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Will Silver Solder NOT stick to Titanium?

Aaron-M

Aluminum
Joined
Jun 19, 2020
Hi All,

This is one of those backwards questions. I do a hidden solder joint on some products, where the solder is encapsulated during assemble, then we put it on a simple steel mandrel, spin it with your finger and get it hot with a torch. Solder melts in the middle of the product and makes an excellent solder joint.

The problem is occasionally it solders itself to the mandrel, which is more of a pain in the rear, than a technical issue. Then you have to play with the mandrel, clean off the solder and work continues. Takes about 5 minutes to resume work, but this ends up happening 3-4 times per run or parts. Of course the steel bar it rusty, of course we spray it occasionally with graphite spray, but it's a ongoing thing.

Maybe it's a testimony to Harris SCLF16 Stay Clean Soldering Flux (liquid) and Harris Stay Brite silver solder, "able to solder in the toughest conditions" either way I', looking for a solution.

I was thinking about getting titanium tube for the mandrel, a little off the deep end, but as long as it solves the problem. I though about a graphite rod, but that would wear away, iron would rust fast with the flux.

So the question comes down to, do you think the solder would stick, and would the Harris liquid flux cause the titanium to corrode or do something weird.

Any thoughts would be great.

Thanks
Aaron
 
Does the mandrel need to be hot enough to solder? Or can you use stainless steel with water (or oil) cooling? It doesn't need to be all that cool to prevent soldering.

Titanium does sound plausible as a mandrel material, but soldering temperature may make it brittle over time. I'd talk to a titanium manufacturer about choice of alloy.

 
Last edited:
Hi All,

This is one of those backwards questions. I do a hidden solder joint on some products, where the solder is encapsulated during assemble, then we put it on a simple steel mandrel, spin it with your finger and get it hot with a torch. Solder melts in the middle of the product and makes an excellent solder joint.

The problem is occasionally it solders itself to the mandrel, which is more of a pain in the rear, than a technical issue. Then you have to play with the mandrel, clean off the solder and work continues. Takes about 5 minutes to resume work, but this ends up happening 3-4 times per run or parts. Of course the steel bar it rusty, of course we spray it occasionally with graphite spray, but it's a ongoing thing.

Maybe it's a testimony to Harris SCLF16 Stay Clean Soldering Flux (liquid) and Harris Stay Brite silver solder, "able to solder in the toughest conditions" either way I', looking for a solution.

I was thinking about getting titanium tube for the mandrel, a little off the deep end, but as long as it solves the problem. I though about a graphite rod, but that would wear away, iron would rust fast with the flux.

So the question comes down to, do you think the solder would stick, and would the Harris liquid flux cause the titanium to corrode or do something weird.

Any thoughts would be great.

Thanks
Aaron

How about a Borosilicate glass rod?

Comes in all manner of sizes. Stands a good deal of heat .. AND thermal shock.

Won't rust. Resists "many" chemicals.

Cheap to TRY it and see how it acts wth your temps, solder, and uber-flux.

NB: "Pyrex".. may or may NOT be Borosilicate, these days.

Page Two:

Alumina & cousins.

Corningware is an example. That is made in rod form, too. MANY ceramics are.

So, too, synthetic Ruby and Sapphire. Aluminium Oxide, basically.

"In theory".. ignorant Aluminium bar, WELL anodized could work.. but that flux?

Seems you got your money's worth on THAT much!

Prolly flow solder to fossilized Dinosaur turd or petrified donkey d**k??

Now.. there's a thought..

Might contact the Democratic National Committee and see what THEY use to keep s**t from sticking?

"First, find the EXPERTS!"
 
Would a ceramic rod work? It should last basically forever and no welding/soldering process will stuck to it. Cheap too:

Round Solid Rod Sample Packs - Max-Gain Systems, Inc.

Some do stick. Glazed Steatite can be MADE to do.

Ages ago, O'Scopes (and not only) were assembled with the lumped resistances, capacitances, and the like laid suspended on their own, straight, axial leads between rows of metallic-lined Vees. In wedges of Steatite, standoff mounted.
Hookup wire was then routed to and fro.

For "field" alterations, a coil of Silver "bearing", not pure, low-eutectic solder would be wound between two spools on the case. Use of OTHER solders at higher temps was known de-stabilize the metal to ceramic bond. Otherwise, it was a very durable one.

2CW. .and a buncha old scopes!
 
Try aluminum. Or just try wiping the mandrel with a wet rag between parts. I doubt if you start cold with the mandrel it will stick first few parts.
 
