What size stays should I go with? Im looking at dieform vs 1x19, what do you say?

Dave

If using 1x19 I would use 3mm sidestays and 2.5mm forestays. The Japanese wire is best - obviously 316. It's hard to get these days though. If you're still buying in imperial it's 1/8 and 3/32.
2.5mm diform can be used on both side and forestay. It's as strong as the 3mm 1x19 but has less windage. Personally I use dieform sidestays and 1x19 forestays and replace them annually or about every 50 to 60 races. I do my own swaging so cost is no great factor. The only issue with swaging diform if you don't have the equipment to do terminal swages is thimble swaging is a bit tricky and time consuming. It's OK with practice and a template.

Cheers
John Dowling
AUS9

Can anyone give me a tutorial on dyform swaging?

Ditto.
How 'bout it John?

The main issue with doing a hand swage with dyform is the alloy is quite brittle and can be fatigued easily. The tools needed are the same as for 1x19. A good quality hand swager and sharp wire cutters. The good nickel plated copper swages are best - don't be tempted to use the cheapies used in balustrading.
I've built a simple template by screwing the right size thimble to a solid piece of wood. A screw inside each end of the thimble with washers keeps it solid on the timber. Now starting at the end of the wire hold the tail with pliers at the sharp end of the thimble and smoothly bend it around the thimble and back to where it started. You are just shaping the wire to fit the thimble and swage just like the 1x19 ends up. You'll find that both runs of wire will need a little shaping where they leave the thimble and enter the swage. This is done carefully so as not to put a sharp kink in the wire. I've found my favourite 30 year old pinch nose pliers best for this. Their edges are a bit rounded through wear and they don't put sharp bends in the wire. Once the shaping is complete fit the swage, pull it up as tightly as possible and crimp it. I'd suggest doing a few practice goes with short bits of wire to get the technique right. After a while you get a nice smooth run with the wire and match the tail perfectly with the end of the swage. I've used these made by AHPC/Goodall and Glenn Ashby for a few years and made my own for the last two years. No failures so far except for the usual wear and tear the same as terminal swages. Like all wire and synthetic rigging, the trick is to check it regularly.

Cheers
John Dowling
AUS9