Epoxy or Polyurethane

halekai36 · #1 (**permalink**) 03-02-2008

Hi All,

just came back from the boat and pulled my cabin sole out to re-finish it. The under sides have never been coated, been that way since 1979, and there are a few spots of mold beginning to develop and the bottom of the boards have that musty bilge smell to them.

I'm wondering if anyone has used an oil based polyurethane such as Varathane or Minwax to coat the bottoms of the sole. I have West Systems epoxy but I'm running low and would need another gallon but I have tons of oil based polyurethane.

I'm going to coat the under side either way and don't mind buying more West System as I'll certainly use it but it had never occurred to me to try a polyurethane. Our kitchen floor at home is done in a Varathane oil base poly and it gets beat on, spilled on colored on (kids) and sand ground into it from dog paws and it's held up extremely well. I'm going to use Varathane satin for the tops but I'm still undecided on the bottom.

My concern with coating only the bottom with epoxy is that once I do, the bottom will no longer breathe, and any moisture will be forced to "release" through the cabin side polyurethane which may lift it. I'm thinking that a poly may breathe a little better and prevent lifting of the top side..??

P.S. This is not a full strip of the top side just a sand and re-coat as I already have seven coats of gloss polyurethane on it and I just want to convert to satin for a little better "kid grip"..

sailingdog · #2 (**permalink**) 03-02-2008

If it is an actual polyurethane finish, then the wood will be fairly well sealed and won't breath on either side. Don't forget to seal the edges.

halekai36 · #3 (**permalink**) 03-03-2008

After prepping a few of the boards last night in the barn I began applying the polyurethane and the sole is DRINKING it..!! I've now got three coats on the backs of a few boards and it barely looks like one coat...

The problem is I need to re-apply within two hours or wait 72 hours and I'll miss my two hour window today...

padean · #4 (**permalink**) 03-03-2008

I did the same thing to my cabin sole (CS34) last fall. Be sure to clean all the mildew off the underneath side with a chlorine solution before covering, and let them dry out well. I sanded each piece down very slightly to get a fresher layer of wood exposed, and hopefully a better seal.

I chose epoxy and it has worked out well. As mentioned above, be sure to coat the sides as well as the bottom, or the mildew will come back and get under either the polyurethane or epoxy. The epoxy (2 coats) actually seemed to provide a little more structure to the sole. I don't know about the CS 36, but the CS 34 has an unusual liner under the sole that is on the hull, but not quite the hull. Good luck with removal of the mildew stains.

sailingdog · #5 (**permalink**) 03-03-2008

Ouch... that two hour or 72 hour option really stinks.

Faster · #6 (**permalink**) 03-03-2008

You can apply "Ultimate Sole" for a superbly glossy finish and really good "kid grip" as you say.

Wierd... I tried to paste the link to their site and it's not there.....

halekai36 · #7 (**permalink**) 03-03-2008

I actually used Ultimate Sole on my last boat and was not all that impressed with the durability and found it considerably softer, and more scratch prone than Varathane oil based poly. It was also not as easy to flow out and get the finish I wanted..

Perhaps they have since changed the formulation but I'm going to go with what I've had good application and durability experience with. Plus ,this is an over coating to the seven coats of Varathane Gloss already there and I really don't want to strip it again....