Best epoxy for adhesion?

I'm repairing an crank handle for a nice old tripod. The handle is made of some sort of black plastic, and the bit made to repair (reinforce
across the break) it is steel. The steel bit sits inside the u-shaped channel of the plastic. I expect there is a bit of draft so the epoxy I'm planing on using to embed the steel bit has to stick good to that plastic.
Recommendations?
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That's a high-energy repair, with rotational as well as axial loads.
I'd probably drill, tap, and screw the piece together with 4 small screws, perhaps with some 3m 5200 adhesive (or ShoeGoo) to initially stick it together.
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On Mon, 28 Dec 2015 04:55:53 -0800, Larry Jaques wrote:

This one's broken right where the end of the u-channel meets the spinner- knob mount. It's across the narrowest part of the 45 degree join. Here's a pic of the handle:
https://www.manfrottospares.com/en/index.php?route=product/ product&product_id’94
The knob mounts into a 15/64" hole that leaves about 1/2" vacant on the back side. I cut a bit of drill that size and silver soldered it into a bit of 3/16" by file-to-fit that is bent at 45 - disappears right into the u-channel and as long as it stays there it will be stronger than the original.
I was wondering if prepping it with an agressive solvent like carb cleaner would help; also though of keying the sides of the channel so the epoxy block would not just be reliant on surface adhesion.
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Whether the epoxy sticks will depend on the type of plastic and how much plasticizer it has in it. In any case, that's a marginal joint.
If that bent piece is long enough, you could wrap the joined area in fiberglass, soaking it with epoxy as you wrap, until it's as ugly as you can tolerate it. <g> Overwrap that with Saran wrap and then sand it off when you're done. That will make it a little neater.
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Why not use the old handle as a pattern, and make another from (say) solid aluminum?
L
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Lloyd E. Sponenburgh <lloydspinsidemindspring.com> wrote:

Or just buy a new one? Manfrotto has lots of spare parts for sale. Any hacked up plastic crank is bound to look horrible after repair anyways.
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Mechanically rough up the surface of the plastic to give it some "tooth", then glue with a good repair epoxy.(I have no brand preference, but I have some "west system" stuff left over from aircraft work that I would likely use in a case like that - if it were me.
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On 12/28/2015 11:15 AM, snipped-for-privacy@snyder.on.ca wrote:

My go to epoxy is Huntsman 10, previously Araldite by Ciba Geigy > http://tinyurl.com/nlnldt3 That's the small tube, I generally buy it in the 9 oz size, but Amazon is out, you can probably find it elsewhere. I has a long shelf life even after opened. I've used it after 10 years. It's grey when mixed.

I did a repair similar to yours on a on my radial arm saw crank handle more than 15 years ago, it's still holding strong. That handle is all aluminum, but I used Fastweld 10 for years on plastic parts in the consumer electronics repair business. Where ever possible we used 0.25" or 0.35" steel rod to pin parts before epoxy. Mikek
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http://antiqueradios.com/forums/viewtopic.php?t 3903
I reinforce handles that have broken and may (will) again with a metal sleeve, a hobby-store brass tube in the center if it's decorative or outside ferrules pressed and swaged onto the ends if it isn't.
-jsw
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There is available now at many hardware stores a two part adhesive made for plastics. I bought some to make a temporary repair to the plastic radiator in a Toyata Camry. The top was cracked so I used the two part stuff with cloth reinforcement to seal the two inch long crack until the new radiator arrived. The repair held for over a week. I don't know how long it would have held because the new radiator arrived and I installed it. I don't know how well it would stick to steel though. Eric
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