Flux paste from ebay

[sn4k3]

Terms like:
RMA: Rosin Mildly Activated Flux, RMA contains a small amount of additional activator to enhance cleaning and deoxidation leaving only a minimum ammount of inert residue behind. Shoud be cleaned
RA: Rosin Active, the RA flux will remove oxidation far more easily, good for old wires or old pcb full of oxidation, must be cleaned
NC: No clean, they can stay on board and not make any damage overtime (Still i recommend to clean that stuff) Good for BGA solder where you can't clean without proper machines
Paste: Soft solid, like the flux that come on the bottles.
Gel:Gel is mid term of liquid and solid, so it's a tacky liquid, most of the flux inside a tube to dispense are gel
Resin = Rosin: Rosin is the correct term in english, in portuguess is "Resina" https://pt.wikipedia.org/wiki/Resina and yes from the trees
Lead: The product contains lead
Lead-free = The product don't contain lead
Flux remover = Flux cleaner: A liquid product to clean and remove flux from board

Aslo read https://www.finishing.com/library/flux.html

Always read flux composition if they have one!

[exe]

Sorry if I'm repeating myself, but let me tell what I really believe is important: flux is far less important than many people think (except some special cases like production line, bga rework, etc). You may get the best flux in the world, but it will barely help, if at all. I used to chase "the best flux", I have more than 10 of them, but I just the cheapest one because it simply does the job and has proven performance. I have 559TF, but I don't use it because it needs thorough cleaning (or proper activation, which is impossible with hand soldering).

[psysc0rpi0n]

Thanks once more for the explanations.

I'm going to order one of each syringes. RMA-223 and NC-559. I'm just not sure if I should buy the MG Chem 835 or if it is not needed! I will probably also buy a tip for my Ersa i-con Pico if they have!

[nanofrog]

FWIW, I use liquid nearly all the time, while paste flux only on rare occasion as I try and avoid BGA as much as possible.

[KL27x]

I'm just not sure if I should buy the MG Chem 835

This is what I use. I do a lot of soldering, and anything that is $10.00 a syringe would be significant expense. I can use 6-9mL of RA on a given day. If the flux is a significant expense to you, you will choose your flux like any other high quantity component... the way exe does. You'll find the cheapest stuff that works for what you are doing.

A lot of people are into gel flux, lately. Amtech 599, along with many/most other gel fluxes, are/were originally designed for BGA. The gel prevents the solvent from drying out as fast, so the flux will remain active for a longer duration during preheat and ramp up with hot air. Probably one reason why someone like Louis Rossman uses it on everything is because he works on multilayer leadfree boards using tiny iron tips at very high temps. This kind of flux can take more heat without burning and building up residue on the iron tip. But he cleans the boards, after, in an ultrasonic cleaner. If you don't want to clean the board, you generally ought to prefer a flux that dries out faster.

For lower temp work, 2 layer boards, and lead solder, you actually won't realize as much of the benefits of a gel flux. But OTOH, if you are like most hobbyists, a syringe might last you over a year, so the cost isn't a factor.

I wouldn't buy the 835, yet. The two syringes you bought are flux, and flux is flux. But if you find a need for larger quantity, the 835 is $25.00 a liter.

[psysc0rpi0n]

Yeah, I'll pass the 835 for now!

I'll buy the 2 other syringes for now from TME. They don't have  in stock the tip I want for my soldering station.

Thanks for the help on the fluxes!