mounting hole fixes

It all depends... On the size of the hole, the available slot the main screw goes through, blah, blah, blah.  I have used an oversized screw, I have used plumbers tape, I have bent the screw mount bracket and I have simply not put the screw back in.

But, mostly I have avoided "screwing" up my holes.  I just hate it when I "screw" it up......

Best I found is to fill hole with epoxy. Then re drill hole.    

I'm like Harry, I use JB-Weld in the hole and then drill it to the correct size.  For broken posts, I slip some brass tubing around the stub and fill it with JB-Weld, then drill a new hole.  I've fixed tons of engine shells this way.

I do the same, although I haven't fixed tons, maybe only a dozen pounds or so of stuff.

I use some epoxy and place a good amount OUTSIDE the post and then apply a small amount inside the screw hole. Supporting the outside is as important as fixing the stripped screw hole itself.

Another method is a thin strip of sheet plastic glued inside the post to give some grip to the screw.

That's what my brass tubing is for Dave.  If the post is split or broken, I use the tubing.  If it's just suffering an enlarged screw hole, I don't put the tubing on it.

Done that too and works well.....only issue is when the screw post has a thick web attached to the body side.....then it's more work than worth it to cut the brass up and try and fit.....but if there is room......good fix.

A Dremel tool makes a nice slot in the brass tubing.   I typically glue the tubing on first with Loctite 380, then fill it with the JB-Weld for material to drill the screw hole.

In some cases I have been able to very carefully drill and tap the hole deeper, then use a longer screw of just the right length. If the end part of the post is completely missing, you can add a small block of material inside the car as a substitute seat to tighten down the frame against. 

Is JB Weld any different than other 2-part epoxies?

The other 2-part epoxy products aren't as workable as JB-Weld, at least in my experience.  Also, JB-Weld can be painted after it cures, something that many epoxies don't work well for.

thanks to everyone for the help

Yes, there were several good ideas.

One more for a quick fix in zamac - just dangle a few strands of electrical wire in the hole before you re-seat the screw.

They make Helicoil inserts down to some pretty small sizes - I have never used them below 8-32, and it does take some skill.

For those plastic MTH poles, the above techniques (JB Weld and brass tube) are practically the only way, other than grafting on a new post.

JB Weld has steel in it (I don't know how much).  You can tap threads in JB Weld, too, just go slow and back the tap out more often.

If the post is intact, and just the threads are stripped, just slip something thin in the hole to take up the gap. Paper matchsticks are good for plastic, wood matchsticks work on wood. they may have to be thinned to the appropriate thickness for smaller holes.

Well, I'll add one more...the technique I use most often on plastic-bodied items w/stripped holes...

I use styrene or ABS tubing.  I select a tubing size that is slightly larger than the OD of the thread.  Using numbered drill bits, I carefully measure the tube OD, select the matching drill bit, carefully drill the stripped hole to a reasonable depth...or through, as the case might be..., cut a length of tubing, put a drop of CA into the hole, tap the tubing home.  Let it dry thoroughly.  Re-drill the tubing bore to the correct tapping diameter.  Re-fasten. Done.

Oh well, TEHO, I say.  Works for me.

BTW, I've used the styrene/ABS tubing technique on diecast metal, too.  It works fine, but I only use it for light duty, cosmetic-type situations...not something that will take a lot of stress.  Otherwise, I use brass tubing in diecast metal.

Meanwhile, back at the ranch....

KD

Lots of ways to skin this cat.

I'm a big fan of JB Weld too. There is an even easier technique that I've used. Gorilla Glue is water activated polyurethane. Fill the hole with Gorilla Glue, wipe the screw with Vaseline and then dip the screw in water. Put the screw into the hole and the glue will expand into the threads. Let it harden at least 24 hours. The Vaseline will allow you to back the screw out of the hole.

Gilly

I've fixed tons of bodymount posts by using plastic tubing as it's lots easier than brass and then filling with Permatex 5 min. hard plastic epoxy. JB Weld takes to long to setup IMHO. 

Chuck, I use JB-Quik, sets up just as fast as 5-minute epoxy.

Pappy I like your Grandfather's saying.

Thank all of you Gentlemen for your repair info.

Ralph