Teak bungs and caulking

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Oct 6, 2007
Vessel Name
Vessel Make
1983 42' Present Sundeck
I removed the ceiling in our aft head shower to locate and repair a water leak. I removed all the teak trim pieces, had to drill and then insert a screw on the teak bungs. I have refinished everything with Bristol Finish and plan to reinstall everything this weekend.*I picked up 3/8" bungs last weekend and tried a test fit and found that the small diameter on the bung is too small to get tight on the boards. It looks like I need to belt sand some of the material off. Any ideas? Other questions:
<ul>[*]No glue on plugs I remember. What holds them in?[*]What is the best way to cut flush after installing? Minimize damage to the board finish?[*]What type of black caulk would I use to seal between the trim piece and the FG stall?[/list]Thanks in advance!
It's just about impossible to get a plug truly flush with the surrounding wood without sanding it flush, which of course damages the finish around the plug. I've tried taping carefully around a plug hole and then carefully sanding the plug down without sanding through the tape, but then the plug is proud of the surrounding surface by the thickness of the tape which can be surprisingly obvious.

The common way to get a plug close to the surface is to use a VERY sharp chisel and mallet, angle the chisel a bit up from the surface, and give it a whack with the mallet. And ALWAYS cut in the direction of the grain in the top of the plug, never across it. Cutting across almost guarantees the plug will break off with part of the top below the surface of the wood its in, which means you either have to live with with the "ding" or remove the plug and try again. Cutting with the grain minimizes this possibility although it can still happen, particularly if you try to get super-flush with the chisel. The chisel is just a way to cut most of the excess plug off. You still need to sandpaper it flush.

The risk here is that if the wood in your boat is old, or has faded due to light, sanding the surface, even a bit, will reveal the unexposed or unfaded wood cells underneath and you won't get a match unless you refinish the whole piece. The wood you sand will generally come out darker than the rest.

Very tricky thing, I've found, dealing with already finished wood and trying to get a match in finish. We have almost always simply opted to refinish any wood trim or components we end up having to remove.

We were advised to secure plugs with Tightbond II wood glue (now Tightbond III which is more water resistant). So that's what we use on all plugs, in the deck, on exterior trim, in the interior, wherever.

When we removed all the teak trim in our aft head/shower so we could repaint the walls, we rebedded the trim in Dolfinite. This is available in "natural" (tan) or white. We used natural since it blends to the wood trim fairly well. We did this to prevent moisture from getting trapped behind the trim. However Dolfinite is not an adhesive so if or when the day comes we have to remove the trim again for some reason, it will be easy to take down. Lucky for us, American Marine did not use plugs in the wood trim strips that cover all the wall-to-ceiling and wall-to-wall joints in the heads, so we didn't have to deal with plugs.

We do not use adhesive sealant on things like exterior or interior trim pieces, exterior window frames, etc.. If a piece needs to be bedded to prevent moisture getting behind them we use Dolfinite. But all the popular sealant/adhesive compounds--- 3M 4200, Sikaflex, Life Caulk, etc.--- are available in black if you want to use a material like that. Just don't use 3M 5200 or silicone....

-- Edited by Marin on Tuesday 19th of January 2010 09:56:57 PM
# No glue on plugs I remember. What holds them in?
# What is the best way to cut flush after installing? Minimize damage to the board finish?

Dip them in varnish , although most are a force fit.

To trim the plug requires a draw saw (cuts on the pull not the push) that has no set on one side.

One side is smooth and flat , the other does the cutting.

Not for building a log cabin but the best tool for trimming plugs , try Hamilton Marine or Wood Workers supply , will* probably be Jap made.

A chisel is iffy as many plugs are cut from scrap and will crack , rather than cut easily.


-- Edited by FF on Wednesday 20th of January 2010 06:07:02 AM
FF got it right, use one of those Japanese style draw saws, incredibly thin and flexible blade, very smooth cut requires little sanding and dip in thick varnish to secure.

What I don't understand is if the plugs are too small, how is "belt sanding" them going to make fit better? It looks like a good way to make your fingertips smaller too.
that looks like a great choice on the saw. It shows that Home Depot can get it also. I like the idea of the Dolfinite- but WM does not have it locally nor our Marine supply source. I will need it by Friday when I go to the boat. Are there any alternatives?
Rick- I hear you about the finger pain. I have a pair of pliers for removing spark plug wires and I thought I would hold one plug at a time and sand the bottom off till I get the proper fit. Not all of the pieces have countersunk screws. Probably about 10 would do.
Mr. Forklift,
** Since your work is inside, I would wait until you can order some Dofinite in somehow.* I've used it in the past and eveything everybody is saying about it is true.
Just an idea... would plumber's putty work as an alternative to Dolphinite?
As Dolfinite was forumlated specifically for the marine environment I'm not sure I would be willing to chance using a substitute that wasn't. That doesn't mean plumber's putty wouldn't work, but I think the characteristics needed to bed and seal materials in a boat might be different than what plumbers have to deal with. The two materials may be very similar, but my philosophy is why take a chance?
Good point. So who is a Dolfinite supplier?
Here in Puget Sound almost every marine store, including WM, carries it on the shelf. What can be difficult to find is the white Dolfinite--- most stores like WM seem to carry just the "natural."

In Seattle, I buy any marine supplies we need, including Dolfinite, from Fisheries Supply, which has a huge on-line store as well, just like Defender, WM, Jamestown Distributors, etc. Fisheries Supply almost always has white Dolfinite in stock, too, which is what we use to bed the window frames of our boat.

In Bellingham LFS, Redden, and WM all carry Dolfinite in their stores but I've never seen the white up there.

It used to be that the smallest container you could buy of Dolfinite was a quart. But I see it's also offered in a pint container, although I have never seen one in the stores we use. So at least you don't have to buy a lot more than you need. It has a reasonable shelf life once it's been opened but it doesn't last forever.
I guess my sanding reference was a little confusing. I ASSumed that the bungs I purchased were tapered when in fact they were cylinder shaped. I assume all teak plugs/ bungs are cylinder shaped.

If the plugs aren't already beveled do so by sanding the end of the plugs with 100 grit and tap them into place with a bit of Elmer's.* To trim them, you can either use a Japanese trim saw - very bendy and available from Jamestown Distributors, or you can set a chisel 1/16" of an inch above the flush surface and tap off the exess.* Don't try to chisel them flush or you'll take out Teak below the flush surface.* Sand them flat.* Black silicon would be my choice, since you'll be able to get the piece off again in the future.* Other caulks, you'll break the piece in removing it.

Hope that helps...
Got it. Thanks.
Delfin wrote:

Other caulks, you'll break the piece in removing it.
THis is why we have always been advised to use Dolfinite for this pupose, although it does not come in black.*

As to silicone, well, this is as controversial as anchors apparently.* Some people like to use it on their boats but all the advice we've been given by shipwrights, former shipyard owners, etc. is to not allow a tube of silicone within 100 yards of the boat.* It's not that the material itself doesn't work, it's the potential problems that can result from it coming in contact with the surfaces of the boat.* Since there are other sealants that do as good a job as silcone but without the side-effects, we have seen no reason to use it.

Other caulks, you'll break the piece in removing it.

Removing a plug always costs the plug, or messes it up so it wont be reused

If you simply dip it in varnish the std technique of using a screw in the center will easily pull it , when required.

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