Sizes of blunt syringe needles for tacky flux (and other consumables)

[FrankE]

I've got some new Amtech 559 V2  flux for surface mount and through hole repairs I have to do. The Amtech 30mL dispenser has a Luer lock so that blunt needle tips of known dimension can be screwed on the dispensing end., and a controlled amount of flux applied.
What ranges (mm or gauge) of blunt syringe needles are suitable for manual dispensing of tacky flux for surface mount and through hole? I'll need to order online and I'm terrible at gauging sizes like that.

I'm used to using syringes for heat txfer compound, adhesives, lubricants but this stuff is pricey and I don't want to spaff it all over a few boards.

What you you folks use to control dispensed amount?

While on consumables, I realised it's time to sort out my consumables when I knocked coffee over my keyboard last night, went for some IPA and sprayed the membrane with surgical spirit (in the UK=methanol + ethanol + some excipients like wintergreen + castor oil).

I'm trying to find bottles that take
Luer lock caps,
screw caps,
atomiser caps.
 
All the same size cap so I can swap out caps. A little faff in selection now saves repeated faff later

I had the bottles from RS with the wash caps (bendy straws). Fat lot of good they were, the caps weren't sealed withe the bottle so when the bottle was knocked over IPA leaked.

[dadler]

Not exactly answering your question, but I got an assortment of these tips for cheap on eBay:

http://www.ebay.com/itm/111856866201

The larger of the sizes in the assortment are best for tacky flux and solder paste, in my experience.

[KL27x]

For paste/flux, I use plastic dispensing needles. I have the 20 gauge needles. You can cut the tip to increase the size or change the angle.

For vacuum pickup, finer 25-26 gauge bent steel needles will be the most useful, in my experience. For picking up SMD passives.

[dadler]

I also got some Amtech flux recently--from Louis Rossman. It came in a 30cc syringe without a plunger (looks like it is intended to be used with an industrial dispensing device or otherwise). Still haven't decided how to dispense it yet.

They sell hand dispensers for this type of syringe (Metcal makes one, check Amazon). But they are $60-70 which seems a bit much.

[dadler]

I just measured the tips that I (primarily) use for tacky flux/solder paste. They are 1.27mm OD and 1mm ID.

[FrankE]

Thanks everyone. I ordered a selection pack of blunts
I think I'll fill smaller luer lock syringes say 2mL, 5mL at most and use that, keeping the 30mL in the refrigerator to fill from.

Those production  dispensers as well as being pricey look like the don't offer much in they way of dispensed volume control

[Cerebus]

I just measured the tips that I (primarily) use for tacky flux/solder paste. They are 1.27mm OD and 1mm ID.

I'd imagine that you probably have access to tools that let you accurately measure the OD but had to guesstimate the ID.

For the benefit of those who go by gauge numbers that looks like an 18 gauge needle which has an OD of 1.270 mm and an ID of 0.838 mm.

[zapta]

For paste/flux, I use plastic dispensing needles.

+1 fit the plastic needles, they have conic internal passage for easier flow of thick paste.

[Dago]

I also got some Amtech flux recently--from Louis Rossman. It came in a 30cc syringe without a plunger (looks like it is intended to be used with an industrial dispensing device or otherwise). Still haven't decided how to dispense it yet.

They sell hand dispensers for this type of syringe (Metcal makes one, check Amazon). But they are $60-70 which seems a bit much.

I've always just put a plunger from a regular syringe and just used it like that. Works fine unless you are doing some actual production work or something.

[dadler]

I just measured the tips that I (primarily) use for tacky flux/solder paste. They are 1.27mm OD and 1mm ID.

I'd imagine that you probably have access to tools that let you accurately measure the OD but had to guesstimate the ID.

For the benefit of those who go by gauge numbers that looks like an 18 gauge needle which has an OD of 1.270 mm and an ID of 0.838 mm.

I measured with my Mitutoyo calipers, but measuring ID this small involves some offset error due to the width of the caliper blades themselves/arc of tube. It was +/-0.9xx mm and I could get different readings by angling the calipers differently. The tips are also cheap from China...

[dadler]

So just an aside on the tacky flux:

I have been using Kester RF741 tacky flux (http://www.kester.com/products/product/RF741-Rework-Flux/ ) for the past few SMD projects, and had just sort of gotten used to it.

