Reddit mentions of MG Chemicals Liquid Rosin Flux, for Leaded and Lead Free Solder, 125 ml Bottle

And as the author of that thread, I could advise you to buy this (in 125 mL):

MG Chemicals 835 Liquid RA Flux 125 mL

And this (or something like it):

Needle Flux Applicator

And a cleaner of your choice, I use:

MG Chemicals 4140 Flux Cleaner

Although I don't clean everything, normally just the solder side of pcbs.

Those needle tip flux applicators are much much better than the pens (in my opinion) and they are refillable so you will save a lot of money buying flux in (hobbyist sized) bulk.

Just keep using a rosin based solder (RMA, RA) with that flux and everything will go very smoothly. As a hobbyist I don't think there is much point in using no-clean because it only takes a couple minutes to clean a board anyways.

As for general information I found these two links helpful:

https://www.youtube.com/watch?v=V1aONINVkSE

http://store.curiousinventor.com/guides/how_to_solder/kind_of_solder

Two things- iron may have trouble heating that much mass, and/or use flux.

Something like 'MG Chemicals Liquid Rosin Flux, Non Corrosive and Non Conductive residue'

Is a game changer, and should be recommended more often in my opinion.

You're getting some great advice here, and I'm glad you're enjoying the process of learning to solder! I thought I'd copy a previous post of mine going over my favorite fluxes. Maybe it'll be useful to you as well!

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Certainly not the same. Over time you'll acquire a number of fluxes that you use for different things. You'll want different types depending on the kind of soldering you're doing, or if you're trying to ensure compatibility (i.e. with a flux-cored solder) between fluxes. I mostly use no-clean but rosin fluxes are great. You're supposed to clean them off but there are plenty of 30 year old boards with rosin flux residue on them that work fine. A note on flux pens, I personally hate them. I'm referring to the ones that are built like those paint markers with the tip you need to push in to get it to flow. Very overpriced for the amount of flux and they never work right. Bonkote brush pens are the best, but unfortunately expensive. They are however refillable and the brush tips are replaceable and relatively cheap. The cheap dispenser bottles work great as well but for very thin fluxes are easier to make a mess with.

Here are my go-to fluxes:

• MG Chemicals RA Flux - This is a classic. Cheap, very effective. Very sticky and easily clogs flux pens/dispenser bottles, but great stuff.
  
  
• MG Chemicals No-clean Paste Flux - Great stuff, I prefer it to the Chip Quick paste flux although that's also quite good and a little more tacky. This is a thicker flux than the liquid rosin stuff, good for removing bridges and such. I transfer any flux that comes in a syringe to a 3mL syringe. Smaller syringe means you use less force to get more pressure, easier to dispense from small needles. Stick 2 syringes together - nose to nose - with a half inch length of silicone tubing. Let's you get maximum flux volume without entrapped air that will cause oozing.
  
  
• Kester 186 RMA Flux - Slightly less active than the MG Chemicals RA but very good. Thinner and easier to dispense. Side note, this seller (Tekline) also has a great eBay store. Only way to get some of these fluxes without buying a gallon of flux or one of those shitty overpriced flux pens.
  
  
• Edsyn FL22 No-clean Paste Flux - By far the best paste flux I've ever used. Nothing comes close for removing difficult solder bridges. It's not cheap though so I reserve it for tough situations.
  
  
• Kester 959T No-clean - Great general purpose no-clean flux. Very thin, like water. It's a true no-clean flux if a board goes through a reflow cycle - it completely disappears if you don't overdo it. It's also excellent for dip-soldering if you use a solder-pot, which is what it is intended for (wave-soldering).
  
  I have a water soluble flux that I use as well Kester 2331-ZX but you must clean all traces of it off before you put boards into service, so it only comes out rarely.
  
  Flux - like solder - is one of those things that seems expensive when you buy the good stuff, but unless you're a CM buying drums of it the cost-per-use is so low that it makes no sense to fuss with the cheap shit IMHO.
  
  And speaking of flux, if you want clean shiny boards then consider getting some flux remover. The best I've used so far is Techspray E-line Universal Cleaner. Used to use MG Chemicals Heavy Duty Flux Remover but this beats the pants off it - does the job in 5 minutes where the MG would take half an hour. Rosin-fluxes clean easily unless you reflow them or let them get baked on. No-clean fluxes don't usually need to be cleaned - hence the name - but if you use rosin flux to rework a board (i.e. solder through-hole parts onto a board that was reflowed with no-clean) and then use bad flux remover, the no-clean will turn into a white powdery film that's very unattractive and hard to clean. Thus a good flux remover is handy.
  
  If you're careful with it you can really stretch it out. I recommend against the aerosol cans of flux remover. While they can work well they're expensive and very wasteful, and by the time you clean off a particularly challenging flux you'll have emptied the $20 can.
  
  EDIT: One little trick that most EEs I've met aren't aware of - pick up a little bit of straight phosphoric acid. It works like magic if you ever need to solder to bare aluminum, steel, or stainless steel. You could probably use an acid flux (usually intended for plumbing) but I can't imagine it being any better than regular old cheap phosphoric acid. You'll never get regular flux and solder to wet steel, but this makes it just as easy as soldering anything else.

Thanks for the information, what temperature should I be using?

I have some braid I can use to try to get it out tonight and maybe clean up the board. Originally I used this flux, https://www.amazon.com/gp/product/B005DNR01Q/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1 but my pen is this (which is the one I normally stick with) https://www.amazon.com/gp/product/B008OC3VMU/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

Supplies you'll need -

• [Solder wick] (https://smile.amazon.com/gp/product/B008O9VLA2/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1) is your best friend
  
  

• you should also get some [flux] (https://smile.amazon.com/gp/product/B005DNR01Q/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1) instead of trying to use solder with a rosin flux core. when trying to desolder you're not gonna want to add more. Make it easier on yourself whenever you can.
  
  
• It comes in a convenient [applicator] (https://smile.amazon.com/gp/product/B008OC3VMU/ref=oh_aui_detailpage_o06_s01?ie=UTF8&psc=1) as well
  
  
• But definitely get some [solder with flux] (https://smile.amazon.com/gp/product/B003AYJWSY/ref=oh_aui_detailpage_o03_s01?ie=UTF8&psc=1) for any future projects you have
  
  Finally, check out parts 1-3 of this [video series] (https://www.youtube.com/watch?v=J5Sb21qbpEQ). It will show you a lot of the basics.

It almost seems to me like there's a problem with the trace getting broken somehow, which is not exactly normal during regular soldering. I'd try reflowing the joints with some flux like this one:

http://www.amazon.com/dp/B005DNR01Q

then if that doesn't help with continuity, try soldering some wire along the affected trace, and see if you have continuity that way.

Don't use plumbing flux. Use rosin based electronics flux.

Haven't used this but it looks good: solder flux pen


I use this and really like it. It's a bit of a mess to clean up but it works really well. rosin flux


I use a dispenser like this one with it: flux dispenser