Release agent question #1

T

timtune

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Decided to do another sohc this winter and I was cleaning up the cases when I found a threaded boss on the outside of the cases that's been busted. I have the full length of thread but only half the diameter. I intend to lay a bolt in the remaining threads and goop it over with JB weld.
My question: What do you use for a release agent in this situation?
My father was an old time pattern maker and for mahogany patterns he would brush on and buff out three coats of paste/floor wax.
I'm wondering about the carnuba wax I have.
Suggestion appreciated.
 
carnuba wax should work, always best to do a test first.
 
I use an actual mold release wax I buy from Canada Composites in mississauga , it might just be carnuba ......

and use three or four coats . it doesnt actually build up, it just insures you dont miss a spot , which can ruin everything
 
JB weld is good stuff, but I dont think it would hold up to any real torque load, weld the boss then drill and retap would be the proper repair
 
crankcall said:
I use an actual mold release wax I buy from Canada Composites in mississauga , it might just be carnuba ......

and use three or four coats . it doesnt actually build up, it just insures you dont miss a spot , which can ruin everything
Click to expand...
Ditto I've got a big can if you're in the 427 / Bloor area. You're welcome to a bit.
 
I don't think this is gonna work out the way you plan.
YES you can put thread in DevCon/JB Weld epoxy, but you can't USE the thread. The second time you turn the bolt you'll pull the thread out. Epoxy is too brittle.
The CORRECT fix is weld it up, redrill and tap the hole.

What MIGHT work: make a drill jig that bolts down and drill what's left of the hole and install an insert. If you try to drill it without a jig the drill WILL wander off center
 
I don't weld aluminum and this is a 50 tear old sohc. I'm going to try the JB and keep in mind that the threads may have a very short life cycle.
 
timtune said:
I don't weld aluminum and this is a 50 tear old sohc. I'm going to try the JB and keep in mind that the threads may have a very short life cycle.
Click to expand...
$10 aluminum soldering rod and a propane torch. I learned to use this stuff years ago from an old codger on Lake Simcoe. He used o repair aluminum boat props by pad soldering. I've repaired bike cases with 2" rod holes, aluminum rocker covers on a Goldie, and countless other small aluminum cracks and dents.

If you can solder, it's a snap. There is only a couple of tricks to it -- 1) it must be freshly cleaned, clean the area with a small stainless brush (Dollarama if you don't own one) -- aluminum oxidizes fast, solder will not stick to dirty aluminum. 2) heat into the aluminum, not the rod (remember you're soldering). Practice on the bottom of a beer can.

You can file, sand, polish, drill and tap the finished product.
 
Mad Mike said:
$10 aluminum soldering rod and a propane torch. I learned to use this stuff years ago from an old codger on Lake Simcoe. He used o repair aluminum boat props by pad soldering. I've repaired bike cases with 2" rod holes, aluminum rocker covers on a Goldie, and countless other small aluminum cracks and dents.

If you can solder, it's a snap. There is only a couple of tricks to it -- 1) it must be freshly cleaned, clean the area with a small stainless brush (Dollarama if you don't own one) -- aluminum oxidizes fast, solder will not stick to dirty aluminum. 2) heat into the aluminum, not the rod (remember you're soldering). Practice on the bottom of a beer can.

You can file, sand, polish, drill and tap the finished product.
Click to expand...
I've done some repairs and fabrications with the stuff. It works but mine tend to be ugly. A file can remove the ugly part.
 
I'll likely bodge it with JB. But I am intrigued. Where can you buy the aluminum rod?
 
Ok so I got some alum rods and played with scraps. It could work but my propane torch couldn't get the corner of the case (a giant heat sink) hot enough. Went with the jb bodge. Pics show the finished bit (painted) along with a test piece I made. Surprised me how much the jb threads will take. Will likely be good enough for a while....IMG_0232.JPGIMG_0237.JPG
 

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