Thread chaser to clean corrosion?

[danacman]

Putting cylinder head back on my 115 johnson. Was wondering how do you clean out the white powdery crud from the threaded holes.? Do I need to squirt something in there?

 

[F_R]

Thread tap in a variable speed reversing drill. You probably will have to do a few holes by hand because of obstructions.

 

[64osby]

I like to do them manually. I've broken a few off with a drill and tend to break less by hand. When they break they a usually a major pain.

Some PB Blaster can or 3 in 1 oil can also help loosen some of the buildup.

 

[danacman]

Didn't break any bolt heads this time, but bolts going in tight so want to clean the holes better

 

[wrench 3]

Blow out the holes with compressed air after.

 

[danacman]

Seems like a tiny wire brush type gizmo would do the trick nicely, never seen one that small

 

[boobie]

Leave your drill in the tool box and do them by hand. Less chance of breaking a tap or thread chaser. Use some ATF for lube.

 

[bwkre]

Several types of thread taps can be purchased. The most common is tapered and gradually cuts threads in new material. This type of tap will not "clean " the threads close to the bottom if it is a blind hole. A blind hole being one that does not go all the way through. For this type of threaded hole you might want to use a bottoming tap. It is designed to cut threads close to the bottom of the hole and will do a better job cleaning the threads down to the bottom. Lots of lube and go slow backing the tap out to clean it often. I always do 1 turn fwd then 1/4 turn back and repeat. Removing every four turn or so to clean the tap. Follow with compressed air to clean as stated above. Just my procedure, good luck.

 

[danacman]

Thanks guys, hopefully I can find something in harbor freight.

 

[F_R]

A guy would have to be a real cretin to break such a large tap running slowly in a variable speed drill. Or have a helluva powerful drill. I've done thousands of them with no breakage. But go ahead and do them by hand. Just trying to make it easier for you.

 

[gm280]

Very good suggestions listed above. I do that every time I take anything apart. It only takes a few minutes (by hand too) and I also wire brush the bolts off on the grinder wire brush to rid any junk off those threads as well. Then blow the holes out with compressed air. You can even apply some light viscosity type lube on the bolts and reinstall. And you will see that it usually only takes a few tapes to cover every size on your project. And most SAE and/or Metric tap and die kits usually cover those sizes without issue. JMHO!