Today, I decided that I'd try the Amtech NC-559-V2-TF Flux that I received a while back (purchased from Louis Rossman @ https://mailin.repair/amtech-nc-559-v2-30-cc-16160.html )

As I mentioned above, the 30cc syringe does not come with a plunger (nor any tips, for that matter).

I used what appears to be an 18 gauge tip (per one of the posts above), and I can say this stuff is incredibly thick and difficult to dispense without a plunger!

I just pressed the back of the syringe with my thumb/fingers, which leaves a mark--because you have to press *hard* as this stuff is thick. Prior to heating, it's not a thin gel like the Kester flux--it seems more like a wax/oil emulsion of some sort. I am going to have to find a more appropriate dispensing mechanism... a plunger that fits the hole on the back of this syringe, or perhaps one of those pricy gun dispensers.

Anyways, this flux is absolutely amazing. There is no comparison to the Kester flux.

It's much thicker even at high heat, it's entirely clear which aids visibility, and it yields beautiful joints/pads.

Hot air still does blow it around, but much less than the Kester flux. It doesn't smell/burn as awful as the Kester flux, either.

The primary win is its viscosity though... This stuff stays where you put it. 

[nanofrog]

They sell hand dispensers for this type of syringe (Metcal makes one, check Amazon). But they are $60-70 which seems a bit much.

A cockroach bait gun will do exactly what you want for $26.00 shipped (Masterline Bait Gun).  ; BTW, cockroach baits use 30ml syringes.   

There are also inexpensive dental impression mixing guns if you want one for 2 part epoxy (available in 1:1/ 2:1, and 4:1/10:1).

[dadler]

They sell hand dispensers for this type of syringe (Metcal makes one, check Amazon). But they are $60-70 which seems a bit much.

A cockroach bait gun will do exactly what you want for $26.00 shipped (Masterline Bait Gun).  ; BTW, cockroach baits use 30ml syringes.   

There are also inexpensive dental impression mixing guns if you want one for 2 part epoxy (available in 1:1/ 2:1, and 4:1/10:1).

Ah, this is excellent. I had previously searched a lot, and even found a couple that look like those (@ China sellers of questionable repute), but didn't think to search for cockroach bait gun  hehe!

Thanks!

[FrankE]

What size syringes do people use 2mL? 3mL? 5mL? 10mL?

[KL27x]

I bought 3mL syringes, because I initially wanted to use them for solder paste, and 3mL is the smallest diameter syringe that I could personally find with a luer locking tip.

A flux pen is 10mL, FYI.

A 3mL syringe of flux lasts a pretty long time, although when I am doing certain pcb assembly, I can go through 2-3 in a day. I will fill 5-6 syringes at a time, in that case. But under more ordinary use, 3mL of flux could last months.

I'd suggest 5mL or 10mL might be ideal for a flux dispenser.

[FrankE]

I've ordered these syringes
http://www.ebay.co.uk/itm/280769928169
http://www.ebay.co.uk/itm/281338157051
and these tips
[EDIT: WHICH AREN'T STANDARD SIZES]
http://www.amazon.co.uk/Plastic-Dispensing-Needle-Blunt-Assortment/dp/B01AXWFHE8/ref=zg_bs_1938358031_14

I'll see how I get on with the different sizes before considering longer or angled tips (account a little for the length / bend)
I can always use spare syringes in the greenhouse for dosing tomato feed.

[nanofrog]

What size syringes do people use 2mL? 3mL? 5mL? 10mL?

FWIW, most of the commercial products I've gotten tend to use 10ml or 30ml (fits dispensing equipment).

That said, CML Supply here in the US breaks down larger containers of Kester RF741 flux and Easy Paste 256 (6ml & 12ml respectively). Perhaps there's such a company in the UK/EU market? 

I'll see how I get on with the different sizes before considering longer or angled tips (account a little for the length / bend)

Very wise IMHO.

[FrankE]

What size syringes do people use 2mL? 3mL? 5mL? 10mL?

FWIW, most of the commercial products I've gotten tend to use 10ml or 30ml (fits dispensing equipment).

That said, CML Supply here in the US breaks down larger containers of Kester RF741 flux and Easy Paste 256 (6ml & 12ml respectively). Perhaps there's such a company in the UK/EU market? 

I'll see how I get on with the different sizes before considering longer or angled tips (account a little for the length / bend)

Very wise IMHO.

