Polyester resin wax question

Hello, I just finished up my old glastron. I put a new transom, stringer, deck and seats in. I used vinyl ester resin from USCOMPOSITE .com and just ran out of resin.

My question is do I need to purchase more resin to put a final coat with the wax additive in or can I get by without a layer of waxed resin? I dont mind the extra work I just dont want to do more work than I have to. The information I found online shows that the wax will allow the surface resin to cure tack free but all the resin is clear, rock hard, shiny and smooth. Thanks

Re: Polyester resin wax question

If the container does not specifically state that it is a Layup Resin, it is most likely the more common Finishing Resin.
If it is "Clear, rock hard, shiny and smooth", it is a Finishing Resin with the wax.
Layup Resin, without the wax, will leave a tacky uncured surface that the next layers can Bond to.

If you were to lay more glass over the top of a Finishing Resin, it will not "Bond", it will stick and look just fine today, but as soon as is sees some significant stress, the layers will separate.

It might last a week or it might last a decade. But the defect is in there.

If you want to add another layer you will need to sand or otherwise remove the wax surface Mechanically to get to the underlying core glass. Solvent washing will not do it.

Re: Polyester resin wax question

The resin I used is unwaxed. I bought a can of wax additive but did not use it. My plan was to use it on the last layer but I ran out of resin. The Resin I used is definitly wax free. Thats why I am asking if I really need it.

My fiberglass work is done. The only reason I would need to add another coat of resin is to do a coat with the wax additive. My question is do I need a layer of waxed resin or can I leave it as is. Thanks for the reply.

Re: Polyester resin wax question

The Wax/Finishing Resin is a cosmetic issue.
If it is hard and smooth and not sticky enough to attract dirt, and you like it, you are good to go.
If you plan to finish it off with a coarse spray of GelCoat or Paint, even better.
100% bare Poly Resin will weather, and if exposed to direct Sunlight, deteriorate quickly.