just wondering if anyone has tried to fix a striped crank with a tap, where the pedal goes in.(tap is a tool that cleans the threads)
If the threads themselvese actually missing/not apparent, you might be kind of screwed. A tap itself only realigns threads if they are minorly damaged and usually if you had slightly cross threaded or if you have a residue that was left on the threads (such as metal shavings or paint) it’s not going to hurt to try, but if the thread themselves are missing, you might be looking at new cranks (or pedal inserts depending on what mind of cranks they are)
True, just plain tapping is only successful if the thread damage is pretty minor, like cross-threading partway on and then noticing, and backing it off. If you’ve been riding with a loose pedal, it’s much less likely you have enough thread left.
There are also inserts you can get, where you tap out the hole to a larger size, then put in the insert to restore a normal-sized pedal hole. Might be more costly than new cranks though…
No, but I did a polka-dotted one once. 
An easy trick I figured out to repair the thread is by screwing the pedal in from the wrong side (put the pedal through the spokes, and screw it in that way).
The damaged part of the thread is usually from starting screwing it in scew.
If you screw in from the other side where the thread is still in tact, it will correct the thread once it is it deep enough.
Take off the pedal, and screw it it from the right side.
Effect is same as recutting the thread.
Loctite form a thread on Amazon.
3 people gave it 5 star review. Might be enough if your threads just need a little help. Go with what Joggling posted and might be a cheap fix.
There is not a lot of ‘pull’ on a pedal. So while pedals need to be tight, they don’t need to be honked down.
I’ve got the Permatex version which I’ll ship to you for free if you want to try it. I used it for a repair on a motorcycle. Only used a dab of it. The instructions for using it are on the permatex website.
Permatex site says it’s good for 23 ft/lbs on a 9/16 bolt.
This and Joggling’s idea about spinning the pedal in from the backside and you might have yourself a repair.
Yes, I’ve tried. (tried means using the tap)
Do you have an actual question?
Let me help the OP out.
I am considering trying to fix the threads in a crank where the pedal connects with a tap of the correct dimension. Has anyone tried this? If you have tried a repair of this nature, did you find that the final outcome was sufficient to continue with more riding without further corrective steps?