Maybe it’s me, but it seems like the 2-part configuration is a bit trickier. This stuff might be repetitive, but here’s what I’ve experienced for what it’s worth:
1. I used to use Bosch bits with 2 cutters which were OK for the old orange sensors, but not the new 4.0 EX Sensors. I learned the hard way after trashing a bunch early on). The holes must be perfectly round for insertion. So you have to use a bit with a 4 blade tip like Wagner’s. Metabo makes these too at about the same price (but they’re slightly longer).
2. Seems like 50% of the holes I drill still require some coaxing to get the sensor all the way in. I bought a little 6” hammer at Harbor Freight for $3 to gently tap on my insert tool to get them in. You can tell by the sound when you’ve hit bottom.
3. As you know, for slabs under 4”, the numbered sleeve has to be removed and replaced with the extension sleeves during the test period, but the sensor itself often pulls up too. I use 3 or 4 connected extensions with my insert tool to push the sensor to the bottom, and gently tap them with my “sissy hammer” listening for that sound that tells me I’m in all the way.
4. After all this pushing and tapping, the sensor might start out reading “Er”. On the old ones, they were usually shot. But for some reason, after a few minutes I get proper readings. Don’t know if Wagner made improvements or what.
5. After a few experiences of junk and debris getting into the sensors between readings, I caulk every cap with LOCTITE after the first reading.
6. As for final sealing, I’m doing something very different. I pull out the top extension sleeve, insert the metal cap, and seal the hole with a cork which I cut down to sit just below the surface. It not only seals it air tight so nothing gets in, it provides a better surface for the Feather Finish to bond to. I found these great tapered corks on line from THE HOME BREWERY for about 1cent each. And if you have to remove them, they’re easy to get out with a utility knife or a cork screw.
Interesting, thanks. I can't see how just pushing and hitting bottom hard them in creates any more stress on the sensor than tapping. They say do not hammer.
I like the advice about the bit. I usually will run the bit up and down a couple times after initial drilling to smooth the hole out.
I think the key is making sure nothing touches the sensor and keeping any vibration from pushing, etc to a minimum. And sometimes no matter how I drill the hole the sensors just need some "coaxing" to get em in
I'm not so sure that the new insertion tool does not hit the sensor either. Anyone want to check that?