Interior repair questions

[AlanS]

I am a woodworker, not too familiar with boats...I have been asked to do a few things on a friend's Freedom 40. Cherry interior, teak/holly ply floors.
Questions:
1. The floor is teak and holly ply panels. The top side is obviously finished, but the underside of the panels is NOT. Should we finish the undersides? My intuition tells me that to reduce moisture uptake and to stabilize the panel, we SHOULD...yes? Then, if yes, with WHAT?
2. There are several teak exterior pieces (steps, some mouldings, some minor exterior panels)with a failing finish (a varnish I am assuming), it is peeling. What finish could we put on the pieces to seal/protect without the hassle of varnish. I have used teak oils for interior work, but it seems that this would "wash away" quickly outside the vessel.
3. Is anyone familiar with the finish used on the interior? It appears to be a satin lacquer. The interior needs some minor touch-ups, is there any harm in using lacquer on a sea-worthy vessel?

[Andrew Craig-Bennett]

Off the top of my head:

1. Yes, I reckon you should finish the undersides.

Above all, seal the edges of ply panels with epoxy.

2. So far, science has not come up with any satisfactory alternative to varnish! But there is an extremely good book on varnishing boats, inside and out, called "Brightwork", by Rebecca Wittman, who makes a business of it - recommend investment in a copy, which will also answer (3)

3. It is probably a varnish. It is most unlikely to be what a cabinet maker would identify as a lacquer. But cabin varnishes have a different formulation.

[sdowney717]

try Nyalic.
crystal clear nylonic polymer coating 100% uv proof.
goes on like water and is 100% waterproof.
There are some really interesting coatings out there that few know about.
www.nyalic.com (http://www.nyalic.com)

[Stiletto]

I would think that there is no harm in using laquer in itself on wood , but my experience is that other finishes often react with laquer on top of them. You dont want a wrinkly finish!

[JimConlin]

The builder, Freedom Yachts (http://www.freedomyachts.com/) might be able to answer your questions about the original construction and materials.

[Bob Smalser]

Lotsa individual choices here that work....but:

Seal the underside of the plywood with whatever you are using as a topcoat....the first coat thinned. If it's thick plywood I saturate the bare side with linseed-turps-drier and let it dry a couple weeks, first.

Either varnish or oil on the teak...the one I choose is based on how conscientious the owner will or won't be about renewing the oil a couple times a year. Won't be any fun removing all that oxidation next time if it's neglected.

I prefer alkyd spar varnish like Epiphanes....it all has to be removed at some point in the future and poly is a relative horror story to repair when it chips.

I doubt the interior cherry is done in lacquer....rub an underside patch of finish with acetone on 0000 steel wool to check....if you get sticky finish on the wool, it's lacquer and must either be entirely removed and cleaned...or be recoated with lacquer.

If it is lacquer....a poor choice IMO (brittle and doesn't like wood movement or sunlight)...then Behlens and other make a brushing lacquer that can be done in place after cleaning and scuffing the old surface, and filling any small chips with a thick flavor of cyano glue like Hotstuff brand.

If there's lots of chipping/crazing, then lightly strip that surface with Formby's Refinisher and 0000 steel wool so you don't lose your stain/sealer and be forced to resand.

Dunno where you are...but some of these procedures don't much like cold, damp weather.

[sdowney717]

Nyalic wont chip crack peel yellow
Nyalic never needs sanding it is self annealing, just paint more on! It will melt right into the old coating.
It is 100% UV proof.
It is clear and colorless.
If you used it on the inside, it would need no recoating, Nyalic eventualy wears away from surfaces exposed outdoors. But it takes many years.
Few people are aware of this product.

[Bob Smalser]

DO NOT use this product on new finishes or new paints. The nyalic specs don't say much about compatability over or under finishes except "old paint".

The specs do say it is thinned with xylene or lacquer, which means it may...may be compatible with lacquer.

Like my acetone and wool test above, test each product you intent to topcoat over the old finish before going final.

[sdowney717]

Use it like varninsh. Dont paint it over a varnish coating. You can paint it over stain.
Nyalic is painted over other paints all the time commercially. It is a very thin watery coating.

[Bruce Hooke]

FWIW - I think it should be noted that teak decks and other teak fittings on the decks of boats are quite commonly oiled. The oil does not wash away. As noted by others, to keep the teak looking pretty the oil does need to be renewed once or twice a year, but this is easy to do. If this step is ignored then the teak will turn grey -- this does not hurt the teak but it is more work to get it back to brown if you don't like grey! Varnish will probably look prettier (more gloss and all that) but it is more work to apply and maintain.