I'm sure there are a few practical jokers out there in the crowd. If you work/worked in a maintenance shop, building/auto/truck/bike/airplane etc. share your gag here. Even if you just pulled one over in your shed out back-fess it up here. Can't wait to hear all the evil!

 

Ok, I'll start.... Thirty some years ago I worked on Piper airplanes. The biggest ones were light twins, 7 place Navajo Chieftans. We maintained several of them. One of the pilots was a real nervous nelly type, an easy target. Before he was a pilot he was a Volkswagon mechanic he tells us frequently. His plane was in for a regular 100 hour inspection which includes routine checks and engine oil and filter changes. While we were busy working on his inspection, Captain Hazard, what we called him, was making time with the girls that ran the desk up front.
After the third visit back to the hanger to tell us how to do our job we decided to give ol' Hazard something to think about. Part of the inspection had us remove and cut open the oil filters to check to see if the Lycoming TIO 540 had a story to tell. I went over to the drill press and picked up several 3-4 inch long curling drill shavings and placed them between the folds of the filter. That wasn't nearly enough so a number of sheet metal screws were added along with some rusted bits of scrap for color.
We summond former Master Volkswagon Mechanic to the shop to have a look at what we had found in his engine. I only wish I had video of the panic attack. No question of how sheet metal screws would be in the engine internals or chunks with part numbers on them would be in a filter of a well running engine. He was convinced that he must have just cheated death on that last flight.
We were kind enough to remove the hook out of his mouth after we had our fun and sent him home. Capt. Hazard quit flying a few months later after he flew into a thunderstorm.

 

It's always good to take a big hammer and slam a steel work bench whenever someone is in deep concentration or working with something volitile :P

 

I inherited a rigged foreign voltage detector from a trainer. Always good for fun with a n00b tech "*beep* HOLY CHIT! DON'T TOUCH THAT!"

 

I use to tell the new mechanics coming into the motor pool from basic that we needed a exhaust sample from all the humvees

 

haha. nice kuro. I want one of those.

 

I almost died laughing when I pulled it on one new guy. The object: a box of cable I just took out of his truck. Wasn't connected to anything

 

Apprentices in the UK come in for the most leg pulling.

1. Send them to the tool stores for a "LONG STAND" - ( the store guys were always obliging !! )

2. Ask them to fetch a pair of tapered parallels !!

3. Request more sparks for the grinder !!

4. Coat the crotch of their coveralls with ralgex, deap heat, muscle rub etc

 

While working as a mechanist, a younger guy told us that he was getting married. We told him that we had to paint his ******* blue or else, as a man to man tradition. He asked what we were going to use and one worker said that we would use dykem blue as that is what is on hand in a machine shop. Dykem blue, BTW, at least back then was a bluing color suspended it acetone. When he said he would put up a fight, another worker pointed to the shop leader who happen to have a few bandages on and who just happen to have been married the week before and told the young guy,"See what happens when you put up a fight?"

When we were all getting ready for lunch break, I saw the kid heading to the men's room with something in his hands. I had to stop him. He had a can of dykem blue. He told me that he was not stupid and was going to paint his own ***** blue and not get hurt. OMG! He would have howled when that acetone made contact.

 

I worked in an appliance shop when it first opened up. The salesmen figured it was a good idea to keep their cleaning supplies for the sales floor under the sink in my shop area. I wired a fill valve with a customized wide spray nozzle to come on when they opened the cupboard...
Then there was the solenoid wired to pull the pin on a water balloon drop over the delivery drivers dog house...they open the door and splash!