Bonding a steel pin to copper sleeve.

For the game of steel tip darts, I have some hammerhead moving points that thread into the dart barrel. http://www.edarts.net/st_darts/hhpoints.shtml The moving points are supposed to prevent bounce outs if the point hits a wire on the board. I don't want the points to move though.
The point is basically a hardened steel pin, and the clip is a copper (I think) sleeve. The clip has an appearance like tarnished copper, and looks like fresh copper if I scratch it. The round cylinder back of the clip has 4 slots cut in it to make 4 leaf springs (sort of) which apply friction to the point as it moves in and out on impact and removal from the board.
I degreased the parts with spray carburetor cleaner, then acetone soak, then isopropyl (rubbing) alcohol soak, then blow dry. I then glued with Loctite 271 thread locker red. It didn't hold very well. One point came loose after a half hour of throwing the darts. The others have held, but if I take the point and place it tip down on a piece of Plexiglass and tap the sleeve with a hammer, it comes lose.
The technical report on Loctite 271 http://tds.loctite.com/tds5/docs/271-EN.PDF says only strength when bonding to brass versus steel. I figured similar on copper but figured I'd give it a try as other dart players have used 271 successfully for this purpose. If I had it to do over again I would have taken emery cloth to the steel points to remove the black coating and get down to bare steel. On the ones I knocked loose, it looks like the failure was along the glue/copper surface though.
So, I'm looking for something that will do a better job of bonding the steel point to the copper sleeve. It has to withstand thousands of cycles of repeated impact during normal dart play.
For prep, and to remove the Loctite 271, I'm going to wire wheel and coarse sand paper the points to bare steel at the bonding surface, and scratch up the inside of the copper sleeves with a needle file.
I'm tempted to try soldering them. I don't want to add much weight and certainly don't want to add un-uniform amounts of weight across the three assemblies. I have some fine solder wire with flux in it that might do the job well. I could apply the solder at the slots in the sleeves and hope a thin layer wicks in around the pin. Not sure whether to use a solder iron or propane torch. I'll try the solder iron first. I'm afraid I'll warp or even evaporate the sleeve with the torch.
Another possibility is the clear Loctite that you see in most hardware stores.
Thoughts on these approaches? Other ideas?
Thanks, Paul S.
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Paul Stivers wrote:

Soldering sounds like just the ticket for that, but the flux cored solder solder you mentioned is probably rosin cored, which won't easily wet steel.
If you don't have some acid flux handy, high over to a hardware store and buy a bottle of it first. "Denton's Tinners' Fluid" is an old brand that may still be available some places. Just a drop will spread out over the steel and then you can use the rosin cored flux along with it. An 50 watt or larger soldering iron should supply plenty of heat for that kind of job.
HTH,
Jeff
--
Jeffry Wisnia

(W1BSV + Brass Rat \'57 EE)
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Just one note: isopropyl (rubbing) alcohol contains a small quantity of oil to reduce friction when rubbed into the skin. I'd not use it to attain a dry cleaning.
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PanHandler wrote:

Good grief, where do you people keep coming up with this utter nonsense. You may be able to buy skin lotion that has isopropyl alcohol and oil in it but if you buy isopropyl alcohol in the drug store, look at the ingredients. All of my isopropyl alcohol bottles says it includes isopropyl alcohol and water. Nothing else is listed. That means their is no oil!
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Paul Stivers wrote:

A couple questions and a couple of observations.
Isn't the whole point of the hammer point to allow the steel tip to slide slightly so the impact with a wire won't cause the dart to bounce off the board? Wouldn't gluing it in place, immobilizing it, just make it the same as a regular dart? It seems to me that you're trying to defeat the design of the dart.
If you scrub off the bluing on the steel, the steel-copper connection will corrode much more quickly due to galvanic action. I don't think that's a good thing, but if you set the dart aside for awhile in the stripped condition, it'll weld itself together.

clip's grip. Is periodic tightening a major problem or just mildly annoying? Is tightening the clip more annoying than watching your dart bounce of a wire?
R
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Paul Stivers wrote:

Try epoxy or silver solder brazing.
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Jeff,
Thanks for the tip on acid flux for steel, and the oil in rubbing alcohol.
I decided to use metal epoxy. About $2. Shear strength is supposed to be 3000 PSI. It was nice and thick, so a good bead of glue behind the tip in the collet. I think it will hold fine.
I decided not to go with solder because of concerns about heat warping the copper collet, weight of the solder, would have needed acid flux for the steel, and muss and fuss.
R, yes this defeats the moving point. Hammerhead makes the nicest threaded point so that you can convert your soft tip darts to steel tip. If they made a fixed threaded point, I'd buy it. They don't so I'm looking to bond the tip in place. The moving point isn't really needed for the new thin wire boards, and the movement in the point is just a distraction.
Thanks Jeff and Tony for the thoughts. I appreciated it.
Paul S.
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