UPDATED: Solder won't stick

I was recently doing some tail spring resistance fixes on some of my Mags (or attempted it) but i came to find out the solder never would stick to the tailspring.

Never had this problem before with anything else, i even removed a small section of the coating, didnt help. Im using standard 60/40 rosin core, is there a special type of solder needed to stick to it?

Re: Solder won't stick

A spotwelder is what you'll need, there has been many reports on battery springs rejecting solder...and its not the coating, its the metal

Re: Solder won't stick

mrartillery said:

I was recently doing some tail spring resistance fixes on some of my Mags (or attempted it) but i came to find out the solder never would stick to the tailspring.

Never had this problem before with anything else, i even removed a small section of the coating, didnt help. Im using standard 60/40 rosin core, is there a special type of solder needed to stick to it?

Click to expand...

A tip for nasty stuff that also doesnt like flux is using hyperchloric acid to tread the surface before soldering.

Re: Solder won't stick

I used 60/40 but I had to buy a new better iron to get it hot enough and big enough to work. I had a pretty small precsion iron previously with a smaller tip.

Also I completely wrap the Spring wire with the contact wire and pull it tight before I even begin the soldering, so there is already a pretty good contact, and the solder just enforces the connection, not only electrically but by making sure the crimped wire cannot unwind.

Re: Solder won't stick

grind into the area you want to solder with a dremmel or file or something similar.

Re: Solder won't stick

Tip from my days of soldering R/C packs: Rough up smooth metal surfaces with a dremel and use flux anywhere you want the solder to go. Tin both surfaces to be soldered separately first. Best to use the acid free flux, if you are using non-lead solder you need higher temps so stick with the lead stuff unless you plan to work with it all day long (lead is bad for your health).

Re: Solder won't stick

You need to get both components that you are soldering to the melting temp for the solder.

It is hard to do that for a mag spring using a standard soldering iron, the spring acts as a great big heatsink.

Re: Solder won't stick

+1 for roughing up the spring, and using flux. Another thing I do frequently when soldering larger metal objects is hit it with a propane torch, this will get it hot enough fast enough. You dont need to get it red hot or any thing, but unless you have a very hot iron, I would say that the temp of the spring is your biggest problem.

Re: Solder won't stick

I don't know what the spring is made of, but I would treat it as stainless, and look for some stainless steel solder at a hardware store -- probably something with some silver in it (silver makes solder 'wetter'). Also clean it with phosphoric acid first, such as is found in milk stone cleaner like dairy farmers use, or navel jelly. Regular silver solder would likely work but it takes more heat than from a soldering iron - a small torch would be needed, but if it gets too hot it will ruin the temper of the spring. Hardened steel is also more difficult to solder (and springs are harder than mild steel).

Re: Solder won't stick

Alright, well i have a small butane torch, ill try and see if i can get it hot enough with that, and BTW i did dremel the area before i started, but didnt help any, i guess because it wasnt getting hot enough.

Re: Solder won't stick

IMSabbel said:

A tip for nasty stuff that also doesnt like flux is using hyperchloric acid to tread the surface before soldering.

Click to expand...

thats certainly a radical approach, whats the word on purity?

mrartillery said:

Alright, well i have a small butane torch, ill try and see if i can get it hot enough with that, and BTW i did dremel the area before i started, but didnt help any, i guess because it wasnt getting hot enough.

Click to expand...

Which tool did you use?
I am going to try the same to see if I can solder to springs in that fashion, I have never been successful with them :candle:
if butane isn't hot enough, theres propoane, then mapp, then acetylene...if not then, I do have nearly a quarter of a pound of magnesium scrapes...

Re: Solder won't stick

Acid flux and 60/40 solder should work fine, I imagine you're simply not heating the large spring up nearly enough.

Re: Solder won't stick

Keep in mind that the end goal is not to make great electrical contact with the spring, but with the aluminum tube body (unless you are doing something unusual). It is not really necesary to have a NASA quality solder to spring, as long as the copper wire is making good contact to the tube body.

As mentioned in my previous post, if your having a problem just crimp the wire around the spring and position it where it will make contact on a de-anodised spot on the tailcap. A hot iron like the one I got did make a good solder to the spring after the first failed to do so, but the bottom line is that the spring being energized is less important than the wire making contact with the tube body directly ( and on the battery contact plate on the other side). Make sure the shape is right to not take away from the spring, and to make maximum contact with the copper lead. This is easier with copper mesh (which I used and made flat on the ends for contact) as opposed to a single wire of course. As long as it handles the current.

Re: Solder won't stick

You could just get one of those crimp-on terminals, like the round or spade tip ones, from the hardware store -- for the right gauge to handle the thckness of the spring wire and copper wire. Work it up onto the spring, stick the wire in, and crimp it. You could even cut off the part ordinarly used to attach to the bolt or spade tip or whatever kind of contact it was supposed to be for -- just use it to splice the wires together. Properly done you get a very good electrical contact with those, and if it's insulated just cut off the insulation and it will contact the exposed aluminum on the flashlight. Should take all of 90 seconds and can be done with a common crimping pliers.

Re: Solder won't stick

Updated: I had a idea of something that might work and it did!

I place my Mag spring in a vise at about a 45 degree angle, and placed my soldering iron through the hole letting it rest on the spring itself, I let it set there for about 5 minutes to let it warm up. After taking the iron out the solder stuck very well :thumbsup:

I just repeated the process for the the larger end, also I hit the spots to be soldered with a dremel prior to soldering!

Thought this might be a helpful hint to someone else who had the same problem i did, and BTW my iron is a 30w/120v just for future reference incase someone was wanting to know.

30w is definitely low power for a job like that. You can never have enough power when it comes to soldering.

Glad you got it done bro.

It's a bummer when one pesky thing stops progress.

For me it's that I still need those power packs that we were discussing a few weeks back.

But I'm being patient as LL's if and when are worth the wait.

p.s. I even considered doing this myself, a small run, and was shocked that the capacitive discharge spot welder I thought would be perfect the purpose was 4 K ish without the head or leads!! I thought something that small would be in the several hundred dollar range.

Databyter,

This is completely off que, but did you get your reflectors from Kaidomain yet?

I just placed a order for 2 more SMO and after transaction, the invoice read BACKORDERED

No, look at my additions to Led Zeppelins post about KD under Cheers and Jeers.

Not only did I not get them, but I recieved no confirmation email upon purchase, and when I went to the site to make sure everything was aok and look at my order I could not log into my account.
I had to make another account (where I still cannot see my order) just to see the contact info/form.

I have sent them 3 contacts via the new account with no response, so I have NO idea what is going on with my 30 dollar purchase. At least now based on your post I have some idea, I am hoping that somehow they will eventually ship it even though I can't see my order and they pretend I don't exist.

If I at least was able to get the notice you recieved I would be a little bit (very little) less peeved. My main issue with them is a broken site, 0 customer service, and no confirmation of business/funds recieved, order shipped/delayed, via my email.

I'm sorta frustrated because I have laid out some pretty substantial investment ( for me) for several builds and I don't have enough parts to complete any of them after a month, and no light at the end of the tunnel in sight unless I go into the manufacturing business.

Ouch! that sucks, i know how you feel though because ive been there! But yeah, the invoice after payment said backordered, so i dont know what the issue may be, either way it should have been listed on their site as backordered in which case i wouldnt have made the purchase.

But either way if you payed with paypal at least you have payment protection if thats any consolation.