adding weight with epoxy/resin?

I was wondering if anyone has tried adding weight to an fhz by pouring precise amounts of either epoxy or resin into the cup?

I haven’t, but If you have small openings, or a crack it won’t work. And don’t pour over the middle hub.

The easiest way is to get fat o-rings that fit inside the hubs. They’re about 3/16 thick. Get some that fit snugly inside the hub. Glue is too messy.

yeah… can you delete this thread for me? or lock it lol

Nah, somebody might find it useful.

Just to add… I’ve worked quite a bit with polyester based casting resins. Haven’t tried epoxy resins, so I can’t help much there…

Polyester casting resins have a finish a lot like glass - they are very hard, but are susceptible to scratches and can be quite brittle.

A big problem is that the resin tends to not stick once cured. You would really need to rough up the surface and put some good cracks in there to get it to stay in place. Even then, because the resin is fairly brittle, a hard knock could cause the bits that hold it in place to snap off, and then you would have a loose chunk of resin rattling inside the half… Part of the issue is the resin contracts as it cures, so it tends to pull away from smooth surfaces.

You can get some great designs by mixing objects into resin and using that (eg. glitter, ants, nuts and bolts, broken glass, etc.). Just bear in mind, polyester casting resins heat up to around 70 deg. C as they cure, so you can’t use anything that has moisture (this will steam and cause air bubbles), or anything very delicate (eg. flower petals) as these will burn / discolour. You also want to avoid anything that has lots of fibres, hairs, undercuts or grooves, as these will trap air and not leave a clean finish (insects can be a nightmare as air bubbles tend to get stuck along all the feelers, legs, etc. Hairy spiders are the worst, but these are usually too juicy anyway).

Another issue, the resin by itself (at least the stuff I get here) is not UV resistant, so it will slowly yellow and denature over time. You might start with a beautiful, smooth surface, but give it a year or two… You can get additives / UV stabilisers which you can add into the resin, but these tend to give the resin a yellow tint.

This was a beautiful resin yoyo I made. It was perfectly clear with the embedded seashells. A couple of years later and it looks like trash:

I used non flowable silicone to add weight to my phenomizm. It works nicely.