New to polyester resin

[Blueknarr]

Poly don't care if used as mold or as part. Only final layer of mold or part needs wax.

 

[ondarvr]

I'd say the percent of waxed resin used would be in the 0.000000000001% range. And that's rounding it up buy a huge margin.

For the most part manufacturers and builders never put wax in the resin for any reason. And only a small percent of DIYrs do.

There are a few situations where adding wax may help, but they aren't common. At one time wax and similar vapor suppressants were used to reduce odor and emissions, but it complicated life for everyone involved, so they fell out of favor.

 

[rxcomposite]

Please explain. why iso and mold making resin need wax ?

"Most polyesters are air inhibited and will not cure when exposed to air. Typically, paraffin is added to the resin formulation, which has the effect of sealing the surface during the cure process. However, the wax film on the surface presents a problem for secondary bonding or finishing and must be physically removed. Non-air inhibited resins do not present this problem and are therefore, more widely accepted in the marine industry." Marine Composites- Eric Greene and Associates

Poly resins are hygroscopic, meaning it absorbs moisture. It grabs the moisture from the air preventing full cure and will remain tacky for a long time. The only way to prevent it is by adding wax solution. The wax floats to the surface sealing it and preventing moisture from being absorbed.

As the article says, it must must be removed before any secondary bond is made. The only practical use to add wax solution is when you are coating the outside layer of the part which needs to cure properly. Add wax solution to the resin or gelcoat for it to cure properly. You need to remove it by acetone or any dewaxing solution then light sanding before painting.

When working on a female mold, the first layer whether it is resin or gelcoat does not need wax solution as it is in contact with the mold. The second/last layer does not need wax because as always, you need to add additional structure such as bulkheads and stiffeners.

If it is a male mold, add wax solution to the last layer. There is no secondary bond to the outside of the hull.

 

[ondarvr]

Some companies that build chemical tanks and pipe still use a waxed resin coat that includes a UV inhibitor. Most apply a gel coat finish, but some like the resin look so you can still see the glass laminate. Without the wax coating you can get water spotting and fiber bloom. This is one of the few instances where the raw laminate look is an exposed cosmetic finish.

 

[redreuben]

Poly resin 101. nothing specific to iso or mold resin.
red herring

 

[mudwasiu]

The PVA curing method is a solid choice if you want to avoid wax. Many DIYers use it successfully. You don't necessarily need an HPLV gun; a spray bottle can work too, just ensure a fine mist. It might take some trial and error to find the right dilution for your application. Don't worry; it's not crazy to opt for polyester – cost savings can make a big difference in the long run. Check out https://zhinkxc.com/ for more insights.