Oxidation stains?


LOVES Wooden Canoes
I have a 1934 OT Yankee that spent its entire life in Galveston Texas. The great thing is the wood is all in excellent condition. However, there appears to have been some sort of reaction between the metal and I am guessing the salt in the air. It is most problematic on the gunwales, where "light" areas surround all the screw heads. The gunwales are the original mahogany. Any thoughts on reducing the visibility of the reaction? Can a mahogany stain be used on these areas?

This will be my first restoration and I am hoping for a fairly straightforward ordeal that includes, removing old canvas, stripping, sanding, new varnish and canvas etc...but just want to be prepared with any tips from all the seasoned veterans on here.

Any tips or ideas are appreciated.

Thank you all

I've got the same issue, halos around all the tacks. I need to figure that out as well. I was going to bleach the whole thing, then add stain to the boiled linseed oil. My canoe spent its life on Long island.
Not sure if this would work, but when we had this discussion once before, Denis thought salt-stain remover made for shoes might be worth a try. This is the answer to a question re salt stains on shoes, which I found on-line:

"An effective salt remover is a chemical de-salter, such as Fiebing Salt Stain Remover, which usually is sold in 4-ounce bottles at shoe-repair shops."

They also suggested trying a weak vinegar solution.

Kathy (who lives far from the salty seas...)
Halos around metal canoe fastenings

The white discoloration around brass tacks and other screws and bolts is the result of salt water usage. The salt, over time, causes a reaction with the brass and the process is called "Dezincification". Do a google search on dezincification - interesting. Brass is an alloy made from combining zinc and copper. The salt causes the zinc to leach out of the alloy and what you are seeing is the zinc which whitens the wood around the fastening. Dezincification causes all the fastenings affected to be weakened as copper is all that is left of the alloy and is much less strong. I have a client's 13 foot 50 # OT in the shop now that has been used for years in Long Island Sound by the owners father . All the brass has been dezincified which has resulted in the brass tack heads to weaken and pop off with just a little pressure on the planking from the inside. The tack heads are all white and white halos are in the planking on the outside of the canoe. What is odd about this one but very good is that there are no white halos showing on the inside of the ribs where the tacks are clinched over. I attribute this to the fact that the old varnish is thick and probably protected the clinched tack ends. I will have to completely re-tack the entire canoe (thankfully it is a 13 footer). There have been other threads on this problem of white halos around the clinched tacks and as I recall, the concensus was that it is very difficult if not impossible to totally remove the halo.

White halos

I just did a search and if you use just the word "halo", it will bring you to the threads where this problem has been covered. I used other search words combined with the word "halo" and got nothing. The very first thread has some excellent photos of the problem.

Thanks Ed,

I have made a new post in that thread as well to see if the OP was successful in any of his attempts to get rid of the heavenly halos.

Yup, I got lots of "halos" on my White and I'm also replacing all the tacks, still worth the effort, another one saved right?! Its a 16 foot White, very lovely lines too. So, if you bleach the whole canoe, will that get rid of the halos? Anything else that might chemically neutralize the white ring?
Posted the same question on the wooden boat forum. Heres a response -

What you are looking at is Potassium Hydroxide Crystals, a base, washing the wood with white vinegar is a start. If that does not work, try bleaching with oxolic acid.