Underside of Deck

[umecheme]

So, I haven't used any polyester resin on the boat yet, and I'm considering using it for the underside of the deck.  In this situation being a single layer of glass, do I need wax additive to the resin or a finishing resin, or can I use an unwaxed resin for this?  I think I remember reading that it needs the wax to fully cure.   

[RickK]

So are you saying for everything under the deck or just the underside of the deck itself? If just a layer of glass, use waxed, it seals off the air and lets it harden.

[umecheme]

Just the underside of the deck Rick.

[mshugg]

You have 4 choices:

1 Use finishing resin.
2 Add wax to laminating resin (Making your own finishing resin).
3 Apply a coat of waxed gel coat over laminating resin.
4 Use laminating resin, then cover with PVA to seal it from air and allow full cure.

The first three options will leave a waxy surface film that must be completely removed before you glue your deck.  PVA washes off with warm water, so there’s a bit less prep.

[RickK]

Actually I was thinking gelcoat when I answered above.  I don't remember adding anything to the poly when I used it.

[Fish Head]

I used finishing resin and got 2 layers CSM down before it setup. After cured wiped down with denatured alcohol and than roughed the edges up with 80grit. Was not so bad.

[mshugg]

You may want to scrub with detergent and water, or wipe with Xylene or a dewaxer like: https://www.jamestowndistributors.com/userportal/show_product.do?pid=336116 

Denatured Alcohol isn’t a very good solvent for removing wax, and if you sand with any wax on the surface, it spreads the wax into the surface. 

[Mwar410]

I’d add wax to your final coat of resin, it stays gummy if not and is difficult to sand. Being under the deck I would want it to at least feel like it was sealed. You can certainly feel the difference in waxed and unwaxed resin. Just wipe it down where it would be glued to the stringers.

[umecheme]

Thanks all, I've got a gallon of finishing resin headed my way.  Hope to have it sealed up by end of next week.  I'll let you know how it goes!