19 replies to this topic

[cooperman435]

I'm aware that nichrome wire requires a special flux to allow you to solder it but cannot find any leads to specifically what to buy or where to get it.

If anyone has successfully managed to solder nichrome to copper then please would you divulge your methods. If anyone has any of the fabled stuff I would dearly love to buy some from you if at all possible?

Ive seared the forum but only found mentions of the fact you need the special flux but not what it is!



and as a side not is anyone else having issues with the new search facility as when I go to the "more search options" part and search only the titles it still comes up with all the titles that have the search words in their posts, not just the ones with it in their titles?

Thanks all


Phill

[marble]

I think you need acid cored solder, you can get it at the hardware store under the plumbing section. If they dont have the solder they should have the acid flux. Your local electronics shop wont stock it.

Hope this helps


Cheers

Edited by marble, 04 June 2007 - 06:37 AM.

[pyrotrev]

Phill - Try Farnell (www.farnell.co.uk) order code 629-509

Edited by pyrotrev, 04 June 2007 - 01:02 PM.

[MFX]

If you're using acid cored flux, make sure any residue is completely washed off after you've soldered the joint, otherwise when you come to fire your igniter you may well find the thin wire has been eaten through I've wondered in the past whether the following might be possible :-

Wrap wire round PCB as usual
Protect the bit of nichrome that's going to do the igniting with a thin layer of varnish (preferably something that won't impede the ignition, or strip the varnish later with a solvent).
Dip the whole lot in a copper plating bath for a few seconds to plate the exposed nichrome.
Solder normally.

Might not be worth the effort though.

[pyromaniac303]

Though not exactly nichrome, but along the same lines, my ignitors are 40swg enamel coated wire around twisted pair network cable. I have found that the thin coating easily burns off above 300 degrees, for those with a temperature controlled soldering iron.

I found this out after spending hours scraping little bits of wire with a razor blade to remove the coating!

[MFX]

That's known as self fluxing enameled wire, however not all enamled wire is self fluxing so that wont necisarily always work. Note also that it gives off a small amount off toxic fumes so do it in a well ventilated area.

[parabolic]

Phill, Read this on my site for an alternative..

http://sh33p.parabol...eheaterse-match

Lee

Edited by parabolic, 04 June 2007 - 08:11 PM.

[johndee]

That's a nice and easy solution, and so simple.

[MFX]

I find the statement "Quite frankly this is very time consuming and boring." on the site a bit strange! If you wrap a spiral of nichrome around a slice of double sided PCB then solder the lot in one go followed by slicing the PCB down the middle and then cutting into individual igniters you could make hundreds in the time he's made 10 with the other method!

[parabolic]

MFX,
I dont agree that you can make your ematches much quicker than mine.
Have you actually tried any of mine to compare?.

I have no problem with both methods, but just to explain the reason why I said that the soldering method is 'time consuming and boring', I have taken the time to plot the operations required for each.
I hope you dont find this 'strange'.

Your Sequence of operation;

1. heat up soldering iron
2. cut 100 lengths of wire.
3. strip both ends(one end for batt source other for solder on pcb)
4. tin wire ends to be soldered to pcb board
5. wrap a spiral of nichrome around a slice of double sided PCB
6. solder wire ends to pcb both sides
7. slice the PCB down the middle
8. cut into individual igniters

Here's my operation;

1.cut wire to length
2.strip one end for batt
3.cut nichrome wire 1/2 inch long
3.push nicrome wire into conductors.

you could make hundreds in the time he's made 10 with the other method!

If you are so sure you can make 100 in the time I can make 10 then I ask of you to make a video on your high speed manufacture of 100 ematches to prove this.
I have no problem with your method its very nearly how its done comercial, and I have seen this done on many a website, which is where you learned it from.
I just dont like it when people just say someting in a knee jerk reaction in a thread without thinking about it, or not trying something out before they write an opinion.

Just from the operations alone we can see its going to take longer.
If we 'do' eventually get to see your video, I will return a video to compare times.

Regards

Lee

Edited by parabolic, 05 June 2007 - 12:25 PM.

[Asteroid]

While I haven't tried using speaker wire in an e-match, I certainly think it'd be worth a try. It's effectively hundereds of high gauge strands of copper wire plaited and put in a plastic sleeve. One strand will get very hot with an AA battery, and burn out with a PP3. 3 or so strands should easily ignite an e-match, and could also be soldered.

[MFX]

OK First an apology, I didn't mean the post to have that tone, but I'd had two VERY long days, lost an envelope containing £80 (Now found luckily) and had a few beers, not a good combination for reading a forum. And yes those numbers were plucked out of the air with no scientific basis However There are still a few points to make that I think are valid.

"2. Cutting 100 lengths of wire"

Surely this needs to be in your list as well, again a quick way is decide on the length of lead you want then cut two thin boards the width of which is half the wire length you want. Bolt them together with a couple of washers in between to create a small gap (Making this doesn't count in the timings as it's a tool you'll always have for the future). Wrap wire round boards, use sharp knife or razor saw blade in Dremel along the gap between the boards. As PCB based igniters can use fairly thin solid core wire rather than multistrand it's easier to cut (and cheaper) than needing multistrand) You also need to cut and insert 100 fiddly lengths of thin nichrome Which I would guess would take longer than cutting up the PCB with nichrome wrapped round it so a time saving there.

Now you need to strip one end, I have to strip two (And you could always leave stripping one end until you actually use the igniter), but as my wire lengths are already folded in half I have both ends in one hand already so stripping two ends is really not going to take that much longer than stripping one end (assuming the use of a automatic stripper) (rough quess of half a second per wire longer tops, probably less).

Tinning the ends, not strictly neccisary unless you're going to leave the wire exposed to the air for a long time before using. They'll get tinned when you solder them to the PCB. If you're doing a lot though you can knock up a simple tinning pot with a high powered iron, a small piece of stainless tube and simply dip the wires in.

On a more technical point, Nichrome wire is covered with a thin layer of Chromic oxide, which is why it needs an acidic flux to solder it (Stainless steel soldering flux is good for this). Just pushing the wire in against copper strands (which may also have some surface corrosion) is going to result in a higher resistance than a soldered joint. The only other method I've seen recomended for attaching to Nichrome is crimping which because of the high pressures breaks through the oxide and in effect creates a cold weld. Net result is PCB igniters will have a far more consistant resistance which is important if you're going to do any series wiring.

On balance your method is OK if you just need a few for occasionally setting things off which I guess is what most people here will be doing. Otherwise for larger quantities I would say the PCB method is quicker overall. Unfortunatly I don't have time to make them (or a video) so I guess it'll have to go unproven, also I'd have no need for the finished item as we use commercial igniters. Although I have made PCB based igniters in the past and still have the reel of Nichrome somewhere.

Edited by MFX, 05 June 2007 - 07:00 PM.

[Arthur Brown]

070341 from farnell is bakers fluid the liquid flux that seems to cure most soldering problems

[aquarius]

Talking about NiChrome wire, is there a online shop useful for buying the stuff? I have som 0,2 mm wire but it is way too thick for a goog and fast e-match.

[Arthur Brown]

http://www.wires.co.uk/

Has anyone used these
Electric Match Heads:

100 pieces $10.00
500 pieces $37.50
1000 pieces $60.00

http://www.oda-ent.c...Price List.html
At £30 a thousand

Edited by Arthur Brown, 10 December 2007 - 03:51 PM.