JB weld or solder pushrod?

[Paul Taylor]

I had a plane given to me and the pushrod solder joint came lose.
Never used this type of pushrod.
Would JB weld hold or should I re-solder?
Thanks in advance.

[Gerald Arana]

IMNSHO, I'd resolder it.

Good luck, Jerry

[Tim Wescott]

Picture!  And, I'd probably solder it.

[Mike Griffin]

I  have used JB Weld for a lot of years and used it for joining pushrods and have never had a failure. 

Mike

[RandySmith]

Solder it, I have had, and have seen  many  failures with JB weld, especially on hard metal, it cannot take the vibration, and  will crack and fall off

Randy

[john e. holliday]

Clean the joint as best as you can and resolder it.   I have used J-B Weld on over lapping new joints with wrapping wire and no failures.  Of course its not as pretty as a good solder joint.

[bob whitney]

Solder,Solder Solder

[Avaiojet]

The only parts I would solder are tiny washers used to hold wheels on and the little extensions placed on gear wire to hold foax wheel gear door covers.

One reason is, even though I can solder kinda well, I don't know enough about solders, especially steel to steel. It's a science within itself.

Kudos to anyone who can solder control surfaces for the long term.

Charles

[Brett Buck]

I had a plane given to me and the pushrod solder joint came lose.
Never used this type of pushrod.
Would JB weld hold or should I re-solder?
Thanks in advance.

   I am not sure what you mean by "pushrod joint". Wire pushrods should never have any sort of joint or soldered connection, at least in the direction of the load - they are notorious for failing (as you found). Two-piece pushrods should be replaced with single piece or a carbon or fiberglass pushrod.

     Do you have a picture of this arrangement? Does it count entirely on solder to hold it?

       If it's music wire and you absolutely have to solder it without a torch, your only realistic option is to use Sta-Brite and just live with the corrosion.

    Brett

[bob whitney]

there is no secret to soldering.clean everything with 400 or 320 sandpaper even the wrapping wire (brass or Copper)

DO NOT BURN any of it.use an Iron or Gun hot enough to melt the solder while getting the pushrod hot enough to take the solder. .I have found a Past soldering flux called Alpha that works great but dosent seem to corrode as bad as Stay-Brite  overlap about 2 in .wrap each end about 3/8 from end and solder .has worked for the last 55 years
  I have heard that if u don't fly the plane ,u can use double bubble gum to hold the push rod on

[Lauri Malila]

Ok, yours has allready been soldered, but I have zero problems with corrosion (when using Staybrite) in piano wire solders. The point is to use the strong acid flux only when tinning the piano wire. Dip the piano wire in flux, heat it enough to make molten tin to stick, and when still hot, wipe quickly with kitchen towel. That leaves a very thin layer of tin over steel. Then clean again and neutralize the flux residue, wrap with copper if necessary and solder parts togerher using some less aggressive flux. L

[Paul Taylor]

Thanks guys. I know a CF rod needs to go in but that will require more holes. Still thinking about it.
Here is what I got.




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[John Rist]

Looks like the original solder joint was never good.  If you can get the old coupling sleeve off I would clean every thing up and solder in a new sleeve,   I don't know if you have good soldering skills but a good solid soldering joint is very strong.  Another trick you can do is drill some 1/16" diameter holes in the sleeve.  Lets the air out and the molten solder in.  As I said looks like a bad solder joint to start with.  Make a good joint and you will be good to go!   

[Trostle]

Given your situation, here is my recommendation.

Remove the coupling.  Completely remove remaining solder and clean both ends of the pushrod.  Add a new coupler coating the pushrod ends with a good flux.  Before you solder, take a piece of 1/32" or .020 music wire to overlap the coupler/pushrods.  Wrap the whole thing with copper wire, 28 gauge or smaller.  Use a good flux and solder the whole thing making sure solder flows into the coupler and attaches the copper wire/small music wire, pushrods and coupler.  Clean.  And the thing will never come apart again.

I did this years ago after loosing several models to pushrod failure like you pictured.  I do not use music wire for pushrods anymore.

Keith

[Noel Corney]

Looks like it has been silver soldered to me, I think I would be replacing the full push rod if the model is a good flyer.

