Supposedly my friend was going to use one the evening after I welded them up. I haven't heard an update from him yet, but will let you guys know the feedback on it. I was thinking if the ringing in the handles is too bad, maybe he could add something to dampen the vibrations.
He's pretty resourceful so it wouldn't surprised me if he figures out something like that by himself.
That is exactly the stuff I used, I am pretty sure. I think I remember finding it cheaper at one of the big box stores than anywhere else. You can buy this type of product (basically a spray can with about ~97% zinc content) from a lot of different places though.
I find it initially dries not very durable, so should be handled with care for the first few days. But leave it for a couple weeks, especially baked in the hot sun, and it will harden at least hard enough to withstand fingernail scratching. It is perfect to use for say a lap joint, where you want the inside to be rust resistant. It is safe to "weld over" (to some degree, just don't inhale the fumes.) It won't "burn" like paint does, at least. Still, the zinc will vaporize at welding temps, so not the greatest to have directly in your weld puddle.
Thanks for adding the link on 309 filler for mild steel, zoama. I used it primarily for aesthetic reasons, and also for corrosion resistance (albeit only right at the weld bead.) At the beginning, I wasn't planning on spraying it with cold galvanized. The main drawbacks to using 309 instead of say 70S6 is that it's much more expensive (per pound). It does seem to be about on par (give or take) to 70k psi steel filler rod in terms of strength. But anyway, as Jody demonstrated in the linked video, it tends to absorb impurities unlike any mild steel filler rod, and leave a very clean, nicely appearing deposit. (That doesn't matter too much when you spray cold galvanized over it though)
That is the reason that I welded it, instead of brazing it (which I almost did, for fun.) The thing that makes me be OK with this is, all the materials used are fairly ductile, so a "sudden" failure is not likely in any case. An expected outcome resulting from abuse would be something getting bent and giving a "gradual failure." In which case, the damage should become apparent and give an indication to stop using the damaged tool, to prevent a complete failure.
I also have pretty good confidence, based on the weld joint I made, and knowing how much penetration and bead build-up that I got, that this weld joint is not going to fail in any event. Any failure that would occur would be in the tubing, right next to the weld joint. Thickening the tubing (such as by using thicker tubing rather than what my friend brought me to use) is really to only way to make it more resistant to this kind of failure.
Thanks for your feedback. I'll reply to it in the skeg repair thread, to keep things organized