[Kirby64]

Likely stronger than welding against drilling. Weld bead is generally pretty easy to drill through. Carbide drill bits you’d need diamond to cut through. Sure you could cut through the JB weld, but you’ll obliterate your drill bits as soon as you hit the carbide.

[sandworm101]

Carbide junk in a hole will not only shatter weak drill bits but also deflect the stronger bits sideways, likely snapping them. Many security devices insert carbide debris, usually ball bearings, as protection over areas likely to be drilled.

[buildsjets]

JB Weld is a run of the mill 2-part organic epoxy, heating it up to 250F is plenty more than enough to dig it out with a shanghai-grade screwdriver from Harbor Freight.

[Kirby64]

You sure about that? J-B Weld claims its resistant to a constant temperature of 500F, and 10 mins of 600F. With the heatsinking of the steel body nearby, it'd be quite difficult to melt out the epoxy. Not impossible, mind you, but... this isn't intended to be a bulletproof fix, I assume. Why would a would-be thief even think there's epoxy there in the first place?

[buildsjets]

The hubris around here. Yes, I’m sure about that.

You are a person who is easily manipulated by marketing, and clearly has zero practical experience in this field. I do. There are no epoxys that are good to 500F. None of them. See username, Buildsjets. The epoxy resins that we build jets out of are cured in an autoclave under high pressure, and at best they are good to 350F, and they are absolutely the highest performing epoxy resins you can buy from the likes of Hexcel, Toray, and other industrial companies that do not distribute though Home Depot. To go higher than 350 you need to go to more exotic and toxic resin systems like Bismaelemide, and we don’t like to do that because they are ITAR restricted, so we could not tell our foreign customers how to repair their aircraft when they broke. Dispose-a-plane.

If JB weld were actually good to 500F, we would be building aircraft parts out of it. But, if it were actually good to 500F, it would be ITAR controlled and Bubbas would not be able to buy it at Home Depot.

To your comment about difficulty of removal, JB weld does not melt. No epoxys melt. They are thermosets, not a thermoplastics. But it degrades at around 250f to the point where you can pick it apart with a mild steel pick. I know, because I have done it. The heat-sinking effect of the surrounding steel is negligible when compared to a 3,500F MAPP torch flame directly impinging on the epoxy.

[exmadscientist]

Yep, most of them crap out right around 350°F. Many of the circuit board epoxy resins go a little higher, but not much, and I presume they have their own issues for composite layups. They're certainly not structural adhesives.

The highest temperature ordinary structural epoxy adhesive I know of is Lord 310, which claims to be good to 400°F (205°C). No idea if it's any good though, that project went another path so we never opened the tube I bought.

[rdl]

I am intrigued to learn more if you post anywhere (nothing in your profile); this all seems intriguing.