Shop practice question

[gnoahhh]

Not gun related, but the techniques could cross over.

In the course of my job (lab tech for a small liberal arts college) I'm faced with a problem I never had to deal with. I need to permanently fasten small steel tubes (3/64"ID) 1/4" long, to various polished steel balls from 1/2" to 1 1/2" diameter. It has to be a neat, tidy job, so epoxy is out. My first thought is solder, but without a serious heat source will I be able to generate enough heat on the larger balls to effect good knitting? IE: propane or Mapp gas is all I have in the shop, no oxy-acetelene.

[Bret4207]

There are glues, similar to "Crazy Glue" that might work. Depends on hoe polished the balls and tube are, how clean you can get them and how much stress is placed on the connection. Mapp Gas may be hot enough for a low temp solder, probably will be in fact, but there will be discoloration.

[Junior1942]

Sounds like a job for a TIG welder.

[gnoahhh]

TIG would be great, except due to the nature of what the final appearance must be, the attachment must be confined to as small and neat as possible underneath the tube. Final weights will be fine tuned to a very small tolerance in milligrams. Am leaning toward solder due to file-ability, and polishability when done. I'm just not sure of heat transferrance in the case of the larger balls.

When soldering steel-to-steel, which knits better: modern lead-free stuff or old leaded solder. I have both. In fact I own a huge variety of lead solder, from50/50 to 95/5.

[dragonrider]

drill and ream a hole in the ball and press fit the tube.

[docone31]

I would silver solder them.
Use easy solder, heat them on a charcoal block, do not pickle! I would tumble polish them after soldering/brazeing.
Easy solder is available in tube form, with flux. With this technique, just enough solder could be applied to make a strong joint.
I would also contour the tube to fit the ball. The closer the joint, the better the joinery. Simple matter to put some lapping compound on the ball and spin it in. If it is too hard to handle, get a pitch cup, and spin the tube. The pitch will come off with the heat of soldering, what little will be there.
Sounds interesting.
Good luck.

[725]

Not understanding the end use or knowing the hardness of the items involved, I would put forth the idea to drill the steel ball & tube, insert an appropriate stud to which each could be soldered. Size and length could be very minor, but might establish a point to add strength for the joint.

[Beekeeper]

I do not know if they even still exist but I use a Eutectic Castillion ( sp) low temp solder and silver solder that I bought many years ago
One of the solders will melt with a cigarette lighter (the first time) and has a tencile stregnth of 25,000 lbs.
I'm sure if they still exist they have the perfect product for what you want to do.
They never let me down in all the years I dealt with them.


Jim

[Trifocals]

I would use a low temp silver solder. Check Brownell's as a possible source. IMHO Mapp gas should work fine. LOL

[wallenba]

Call around to some hot-rod shops and ask how they make custom pushrods. They are steel tubes with balls welded on the end electrically.

[gnoahhh]

Thanks guys! Enough ideas to get me started. (I should have mentioned these tiny tubes need to lay on top of the balls. Monofilament will pass through and suspend them in a complicated equilibrium/inertia experiment.) Great job, they essentially pay me to tinker.

[JIMinPHX]

Might be a good application for a spot weld.

Might be a good place for a small saddle & some #2-56 screws.

Might be a good place for a toolmaker's ball that is ground to a cylinder & then threaded into the ball.

Might be better off having a piece custom ground from solid stock.

It all depends on what you want it to be able to stand up to.

[WickedGoodOutdoors]

Whats the purpose of the project ? If it were an engineering College I would tell you that the Form MUST follow function. Who care what it looks like as long as it works! Thats my motto.

However: Since it is a Liberal Arts College where studants use our tax dollars to attend school as a lifestyle choice with assperations of saving the world with their ethical compassionate values andpolitics. the project may be for some piece of athiticaly; however elegant; non offensive piece of **** like this.

Notice Steel Balls on Rods.

Just use Crazy Glue. It will end up in Halfmoon Harrys anyway.

http://shop-handmade.craftcompany.com/media/products/yardbirds/flower-pots/4in-cat-f27sm.jpg

http://shop-handmade.craftcompany.com/media/products/yardbirds/flower-pots/4in-cat-merlot-f187sm.jpg

[looseprojectile]

and tubes to a body shop where they straighten out dents in vehicles.
They have a spot welder that welds studs to sheet metal to pull out dents.
Shouldnt be much of a stretch to weld the tubes. If you really want to do it yourself set up an EDM [electronic discharge machining] setup to make the holes in the balls to press the tubes into. Hope you have some success.

Life is good

[largom]

Better check the balls to be sure they are steel and not stainless steel!
Larry

[6.5 mike]

How about accu-glass stock bedding?

[Jon K]

Silver solder w/mapp gas..........clean & flux and try to concentrate the heat on the larger balls while trying to solder.....it'll transfer heat to thinner pieces, the problem wiill be getting enough heat to the big pieces.

Would be much easier if you had a better heat source.

Have Fun,
Jon

[jbunny]

do a google search for SOLDER IT . its a low temp silver bearing solder paste that comes
in a sringe. it melts at 430 deg f. make a jig to hold the balls and stand the tubes
on top of the balls and put them in a oven. this stuff will work on ferrous and
non ferrous metals. oh the tensile strength 10,000 to 25,000 psi
jb

[roadie]

Sounds to me that the tubes are laying parallel to the bearing surface right?

If thats the case, it'd be easy enough to get a slot run onto the bearing, say 1/4 depth of the tube, then you have lots of surface to bond to.

Epoxy then would have plenty to hold on, you might even slot the bearings with a round file.

roadie

[MtGun44]

Brownells HI Force solder and use their flux. Easy, low temp and very strong.

Bill