RTV Mold Expected Life

[Jigfishn10]

How long and how many lures can you expect out of these molds? Any way to "doctor" the mold to add more life?

[Mike - Alumilite]

Politician's answer is it depends on type of mold (1 vs 2 piece), type of material being poured, process times, and process itself.

Main factors are: type of material being poured ... Alumisol is very easy on the molds and they will practically last forever, White and RC-3 are much more aggressive and you should only expect 40-60 parts out of a simple mold. Some say they only get 30, some say they get well over a hundred. Rule of thumb is approx 40-60 for a simple piece without drastic undercuts or negative drafts.

Mold release will increase the mold life significantly if used every pour (only needed with resin ... not Alumisol). There are also bake out processes and silicone oil that can be applied to the surface of the mold to recondition them when you are done pouring parts for at least a few days that increases the mold life expectancy.

Another big one with resin is not letting your parts sit in the molds for long periods of time before demolding ... like pouring them at night and demolding in the morning. Short cycle times and removing them from the molds sooner than later helps.

These are the bigger factors that affect the mold life.

Mike

[a-mac]

Since my molds are conical in shape (to fit in a solo cup), I just use cling film plastic wrapping stretched over the top. For some reason, this has helped prolong my molds and helps prevent the silicon from cracking.

To get the mold to fit snugly in the cup, I have to apply a small amount of petroleum jelly to the surface. I've noticed that when I demold the lure, the PJ is gone. I guess the rtv must absorb the PJ. I'm not which helps more, the cling wrap or the PJ, but I've had good success with this.

Just an fyi, the rtv I'm using isn't an alumilite product, so I'm not sure if this process is repeatable with other brands. Also, I think the PJ and cling film help more with storage rather than lure cast increases.

[Jigfishn10]

Thanks for the explanation and tip Mike and Aaron.

I'll have to look into this a little more. I only have 1 mold - 2 pc - right now and that was really a great learning experience, but I can see myself making a couple more. If I had the RTV duplicated with Aluminum, I'm assuming I'll need to apply some type of releasing agent prior to pouring the resin? I'll have to look into that as well.

Again, thanks for the response guys.

[Mike - Alumilite]

Yes, mold release is required everytime. I'd recommend our UMR if you are going to be painting afterwards and the Stoner if you do not need to paint it.

Mike