Recommended plywood sealer?

[MushCreek]

I recently ordered a gallon of Pettit 2018. The vendor waited two weeks before telling me that it is no longer available from them. With that, I need some plywood sealer. Any recommendations? The Pettit is a lot more expensive by the quart, but most places don't carry gallons. The plywood is meranti marine. Thanks!

[wizbang 13]

Cpes

[David G]

Tell us more...

Is this to go under some other topcoat? What?

[Ian McColgin]

20 or 30 years ago I helped a friend and his pal build a couple of Gloucester Gulls. One boat was sealed with CPES. Both boats lived year round otsn the beach, got painted once a year, a normal beach boat life. Last time I saw the Gulls about ten years ago. The CPES'd boat was in great shape. The other was reaching the plywood limit. Worth the price.

[JimConlin]

I’ve gotten to like Jamestown’s TotalBoat 2-part epoxy primer.

[MushCreek]

I'll top coat it with a marine one-part paint. I haven't selected the paint yet, either. How is the epoxy primer for sanding? I nixxed covering the whole hull with epoxy because it is so hard to sand. The boat will be stored indoors.

[TerryLL]

CPES is incredibly stinky stuff. You can make your own version by thinning low viscosity epoxy with denatured alcohol instead of acetone.

[wizbang 13]

CPES is incredibly stinky stuff. You can make your own version by thinning low viscosity epoxy with denatured alcohol instead of acetone.

No you cant
anyway , CPES goes into the wood , it does not sit on top of it , so there is no or minimal sanding . Yea it stinks, for a day .

[MushCreek]

The odor isn't a problem, as I wear a chemical respirator working with the stuff anyway. Does CPES need to be sanded or treated in some way before putting on a top coat? Is it better to go one coat of CPES, or two? Thanks!

[wizbang 13]

The wood might like two blasts of CPES, softwood takes more than hardwood. As soon as it seems to be laying ON the wood rather than penetrating… stop. Switch to whatever normal paint schedule you like . Water, alkyd,epoxy or urethane .

[TerryLL]

No you cant
anyway , CPES goes into the wood , it does not sit on top of it , so there is no or minimal sanding . Yea it stinks, for a day .

The epoxy label says you can, and I have done it. Why do you say no?

[Clinton B Chase]

People on the Forum love their CPES - use industry standard stuff, typically a low viscosity, non blush epoxy or West with special hardener.

[TerryLL]

CPES is basic two-part epoxy thinned out with xylene, toluene, various esters, and alcohol. If you don't care about losing a bunch of brain cells, that's the stuff to use.

Total Boat offers a low-viscosity two-part penetrating epoxy, 100% solids, that can be thinned 50% with alcohol. You'll get a similar result without the toxic off-gassing.

[willin woodworks]

I switched to the TotalBoat stuff a couple of years ago after I used up my stash of Smith's CPES. Thinned with denatured alcohol it seems to do exactly what Smiths did. Im perfectly happy with it.

[MushCreek]

Some of the things I read about pot life concern me. I have an 18' boat to paint with the stuff. Do you mix a new batch every 15 minutes, or? Years ago when I worked with polyester resin, I'd refrigerate it, then mix it in a metal can, and put the can in an ice bucket. Keeping it cold until spreading it on the intended surface slows it way down, extending pot life. I assume epoxy is similar?

[TerryLL]

Some of the things I read about pot life concern me. I have an 18' boat to paint with the stuff. Do you mix a new batch every 15 minutes, or? Years ago when I worked with polyester resin, I'd refrigerate it, then mix it in a metal can, and put the can in an ice bucket. Keeping it cold until spreading it on the intended surface slows it way down, extending pot life. I assume epoxy is similar?

Pot life and your ability to get the stuff applied is a balancing act. I believe CPES recommends only mixing what you can apply in 20 minutes, and that certainly will vary with temperature. That is the nature of epoxy. Mix small batches and work quickly.

[Christopher Morgan]

What would be the advantage of using a straight epoxy or penetrating epoxy under paint compared to an epoxy primer like Interlux's Primekote (404/414)?

[JimConlin]

CPES goes into the wood and then slowly evaporates, being mostly solvent.

[willin woodworks]

You dont want pot life, you want pan life. Surface area is your friend. Mix the stuff and pour it into a roller pan, not a pot; it will last a lot longer without kicking.

[MushCreek]

There seem to be different types of CPES. Smith talks about pot life of hours, while others say 15-20 minutes. Hours would be better for this old man.

