Michael Burbidge

Michael Burbidge

Well Known Member
The instructions for the smaller aileron push rod say that instead of using two rivets to connect each rod end to the rod you can weld the rod ends to the rod. So I thought that sounded easier than trying to drill a straight hole through steel with such a small radius.

So I took the rods to my local welding shop and had the ends welded to the rod. But now I'm wondering how I know if the weld is good. With rivets you can just look at them and see that they are still secure. But with a weld you can't. This may always be in the back of my mind because this is such a critical connection.

Did anyone else have these welded and have similar thoughts?
 
Is there a reason to not trust the weld shop? Do they have experience in this type of welding? You can stress test it I suppose.
 
AC 43.13 does give you requirements to inspect welds to make sure they are airworthy.

As LarsonAero said, if the shop has expierence welding the type of material that the rods are made out of then you are probably not going to have an issue.
 
Weld X-Ray

I have been involved in pressure pipe design and installation and 5% of all those welds have to be X-Rayed, if three fail then that welder is out of a job! I see you are in the Seattle area and there should be a number of companies that will do material testing. If you can take the rod to them which I assume that you can, then the cost will be reasonable, In this instance it will likely cost the same for multiple parts so if you have anything else that you want assurance on, do it at the same time.

If the shop that you took the part to to weld does pipe or structural welding their welders will be very good. Also they will be used to having their welds tested routinely and will not get PO'd for you having tested the weld integrity, they may even be able to do it for you.

I think that I would get the weld X-Rayed just for peace of mind.

Bob Parry
 
[email protected] said:
The instructions for the smaller aileron push rod say that instead of using two rivets to connect each rod end to the rod you can weld the rod ends to the rod. So I thought that sounded easier than trying to drill a straight hole through steel with such a small radius.

So I took the rods to my local welding shop and had the ends welded to the rod. But now I'm wondering how I know if the weld is good. With rivets you can just look at them and see that they are still secure. But with a weld you can't. This may always be in the back of my mind because this is such a critical connection.

Did anyone else have these welded and have similar thoughts?
Click to expand...

Post a pic and I'll tell you if looks good.
 
Considering a homebuilt "kit" used to mean a bundle of 4130 tubing that the homebuilder was to cut, fit and weld together (learning as they went), I'd say a professional welding shop is a pretty safe bet. I mean, if people used to learn to weld while building the entire primary structure of the airplane they were going to fly, I'd say having the pushrod tube x-rayed is extreme overkill.
 
IIRC, it was tight fit between the push rod ends and the push rod tube. I had to use my plastic mallet to fully seat the shoulders against the tube ends prior to the welding operation.
Use a wire wheel to remove about 1" of powder coat before welding. Use Van's touch-up paint on the rod ends post weld.
Note the cadmium plating on the fitting may be consumed in the weld. A drop or two of oil or Rustlick on the threaded end will keep corrosion away. Inspect periodically.
 
I welded mine also (certified tig welder). I plug welded mine and around the fitting. One thing that we did was add about a 1/2 teaspoon of line oil inside the tube before welding the other end. It prevents internal corrosion. If you have welded yours you can drill a hole in the tube and reseal with a rivet designed for that purpose. That's what we do to tube and fabric units. Old school I guess.
 
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