This may be a bit over simplified but it has worked for me and countless others on certain applications. I would try to "candle" the mandrel before you start to solder. Nothing seems to want to stick to oily soot.
 
I’ve used graphite a couple of times, the posts advocating ceramic look sensible, graphite alumina, fused silica even borosilicate glass, not sure of its MP softening etc
Mark
 
How about chrome plating the mandrel? That might be slick enough to keep the solder from sticking.
 
To add to Thermite's point, high-power vacuum tubes use soldering between ceramic components.

Lot of engineering and lab work has gone into stuff like that, though.

Take "platinite" alloy. matched to the coefficent of expansion of glass:

platinite | Encyclopedia.com

.. so an ignorant mass-produced Edison-base incandescent light-bulb didn't self-destruct.

Universal solution? Not really. It is matched to the SPECIFIC low-cost glass they wanted to utilize to keep the cost of a "consumable" lamp affordable!

There are easily as many "alloys" of the family of "glass" as there are of the family of "metal"! Some are even "both".

Ceramics? Oy! Now THOSE, mankind has been tailoring for this or that since our earliest days.

And more recently.

See "Kyoto Ceramics" or "Kyocera" for some interesting history, "recent" being a relative term.

:D
 
I don't think anyone mentioned tantalum.

If you can't find a material to work for your mandrel, eliminate it. Spin the part fast enough to use centrifugal force to your advantage (if practical and can be done safely).
 
I don't think anyone mentioned tantalum.

If you can't find a material to work for your mandrel, eliminate it. Spin the part fast enough to use centrifugal force to your advantage (if practical and can be done safely).

I'd try a chilled hollow tube, first. We've all heard of "cold solder joint" as one that was NOT a "solder joint". Because it did not 'wet' properly.

Ever try to solder a Copper waterline if even a LITTLE leakage was getting at it?

Cooling can be cheap and easy even with solid mandrels.
Do it the way ecology-minded "green" Texas oilmen usta do:

Drive a VW Beetle with no air-con instead of a monster SUV.

Beetle gets warm?

Return it to the drive in steaks freezer.

Pull a cold beetle out of the six pack.
 
I don't think anyone mentioned tantalum.
All the Tantalum ("sponge") capacitor I ever got at the innards of by accident or curiosity had used leads soldered to the goods. There are all KINDS of "solders" and fluxes, though.

MOST of the metals suggested for a mandrel?

"Non-stick" is all about their Oxides at the skin anyway. That's why his flux is a player.

I've been tin-lead 60/40 "soft" soldering ground wire or terminals to sheet aluminium for.. about 68 years?

Hams & audiophiles did it all the time. Razor-blade and a small drop of oil.

BFD.

Could was all he has to do is cera-kote or hard-anodize a stash of shiney-wood mandrels, stash 'em in a cooler, use 'em chilled, cycle them for routine surface renewal?
 
Hi All,

We've just listed every cooky alternative product known to man. :) Anything glass or ceramic has a 5 minute life span in my shop. I think we're going to go with the titanium tube. There is a piece on Amazon 12mm od x 250mm for like $15. I'll stick a steel rod down the center of and let you know the results. The steel rod in the center will help it in case if fails.

The trick is to complete 100 pieces in 120 minutes, so the torch basically heats that mandrel for 2 hours, so yes it's at solder temp after about 5 minutes, cooling it every part, not really viable.

We'll see what happens with the titanium tube.

Thanks
Aaron
 
Hi All,

We've just listed every cooky alternative product known to man. :) Anything glass or ceramic has a 5 minute life span in my shop. I think we're going to go with the titanium tube. There is a piece on Amazon 12mm od x 250mm for like $15. I'll stick a steel rod down the center of and let you know the results. The steel rod in the center will help it in case if fails.

The trick is to complete 100 pieces in 120 minutes, so the torch basically heats that mandrel for 2 hours, so yes it's at solder temp after about 5 minutes, cooling it every part, not really viable.

We'll see what happens with the titanium tube.

Thanks
Aaron

Two hours with the heat at the gallop?

Do your own due diligence. I'd surely run some tests with no product at risk, first.
 
I would look into fused silca. In another life I was involved in glass tempering furnace R & D. We used fused silca rolls to support and move the glass horizontally through the furnace. Very stable material, but there are many different "grades". George Ford and son was the best supplier, I don't know if they are still around but if so they were a great group to deal with. Explain your needs and would give 110% to get you what you need.
 








 
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