How to Remove Wooden Bungs to Expose Screws

[Beersmith]

A huge part of this project has been the removal of nearly every single piece of wooden (mostly teak) trim, joinery, cabinetry, etc. for restoration or replacement. Each piece of wood was held in place by slotted (flat) screws which were hidden by plugs called bungs. To access the screws, one must remove the bung first. There were literally THOUSANDS of these bungs and screws that needed removal, and over time I have tried many different methods of removal. As I began to remove the last remaining pieces of trim from the boat, I figured it was time to chronicle my techniques and hopefully give aid to those who need to tackle a similar project in the future.

These are bungs:






As can be seen, the bungs aren't exactly easy to locate. Sometimes you really have to look close with good lighting to find them all. Before you try to remove any piece of wood, triple check that you have located all of the bungs. If you try to pull off a piece and a screw remains, you have a good chance of damaging the wood. Ask me how I know .

Once you have located the bungs, you need to assemble your tools:

-An impact driver with the correct bit (flat head for my screws)
-A drill with a 1/4" forstner bit
-Hammer
-Cheap 1/4" chisel

By cheap chisel, I refer to the kind you can get from Home Depot in a 5 pack for about $15. I am not referring to a fine woodworking chisel. Some woodworking tool enthusiasts see my use of chisels as an improvisational tool and nearly choke on their drink at the misuse of the tool. These people need to chill out a little bit and realize that the chisels I use are very cheap, sturdy, and can take abuse. Save the fine woodworking chisels for their purpose, but don't be afraid to abuse the cheap ones for whatever you can come up with.







The first step is to drill out the bung in the center using the forstner bit. Use a forstner bit that is smaller than the bung size, in my case a 1/4" bit. Apply enough pressure and drill until you reach the screw hidden beneath the bung. Do not drill too hard into the screw or you can tear up the head.



After drilling:





Grab your chisel and insert it into the small hole you made. Work the tip of the chisel around in the hole, applying pressure and spinning it around. The goal is to expose the screw head and slot like so:





Most of the time the screw slot will be filled with glue or wood from the bung, and the chisel is required to clear the screw slot. Usually you can do this with a little effort by hand, but a tough one will require you to hammer the chisel into the slot to clear the junk.

This brings up a point about these slotted screws. Before I developed this system, I began to seriously loathe slot headed screws and cursed the boat maker for using them to hold on everything. The slots are so easy to slip out of (until I found the joy of the impact driver), and easy to strip the slot of its edge. I figured anything other than a slot headed screw would be preferred.

However, the genius of the slot headed screws is that if you strip the head, you can still use it with some working of the chisel and hammer. Insert the chisel into the slot and hammer away on it, using both sides of the chisel to create a deep enough groove for the driver bit to latch onto. If these were phillips or other type of screw heads, you would strip the head and be completely screwed (lol) and would have to resort to more difficult methods of removing the screw. The slotted screws have enough un-cut space on the head to give you room to re-bore the screw slot and give it a new edge. While some screws took a bit of effort with the chisel and hammer, re-stripping the screw, chisel and hammer, repeat....they all eventually came out. Just keep at it and it will work.

Continuing on....depending on the bung and how it was glued in, you may be able to skip the next steps and just use your chisel. Some bungs that are not solidly glued in will come out with a little bit of effort on the chisel. With the chisel inside your pilot hole, you might be able to wedge it underneath the bung and carefully pry it out. Sometimes you might even be able to break up the bung with the chisel in the pilot hole and easily remove it. However, most of my bungs were glued in and wouldn't come apart easily so if that is your case, continue on with the next steps.

With the screw head exposed, there should be enough room to insert your driver into the screw slot and slowly, CAREFULLY, back the screw out. I always test to see if the screw will back out easily turning by hand using either the chisel or another small screwdriver. Sometimes it will back out, but most of the time it requires the impact driver and all the power behind it. As the screw backs out it will push the bung out with it and if all goes right, create a clean hole.





With clean holes, you will be able to refinish the wood or whatever need to do and insert new bungs when re-installed.

Now let me take the time to address a few issues you might come across, and other methods of bung removal. One of the most common methods of bung removal that I see recommended is that of drilling a small pilot hole, then turning a screw into the hole until the bung backs itself out on the screw. This method works just fine, and is a very reliable one....on certain bungs. When bungs are not solidly glued in, this method will back out the bungs easily and efficiently.

