Reply
 
Thread Tools Display Modes
 
Old 11-16-2014, 06:12 AM   #1
Veteran Member
 
alberto's Avatar
 
City: Valencia
Country: Spain
Vessel Name: Song of Summer
Vessel Model: GB 42 Classic
Join Date: Nov 2012
Posts: 85
Teak bungs black marks

Hi,

Some of the repaired bungs show these black stains around the.
Do you know why?
How to remove them?
Thanks
Attached Thumbnails
Click image for larger version

Name:	IMG_0438 - copia.jpg
Views:	129
Size:	154.1 KB
ID:	34492  
__________________
Advertisement

alberto is offline   Reply With Quote
Old 11-16-2014, 07:44 AM   #2
Guru
 
Capt.Bill11's Avatar
 
City: Sarasota/Ft. Lauderdale
Country: USA
Join Date: Apr 2014
Posts: 5,422
Are there SS screws under the bungs? Usually the black marks form due to water getting under them and reacting with the SS screw.

Since the discoloration is coming from the bottom up, the only way I have found to remove it in most cases is to remove the bung, change the screw to a bronze one, drill the hole over size to remove the discoloration and rehung it with a larger bung.
__________________

Capt.Bill11 is offline   Reply With Quote
Old 11-16-2014, 11:55 AM   #3
Guru
 
Scary's Avatar
 
City: Walnut Grove Ca
Country: USA
Vessel Name: Cary'D Away
Vessel Model: Hatteras 48 LRC
Join Date: Apr 2012
Posts: 884
+1

Quote:
Originally Posted by Capt.Bill11 View Post
Are there SS screws under the bungs? Usually the black marks form due to water getting under them and reacting with the SS screw.

Since the discoloration is coming from the bottom up, the only way I have found to remove it in most cases is to remove the bung, change the screw to a bronze one, drill the hole over size to remove the discoloration and rehung it with a larger bung.
You can remove the bungs with a small screw driven through the center of the bung. Pre- drill the bung with a small drill before running the screw. Some guys like to dig out the bung with and awl or 1/4 inch chisel, I find it is really easy to dent the edge of the bung hole this way so the screw method is a safer system. if your brave and good with a drill, you can drill them out with a brad point drill of the same size or slightly smaller. If your careful with the brad point drill you can remove the black stain and glue the new bung in with Tight Bond water proof glue. The green bottle with a duck on it. The tight bond is about the color of natural teak and blends pretty well. A lot of people like using Varnish to glue in bungs, this is fine for varnished surfaces. I install a lot of bungs, I like using Tightbond as it sands off and the glue line is almost invisible. If the stains are really bad of course you can install the next size bung.
Scary is offline   Reply With Quote
Old 11-16-2014, 02:26 PM   #4
Veteran Member
 
alberto's Avatar
 
City: Valencia
Country: Spain
Vessel Name: Song of Summer
Vessel Model: GB 42 Classic
Join Date: Nov 2012
Posts: 85
Thanks,
I am realizing that all with the black stains are the ones that I replaced with ss....
alberto is offline   Reply With Quote
Old 11-16-2014, 02:45 PM   #5
OFB
Guru
 
OFB's Avatar
 
City: Richmond bc
Country: Canada
Vessel Name: Invader no1
Vessel Model: Kishi Boat works
Join Date: Mar 2012
Posts: 640
Alberto, the black on the teak around the bungs is from water penetration, usually from water ingress through the finish. Its a sign of something needed to be sealed up. You can try and "bleach" the wood back for color but the black is telling of water penetration. Needs to be sealed. IMO. SS is not the issue water is. Take pictures, document and watch cause the wood will rot out, the core will be an issue of not sealed. Again all my opinion.
OFB is offline   Reply With Quote
Old 11-16-2014, 08:47 PM   #6
Guru
 
Xsbank's Avatar
 
City: Pender Harbour, BC
Country: Canada
Vessel Name: Gwaii Haanas
Vessel Model: Vancouver Shipyards Custom Aluminum 52
Join Date: Sep 2013
Posts: 2,447
I used the small blade of a Swiss Army knife to remove, oh, 10,000 bungs. Well, it felt like that many! Stick the blade down the grain of the plug and just pry it up. No damage to the hole. Usually the bung split in half and was very easy to remove.