[Randy Cuberly]

I've lost two stunters to failed pushrod solder joints in the past that looked very much like the one in the presented picture.
I would add that I know how to solder.  I was a MIL-Spec trained Solderer for both electric and mechanical joints, and also trained as an inspector for soldered joints.  I am a mechanical engineer and a strong understanding of materials and processes and failure analysis.  My opinion is that a soldered joint like the one shown is not reliable and has a high risk of failure.  (and I proved it twice!) 
A good soldered joint is very strong but the problem with the type of joint shown and the ones that failed on both my airplanes is that there is no real way to tell what the integrity of the joint is without x-ray and even that can be a little wish-washy.
I do not now nor will I ever again use a joint like that even though they are very convenient they are very risky.

I do believe the repair mentioned by Keith Trostle would likely work but from the description it would probably work without any solder in the tubing joint providing the external wire and solder was properly done.

Randy Cuberly

[Dan McEntee]

   If you must use a coupler to connect two pieces of music wire, simply cut a slot the length of he tube coupler. When ready to solder, flux everything up and you can solder the whole length of the coupled joint, not just the ends. Make the slot just wide enough so you can see how the solder flowed. This way you will have a solder joint that is the entire length of the coupler. I think Dubro sells coupler like this, or you can make one from brass of copper tubing. As mentioned, get the music wire shiny bright first. I like good old fashioned Ruby Fluid soldering paste. if done correctly this joint will last. But with all that said, I would probably change it out for a carbon or arrow shaft push rod.
  Type at you later,
  Dan McEntee

[Eric Viglione]

If you could remove the sleeve and bend an L on the end of that wire in place (will take strong hands and good tools, might be tricky) then i don't see why you couldn't do an arrow shaft with hole.drilled for the L and dowel w/epoxy type arrangement from that point back? I used to use arrow shafts and wood dowels all the time back in the day, never had one fail.
Just a thought.
EricV

[Paul Taylor]

Thanks for all the feed back. A ton of good information here and a few options to boot. Now to see what will work best with the tools and skills I have.
I will report back.

[Paul Taylor]

Ok I was able to make up a new CF pushrod.
Now I have a brand new solid rod. Now the elevator has slop. Not sure I had it before.

Not sure you can see the space in the hole.




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[Paul Taylor]

The brass one is what came out


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[Brett Buck]

What is the relevance of the Kwik-link? Surely that was not what you put back into it, right?   This airplane had two disastrous/fatal issues in one pushrod.

    I don't know where you got this airplane, but you need to inspect *everything* for the sake of safety, because this may just be the tip of the iceberg.

    Brett

[Air Ministry .]

Now the elevator has slop. Not sure I had it before.

Shouldnt worry it , if the FLAPS DONT .

Solderings a Art. Pre Tinning before anything goes near the plane ,

and a 80 watt Iron ,

CLEAN FLUX . Fresh . Throw out dregs or put in ' spare ' bottle .

THE FLUX MUST BE VIRGIN CLEAN . Phospheric Acid based for Stainless Soldering .

A CLEAN JOINT wether your glueing soldering or using chewing gum , is the only way to go .

The IRON must have sufficent heat reserve to not ' cool off ' on use .

And the seam from the liquid flux will get in things , so the open window / fan . outdoors arnt a bad idea .

The Steam or spilt flux will ruin lines . Do not store near the ' metalwork ' area . 

[Air Ministry .]

but you need to inspect *everything* for the sake of safety,

YES .

Just Got Given a Windwotsit ,

Easiest fix for controls was tease the steak knife thru over the top of the wing , Slice Nose horizontally under tank , Vert Cut under TE ,
Cut Hatch over bellcrank - Its behind the spar . Replace whole system . Plane will be donated to someone for that tho . ok for a hack .
Up Fr of Rudder , along under tailplane , 45 up n fwd fr of fin . The super market knife sets even cut tin cans , tho blunt eventually .
Ive found them a usefull tool , scrapeing planeing , cutting ply , and ' removing ' things . Need to keep the fingers out of em tho .

[Blaine Buchtel]

Am I  the only one who has no idea what Matt usually has to say? He seems knowledgeable enough but he speaks in a language I don't know. I usually skip over his replies because I have no idea what he is trying to say . His command of the English language is certainly di fferent from mine. Anyone else notice this or is it just my problem?  Best regards,  Blaine

[Air Ministry .]

This is Because it is ' The Queens English ' , rather than George Washingtons . 

This is a Wind , were a series , all wind - wotsits , bar Wind Walker & Wind Bag .  Wind Dancer?? and suchlike .



Was donated one built by someone else . 16 g. ? horns were flexi plus , so ' got to the heart of it ' , surgically - useing primarilly a steak knife , combined with a razor saw . Was built ok out of rather tough wood . Thought useless without stiffer control system . 20 - 30 minutes to disect . But will pass it on to a worthy
chap . Thus he can get into trying aerobatics with minimum investment . Ive insufficent storage for almost nearly but not quites . 

