EDMo

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Posted

When balancing the elevator on my large RC models I will just stack lead weights on the from of the air horn until it holds itself level.  Then I weight it all and mix up some epoxy and lead shot on the scale until I hit that weight then pour it in the front of the horn.  Its easier than trying to use just lead shot and epoxy and making a mess trying to figure out how much I need by adding it then grinding some out etc.  I have never bothered with balancing the rudders.

:BC:

 

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Posted

Thanks for the advise on the lead shot!  That is exactly what I used and mixed with 100% silicon and it worked great.  It took 2.2lbs to balance the elevator.

Barry

85.jpg

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Posted

Looks nice. For those that don't know, most silicone caulk/sealant has acetic acid that is known to foster rust/corrosion issues, Auto parts stores carry some that is not corrosive.

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Posted

Looks nice. For those that don't know, most silicone caulk/sealant has acetic acid that is known to foster rust/corrosion issues, Auto parts stores carry some that is not corrosive.

Kitfox manual said to use GE Silicone Caulk to seal gas tanks to spars.   EDMO

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Posted

Many seem to not have troubles, but I've seen it addressed in aviation circles and in an auto glass installation training session as well. Nothing conclusive in personal experience but I've used the noncorrosive for any aviation applications.

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Posted

Being in the auto glass business, I'd really like to know the application for silicone in a window installation.

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Posted

Being in the auto glass business, I'd really like to know the application for silicone in a window installation.

Actually, that was the point. They said any applications of silicone ( and backed it up with pictures) would result in rust.

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Posted (edited)

My memory is currently about like scrambled eggs - I attended a Loctite seminar years ago, and I think they were saying, "If it smells like vinegar...." and I would have to get the books out to remember the rest.  Sorry for the incomplete, incompetent, incoherent, writings.  I am not totally "here" now, so bear with me.  ;<) 

Larry,  What kind of stuff was that black ribbon or caulk they put the windshields in with when I worked at Chrysler, 1965-1991?  EDMO

Edited by EDMO

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Posted

My memory is currently about like scrambled eggs - I attended a Loctite seminar years ago, and I think they were saying, "If it smells like vinegar...." and I would have to get the books out to remember the rest.  Sorry for the incomplete, incompetent, incoherent, writings.  I am not totally "here" now, so bear with me.  ;<) 

Larry,  What kind of stuff was that black ribbon or caulk they put the windshields in with when I worked at Chrysler, 1965-1991?  EDMO

Yes Ed, the acetic acid is is what smells like vinegar, and that is the stuff to avoid.

Hope you bounce back quickly!

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Posted

seems like its more prevalent causing corrosion on aluminum than powder coated steel.  If it sticks and if it cures all the way through I would say its fine.  I might put a wrap of cloth over it when covering just to make sure it stays in place if adhesion were to be an issue with it.

:BC:

 

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Posted (edited)

seems like its more prevalent causing corrosion on aluminum than powder coated steel.  If it sticks and if it cures all the way through I would say its fine.  I might put a wrap of cloth over it when covering just to make sure it stays in place if adhesion were to be an issue with it.

:BC:

 

I doubt if it will do any damage at all to powder-coated steel.  Also guessing that as long as the O2 is sealed out, there wont be rust?  My tanks were sealed to the spars with it about 25 years ago and when they were removed 15 years later there was no corrosion.   There is no problem with adhesion - It really sticks!   Kitfox said an option is to wrap the spars in Saran Wrap before gluing the tanks in - Mine didn't have that, and it took a lot of cutting and scraping to get them out, and to get the GE Silicone off.  EDMO

Edited by EDMO

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Posted

      What is the advantage to adding weight (balancing) the rudder and  elevator horns

thx rjg  

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Posted

It make your control inputs "balanced" or in other words, the weight that you feel on the control stick as you move it will not have a heavy or harder input in any direction. Also in higher speed aircraft, it helps prevent flutter, but this will not be an issue with a Magnum. I am sure there is more out there on this subject, this is just my understanding.

 

Barry

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Posted (edited)

It make your control inputs "balanced" or in other words, the weight that you feel on the control stick as you move it will not have a heavy or harder input in any direction. Also in higher speed aircraft, it helps prevent flutter, but this will not be an issue with a Magnum. I am sure there is more out there on this subject, this is just my understanding.

 

Barry

It can also help prevent flutter.  Oh - you said that - I must have blinked!   EDMO

Edited by EDMO
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Posted

     Would the horn itself (being in front of the hinge pivot point) catch air and lighten the elevator/stick and rudder/ peddle forces

thx rjg 

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Posted

RJG,

In my opinion, the rudder is facing into the wind most of the time, so wind forces will not help balance in any way.  Hope I am understanding you correctly.

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Posted (edited)

     Would the horn itself (being in front of the hinge pivot point) catch air and lighten the elevator/stick and rudder/ peddle forces

thx rjg 

Yes - There have been instances where air pressures on large unshielded horns have even reversed the forces on the controls - This becomes more critical with faster flight - Usually this is corrected by cutting back the horns shorter, or also putting a solid part of the stabilizer in front of the horns to make them sheilded.  The weights in the horns may help prevent this.  EDMO

Edited by EDMO

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Posted

RJG,

In my opinion, the rudder is facing into the wind most of the time, so wind forces will not help balance in any way.  Hope I am understanding you correctly.

The air horn on the front/top of the rudder does help to lighten the forces on it.  same with the airhorns on the elevator. 

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