Thursday, January 5, 2012

How To Remove Wood Bungs to Expose Screws

Windsong shows us how to remove wood bungs to access the screws. Here is his method...
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.

 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.

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.

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