Which do you use, Silver or regular 60/40 Rosin Core when you do a clevis to 2-56 rods?

STAYBRITE SILVER SOLDER...ZERO FAILURES

Either one will work just fine. You don't really need to spend the money on the silver solder for this. Just make sure you clean off all the flux after you have finished the solder job.<div>
</div><div>Ken</div>

"Silver solder" is not a well defined term. To a plumber, silver solder means an alloy containing a very small amount of silver. It is a modern replacement for tin/lead solder, which is no longer used for plumbing because of the health hazard associated with lead. Its melting temperature and mechanical properties are similar to the old plumber's tin/lead solder. It costs about the same as tin/lead solder, maybe a little higher.

Silver solder to a jeweler means an alloy containing almost pure silver. It is very expensive. Melting it requires an oxy acetylene torch. Joints made with this solder are very strong.

I'm not sure what the Sta-Brite silver solder is - I suspect it is about the same as plumber's solder.

Electronic tin/lead solder (60/40 and 63/37) is a different alloy than the old plumber's tin/lead solder. It melts at a lower temperature and is not as strong.

Either tin/lead solder, plumber's silver solder or Sta-Brite should work fine. For soldering steel you will need an appropriate flux. The rosin core flux used for electronic work will not work very well. Get a can of plumber's flux from Lowe's or Home Depot. The flux that comes with Sta-Brite works really well.

Seldom do solder clevis anymore as I use a different set up on pusnrods but when I did I preferred to use 60/40 Acid core as it is easier to solder the pushrod or piano wire with rosin core. Of course not for electrical and use a water wash cleanup.

Acid core is also ideal for soldering wheel collors on axles or soldering washers for wheel retainers.

John

Curious, since you seldom solder clevis what type of setup do you use now and do you find your current method much easier, better, or just don't desire to use solder? I have never had a solder joint fail on a plane, but then again I am not an extremely agressive flyer either.

I use the Sta-Brite on one end and threaded ball link on the other. There are other ways of doing anything. This way is hard to beat.

david

As Ken said, plain old electrical 60/40 solder works just fine, more than adequate. Just make sure that you clean the objects to be soldered well before soldering; i.e. remove any oxides or dirt.

Luchnia I have no issue at all with soldering a clevis and I would certainly not be worried about the security of such. The point is I virtually never anymore do pushrods with double ended clevis and therefore no worry about turning the pushrod into a big turnbuckle and there is no need to deadend one of the clevis, I never have two clevis.

What I use these days for all the ships that utilize the 2/56 rod ends for the pushrods (and thats most right up to the ninety sized stuff) is Carbon Fibre rod and at the control surface there will be a threaded rod end inserted to the rod with a clevis (this allows adjustment without disassembly of the wing) at the other end will be a short (several inchs0 of 2/56 rod end without threads but a formes Z bend. My rods never have any bend at all in the rod ends I keep the pushrods dead straight. The outlet holes in fuselages are position by me to allow this not neccessarily where some kit or arf possitioned the outlets.

Pushrods with bends in the wire ends no matter what will cause the wet noodle pushrod syndrome. Now I do not use carbon fibre rods from the normal suppliers for my 2/56 rod ends Instead I use the difficult to find rod that is a perfect slip fit for the 2/56 rod end wire. It comes from Darrol Cady (this is searchable to find them) a cottage industry supplier to the pylon racing industry.

These wires are increditably easy to do even over the larger carbon rods or conventional pushrods. At the wire end at the servo (these wire ends are keept short) the Z bend is bent in before assembly wire has several inchs of radial notchs cut in the wire and this provides pockets perfect for the epoxy when it is slipped in the CF rod. But not glued now. Next the the wire end with the clevis threads is notched the same and this end is glued. now the entire rod is inserted into possition and the clevis is installed on the control surface at mid thread. Up front at the servo the the wire end is inserted into the CF rod and wiht radio on at neutral and the servo arm cross ways or wherever you want it the control is held neutral and a sharpie mark is made on the wire at the end of the CF rod. This wire in that section already has the radial notchs and the carbon is slipped off, epoxi is applied reinserted and the control set neutral. Bingo when set you have a perfect length and adjusted stiff pushrod.

This set up can be done much faster than most other types for fuselage rods and far stiffer as well as very easy to do. Not so easy to describe in print. I introduced my LHS to this method and connected him with Darrol Cady so he can supply the rods and now the vast majority are using this system here locally and not just pylon racers actually who are benefiting the most are the fellow with trainers.

Now as I suggested in other threads to the OP for now stick to the plans on your Kadet and use a Z bend up front and there is no need to solder. Later if you like with subsiquient airplanes do consider the Cf rods as I have described if you like.