Use bronze screws, they are soft and can break easily so pre drill the holes. You might seal the hole with the bung but water penetrates the wood anyway so the fastener may get wet. I used carpenter's glue but many suggest epoxy. Good luck getting out a bung glued in with epoxy!
__________________
Don't believe everything that you think.
Xsbank is offline   Reply With Quote
Old 11-16-2014, 10:01 PM   #7
Guru
 
Capt.Bill11's Avatar
 
City: Sarasota/Ft. Lauderdale
Country: USA
Join Date: Apr 2014
Posts: 5,422
Quote:
Originally Posted by OFB View Post
Alberto, the black on the teak around the bungs is from water penetration, usually from water ingress through the finish. Its a sign of something needed to be sealed up. You can try and "bleach" the wood back for color but the black is telling of water penetration. Needs to be sealed. IMO. SS is not the issue water is. Take pictures, document and watch cause the wood will rot out, the core will be an issue of not sealed. Again all my opinion.
I believe the plugs he is referring to are in the deck. So there is no finish over them per say. And the black discoloration is coming up the seam between the plug and deck. There is no way to bleach the discoloration out since it goes all the way down into or up along the seam. So you can bleach the surface all you want but the stain will still be there or just come back.
Capt.Bill11 is offline   Reply With Quote
Old 11-17-2014, 08:00 AM   #8
TF Site Team
 
Larry M's Avatar
 
City: JAX, FL
Country: USA
Vessel Name: Hobo
Vessel Model: Krogen 42-120
Join Date: Nov 2008
Posts: 5,742
Quote:
Originally Posted by Scary View Post
...glue the new bung in with Tight Bond water proof glue. The green bottle with a duck on it. The tight bond is about the color of natural teak and blends pretty well. A lot of people like using Varnish to glue in bungs, this is fine for varnished surfaces. I install a lot of bungs, I like using Tightbond as it sands off and the glue line is almost invisible. If the stains are really bad of course you can install the next size bung.
I like the Tight Bond idea alot. I've always used epoxy for exterior or varnish for interior work on bungs. The epoxy is hard to clean up around the plugs unless I'm replacing planks and sanding. I've also found the epoxy leaves a dark glue line between the plank and bung over time as it ages.
Larry M is offline   Reply With Quote
Old 11-18-2014, 03:24 PM   #9
OFB
Guru
 
OFB's Avatar
 
City: Richmond bc
Country: Canada
Vessel Name: Invader no1
Vessel Model: Kishi Boat works
Join Date: Mar 2012
Posts: 640
Quote:
Originally Posted by Capt.Bill11 View Post
I believe the plugs he is referring to are in the deck. So there is no finish over them per say. And the black discoloration is coming up the seam between the plug and deck. There is no way to bleach the discoloration out since it goes all the way down into or up along the seam. So you can bleach the surface all you want but the stain will still be there or just come back.
Capt Bill

My point really is that its water getting to the fasteners that's the issue. Not that the fasteners are stainless. The finish is natural teak on the decks including the bungs. The black is caused by water getting in under the bung, under that teak finish. But ya my written word is not so grand. Sorry.
OFB is offline   Reply With Quote
Old 11-18-2014, 04:44 PM   #10
Veteran Member
 
alberto's Avatar
 
City: Valencia
Country: Spain
Vessel Name: Song of Summer
Vessel Model: GB 42 Classic
Join Date: Nov 2012
Posts: 85
Thanks again,
What I did really was to subsitute brass fasteners by ss fasteners after re-drilling to gain space for the bungs.
Maybe the point is that I used carpenter white glue, which is enough for retention but obviously not for sealing.
I will do some testing, as this is an interesting subject, (still many bungs to replace...)
alberto is offline   Reply With Quote
Old 11-18-2014, 08:17 PM   #11
Guru
 
Capt.Bill11's Avatar
 
City: Sarasota/Ft. Lauderdale
Country: USA
Join Date: Apr 2014
Posts: 5,422
Quote:
Originally Posted by OFB View Post
Capt Bill

My point really is that its water getting to the fasteners that's the issue. Not that the fasteners are stainless. The finish is natural teak on the decks including the bungs. The black is caused by water getting in under the bung, under that teak finish. But ya my written word is not so grand. Sorry.
I see what you mean now. Yes water is the issue. But I've only seen the black rings form around bungs that are covering SS screws. I don't think I've ever seen them form around bungs over bronze screws.
Capt.Bill11 is offline   Reply With Quote
Old 11-18-2014, 11:38 PM   #12
Guru
 
boatpoker's Avatar
 
City: Port Credit
Country: Ontario
Vessel Name: DIRT FREE
Vessel Model: Benford Fantail 38
Join Date: Sep 2012
Posts: 2,011
Stainless steel corrodes with the absence of oxygen. Water weeps through the wood and becomes stagnant. Stagnant water is simply de-oxygenated water. Stainless steel is inappropriate for this purpose, better off with bronze.
__________________

__________________
If you can live with the consequences, go for it - wg
Y'am what I y'am an' thats' all that y'am - Popeye
As God is my witness, I thought turkey's could fly. Mr.C
boatpoker is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 04:03 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012