Delcast Rosin Paste Soldering Flux for Electronics Circuit Boards and Copper Electrical Wire

Works as it should. I had to transfer some wire fittings on my tractor to a replacement component and was easily soldered into place. I’ve tried without flux and it’s very difficult

Case is not reliable to stay on, so use caution when storing. Excellent product - performed just as well or better than expected. No complaints and priced perfectly

It works as intended for solid connections when soldering

Rosin Soldering Flux Paste 50G arrived quickly from CMT and the paste was of very thick consistency. It arrived in an opaque white container instead of the translucent package in the photo. Color of the flux is darker than what appears in the photo, but it could be due to the different opaque container and photo lighting. One reviewer claimed it wasn't actual rosin and I disagree, but maybe they've updated the product. The seller followed up well after I received the product and expressed sincere interest in my satisfaction. Based on this ambitious behavior I would not be surprised if they are attentive to feedback.Before knowing better, I've used water based flux on some electronic projects. DON'T DO IT! Unless maybe you're in a true pinch and can guarantee returning to rework the job, but, even still, it's a bad idea. Incorrect flux must be thoroughly cleaned, and the chance of missing some or forgetting where it was used is not worth the risk. The cost of rework is threefold and doesn't include the mental anguish of doubting integrity. Do it right and get the right stuff.For years I've counted on the flux built into rosin-core solder, but, as my skillset improves and scope of work widens, the need has overcome the "want". Additional solder is a Godsend with terminal connections, rework, salvaging components, and conserving solder when running the iron for multiple connections. The flux, among its other functions, allows heat to flow and solder follows suite. Heat flow is especially useful when soldering small terminals with an iron instead of flame. Without flux (dry) the iron needs to be in contact for a much longer time; the heat transfer is slower than the dissipation; you end up melting wire insulation and taking an eternity to solder connections. For rework and salvage, faster and more direct heat transfer helps to get in and out without burning up the component you are pulling as well as the surrounding components; this is also good for virgin work, but rosin-core solder usually does the job. However for tasks that require leaving an iron on between multiple connections, the solder sits on the tip between tasks and the flux eventually burns off. Later, when you're ready for the iron again, rather than cleaning off the tip and reapplying solder, you can apply some rosin flux directly to the connection and simply use the solder that is already on the tip.I used this flux immediately for a 1/0 battery terminal lug and time will tell how well it holds up, but I am confident it will protect protect it well. If something changes, then I will update this review.

I bought this so that I could replace the internal batteries in a few GameBoy Advanced Pokémon games. It really helped clean up the contacts from the old solder so that the new batteries could sit in properly and snugly. I still have plenty left, and this jar was cheap enough that having the excess wasn't a problem and just means I'll be happy to be ready to do more with it in the future.