Removing broken nylon bolts

Jul 05, 2007 17 Replies

I am restoring a Wyco 993 concrete vibrator. It was missing a cover, shaft, and switch. I had a matching switch in my parts pile. I bought this vibrator as a pile of parts from an auction (along with 5 working vibrators and a lot of shafts and other parts). It was broken due to physical impact (plastic cover broken). It is easy work, got the cover on ebay, have other parts etc. Vibrator runs fine after I put on the switch. No complaints.



My only problem is that in a certain place, they use 1/4-20 nylon plastic bolts, probably for electrical insulation purposes. The bolts are broken, they broke off as the cover, that they held, was hit and broke off. My question is how to remove their remains from holes.



i

Drill out to tap drill size for 1/4-20 and then use needle nose pliers to pull out the remaining scrap. Do this on the Bridgeport where you can precisely center to avoid clipping the threads.

Pete C.

Maybe I'm missing something.... but is there some reason you can't use an EasyOut, or a LHT tap?? Seems like nylon bolts oughta be pretty easy to drill.

Another option might be to drill out everything but the threads, then run a tap into the holes.

Or drill out everything but the threads, then burn the remainder.

You are kidding, right?

Gunner

"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.

Think of it as having your older brother knock the s*it out of you for torturing the cat." Gunner

I usually heat a screwdriver till it's hot enough to put a slot on the screw then simply unscrew the threads out. Please wait untill the screwdriver cools

Like Gunner says, you're kidding! You should be able to jab a sharp narrow screwdriver into the remains and back them out. If you just gotta use power, find a left-hand drill and use a cordless drill in reverse. Or one of those screw-out gizmos they've been hawking on the cable channels. Should be easy to get out, nylon is a lot more elastic than soft steel bolts would be, shouldn't have any sort of burrs developed to impede the flow of progress here.

Stan

I was not kidding. They are sort of fragile, hence my question. I do not care, as such, to use power tools, I just want to take them out and finish what I started to end up with a nice vibrator.

I will try manual approach first, if that does not work, I will drill the hole, maybe will use a bottoming tap to remove the remains of these nylon bolts.

i

Finally *one* of Ignorerat's postings where you realized that!

You're getting better!

Nick

Take an old screwdriver that is narrower than the bolt hole, heat the end of it and push it into the nylon. After you have a hole about 1/16 -

1/8" deep remove the screwdriver and allow the nylon to cool and harden. You should then be able to use the same screwdriver, unheated, to remove the screws.

Jim Chandler

Arkansas flame wrench.

(well, SOMEONE had to say it!)

I removed them. I could unscrew one. With another one, I used an endmill on my bridgeport to drill out almost the ID of the hole, and then I used a bottoming tap to remove the rest. I kept these standoffs in hydrochloric acid for 10 minutes, and am going to oil and tap them again to remove the remainder of the rust in their internal threads.

i

I was going to say "Heat an old-style square shank E-Z-Out screw extractor, melt a hole, wait for everything to cool, then back 'em right out." But you already got it.

Before you even think of replacing them with metal screws check to see if the nylon is really needed for electrical isolation, and/or analyze the design to see if they used nylon screws as a Safe Destruct Point for the tool, like a shear pin protects the transmission - it's always better for the 10-cent screws (easily fixed) to break rather than the $100.00 housing (that isn't).

-->--

They are most likely needed for isolation, I will buy a box of nylon screws at mcmaster to avoid taking any potentially unsafe shortcuts. I am going to sell this vibrator.

i

1/4-20 nylon bolts are stock in trade for the R/C airplane guys. They are used to hold the wings on a lot of models, and are used because they shear off without destroying things on a bad landing.

Cheap and available!

And easy to remove!

Cheers Trevor Jones

Finally a use for an "easyout" what a misnomer. (the right name is 'easy breakoff in the hole')

John

Hydrochloric acid embrittles Nylon.

Don't ask me how I know this firsthand.

Indeed.

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Exactly!

If you don't have a hobby shop with RC planes - the on-line stores have them. If you have a hobby lobby in town - good try - their web has and the big catalog did have - RC stuff.

Martin

Mart> Bruce L. Bergman wrote:

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