SRA Solder 135 Rosin Paste Soldering Flux For Electronics, No Clean Flux Made for Lead and Lead-Free Solder Circuit Boards and Copper Electrical Wire – Safe Clean Residues with No Goopy Mess (2oz Jar)

Price: $10.99 - $8.49
(as of Oct 18, 2023 17:43:49 UTC – Details)

From the manufacturer

Appearance of the Flux

SRA #135 flux is an amber colored paste. The consistency of the flux should not be gooey or hard to puncture. In other words it should be solid but also easy to dip wires and applicators into. If you see crystallization (rosin hardening) at the surface of the flux this is absolutely normal and NOT an indication of expired or tampered with flux.

SKU: FLS135

About

SRA #135 is a petrolatum-based soldering flux, containing Rosin and organic acid activator. Unlike many paste fluxes, it contains NO Zinc Chloride or Ammonium Chloride, making it ideal for electrical and electronic repairs. The Rosin also leaves a protective coating over the soldered area that can prevent corrosion.

Ideal for electrical and PCB repairs Does not need to be cleaned Contains 2 ounces (56.6 grams) in a jar Type RA (Rosin-Activated) Flux Active Temperature Range: 93 – 315°C / 200 – 600° Dimensions: 2.5″ Dia x 1″ H (64 x 25.5 mm) Weight: 2.5 Oz (70.8g) Made in USA

Flux Comparison

Soldering without flux is like trying to put a new registration label onto your license plate without first wiping off the layer of dirt and grime that has accrued on your license plate since last year. The surface needs to be clean so the adhesives on the label can do their job.

Why Use Flux?

because solder cannot bond without it!

In order for solder to do its job, the layer of oxides on the metal surfaces you’re soldering must be removed. A good flux, like #135, removes the oxides and sets the stage for soldering. The solder follows the flux, as if the flux were clearing a path for the solder and telling it where it to go. For many soldering applications, using only flux-core solder wire is sufficient. However, there are benefits of adding an externally applied flux such SRA #135, these benefits include:

More control over where the solder will travel – Wherever you apply the flux, the solder will flow to. Expedites the soldering process – It takes less heat and time to get the solder to flow where you need it. Results in a stronger connection – The flux allows the solder to bond properly throughout the target area. Protects the solder joint – This rosin paste not have to be cleaned off after soldering and the residue actually provides a protective coating from corrosion.

How it Works

Prep Surfaces

Prep the surfaces by removing any dirt, rust, grease, paint, and other contaminants with sandpaper, wire brush, steel wool, etc. For many applications, the residues can be removed with just a rag and some isopropyl alcohol. These impurities may prevent solder flow so it is important not to proceed until clean metal is visible.

Choose an Applicator

Various tools can be used as an applicator for the flux including toothpicks, acid brushes and spatulas. Wires and components can simply be dipped as well. One of the benefits of paste flux opposed to liquid is that it will stay put wherever you apply it.

Apply the Flux Paste

Using your applicator of choice, apply the flux to the target areas you are about to solder. The exact amount applied will depend on the job but in general use just enough to cover the area to be soldered in an even coating. Remember that the solder will flow to where the flux is so make sure to apply only where it is needed to prevent solder bridges and mess.

Apply Heat and Solder

Apply heat using a soldering iron or hot air gun to bring to melting temperature and solder. Remove heat and allow to cool. Remove residue with rag if wanted.

Frequently Asked Questions (FAQs)

Is it effective when working to simply dip the solder wire into the flux and solder or is it significantly better to apply to the joint and why? You want to apply the right amount of flux. Too little and you won’t get good soldering results. Too much and you run the risk of the solder flowing where you don’t want it to, since solder follows flux. You want to apply the flux in the manner that will best ensure you lay down the right amount. Usually this means using a tool to apply the flux to the area being soldered and not dipping the part into the #135. SRA #135 is not runny, and if you dip the part into the flux, you might not get enough flux on it. That being said, I am sure there are people who do dip their part into the #135 flux and get good results.

Is it advisable to heat up the flux with a heat gun if it is too hard/solid? You would want to do this very carefully since you don’t want the ingredients in the flux to separate. Quick, intense heat could cause the flux to separate into disparate ingredients. While this is not too likely, it can happen.

If the rosin flux becomes dry is there anything you can do to return it to more of a paste? You would want to gently heat it until it softens up, but you need to be careful not to heat it up too quickly or at too high of a temperature.

Does dipping your soldering iron directly into the flux help keep the tip clean, are there any benefits? Not a great idea. It wouldn’t be good for the solder iron because if you get too much rosin on a solder iron, it can be hard to clean off. Also, it can cause the flux to separate. Better to put the flux on the part that you are soldering, and to then apply the solder wire and solder iron to the area where the flux is. Of course, the solder iron will usually contact the flux, but you don’t want to ‘bathe’ the soldering iron inside the flux by sticking it in the flux jar.

No Goop Solder Flux – Semi-solid solder wax consistency gives you superior control over application. Simply dip copper electric wires or apply electronic rosin flux to PCB and watch the solder flow!
Electric Solder Flux – Unlike paste flux wax found at the hardware store, SRA 135 acid free electronics soldering flux is the safe and effective choice for electrical and electronic applications.
Flux Specifications – 135 is a type RA (Rosen Activated) Flux with an Active Temp. Range of 93 – 315°C / 200 – 600°F. This listing is for one 2oz (56.6g) jar of electrical flux paste.
Flux for soldering DIY electronics projects including Car Audio, Stereo & Hifi, Computers, RC Vehicles, Drones / FPV, Musical Instruments, Gaming Consoles, Model Railroad, Arduino / Raspberry Pi, etc.