Where and what types of Flux do you get?

[Nitrus]

Hi guys,
I ran a search before posting this as I thought it'd be a quite discussed topic, and I got some hits but not that specific.

With SMD/SMT soldering Flux tends to go by pretty fast, and when you only do it for personal projects it gets quite expensive. Some times you use it up, some times it just expires and stops working well, like with solder paste.

So, where do you guys get your flux? Do any of you use pens, and if yes where do you get them from? I find them useful in the short term, but they seem to dry up or the bristles get all tacky after a while.
Do any of you make it yourself perhaps? I've seen many people make it from tree sap/gum

How do you best tackle this necessary expense?

[RayRay]

This is what I use:
http://www.banggood.com/NC-559-ASM-TPF-Flux-Anti-Wet-No-Clean-100g-Cream-AMTECH-Solder-Paste-p-975156.html?rmmds=search
You could also get it from ebay/aliexpress. I just apply it with a tooth pick when needed (although, some people prefer to use a flux bottle with a needle, or a syringe instead) overall, it has a great quality/price ratio (not to mention quantity!), it works exceptionally well, doesn't make any nasty smell and is easy to clean also (I use 95% alcohol with q-tips for that purpose) 

[matkar]

But are these Amtech branded fluxes from China original? Amtech is USA based company so it is a bit strange most of the sellers on ebay, aliexpress, etc. are from China. And those who are not are selling for much higher price. I recently bought RMA-223 from ebay. It is greasy, not water soluble and floats on water. Is there a way to distinguish the original from the fake?

[Nitrus]

I've always seen professional technicians recommend the no-clean Amtech solder (well, and the tacky one as well, depending on the job), and was never really secure in the knowledge that what I've bought from any of the numerous Chinese sites was original.
When it worked well I wondered if it could work better, when it worked bad I was sure that I got scammed...

However, I'm pretty much stuck with Chinese sellers or ebay because ordering from USA (or even the European Amazons) means that the shipping cost will far surpass the flux cost

@RayRay does yours have an expiry date?

[RayRay]

But are these Amtech branded fluxes from China original? Amtech is USA based company so it is a bit strange most of the sellers on ebay, aliexpress, etc. are from China.

It says that it's made in the USA, although, I highly doubt that's actually the case (due to some obvious spelling errors!)
But regardless, it works great, so I don't care about that part.

@RayRay does yours have an expiry date?

Nope.

[BBBbbb]

First of all, of course it is not Amtech. Any trusted brand of no clean flux paste would cost a lot more. Amtech fakes are so common that it is really hard to find originals on sites like eBay and even Amazon.

But that does not mean it is unusable, I just would not rely on a no clean part of it. Another concern might be the purity, but you should be able to see any significant particles after using it.
Classic flux (rosin+alcohol) is not that expensive nor hard to make, so this Amtech copy should be something like that.

P.S. If you're looking for a budget version just get a one you do need to clean (cheaper) at your local store (hopefully trusted one), or buy rosin and make it yourself.

[KL27x]

I buy MG 835 RA flux by the liter. Costs like 25.00. I pour some into a small jar from which I can refill my dispensing syringes. Then top off the jar from the liter bottle.

I usually leave the residue on the board, but I have never had to worry about life critical reliability.

Sold at mouser/newark/digi/ebay/amazon. Wherever.

It doesnt need refrigeration. It doesnt need shaking. It doesn't go bad. Just keep the cap on.

I use plastic needle with a string threaded thru so it works kinda like a pen. This prevents accidental squirts but still allows the flux to be applied fast and easy.

[Back2Volts]

I use a flux pen.  Days back I noticed the fiber tip was clogged.   It occurred to me to place a few drops of alcohol on the tip and let it rest.   The next day it was back to normal.