John


This is a picture of a threaded rod ready to glue into the CF rod. The radial notchs are cut in just seconds by holding aginst the corner of a stone in a bench grinder and rotating as you go. This short (just a few inchs) wire will either have the 2.56 threads or a premade Z bend.

Actually, silver solder to a plumber is brazing rod. Plumbers, at least the one I used to work for, still call lead free solder just plain solder or soft solder. Stay Brite is a harder version of regular solder that is also corrosion resistant. For those who don't have experience with this stuff, you'll be surprised just how strong a properly made joint is with just plain old soft solder. The strength comes from a proper mechanical fit of the two parts then using the solder as a glue to hold them together. I can't imagine any application where a solder on clevis on a properly sized rod could come loose assuming the joint is completely full of solder like it's supposed to be.

Jester s1 makes a very good point. Getting a good, tight-fitting mechanical connection before soldering is the most important thing. Solder sort of "locks in" the mechanical connection. Solder doesn't have great strength by itself.

There are really only two ways a soft solder joint can fail when we're talking about mechanical things instead of plumbing. The first is to have the two parts moving back and forth to squeeze the solder back and forth until it work hardens and breaks. That's the result of a badly fitted joint. The second is for corrosion to weaken the parts themselves, which can happen with acid flux if you don't wash it off after you're done. To test your joint, all you have to do it put the thing together and wiggle it. If you are able to make the parts move hardly at all, then it's not right. So for clevises, you'll need to be sure that the wire you're soldering in is sized well to the clevis itself. For things that can't make a good mechanical connection like a loose socket connection or trying to join two pieces of music wire for a landing gear without wrapping them in fine copper wire, brazing rod is the right stuff to use because the filler is nearly as strong as the material and will tolerate the stress that soft solder will not.

Make sure you get ENOUGH HEAT on the metal joints to properly FLOW the solder. In addition to a clean joint that is properly fluxed, the metal must be HOT, otherwise, you will have a cold joint that will fail. A well flowed joint, will be smooth and shiny.....and when the metal is properly hot, it will flow and absorb solder like a sponge absorbing water. A COLD joint, will have messy solder that looks like cake frosting.

I don’t use 2/56 for anything. Solid carbon fibre rod of the same diameter is stiffer, stronger and lighter so if I have need of small lightweight control rod carbon is my go to.

I use 4/40 and up depending on size and force needed. Again the bulk of the control rod for anything over 10/12 inch’s is carbon fibre tube that just fits over the end pieces of 4/40 rod. I try and keep the 4/40 rod as short as possible. The 4/40 rod I like are the packages of threaded double ended rod in various lengths. For the adjusting end I pick the length of rod that allows one threaded end to slide inside the carbon rod and the other end out for the clevis of your choice. Rather than grind or try and form notches in the end you are epoxying inside the carbon rod the other threaded end will do a much better job at creating a solid anchor.

For the other end that I am going to solder the clevis I cut one of the longer double enders or use a single threaded end rod and insert the threaded part with epoxy inside the carbon rod. I leave the unthreaded end a little long to be fitted at assembly.

If you use actual 4/40 rod for this you will find the clevis will have to be turned on to the rod and should hold its position during soldering. Position the clevis on the threaded rod so there is enough exposed thread inside and outside the clevis to allow for adjustment both directions and attach to one end of the connection preferably where you need/want to do any adjustments.

Servo arm is centered and a locking nut is in place on the pushrod behind the clevis. I lock the control surface centered by using a bit of balsa strip top and bottom and held in place with two close pins or light weight spring clamps.

You can attach or push the clevis pin into the control horn and lift the rod to align with the clevis, mark and cut to length. A clevis such as the Sullivan should have 1/8 of the steel pushrod exposed inside the clevis. Because the clevis is so snug a fit on the 4/40 rod any solder on this exposed part will not allow the rod no mater what to pull through even if your solder joint should fail.

Sand/clean the rod and use a little acid flux on both the rod and clevis then wind into place checking for length by again aligning the clevis pin with the hole in the control horn. When you have it right just let the whole thing hang free and apply a bit more acid flux and solder in place. Any slight misalignment that occurs is easily adjusted at the other end.

Since the flux is acid I mix a slurry solution of baking soda and brush on the solder joint then clean with soap and water.

I prefer Stay bright only because of the convenience any other solder will do the job just fine. The Stay bright joint always looks nicer.

Dennis

Has anyone ever tried super gluing a properly fitted rod and clevis together? How did that work for you?

Come on, guys. I can't believe nobody has had to use CA at the field in an emergency situation just so the trip wouldn't be wasted. I simply wondered how it held up for them. Doesn't make you a bad guy if you did it.

I won't fly with any repairs that might be short lived.....I won't put my planes nor my safety or anyone else, at risk.
When I fly, I preflight, like my butt is riding in a full size plane.

SO yeah......I'll waste the trip, instead of taking an unnecessary chance.