We are working on a great project bringing a Dumas 55\" Miami Vice scarab to life. That is until yesterday when I could not get the solder to take on the flex shaft. Directions say to tin the flex shaft with solder, insert 1/8 inch into ferrel, heat ferrel till it discolors 3/4 of the way down and push the flex shaft the rest of the way in but I could not get the solder on the flex shaft. It just kept beading off of it. We preped it with acetone, and then tried paint thinner, but to no avail. I was using a torch to heat the flex shaft and ferrel. Solder was silver solder at first but then tried regular solder with a resin core.

Any idea as to what we are doing wrong?
Thanks,

PS. I will post some pictures as we proceed. We are attempting to us a Homelite 26CC trimmer engine in our setup.

Soldering the cables can be tricky...especially used ones as it is nearly impossible to get them perfectly clean on the inside. I acetone also and brake cleaner. I think the single most important thing (well the 2 most important things) are NOT TOO MUCH heat and GOOD FLUX. I use Staybrite silver solder with liquid flux and a small butane torch (the ones powered by a lighter inside if you know what I mean). Any small butane torch will do. Hold the cable upright in a vise leaving only about 2\" sticking out of the vise. Pour on liquid flux and heat the area below the tip of the cable...The solder should start feeding in the tip after the flux is bubbling. Do not heat the tip directly...gently heat just below it going around the cable. Direct heat will cause soot buildup on the cable and solder will not flow...I keep adding flux often. If a bead of solder forms, try dropping liquid flux on it while it's hot, it will most likely get it flowing. Once you got plenty in the tip, you can use a steel wool to clean the outside and flow some from the outside of the cable too...always gentle heat..if you heat it up red hot, you should throw it away right now as it will make the cable brittle and it will break at a later time.

Rudy did a good article on the subject a little while back: www.modelgasboats.com/Magazine..._Soldering.html

Before the solder will take, you have to tin the end of the cable through and through. You also need to make sure you bind the inner coils with the outer ones.

It may seem like your not getting anywhere but just about then it will bond. You have to clean, clean and re-clean the cable with a paste or liquid flux. this will clean the metal to the point it will accept solder.

Stick with a good quality \"Silver Bearing\" solder, this is the strongest. The secret to soldering cables is to get them super clean

clean clean clean then staybrite liquid flux low heat and just enough heat to melt the solder with the cable

Dave

Thanks guys. I will give that a try this weekend. I can't wait to see this boat in action.

James