Companionway varnish looks ugly

[Joe500]

My two companionway boards need some varnish but I’m having trouble making them look good. The side of the board that goes on the inside of the boat still looks nice but the side that has been exposed to the elements needs attention. I tried sanding it and then applying cetol marine. I wasn’t able to sand all the old varnish off, as I wasn't sure how long to sand for and how much of the surface to remove. So I sanded first with 120 and then with 220, and then used a paintbrush to put cetol on top.

The result was not pretty, unfortunately. The cetol that went on top of the old varnish looks good. The cetol on top of the grey plywood still looks grey. What should I do? If I keep adding more layers of cetol, will the grey plywood eventually turn a nice brown color? Or do I need to sand everything until it's all grey and then use a varnish other than cetol? Any other suggestions? Someone mentioned to me many years ago that perhaps it was a veneer that I was sanding off and not varnish, but the layer looks pretty thin to me, and I assume it's old varnish.

See attached pictures. Photo 1 - board after sanding before cetol. Photo 2 - board after applying cetol. Photo 3 - other side of board facing inside of the boat. Photo 4 - side view to see layers of board.

[Ixium]

I used acetone on a rag and let it soak a bit, then a light scrapping

I had a teak table that I had to do with a bunch of nooks and crannies. Super annoying. Took about a day.

Sanded afterwards until the grey was gone, and just applied oil.

You can see the middle part of it hadn’t been done too much yet, but the sides turned out well enough

[wholybee]

That needed a lot more work before applying any finish. All the varnish needs to come off. Varnish can usually be easily removed with a heat gun. Heat it until it bubbles, then use a paint scraper while still hot. Be careful not to burn the wood, which will happen right after it starts to bubble if you don't stop.

Once all the varnish is removed, you can either sand it alot to bring back the color, or use a chemical cleaner and brightener, followed by sanding to get a smooth surface for the finish. Using the chemicals is preferred, as it removes less wood.

https://www.youtube.com/watch?v=oRnM--08Iwo

[Joe500]

How can I be sure that there is brown teak underneath, if I sand it enough or remove enough layers with chemicals? I assumed this was some kind of marine plywood, and would be grey throughout.

[Fore and Aft]

Joe500, white paint is my favourite varnish.
I would say those washboards are plywood and once you go through the first veneer, then you can forget getting a good finish.
Cheers

[osprey877]

The panel is likely plywood so heavy sanding likely to be problematic. I sanded mine flush then glued on a new teak veneer. Much easier than trying to restore badly weathered outer ply and when finished it looked like new. Veneer is cheap and readily available at any specialty plywood store.

[Onthewater222]

Like Osprey said or specialty plywood shops sometimes cut to size so why not just put a new piece in, probably about $30 worth

[Bowdrie]

The Cetol has screwed the surface for trying to get a new veneer glued on, and it seems that most of the commonly sold veneers are just about thin enough to read a newspaper thru.
Got a few tools and a modicum of skill? if so, making a new part from some new plywood is not difficult nor particularly expensive.
Or has been suggested, paint it.
A decent paint job will always look better than a half-decent varnish or Cetol job, and a stainless vent will look better too.
The easiest solution? see if you can just buy a new one from the dealer.

[Bowdrie]

Originally Posted by Onthewater222

Like Osprey said or specialty plywood shops sometimes cut to size so why not just put a new piece in, probably about $30 worth

Cutting a piece of plywood is cheap.
That original hatch board in the pic has teak edging on sides and bottom.
That's the "money" part of the job if you hire it out.