Replacing Teak Deck Screws and Bungs

As a teak deck ages and wears down, the teak screw covers, or bungs, will come off. You normally can't just put on a new one as there is not enough clearance above the top of the screw to secure it. The proper fix is to take out the screw, drill out the hole a little lower, and replace the screw (with some sealant) and cover.

What you'll need:
1. Forstner drill bit 3/8" diameter. This drill bit allows you to clean up the existing hole, and if necessary, drill deeper into the wood to provide more clearance above the screw. The Forstner bit leaves a flat (not beveled) bottom to the hole.
2. Specialty deck screws. These screws are of a flat head sheet metal design, but there is no countersink under the head, allowing for the screw to sit lower in the hole. This is important since your deck is getting thinner, and you need all the clearance you can get on top of the screw for the screw cover. Hallberg-Rassy parts (info@hr-parts.com, www.hr-parts.com) sells very nice torx drive deck replacment screws and covers.
3. Torx hand driver bit. For the screws.
4. A saw that cuts the bungs off flat. Sorry, I don't know what these are called. There are two types; the first is the flexible blade Japanese wood saw. The second is a saw that allows you to cut flush above the work. Both are much superior than any chisel. The problem with the chisel is that if the wood splits, the crack propogates in random ways, potentially taking out wood below deck level. You can find the saws and Forstner bit at a woodworking store. Home Depot and Lowes did not have them when I checked.
5. Mallet. To whack (gently) the new screw cover back into the hole. Lately, I have not been putting any adhesive in the hole to secure the cover, it seems like the friction alone has kept the covers in place. Plus the adhesive oozes out of the hole and stains the deck.
6. Sealant/adhesive. I stick this on the threads of the screws before insertion to waterproof the hole. 3m 4200 is nice, as it remains a bit workable. Others recommend other sealants.

Notes:
1. Be careful: Don't drill too much teak out!
2. Screws not necessary: Some people believe that on an HR, it is not necessary to put a screw back into the hole. Just clean it, plug it with sealant, and put the screw cover back on. Hallberg-Rassy glues its decks on, and in most deck location the screws may not be necessary. If at the end of a board, or in a complex location, I'd use a screw, though.
3. Buy the saw. These saws are great, if you do it right, no sanding is required!