However, among the thousands of bungs I removed on Windsong, only about 5% would come out easily with this method. Most of the bungs were glued in solidly and would generally crack and crumble when the screw is trying to pull them out. Not only that, but if the screw really bites on the bung and pulls it out while solidly glued, it might crack and damage the surrounding wood as it is forced out. I ruined many a good bung hole (HA!) using this method.

When the bung cracks under this method, a mess is left behind that needs to be cleared out by the chisel. I find that using the forstner bit to make a large pilot hole for the chisel before anything else is far more efficient and safe for the wood. As mentioned previously, sometimes all you need is the forstner bit hole and chisel to remove the bung. If you need more help, at least you are left with a flush pilot hole instead of a chopped up mess. Through much trial and error, I came to appreciate the method I outlined above.

However, no method is 100% fool-proof. You will strip many screw heads, and if you do, follow the advice I gave above on slotted screws. Sometimes no method seems to work well, and you end up just chiseling away at the wood and damage the surrounding area, or you just accidentally ruin the flush hole. Fear not, as long as it isn't serious and large damage, you can just drill out a larger bung hole later on. For example, on all of the bungs I screwed up I plan on drilling out 1/2" holes to re-plug.

I hope this helps some people who are stuck trying to figure out how to get those damn bungs out. With the removal of this companionway trim, I finally have a completely bare boat. Paint will come soon, and with it momentum towards putting it back together!

[Ram]

Thanks for the info great post !!

[markprice]

Wow all this time I have just drilled a small hole in the center of the bung and then inserted a square drive screw and screwed it in. When the square drive screw hit the screwhead below the bung, the bung backed out sometimes in pieces and sometimes whole. Then the rest is figureing out what type of screwhead you are dealing with and like you showed getting it out. Good tip on the cheap chisel to recut the slot if you have slotheads. Most of mine have been phillips, which I have gotten out or had to use a plug cutter to drill around the stripped screw then plug the bigger hole with larger bung.

Thanks
Mark

[Marksman]

Great post! I have to rebed my teak toerail which requires removal obviously. The rails contain a couple hundred bungs and I've been scratching my head on the best way to do this. If I can't simply remove the nuts from the fasteners and slide them out I will be employing your proven technique. Thanks again for doing the R&D on this, Good form!

[SkiprJohn]

When you replace the bungs it would definitely look better and indicate a more professional job if you matched the grain direction of bung and teak.

Thanks for the description. I've always used a chisel or sharp screwdriver to cut through the bung. I'm going to try your way the next time.

kind regards,

[David_Old_Jersey]

Nice post

FWIW I had a lot of similar to deal with (but it's useful when stuff can be unscrewed - even if it takes a bit of effort!, rather than having been expoxied - something I have born in mind when refitting) .......my technique was to use a small screwdriver (an electritians size) and simply hammer it in - the idea being that could then lever the bung out (sometimes whole - usually not ).....usually takes a bit of a "wiggle" can repeat if one side of the bung not playing ball and also use it as a chisel!

For cleaning the bunghole I used a mix of same screwdriver and a small chisel - including for the threads, but was not looking for perfection. I would also give the screwdriver that was removing the screws a gentle tap into the thread / to break any glue seal as well as making sure it was well inside the slot..........and then slowly (but with great force) start backing the screw out - the screw head was effectively used to "clean" the bunghole, so on some had to repeat the bunghole cleaning process half way through.

When refitting some of the wood I have not always stuck to the original wooden plug approach - especially where I think it may be me doing the next removal job! (even if just to make re-painting / varnishing easier).....so have gone for a mix of semi-domed (chrome screws) with cupped backing washers and simple flat head screws that have only been countersunk and therefore remain visible.

[Cheechako]

Originally Posted by markprice

Wow all this time I have just drilled a small hole in the center of the bung and then inserted a square drive screw and screwed it in. When the square drive screw hit the screwhead below the bung, the bung backed out sometimes in pieces and sometimes whole. Then the rest is figureing out what type of screwhead you are dealing with and like you showed getting it out. Good tip on the cheap chisel to recut the slot if you have slotheads. Most of mine have been phillips, which I have gotten out or had to use a plug cutter to drill around the stripped screw then plug the bigger hole with larger bung.

Thanks
Mark

yeah, just take a small philips head screw, no hole required usually, and force it in with the drill, as mentioned, the bung comes right out when the screw hits the embedded screw...! unless.... you have 8 coats of varnish over, then you might end up with a big chunk alongside coming out also no matter how you do it!

