So after a complete nightmare trying to assemble my most important armature, I am looking for some solutions to my problems. Basically i used silver solder on some of my threaded rods and ball bearings which have worked but the larger hip and torso steel wouldn't get hot enough to allow for a good bond with the solder resulting in the thread just unscrewing. I tried loctite threadlocker but this always gives way if up against a silver soldered joint. Has anyone tried JB weld (metal re enforced epoxy) to bond threaded rod? Apparently it's brilliant for joining metal but I am unsure how well it will hold in a thread? any help would be brilliant.
When I used to use threaded rods, Jim Danforth said to me, "Why? I don't." He explained how unnecessary it was, and since Jim is also a master armature designer and builder, I went with his advice. If the silver solder is of the correct type and properly done, having threads only complicates things, imo.
Putting a rod into a block generally isn't soldered. two edges at 90 degrees are filed, and then holes drilled in the block from 90 degree angles, and set-screwed in.
Also, I've never found a "glue" that can actually take the incredible stress they sometimes need to, or hold the bond over many stresses over time. Worst thing in the world is a joint coming loose on a fully-skinned puppet, so I used silver solder or set screws.
Ok, so the Jb weld did not work in this instance, I tested a ball and rod and left to cure for a full 24 hours before testing it's strength, but unfortunately it cam loose with some mild pressure.
Thanks for the info Rick, the rods are threaded as that is what is supplied in the kit, I really dont want the problem of a loose joint with a fully skinned puppet, however I am not really equipped for soldering large pieces of steel as i just cant get them hot enough for the solder to flow. Also it seems that the balls become "rougher" when heated up leading to certain areas where there are discrepancies and then the joints become stiffer in some areas and loose in others.
I completely understand that soldering is the way to do things, but I have only a little experience with it and lacking in equipment. I ordered some fresh ball bearings and will probably have to use loctite on these and hope for the best!
I never had anything fancy. I just went to the hardware store and used Maap gas burner..propane wasn't hot enough. Always be careful! You could purchase some steel rod stock pretty cheaply to use instead.Forget locktite; I think you will be very disappointed.
I'm curious as to why your metal parts are too big to heat through - what kind of design are we talking about? Can you show any pictures or describe? There must be a fairly simple way to work around that.
Ok let's see if I can make this pic show up here:
So you must be referring to the rods emerging from the chest block and pelvis block? The metal doesn't look all that thick to me, but maybe it is - can be hard to tell from a picture.
Couldn't you just file down the metal where it's too thick? I see no reason that wouldn't work. Or wait - maybe you'd need to file front back top and bottom of each piece, and that would be pretty impossible.
What I would do is drill into the metal to make a hole you can insert the rod into and then drill in from the side and thread the hole and use a grub screw to secure the rod. If you also file a flat area on the side of the rod right where the screw will go against it that should work to lock the rod in so it can't slide out.
Other than those the rest of the balls would be no problem.
Just took nother look and I see you'd probably also need to do this to attach the head hands and feet.
I hope you can see this pic clearly - or at least semi-cleary. This is an alternative way to make the chest/pelvis blocks so you don't run into the thick metal problem. They're not actually blocks here, they're plates. You still need to make sure they're not too thick though. What you have to do is set the plate up on a couple of extra rods or something so it's raised off your soldering block - otherwise the block acts as a huge heat sink and you'll never get it heated up all the way. And here's a little trick I learned from Jeremy Spake way back on the old board - you sort of melt the silver solder onto one piece first (don't remember if it was the rods or the plate) and then you pin your pieces together securely or wire them up - however you're gonna hold them in place, and start heating it all up again. When it gets hot enough the pre-placed solder will re-melt and they'll suddenly sink together.
Oh ok - that's right, I didn't do the pelvis that way - but that's still a small enough piece of metal I had no problem heating it through.
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It's starting to come back to me now - I did file trenches for the rods to sit in on the chest block, and I don't think I ended up needing to pre-melt the solder the way he recommended. I was holding that trick in reserve, but I believe it worked the first time when I just heated all the metal through and then touched the end of the solder wire against the joint - it just flowed all around.
I tried using adhesives, glues, locktite, JB weld over the years, and it just wasn't strong enough to withstand the tension on the joints for my armatures. Mark Sullivan steered me to the direction of a product called Muggyweld. http://www.muggyweld.com It's a paste that has both the flux and solder built into it. Drop a bit of it into the bearing, high-temp braze the rod in, and voila, a braze seal that will never come off. it's all I use nowdays. I've only had one ball come off since I've used it, but that was because I was careless and in a hurry. It's kind of expensive, but one tube will last a long while.
Great stuff, thanks Tom.
I had a look on the website and it seems like a great chioice for sturdy armatures. I may stick with the locitite for most of the human puppets as I believe that if I heat the joints up the Loctite dissolves and I can reuse the joints on another puppet if needed further down the line. Also they are much lighter so I guess the joints wont need to be tensioned too tight. When it comes to puppets to be encapsulated in a silicone, latex, e.t.c skin then I will get some of the Muggyweld. Unfortunatley I am already past the armature stage of the Devil puppet now but It should be invaluable for the next assembly.
Many thanks for the insight Tom.