Steel hull zincs - screws or welding

If you have bolts now why not keep using that? Of course replace all the related hardware.

Here is a link for you.

http://www.kastenmarine.com/_pdf/mbqCref.pdf

No, you want to be able to change the zincs in the water. Not have to haul the boat to change a wear item like zincs. As long as the bolts are making good contact, they are fine.

Capt J is 200 +% correct. Keep the bolts setup, and forget about welding Noa Ramot. Just get new zincs and bolt them up.

Bolts are way better. Welding is a pain especially if the opposite side of the hull is not easily accessible . Recommend you chase the threads on the studs and use some marine grade never seez and lock washers when you bolt on new zincs. If you are blasting and painting the hull just cut some short pieces of an old hose that fits snug on the studs and that will protect them while you blast and paint.

I always enjoy learning, I would never have thought welding zinc sacrifice plates to a steel hull would be efficient or even possible

I deal with weld-on zincs regularly. They are very typical on commercial, steel hulls. The zincs come with steel tabs to weld to the hull. But as mentioned, bolt-on are much easier provided they are done correctly.

Welding is a pain. I prefer bolts