Syringes

Aug 14, 2018 16 Replies

This may be the most stupid question here this year.



I bought a reel of solder from our Asian friends, and discovered it had no flux cores.



So, found a set of 12 pieces of gel solder flux at a bargain price on ebay, which arrived about a month ago. Last week I got one out and looked at it. It is a gel in a 10cc syringe, with a red removable cap at the top and a black cap at the pointy end, just like the one shown in



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I'm used to using syringes to mix epoxy, but they all come with plungers. My flux has no plunger, so there is nowhere to put my thumb.



What is the normal procedure here? Do I whittle a stick down to make it poke tightly down the syringes or do I have to try to source a similar syringe and steal its plunger?



I see there are a number of similar things sold this way, so assume there must be some standard technique.


Luer lock?

This one is solder past, rather than flux, but the plungerless syringe is designed for pneumatic operation ...

Discovered? Was it sold as multicore? Solder on a reel can be either.

Well, his attempt in the video didn't work. It looks as though there are manual syringe dispenser applicators, but they are either too expensive or I've not yet found the right search string for ebay.

I'd have thought that a straightforward thumb operated plunger would be much more controllable and handy than compressed air unless you had some means of instantly releasing the pressure when the flow needed to stop.

I'll have to stagger into the shed and see if I can find a 10cc syringe and liberate the plunger. I see there are 8cc plungers on ebay and at least one picture of an 8cc syringe shows a label on the body saying

10cc. I wonder if an 8cc syringe is a 10cc syringe with a bit of air space at the top?

In message , "Dave Plowman (News)" writes

We all make mistakes!

If I'm right its a kind of thing like a cheapy glue gun sort of affair. I know there is probably a name for it, but my brain refuses to retrieve it. brian

Yes you can usually tell by bending it, iffy its quite soft then its fluxed. I'm not convinced that trying to solder with paste and solder is any good for anything other than large jobs. Brian

We do. But you implied it was someone else's mistake. In a sort of racist way.

I remove the cap and use the handle of a small screwdriver as a plunger. I don't fit a needle, I tried one from an inkjet refill kit, but the flux is far too viscous.

I also have a couple of small bottles of liquid flux and some in a "felt tip pen" dispenser. Is flux as toxic as the labeling suggests?

I also have a small container of tin/lead solder paste that has no label on whatsoever, and no invoice etc enclosed It took so long to arrive I completely forgot that I had ordered it and had to match the seller up with my Ebay purchases to be sure what it was.

In message , "Dave Plowman (News)" writes

OK, maybe what I actually discovered was that the cores in multicore solder actually do make a big difference. I really can't see how a light hearted reference to an ebay purchase implies racism in any form.

In message , Graham. writes

Thanks, Graham, it's good to know that someone else has addressed the problem and solved it. I'll sort something out to poke down the hole!

Yes, the labelling about toxicity is scary, and I have no idea whether there might be any problems. I think, with the amount of soldering I do now, I'm probably fairly safe.

I suspect they are 'refills' for some soldering machine or dispenser.

You can get cheap syringes off ebay for dispensing flux, solder paste etc.

However, there are also flux dispensers which look like felt tip pens. I use then for some difficult to solder jobs. They aren't expensive, may be a pound or so.

As someone who never used separate flux when soldering was my day job, it wasn't even orderable from stores, I now have four different fluxes to chose from at the moment.

Ironically using another normal syringe as the source of compressed air would probably have worked better!

A quick bodgy solution is to stick a stick down the thing & push.

Flux toxicity depends on what it is. Rosin flux fumes can cause asthma, though seldom does. Acid fluxes... they're acid, but you shouldn't use those on electronics.

NT

bloody brexiteers it's all their fault.

We should be allowed to buy from anywhere but the EU.

No surprise there. If it really needs 50 psi there's no way he'd achieve that by stamping on a cheapo airbed bellows pump.

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