Repairing Small Patches of Delaminating Varnish in Interior ?

[dennisail]

My partners boat is of ceder strip construction and what looks like satin or matt varnish on the inside. Can anyone tell me what the finsh might be from the pics? The small side hatches have screw knobs that when open rub on the varnish and have cause delamination in those areas along with wet rot/or soft wood as water got the the ceder. Some don't have the rot just the blemished varnish. The areas of soft wood rare no bigger than a fingernail and probably not too deep and the delamination extends a little further. She has some putty with the boat which appears to be the right colour and looks like it has been used to fix something similar before.

How do I go about fixing this without making a the patches even larger and more unsightly? I am worried about sanding too much as even a sanding block will cover a area much larger than the affected areas.

See pics (sorry for bad pics) this is the worst one. As you see its no big deal but I was hoping to get this before it gets bad.

[PAR]

That's where a person's knuckles have literally rubbed the finish off the ceiling or panel, as they've twisted on that knob.

No, it's not possible to tell what type of finish it is from photos. I could tell with a personal inspection, as could any experienced finisher.

The finish in this area is gone, so you have to feather the surrounding area back, removing all of the flaking material and then reapply more finish. The idea is to fill the damaged area with new finish, but keep the surrounding area from building up. This is a lot easier to say then do, especially on a vertical surface like this appears.

Also if the finish is one of the harder polyurethanes, you'll have difficulty just with the repair approach, but for this, lets assume you can feather the area back and repair it. Do this with 120 grit at first to remove the bulk of the bad stuff and progress through 180 - 220 grit to remove scratches. Sand with the grain. With the old finish tapered back a few inches all around the damage, apply just enough finish to cover the raw wood. To this three or four times, letting the previous coat get very nearly dry before applying the next. This will bulk up some finish over the damage. After all this is well dry (at least 24 hours), block sand the area with the idea of removing any high spots on the damage, not removing additional material in the surrounding areas.

With high spots removed and any lows filled with more finish, you can move onto to finishing the whole area.

This is the "Cliff's" Notes" version and the actual the process could get quite involved, but most settle for considerably less. I'll let you decide when you're done.

Another approach would be a brass, bronze, plastic, stainless scuff plate over the area, knowing it will receive abrasion during the use of that knob. This certainly will be a much easier thing to affix.

[dennisail]

Thanks again Par. The abrasion is not from knuckles but from the knob itself. It hangs downward when it is in the open position. I was going to stick a clear patch of vinyl over the area after I finished it. As I expected this isn't going to be an easy job to get right. I am still not confident enough to try it. I don't want to end up doing the whole boat from stuffing it up!

[SabreKai]

What PAR said, with the added cavit: If it was me doing it, I'd sand the area, and then apply the finish with a modelers' airbrush. Thin the finish down a tad and apply lightly in several coats til the divot is filled. This way you can limit the amount of build up on the existing finish easier, even though its a vertical surface.

Sabre

[David_Old_Jersey]

Originally Posted by PAR

Another approach would be a brass, bronze, plastic, stainless scuff plate over the area, knowing it will receive abrasion during the use of that knob. This certainly will be a much easier thing to affix.

Or wood? (doesn't have to match).

Would be my first choice - especially given that a simple (lol!) refinish will still leave the underlying problem.

If feeling adventurous could even let the scuff plate into the surface for a flush finish..........