Black spots on the wood - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance
 Not a Member? 


Like Tree5Likes
Reply
 
LinkBack Thread Tools
  #1  
Old 08-22-2012
Member
 
Join Date: Jul 2007
Location: Vancouver, B.C.
Posts: 44
Thanks: 2
Thanked 0 Times in 0 Posts
Rep Power: 0
RossC32 is on a distinguished road
Black spots on the wood

I've been working on refinishing the wood toe rails on my boat. I've had good feedback from Sailnet members on how to remove the old varnish (thread: "Power tool for sanding toe rail") and now I'd like to tap the collective knowledge on this forum on how best to deal with the parts of the rail that have become so aged/exposed/worn that there are very dark spots in the wood. I would guess that this is the beginning signs of surface rot, maybe.

How have other people effectively dealt with this? Should I sand more deeply, bleach it, sell the boat and buy a big-screen T.V.?

Ross
Reply With Quote Share with Facebook
  #2  
Old 08-22-2012
PorFin's Avatar
Señor Member
 
Join Date: Sep 2007
Posts: 1,340
Thanks: 1
Thanked 8 Times in 8 Posts
Rep Power: 8
PorFin is on a distinguished road
Re: Black spots on the wood

Ross,

The discoloration is perfectly normal, and is NOT indicative of rot. What I'd recommend is to begin with the least destructive method first then progress to bigger guns as required.

That said, you probably won't need to go beyond a gentle cleaning with water, a white scrub pad and some Bar Keeper's Friend.


The key ingredient in BKF is oxalic acid, which will bleach out the discolored areas. It also has no abrasive material that will do damage to your teak. Likewise, use the white scrub pad (never a green one) to keep from removing the softer wood between the growth rings.

You could also try a commercial teak cleaner, but I'd try BKF first since it's cheap and a can will last a long time.
Reply With Quote Share with Facebook
  #3  
Old 08-22-2012
Senior Member
 
Join Date: Oct 2011
Posts: 1,322
Thanks: 6
Thanked 24 Times in 24 Posts
Rep Power: 3
Seaduction is on a distinguished road
Re: Black spots on the wood

My experience has been that the dark spots are "mold." I just use household bleach to bleach the spots back to bright teak.
Reply With Quote Share with Facebook
  #4  
Old 08-22-2012
TQA's Avatar
TQA TQA is offline
Bombay Explorer 44
 
Join Date: Apr 2009
Posts: 2,549
Thanks: 0
Thanked 41 Times in 37 Posts
Rep Power: 6
TQA is on a distinguished road
Re: Black spots on the wood

Household bleach works fine - may need more than one application.

Wash the bleached spots in fresh water afterwards.

Doing it at this moment on my woodwork.
Reply With Quote Share with Facebook
  #5  
Old 08-22-2012
oysterman23's Avatar
S/V Wyndwitch - Morgan 24
 
Join Date: Jul 2011
Location: South Shore LI. NY
Posts: 292
Thanks: 91
Thanked 7 Times in 6 Posts
Rep Power: 4
oysterman23 is on a distinguished road
Re: Black spots on the wood

I go with PorFin on the Bar Keepers Friend. If the discolorations remain after a scrubbing with that product, go to West Marine or a paint store and buy powdered Oxalic acid which you can mix to a more concentrated solution in warm water, and then load into either a spray bottle or a small garden sprayer (works best) give it all a good soaking keep it moist until the wood appears uniform. You can do it in stages. I have and do use all sorts of things on teak and exterior woods but Oxalic Acid is far better than alot of people think and need not be used at harsh levels unless you are just plain impatient....If it is giving your hands a good tingle when sprinkled on the back of your hand it is plenty good enough to remove the discoloration and kill most mold or fungal activity. Rinse real well, and if you want to be very very thorough then use a very mild soap to neutralize an further activity. I have recently done this to the Morgan I have and the teak is now fresh and clean as new....this includes the seam area on toe rails where growth has a tendency to hide on older boats
cod

Last edited by oysterman23; 08-22-2012 at 06:35 PM.
Reply With Quote Share with Facebook
  #6  
Old 08-22-2012
Senior Member
 
Join Date: Oct 2011
Posts: 1,322
Thanks: 6
Thanked 24 Times in 24 Posts
Rep Power: 3
Seaduction is on a distinguished road
Re: Black spots on the wood

They will all work. Wood bleaches vary in strength from sodium hydroxide (very caustic), chlorine bleach (sodium hypochlorite solution) and oxalic acid. The latter two work great without need to neutralize the caustic pH. Using sodium hydroxide requires application of an acid to neutralize the caustic solution (as in typical 2-part teak cleaners).
By the way, thorough rinsing should be done with clean water.

Last edited by Seaduction; 08-22-2012 at 07:11 PM. Reason: further clarification
Reply With Quote Share with Facebook
  #7  
Old 08-23-2012
CharlieCobra's Avatar
On the hard
 
Join Date: May 2006
Location: Bellingham, WA.
Posts: 3,503
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 10
CharlieCobra has a spectacular aura about CharlieCobra has a spectacular aura about
Re: Black spots on the wood

When ya rinse be sure to flood it with water, not spray it off.
__________________
Baggett and Sons Marine Restoration
The Landing at Colony Wharf
Bellingham, WA.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
  #8  
Old 08-23-2012
Senior Member
 
Join Date: Feb 2010
Location: Narragansett Bay
Posts: 8,925
Thanks: 10
Thanked 135 Times in 121 Posts
Rep Power: 6
Minnewaska will become famous soon enough Minnewaska will become famous soon enough
Re: Black spots on the wood

Quote:
Originally Posted by CharlieCobra View Post
When ya rinse be sure to flood it with water, not spray it off.
That's a new one on me. How come?
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Jeanneau 54DS

In the harsh marine environment, something is always in need of repair. Margaritas fix everything.
Reply With Quote Share with Facebook
  #9  
Old 08-23-2012
jimrafford's Avatar
Senior Member
 
Join Date: Jan 2011
Location: ct
Posts: 567
Thanks: 0
Thanked 10 Times in 10 Posts
Rep Power: 4
jimrafford is on a distinguished road
Re: Black spots on the wood

I assume spraying can splash the bleach places you don't want it. Like canvas. Don't ask how I know.
Jim
__________________
S/V Deja Vu
CS 40
Reply With Quote Share with Facebook
  #10  
Old 08-23-2012
CharlieCobra's Avatar
On the hard
 
Join Date: May 2006
Location: Bellingham, WA.
Posts: 3,503
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 10
CharlieCobra has a spectacular aura about CharlieCobra has a spectacular aura about
Re: Black spots on the wood

The bleaches penetrate into the pores. Flooding it with water gets it out so it doesn't attack your finish from underneath. Kind of like flushing acid or something out of your eyes. You flood it, not spray it.
rugosa likes this.
__________________
Baggett and Sons Marine Restoration
The Landing at Colony Wharf
Bellingham, WA.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Replacing wood "curtain" with wood door in head area? Catalina 27 7tiger7 Gear & Maintenance 28 05-15-2014 09:21 PM
black piano wood? NewportNewbie Gear & Maintenance 17 08-25-2011 04:55 PM
Black smoke and black water bruceyp Gear & Maintenance 25 08-04-2008 12:00 PM
Best wood-to-wood adhesive kwaltersmi Gear & Maintenance 16 10-27-2007 07:25 PM
At sea. Volvo Ocean Race: Brasil 1 spots spinnaker problems on Black Pearl @ BYM Sailing News NewsReader News Feeds 0 04-12-2006 02:15 PM


All times are GMT -4. The time now is 06:24 AM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.