Would I been correct in thinking, if I have lazy jacks I would not need a topping lift?
Thanks
Ric
If you need to support the boom when the sail is down, at the dock or moored for instance, you can disconnect the main halyard and clip it to the end of the boom. Counteract this with mainsheet tension to minimize swing, or location the boom to one side to open up the cockpit. Some boat will have a short, wire pigtail attached to the backstay for this stowage purpose. Never saii with the boom attached to the pigtail.
When sailing, if your boom weighs down the mainsail excessively when the wind is very light, the topping lift can hold it up so the sail's trim won't be ruined. The topping lift normally has a method to adjust its length. Either a static line with a short tackle system that can be reached from the cockpit, or it can be rigged like a halyard where the entire line moves. Adjusting the topping lift can often be an annoying job, especially if you have full length battens on a full roach mainsail.....a real PIA.
If you don't currently have a topping lift, I encourage you to hold off installing one and, instead research a "rigid" vang system. The rigid vang eliminates the need for a top lift altogether. There are two common types. The first is an assembly that uses a piston and a complex tackle system. The second will he a set of torsion rods that augment your existing "soft" vang... commonly called a "boom kicker". On your 19 footer, if you already have a vang, the boom kicker route may be your best option. I you prefer the rigid vang, look at Garhaurer Marine's products. You would need the smallest one they make which means a pretty inexpensive option. You can set the device up to quickly disconnect for trailering.
I installed the Garhaurer rigid vang on my boat years ago, it was one of the best upgrades ever. My sailing experience was vastly improved.
Good luck, have fun.