[Beersmith]

Originally Posted by Cheechako

yeah, just take a small philips head screw, no hole required usually, and force it in with the drill, as mentioned, the bung comes right out when the screw hits the embedded screw...! unless.... you have 8 coats of varnish over, then you might end up with a big chunk alongside coming out also no matter how you do it!

I mention near the end of my post what happened when I tried this method. The tougher the glue/varnish used on the bung, the more it breaks up and even potentially damages the surrounding wood. However, if the bung isn't held in place by hard glue or a ton of varnish, the screw in the center method works pretty well. It only worked on a few of them for me, and you don't know if it will work or not until you destroyed the bung and the wood. So I just skipped trying this method and ended up with the system I outlined to limit the damaged wood.

[Cheechako]

Originally Posted by Beersmith

I mention near the end of my post what happened when I tried this method. The tougher the glue/varnish used on the bung, the more it breaks up and even potentially damages the surrounding wood. However, if the bung isn't held in place by hard glue or a ton of varnish, the screw in the center method works pretty well. It only worked on a few of them for me, and you don't know if it will work or not until you destroyed the bung and the wood. So I just skipped trying this method and ended up with the system I outlined to limit the damaged wood.

Yes good point. The majority I've done were teak decks, unglued and unvarnished. I never glue plugs in unless the hole is so buggered that it wont stay! I thought they were meant to be a press fit...? anyway, I suppose some places do glue them...

[Beersmith]

Originally Posted by Cheechako

Yes good point. The majority I've done were teak decks, unglued and unvarnished. I never glue plugs in unless the hole is so buggered that it wont stay! I thought they were meant to be a press fit...? anyway, I suppose some places do glue them...

indeed some do glue them in. I curse them

[Tripod]

Hi neighbor. Great post and great tips. I'm currently doing a bit of this kind of work aboard Adagio. I use essentially the same method you describe - definitely a job for a cheap chisel. I've found a sharp awl also works well to clear the remains of the bung and clear screw slot. Would love to check out your project sometime.

Bob

[Beersmith]

Originally Posted by Tripod

Hi neighbor. Great post and great tips. I'm currently doing a bit of this kind of work aboard Adagio. I use essentially the same method you describe - definitely a job for a cheap chisel. I've found a sharp awl also works well to clear the remains of the bung and clear screw slot. Would love to check out your project sometime.

Bob

Greetings! I am at Oasis Boatyard off Riberia. If you are ever near by and would like to check out the mess that is my boat, I'd love to give you the tour.

-Erick

[Tripod]

Originally Posted by Beersmith

Greetings! I am at Oasis Boatyard off Riberia. If you are ever near by and would like to check out the mess that is my boat, I'd love to give you the tour.

-Erick

Will do. We're walking distance away at the Municipal Marina and aboard most weekends. You're welcome to come check out our mess too. If you run into anything where you need an extra hand, just let me know.

Bob

[roverhi]

I use a 3/4" long #14 hex head self tapping screw and the appropriate nut driver in a Milwaukee 12v screw driver. The hex head screw and driver give are very stable and are easy to start in the center of the bung without a pilot hole. For the most part, they pull out the bung without collateral damage. If the bung doesn't come out clean, the screw usually just screws a hole in the center that is large enough to get a screwdriver bit on the screw. I use a cheap narrow chisel to clean up any of the plug that's left in the puka. Use a cheap chisel and sharpen often because I often hit the screw head, if it's still there, which doesn't any good for the cutting edge of the chisel.

I've always glued the plugs. Fell sorry for anyone who has to remove the bungs I've set. Will start using varnish now that I've got a tapered bung cutter.

Talking of bung cutters, discovered ones made by Hitachi. They have a retractiable center pointer that holds the bit in position so you can cut plugs with a hand drill. I've only used it a couple of times in a hand drill when I needed just a plug or two for a quickie. Worked a treat compared to trying to cut a plug with a standard Fuller type cutter in a hand drill. A bench press definitely makes cutting multiple plugs a lot easier, however, even with the Hitachi bits.

[Beersmith]

Originally Posted by roverhi

Talking of bung cutters, discovered ones made by Hitachi. They have a retractiable center pointer that holds the bit in position so you can cut plugs with a hand drill. I've only used it a couple of times in a hand drill when I needed just a plug or two for a quickie. Worked a treat compared to trying to cut a plug with a standard Fuller type cutter in a hand drill. A bench press definitely makes cutting multiple plugs a lot easier, however, even with the Hitachi bits.

Thanks for that tip. I'll look into the Hitachi cutters when I need to cut new bungs