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.
silver solder, or two component epoxy metal glue usually works just fine,. rods has to be isolated as much as posibe from clamps or any matirial that will take heat on himself, maby try to use long tip pliers for holding. If your brener is not strong enough try to combine it with gas stove if you have one (and just for record, It's not smart thing to do). never tried tried JB weld, but it sounds interesting,., anyway i have small Dremel versatip heat tool that usually does work for me
As far as I can tell the JB weld is a two part epoxy metal glue, I will certainly give it a try and post the results. Thanks for the advice, How does your versatip tool work? have to say I haven't come across one of those before but it looks useful.
Hi, I've used JB Weld on several armatures-and it's NEVER come loose....however, I didn't bake foam around these-they were always "build up" models, So I'm not sure what baking temperatures would do to the JB Weld in the way of weakening. I thread ball bearings and then glue the threaded rod into the ball bearing with JB Weld all in there-never had any come loose....I've also JB'd socketed plates into position with it. Just remember to clean the holes first with alcohol so there's no cutting oil residue or anything left in there.Anyway...experimentation is recommended- some things work better for some than others.
I've used JB weld a lot, and with fairly reliable results- a threaded rod into a threaded ball, such as those that come with kit armatures do sometimes come loose, but actually, i think the quality of the mix of the jb weld, and preparation also makes a big difference- i sometimes try to combine jb weld with a little 'fouling' of the threads to try and discourage things just coming lose too easily- also a tiny milliput (epoxy putty) cap, is also not a bad safeguard-but sometimes these things do still work loose- being careful with an initial tensioning also goes a long way...
jb weld on a roughened surface, strictly metal to metal, is a pretty reliable bond...
i am trying to step up to silver solder urgently next, and understand it is far stronger?
I use a 5 minute epoxy to hold aluminium wires into wood or aluminium blocks, on just about all my foam latex puppets (more than 100) and I have never had a problem with the heat (95 - 105 degrees Celsius for 3 or 4 hours) affecting the epoxy. So I wouldn't think there would be a problem baking the JB weld.
I also use epoxy to stick the rod into an aluminium "bone", but that is a fairly long hole so there is more surface for it to grip. The hole in the ball is much shorter, and I've always used silver solder to stick the rod to the ball (on the 4 or 5 jointed armatures I've made). I use smooth rod, there is no threaded hole. For several years I had terrible trouble with the solder not sticking to the steel rod, regardless of cleaning, sanding, acid, flux, or whatever, it just beaded off. That's why I got so good at wire armatures! But it turned out a different silver solder worked fine. Those armatures also got baked, and it didn't hurt the epoxy adhesive. It wasn't even the special stuff for metal, just a cheap clear 5 minute epoxy from a discount shop. I've never seen JB Weld for sale here but it would be at least as good, probably better.
I'm not sure exactly what JB Weld is, but it's different from liquid epoxy or any other kind of epoxy putty I've used - it's flexible. I didn't realize that until one time I had to scrap a join and do it over - when I tried to chip it out it turned out to be flexible and sort of gummy, like hard rubber. Maybe that makes it less brittle - I don't know. It's never failed for me on anything I've used it on though (never used it on anything going into the oven).
Ok, just looked it up online and it can withstand temps up to 300 degrees f - so that should be able to handle foam latex curing temps easily.
Guys, all replies have been super helpful. I have ordered some JB Weld and will certainly test it on a piece to determine the results. The final puppet is silicone based so will not require any excessive heat, only a gentle warmth to accelerate curetime so it looks positive in that regard.
I have used thread lock before on my pizza boy armature and it has worked perfectly, i think my problem has occurred due to the fact some balls were silver soldered and some were not. once soldered, the balls become carbonated (not sure if it is carbon but they dis-colour) even after polishing them up they seem to be less smooth and hold more tension. This means that when I have a silver soldered ball up against a ball that has just used loctite the silver solder always wins!
If i could re do my armature i would only use thread lock. However my plan is to keep the leg and arm sections as they are and replace the hub sections which have fallen apart. I f the JB Weld holds up under scrutiny then i will continue to use that.
Also John, you are correct silver solder is really strong and is definitely the way to go with armatures, however its a bit of an art to get right, soldering balls onto rods seems to be quite easy, but I had a nightmare soldering into big pieces of steel, just couldn't get the metal hot enough.
Again, thank you for all the replies, i really have been pulling my hair out and been super grumpy over this armature! So all your help is great.
Yeah thick pieces of metal are a problem. I ended up getting a Mapp gas torch which burns hotter but it still couldn't do the job. Then I discovered there are special types of torch heads designed to swirl the flame in some way that makes it even hotter. Haven't got one of those yet. One possible solution of course is to grind away excess metal where it's not needed. Thin those thick pieces down a bit. Or else use screws rather than brazing, or braze onto a smaller part that can be screwed onto the bigger part.
Also, I notice the KwikWeld sets in a few minutes but takes several hours to fully cure, and now I'm not sure if it was flexible for me because maybe I just hadn't let it fully cure? Possibly after a full cure it's no longer flexible. To be honest I don't remember the situation or how long after applying I tried to cut into the stuff, so I can't be sure. And I also don't know if KwikWeld is the same formulation as the slower-setting J B Weld.
From what i can gather J-B weld stays pliable for quite a while after applying and takes a good 24 hours to fully cure, but as John Horabin said it needs to be mixed thoroughly for the best results. I should get some through the post soon so I will try and give some feedback on how it performs. I will try it out on a spare ball and bit of rod first, if it is not suitable then Its back to Loctite, however there seems to be lots of positive feedback for the JB Weld. Funny as I'ts the first time I have ever heard of this stuff, but then again Im not so hot on my metalwork!
there are 2 types of jb weld- jb weld itself, which remains usable for about an hour at least, and takes 24 hours to set- and the jb quick version, which remains workable for 3 mins or so, and officially bonds in 5- but, tbh, i would always leave it much longer than 5 mins to apply any stress...
again, tbh, i think the 5 minute version is probably not as solid a bond, but this is what i've been using for the last 12 months or so- because of time constraints- you can't always wait 24 hours for a joint, y'know? It is rare it lets me down...
the other thing is to give the metal surfaces a decent filing beforehand to allow the jb weld to 'key' into the join a little better.
The KwikWeld actually sets in about 4 minutes and takes I think 4 to 6 hours to fully cure. I just looked at this info online a couple days ago, but it seems to have been deleted from my short-term memory axcept as a vague idea.
ah- thanks for clarity- my bad.