Soldering to Bi-Pin lamp

I'm trying to solder my new Carley Bi-Pin lamp onto a PCB - but just can't get the solder to take to the pins.

Don't know what the solder mix is specifically....Other than it's the regular stuff you'd use for PCB work.

I've tried scuffing the pin surface with a scalpel and applying flux, but it wont take.
The solder blob is sitting nicely on the PCB board in a nice little Doughnut around the pin

What am I doing wrong
What are the Bi-Pin legs made of
Would a different solder mix do the job or am I

Thanks,

Tim.

(If this is in the wrong section please feel free to move it!)

Are you gettint the pin hot enough?Will the operating temp remelt the solder ?

C

You might have to use flux on the pin. Most pins are iron, or nickle-plated iron, which would require use of flux.

If the pin is aluminum you will probably need a different solder. Test with a magnet.

And like Cristoph said... make sure the pin is hot enough itself to melt solder.

I'm using flux...Always do - despite the solder having a flux-core already.

I'm pretty sure I'm getting the pin hot enough.

It should be the same technique as soldering a resistor to a PCB which I have no problems with.

Now I've got so frustrated - I've put so much heat onto the PCB that the copper dot has come off the PCB

I guess my little project was never meant to be.


Tim.

When I am having trouble soldering where the solder sticks to one piece but not the other, I do pre-tinning. This involves putting the solder on the two pieces seperately at first. If you are lucky, you can get a very thin coat of solder on the parts. If you are not lucky and get too much, desolder the leads with solder wick or a desoldering bulb. This will still leave a very thin coat of solder on the leads. Once you have even the thinnest coat of solder on both parts, you are virtually guaranteed to be able to get the solder to stick to both parts when you try to solder them together again normally.

OK......Thought I'd give pre-tinning a go with a cool head today.

Had a really good scrape at the pins with a fresh scalpel.
Coated pins in flux
applied iron to pins....Nothing
Applied solder to pin and it melts it - and flows straight past the pin and collects on the iron tip

Something I noticed when scraping at the pins....A fresh scalpel blade struggles to impact on this material.
It definately worked as the pin leg got shinier....but it took a lot of scraping.

I guess the pins must be a very hard metal....Maybee its the same material as the filament......Tungsten - perhaps ?

Anyone have any further suggestions


Tim

On very smooth and/or hard to solder surfaces, what I do is 'scratch-up' the surface in order to give the solder something that it can try to 'grab' into.

If everything else fails, I guess your only resort is to use a bulb holder.

If the pin is non-magnetic it probably isn't solderable with common electronics solders. Non-magnetic could indicate the pin is aluminum or stainless steel, but since you mention it's hard on your blades it may well be stainless steel. Is the bulb low-wattage enough that you could use an LED socket or two pins of an IC socket?

scott.cr said:

If the pin is non-magnetic it probably isn't solderable with common electronics solders. Non-magnetic could indicate the pin is aluminum or stainless steel, but since you mention it's hard on your blades it may well be stainless steel. Is the bulb low-wattage enough that you could use an LED socket or two pins of an IC socket?

Click to expand...

My Neodymium magnets don't attract the pins - So I guess stainless steel is right.

The lamp is a Carley 1499 (2 Amp) so an LED socket aint gonna be upto the job

Guess I'll just have to find another host for these great little lamps.


Tim.

Many leads used in bipin halogens are a moly wire. You won't be soldering moly, they require welds.

If this is the case resistance weld each led to a small tab and solder them.

Have you thought of using screw down terminal blocks similar to this one:
http://www.radioshack.com/product/index.jsp?productId=2102861&cp
The spacing is pretty good for matching up with bipin bulbs. I've used them for temporary bulb holders.

I also tried to solder to pins with ZERO luck. If I where you I would either get a halogen socket or just solder pins to the board then push the lamp into the pins. This is how Tiger Light does it.


Mac

Thanks for the suggestions guys,

Unfortunately I don't think any of the suggested alternatives will do.

My idea was to transplant an H1499 lamp into my blown G&P G120 Lamp assembly.....It seems like such a waste to have to throw the assembly just because the lamp has blown.
I just thought the H1499 would be a blinder (pun intended) in one of these assemblies driven by 2 x 17500's

Bummed that I can't make it happen. :thumbsdow


Tim.

Im not familiar with that particular lamp but it seems to me that when you turn the light on for any significant amount of time (like more than 5 minutes) that the bi-pins of the lamp would heat up and melt your solder connection.

jashhash said:

Im not familiar with that particular lamp but it seems to me that when you turn the light on for any significant amount of time (like more than 5 minutes) that the bi-pins of the lamp would heat up and melt your solder connection.

Click to expand...

If that were the case then these lamp assemblies that have soft soldered pins as standard would be melting all the time.......and I've never heard of anyone reporting this.


Tim.

It's good to hear that nobody here has had problems with solder connections melting. Still... I wonder if some of those 100 watt bulbs would be capable of melting a solder connection.

Carley sells sockets with wire leads and another type to convert a bi-pin bulb to a PR base. Has anyone noticed that in the Carley webpage,
they mention that Halogen bulbs have soderable nickel leads but the Xenon/Argon lamps don't mention solderability. I seem to remember that you can order any of their bulbs with nickel plated leads for soldering.