[W Grabow]

"I nixxed covering the whole hull with epoxy because it is so hard to sand."

I use epoxy often, but I know what you mean about sanding an entire hull. I will if I have to, but try to avoid it.

[Ian McColgin]

CPES is so thin that the cured surface is as smooth or as rough as you left it. Sand your wood smooth before adding CPES to seal. While most quality marine plywood is already quite smooth, but most big box ply has a wavy grain that will sooner of later need some filler.

My best luck for smooth hull or surface for sign painting was:

Sand as smooth as possible down to 120#;

CPES soaking in but no puddling;

Wash away amine blush;

Block or long board sand to 120#;

Wipe with acetone to craze depressions that sanding did not reach;

Smoothly plaster with epoxy thickened with microballoons;

Wash off amine blush;

Sand flat to whatever level of perfection suits;

Tack clean;

Paint or other finish.

G'luck

[pcford]

I recently ordered a gallon of Pettit 2018. The vendor waited two weeks before telling me that it is no longer available from them. With that, I need some plywood sealer. Any recommendations? The Pettit is a lot more expensive by the quart, but most places don't carry gallons. The plywood is meranti marine. Thanks!

Or you could buy 2018 from Fisheries...they have an active interstate shipping dept...they have to ship to Alaska all the time.
https://www.fisheriessupply.com/boat...nd-protectants

[MushCreek]

As I said, the Pettit is a lot more expensive by the quart. I had ordered a gallon for $77; less than $20 a quart. Fisheries is $46 a quart. I'm doing the inside and outside of an 18' boat.

[wobide3]

I'm sorry to hear that the vendor was unable to fulfill your order for Pettit 2018. When it comes to selecting a plywood sealer for marine use, there are several options available. Here are a few recommendations:


TotalBoat Wood Sealer - This two-part marine-grade epoxy sealer is designed to penetrate and seal wood fibers, providing long-lasting protection against moisture and UV damage. It can be used on both old and new wood, and is compatible with a wide range of marine coatings.


Interlux Clear Wood Sealer - This clear, water-resistant sealer is formulated to protect marine plywood against moisture and abrasion. It can be used as a stand-alone coating or as a base coat for varnish or paint.


Epifanes Wood Sealer - This clear sealer is designed to protect marine plywood against moisture and UV damage. It can be used on both new and old wood, and can be overcoated with a variety of marine finishes.


Smith's Clear Penetrating Epoxy Sealer - This two-part epoxy sealer is designed to penetrate and seal wood fibers, providing long-lasting protection against moisture and decay. It can be used on both above and below the waterline, and can be overcoated with a variety of marine finishes.


All of these options are suitable for use on meranti marine plywood, and should provide long-lasting protection against moisture and UV damage.

[MushCreek]

I should have followed up; I ended up going with the Smith's CPES. It was easy to work with, and I guess it helped. Two coats were not enough, but that's all I could afford, so it will have to do. Meranti seems awfully dry and thirsty. The solid wood bits sealed up in one coat.

[MushCreek]

A further update- I've finished painting the outside of the boat. It's not perfect, but it's as good as it's going to be for now. I figured it costs me about $50 per coat of product, and I've put on 6 coats total. Two coats of CPES, primer, and three coats of paint, with lots of sanding in between. Apply a $50 coat of paint, and sand $45 worth off. The problem is this: Nothing filled the grain on the meranti. Due to the hundreds of screw holes, I filled them with epoxy putty. No matter how close you apply it, it fills in the grain surrounding the hole. As a result, the boat has some wood grain, with hundreds of shiny spots where the grain is fully filled in. Of course, I painted it a dramatic dark green, which shows every imperfection. Lesson learned; I should have painter her with a semi-gloss white, like I'm going to do on the inside.

[wizbang 13]

I'm going to guess that you did something wrong, for meranti grain not to "fill".
perhaps excessive "sanding off".
perhaps your choice of "epoxy putty"
perhaps only one coat of primer with three topcoats .
the shiny spots where the screw hole were.....the whole boat supposed to be like dat
don't proceed to topcoats until the undercoater looks as good as it can

[MushCreek]

The epoxy putty is simply thickened epoxy. I thickened it with wood flour. The stuff is harder than a woodpecker's lips. You have to be careful sanding, because it's so much harder than the surrounding wood.

[wizbang 13]

That's why they make special fillers that are not ten times harder than wood
WEST 407 and WEST 410
wood flour ....pffft