Rebedding instrument fittings

[Juanvaldez]

Getting a new to me Hughes 26 ready for launch. While cleaning up a compartment noticed gobs of silicone around the knotter meter what I'm guessing is a transducer?

Assuming these can be rebedded with 4200 from the outside? Any gaskets or seals to replace? Any pitfalls to avoid with these types of fitting?

Thanks in advance.

Cheers

[sailormed]

When you rebed you will have to keep in mind that from time to time you will have to take out the knot meter for cleaning, even with the boat in the water. They attract a lot of critters blocking the vane rotation.

[tkeithlu]

Here's West Marine's guide to sealants. 3M 4200 is likely to be a PITA when you need to disassemble. Silicone sealant that has a 30-year rating may be best at low cost. For a really good seal in removable material, let the goo set overnight before you give it the last little bit of torquing. That way you are compressing a solid collar rather than simply squeezing liquid.

https://www.westmarine.com/WestAdvis...two%20surfaces.