Dunno whether this belongs here or 'How To?'
Move if reqd.
Anyone know how to ream this stuff, Whale Brand, 1/2" sheet?
Got three rough squares of this, epoxied together to make a 3" Sq. x 1 1/2" block.
Want a 1/2" hole thro' centre, objective is a 70mm dia. x 30mm solid cylinder to bore out into a cup shape with a 5/8" hole in end.
Want the 1/2" hole thro' to mount on mandrel to turn OD.
Drill 1/4", 15/32", ream 1/2".
OK? ....NO! ...1/2" round bar will not enter hole!
Reamed again. Reamer removes nothing. Still can't get 1/2" bar in.
Reamer IS 1/2", try another reamer.
Nothing in flutes. Not taking anything out.
1/2" bar still won't enter.
Bar is miked at .0015 undersize, not that then. No burr on it. Try 1/2" drill shank. That won't go in either.
At this point I decided any *****in' hole about 1/2" will do, as the item is not all that critical, so ..
Poked a 1/2" drill thro'.
That damned 1/2" bar will still NOT go in.
Revelation! It's got hot. Expanded and now gripping! Left it for 2 hours in a freezing cold garage.
Returned, Just the same.
So, snarling with rage and indignation, slammed a boring tool thro' it, and did the job.
Tried the same stunt on a bit of round steel, nothing seems amiss with drills, reamers, 1/2" bar etc. Did what I expected.
As I know they use the same stuff for bearings, gears etc, someone knows how to deal with Tufnol.
I don't think the epoxy was significant, it had been done for a week and cured in the house at room temp.
In any case, the bar would have to go in by 1/2" to reach the epoxy join, didn't get anywhere near that far in.
Any suggestions ? (Yes! I have thought of stopping using Tufnol).