Make Your Own Eco-friendly Soldering Flux

Flux is used in soldering to remove oxides from the contacts of the parts to be soldered together. Fluxes can be made from hydrochloric acid, zinc chloride or rosin. Here is a simple and easy homemade rosin flux made from pine cones.

Step 1: Go Shopping!

Only two ingredients are required:

10 to 15 pine cones with pine tar (sap) on the ends of the cone leaves (found around pine trees)
1 Quart Denatured Ethyl Alcohol (found in the wild at a hardware store or you could distill your own)

Tools required:

2) Metal or plastic containers with a lid (coffee cans work great - consume coffee first)
1) Pair of rubber gloves (removed from kitchen without Mom's knowledge - disavow later)
1) Tea strainer (likewise but wash after using and return to kitchen under cover of darkness)
White coffee filters
Scissors or shears
Empty Bactine bottle for application
24 hours

Step 2: Mix It Up

Rinse the two containers with a little alcohol to remove any coffee grounds.

Cut the cone leaves from the pine cones and place them in one of the containers.

Pour the alcohol over the cone leaves making sure they are submerged. Save the empty can for storage of your finished product.

Cover and let soak overnight.

Step 3: Refine Your Product

Stir the container of cone leaves and alcohol to insure that all the sap has dissolved.

Place the strainer over the top of the empty coffee can and pour the contents of the cone mixture through the strainer to remove large pieces of debris.

Throw away the debris in the strainer and the remaining pine cone debris in the can and rinse the can with clean alcohol.

Place a white coffee filter in the strainer. Place the strainer on the clean coffee can and slowly pour the contents of the strained liquid through the filter.

The liquid will be light amber in color and smell of pine.

Filter again if you like and /or bottle your product in the empty alcohol container. Use a small bottle with an attached dropper (like an empty Bactine spray bottle) for applying your flux to your project before soldering. Yeah!

Comments

[JQPublico]

Someone commented on using phosphoric acid mixed with isopropyl alcohol. Warning!! Please check this out - https://fscimage.fishersci.com/msds/91335.htm

[eel_dahc]

Tried this out today, in Texas, plenty of pine trees to walk around and pick off the rosin blobs that form where the bark had damage.

[nikko_47]

quick question regarding diy soldering flux can i use gum rosin to make the flux

[iFix8]

Heck with rosin flux. I've found what may be the single best, cheapest alternative that is already being sold for as low as $15 per gal in most hardware and department stores. When added to desoldering wick, it turns it into super wick with about 10x the effectiveness. I'm still experimenting with it, but after using it to successfully solder to any type of coin, battery, etc., I'm pretty sure it works better than flux and has less ill health effects. It also has many other beneficial uses around the house and shop. Can you guess what it is?

[sjones124]

What gives? I didn't see anyone guessing, and you didn't give it up either. $15/gal for flux is cheap enough to keep me from hunting sap covered pine cones. Given the topic of this Instructible I'd guess a pine cleaner, like Pinesol?

[iFix8]

Sorry, I thought I'd answered you. Since flux basically turns to acid when heated, and the acid is what de-oxidizes the metal, I figured I'd just go with a cheap, weak acid that was readily available. There may be a lot of these around, but I chose the one acid that is safe, readily available and found in a lot of foods, probably one or two that you've had this week -- phosphoric acid. It is found in many foods because it slows the growth of molds and bacteria, so not only does it add the zing to soda pop (not citric acid, as you might have thought), but it keeps the sugary treat from becoming a bacterial soup. Got to maintain those profits!

You can get it online, but it is only $15 per gal at Home Depot under the label, KleanStrip Prep & Etch, for cleaning and etching cement floors, etc. It needs to be diluted with alcohol, of course, which means it is even cheaper than $15 per gallon. Try it on a circuit board to see if it is diluted enough. If it doesn't eat away at the coating on most circuit boards, it should be fine, but you can always clean away the acid after you're done soldering, just as some like to do with flux.

I've mixed my own flux with pine resin, and that stuff is super sticky and not fun to use. It really has to be diluted. But why bother if phosphoric acid does the job without the complications? I've also filled cheap markers to use as flux pens. Dip your wick in it and it becomes super wick! It's wick'ed stuff.

[Gadisha]

Interesting... I know that you can hard solder copper with copper- phosphorus solder, but didn't know it could also be used for other soldering appliances.

In combination what kind of solder and metal did you use the phosphorus acid?

Thanks for posting btw.

[kedwa30]

I'm going to guess: Turpentine?

[Gadisha]

Interesting... I know that you can hard solder copper with copper- phosphorus solder, but didn't know it could also be used for other soldering appliances.

In combination what kind of solder and metal did you use the phosphorus acid?

Thanks for posting btw.

[DaMonkey]

Going to go out on a limb here. CLR?

[rpotts2]

Nice 'ible! I have a small container that I made from rosin gathered on a hike. I think it may be easier to harvest if you cut the tree a bit (nothing huge, just an inch or so) and just wait a while (days or weeks). if you plan far enough ahead you can harvest the brittle stuff.

[afridave]

cool...I have two large pine tress in the front garden...im going to look for some blobs of sap and try disolving that in some form of alcohol and give it a bash..

[afridave]

cool...I have two large pine tress in the front garden...im going to look for some blobs of sap and try disolving that in some form of alcohol and give it a bash..

[afridave]

cool...I have two large pine tress in the front garden...im going to look for some blobs of sap and try disolving that in some form of alcohol and give it a bash..

[afridave]

cool...I have two large pine tress in the front garden...im going to look for some blobs of sap and try disolving that in some form of alcohol and give it a bash..

[afridave]

cool...I have two large pine tress in the front garden...im going to look for some blobs of sap and try disolving that in some form of alcohol and give it a bash..

[JohnJ21]

[Parnian.Ahmadi]

Hello thank you very much great instruction , I want to know the exact ratio of HCL ,

ZnCl۲ , or maybe SnCl2 in tin -lead 63-37 soldering Flux the exact ratio the percentage ???

[solar world]

Thanks

[solar world]

Thanks