removing stripped spark plug - suggestions?

It's not possible to grasp that plug with any vise grips I'm familiar with; head on or off. Stripping the hex on the spark plug isn't unheard of. The remedy is to grind a bevel or chamfer around the end of the spark plug socket so that it can reach lower in the spark plug well and grip what ever is left of the hex. If the hex is truly and completely gone, a 20mm 12 point deep socket driven over the remains of the plug might work.

Last resort, you could sacrifice a socket... Apply some JB Weld and let it set over the plug until it dries. Never tried it, but it sounds reasonable as long as you're careful not to "weld" the socket to the camshaft cover. Guess I would try this as a last resort.

Thanks for the responses, I will look for this needle socket and see if it looks likely to do the job, otherwise I will go with the JB Weld method. My main concern is that JB Weld is very drippy and takes a long time to set up, so I would really need to protect the spark plug from becoming permanenty attached to the engine, as was mentioned before by Bryan. I will also try the 20mm socket first, but the hex on the spark plug looks like it is truly gone, someone has tried to remove this before I got to it.

There is a quick-set version of JB Weld, I'll probably try it first and see if it holds on enough to break the spark plug free. I am thinking about stuffing the area below the socket contact point with plastic wrap or some other non-absorbent material. Any other suggestions on keeping the bonding agent out of the spark plug threads/manifold area would be very welcome.

Sacrificing a socket is no big deal, as I think that this is a good, recently serviced engine that I can use in another miata or sell it if I can get that plug out.

Thanks again and I will let you know if it works.

Pat

Wax? Oil? They always say the surface should be clean.

Leon

Wax, I never thought of that. It should be easy enough to drip some in around the edge of the plug contact point with a candle and let it dry before trying to bond the socket to the plug. I'll give it a shot this weekend.

Thanks,

Pat

I think that what he is saying is to use oil (or wax) to keep the JB Weld from bonding to the engine and spark plug threads. The instructions on JB Weld say to apply to a clean, non-oily surface. That is probably what he was referring to, not the condition of the tools themselves.

Pat

But - the goal here is not to bond to the surface, the goal is to create a form-to-fit socket around it. So wax/oil that prevents the epoxy from permanently bonding to the plug and/or socket (or even head casting) doesn't seem to be problem at all, as long as the epoxy cures and hardens.

Right?

Cheers - Dana

P.S. Good luck, Pat, hope you get it out...

Thanks, just tried it tonight, we'll see tomorrow after it dries.

Pat