What is a good way to clean spark plugs? Can a guy sandblast them and blow them off with air?

 

You can but sand will wedge between the electrode & ceramic .If you blast use some thing very fine like dirt dust , salt & etc.. Give them a good blowing off when done .

 

I have a Harbor Freight-type (i.e., cheap chinese) spark plug cleaner I bought 30 years ago. It hooks up to compressed air and has a self-contained supply of black media. Cleans a plug in about 10 seconds with no mess. You do have to make sure you get all the media out of the ceramic-shell gap. I wouldn't use it on a really oily plug. It recycles the media, I haven't needed to change it in 30 yrs.

 

Years ago, every service station had one of these. The important thing is to get all the cleaning media out of the plug when finished.
CHAMPION SPARK PLUG SERVICE TESTER CLEANER STAND CABINET ADVERTISING GAS OIL 2 | eBay

 

LOL that is because champion plugs foul as soon as you take them out of the package!

 

Denny is right. Sandblasting or media blasting is not a recommended procedure and hasn't been for many years for the reason that he stated. If the electrodes are still in good condition and the ceramic inside and out is not cracked or chipped a wire brush is better then just re-gap them. Other than that just replace them. I'm not sure that the new high mileage plugs are worth the high price since our engines do not run very hot and the combustion is not as tightly controlled therefore deposits do not get burned off as well.

 

I remember when I went to auto mech school they had a plug blaster. Never used it, easier to wire brush them.

 

I use a wire brush and some brake cleaner. And since the brush doesn't really get in the gap I use one of my tiny files inside the gap so the sparking surfaces are fresh bare metal.