[Brett Buck]

This is Because it is ' The Queens English ' , rather than George Washingtons . 

  Queen perhaps, but of which planet?

  Seriously, however, no one wants to offend, but to be honest with you, I cannot understand what you are saying almost all the time, and only with careful analysis do I even get the gist of it. There are at least 7 grammatical and punctuation errors in one 12-word sentence above, even by the strict Oxford style guide that I am led to understand was written by Englishmen. I am no stickler by any stretch of the imagination, but that's pretty rough.

     Do as you wish, of course, but I would guess that 95% of what you are trying to say is getting lost, whether it is conceptually valid or not.

     Brett

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This is Because it is ' The Queens English ' , rather than George Washingtons . 
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[john e. holliday]

Remember guys he is on the bottom side of this piece of space rock.  As I told the New Zealand team at the 2004 Worlds I speak my version of American.  When you've had the influence growing up around people from the south and those from the north it gets confusing.  Nothing like being in a AT&T class with people from all around this great land.

[Avaiojet]

Am I  the only one who has no idea what Matt usually has to say? He seems knowledgeable enough but he speaks in a language I don't know. I usually skip over his replies because I have no idea what he is trying to say . His command of the English language is certainly di fferent from mine. Anyone else notice this or is it just my problem?  Best regards,  Blaine

I think Matt is the second most interesting guy in the forum. No doubt about it. Here's to you Matt. 

Well, I do spend hours trying to figure what he's talking about. 

CB

[Don Hutchinson AMA5402]

When soldering wire into a brass tube, you need toi drill a tiny hole in the middle of the brass tube, otherwise, the air inside heats up and pushes the solder out.  Look at the photo, all the solder is right at the end of the brass tube, none has gone inside. The forward end is probably OK as the solder was free to wick down the wire/tube joint but I would change it as you don't know if it was done right.

[Brett Buck]

When soldering wire into a brass tube, you need toi drill a tiny hole in the middle of the brass tube, otherwise, the air inside heats up and pushes the solder out.  Look at the photo, all the solder is right at the end of the brass tube, none has gone inside. The forward end is probably OK as the solder was free to wick down the wire/tube joint but I would change it as you don't know if it was done right.

     Absolutely, I have seen many of them just like that fail in exactly the same way, for the same reason. Unfortunately, drilling the hole creates a stress riser which will frequently cause the tube to crack. I have seen people attempt to use roll pins since they have a slot down the entire length, but unfortunately, they are almost always black-oxide finish, which won't solder properly without extraordinary effort.

     Both Kwik-Links and soldered-together pushrods, almost no matter how you do it, are just disasters waiting to happen, with a sad record of failure after failure over the years.

     Brett

[Tim Wescott]

When soldering wire into a brass tube, you need toi drill a tiny hole in the middle of the brass tube, otherwise, the air inside heats up and pushes the solder out.  Look at the photo, all the solder is right at the end of the brass tube, none has gone inside. The forward end is probably OK as the solder was free to wick down the wire/tube joint but I would change it as you don't know if it was done right.

I make sure there's solder down inside the tube, and that the music wire is tinned.  If solder isn't clearly being pushed out by the action of shoving the hot wire into the hole, then something's wrong.

I haven't had a failure yet, but I took a long break from flying, so I only have 1000 flights or so on the various airplanes I have that are all done that way, with a high-water mare of only 600 flights or so on the most-used one.

[Randy Cuberly]

I agree completely with Brett.

As I said before I've personally had two failures that were with a slotted bushing.  I've personally seen at least a dozen over the years and heard about several others.  Soldered pushrods and kwik-links are a recipe for disaster.

I even saw one pushrod failure that did not fail at either of the solder joints but the brass tubing failed in the center between the two ends of the pushrod. 

There are other ways to do this important task why risk a method that everyone knows is risky!!!

Randy Cuberly

[Paul Taylor]

Thanks for all the feed back.
I went a new CF pushrod.
I did not have a lot of room in the back so had to use a kwik link. This is just a knock around plane at this point.

[Dan McEntee]

   The only kind of metal clevis I use, even on knock around,foo foo models, is the Great Planes version. It's made of a bit thicker material and has a nicer nickle finish and takes solder well if you need to. I have seen Dubro Kwicklinks fail from vibration and stress from opening and closing. Never has a Great Planes unit fail me.
  Type at you later,
  Dan McEntee