I meant to use on the bench (easy to handle size and to get under the 'scope
) rather than to the size of the syringe the flux/paste is supplied in. I buy the size that gives best value accounting for one's usage and for the shelf life plus estimate of the safety margin. I got 30mL


I've spent a small fortune on the 'little' bits and pieces this week syringes, tips, scalpel blades, bottles, brushes, wipes, tapes and I've still got leaky bottles to replace. It all adds up and I've barely put iron to copper.
Oh, I did treat myself to some new stainless steel and some glass.

[nanofrog]

I meant to use on the bench (easy to handle size and to get under the 'scope
) rather than to the size of the syringe the flux/paste is supplied in.

Makes sense.  FWIW, I haven't sprung for a microscope yet as I try not to go below 0402 passives (prefer larger), but haven't had issues with paste flux or solder paste (I lay it in a line, not dots per pad).

I've spent a small fortune on the 'little' bits and pieces this week syringes, tips, scalpel blades, bottles, brushes, wipes, tapes and I've still got leaky bottles to replace. It all adds up and I've barely put iron to copper.
Oh, I did treat myself to some new stainless steel and some glass.

I hear you. Good consumables add up quick.   

[FrankE]

I gave up trying to standardise bottle sizes in 50mL, 100mL and 200mL with interchangeable caps as I couldn't find anywhere with the full range of screw cap, Luer lok cap, wash spout cap and push spray cap. Well, not strictly true, I found companies that stocked everything but either horrendously expensive, without e-commerce or large minimum quantities of each item. I recall this over 10 years ago the last time I tried to sort my consumables out.

The 60mL  flux bottle from RS £2.46 ended up as good value as anything I found.
It has a Luer taper cap rather than a Luer Lok. You push on the tip rather than screw on. Harder to find push on tips that Luer Lok ones, i'll tell ya.

The syringes arrived today from Acuflow (ebay) BD 3mL and 5mL with luer Lok screw fitting. Same length, different bore. I'll order 10mL ones as well and since I'll wait an age for the blunt tips from China, maybe .

[FrankE]

I received the Luer Lok blunt needle tips today. They don't appear to be the standard colours and sizes defined on dispensing sites. The colours I have and their OD in mm (which is all I'm tooled up to measure) are:
Colour................OD mm
Orange Dk.........1.74
Olive.................1.74
Slate.................1.55
Green Bright......1.21
Brown...............0.96
Pink..................0.84
Purple...............0.74
Blue..................0.64
Orange Lt..........0.57
Red      0.45
White      0.44
The product description states

11 different diameters:1.55 / 1.37 / 1.16 / 0.84 / 0.7 / 0.60 / 0.51 / 0.41 / 0.34 / 0.26 / 0.21 mm.

It's not important, it's for rough manual dispensing of "what looks about right" which is quite a broad goldilocks band. I'm not running continuous process plant calibrated to dispense a known bolus volume or mass through a defined tube diameters in a specified shot time.

I'm currently using the pink (OD 0.84mm) for 0403 SMD rework electronics and bright green (OD 1.21mm) for through hole flux dispensing. I haven't set up a syringe for heatsink compound yet but
I'll experiment and find a size

Industry standard correct colours, gauges and dimensions:

Colour.....Gauge....ID in.....   ID mm...OD in.....OD mm
Olive........14.......0.069.....   1.753.....0.083.....2.108
Orange.....15.......0.059.....   1.449.....0.072.....1.829
Purple......16.......0.053.....   1.346.....0.065.....1.651
White.......17.......0.048.....   1.219.....0.058.....1.473
Pink.........18.......0.038.....   0.965.....0.049.....1.245
Brown......19.......0.033.....   0.835.....0.043.....1.092
Yellow......20.......0.025.....   0.635.....0.036.....0.914
Green......21.......0.022.....   0.559.....0.033.....0.838
Black.......22.......0.020.....   0.508.....0.028.....0.711
Sky Blue..23.......0.016.....   0.406.....0.025.....0.635 About right amazon one 0.64
Red.........24.....   0.015.....   0.381.....0.022.....0.559
Blue........25.....   0.012.....   0.305.....0.020.....0.508
Cream.....26.....   0.011.....   0.279.....0.019.....0.483
Grey........27.....   0.009.....   0.229.....0.016.....0.406
Lavender..30.....   0.006.....   0.152.....0.012.....0.305