Removing Salt Water Affected Tack "Halos"

[Fitz]

Has anyone had any luck removing the halos in the cedar left by tacks affected by salt water?

My impression is that they are persistent, deep into the grain, and may likely remain even after stripping the canoe and potentially cleaning, bleaching and sanding the hull. But I have not specifically tried to remove the halos.

If you have dealt with them and removed them before new varnish, please let me know.

Fitz.

 

[pat chapman]

Short of painting over them, or replacing the wood, I've never found anything that will deal with the halos. They don't take stain, you can't sand or scrape them away, so you'll have to live with them. You should probably replace any tacks that are the source of the halos as they have deteriorated and lack the strength to hold the canoe together for very long.

 

[pklonowski]

I wonder if something acidic, like lemon juice or vinegar, would dissolve the zinc and lift the stain? Just speculating here; someone may have tried it previously. You'll definitely have to do some color matching with stain afterwards, which may be more trouble than it's worth.

 

[Kathryn Klos]

I've been poking around the internet and have run into the recommendation of using oxalic acid, although not for this specific thing, but to remove rust stains and such from wood-- but we've discussed oxalic acid before and I figured you've looked into that. If anyone else reading this isn't familiar with this chemical for bleaching wood, you get it from a pharmacy and you don't put it in your eye or huff it into your lungs. It's what makes your teeth feel funny when you eat spinach.

Anyway, I ran into an interesting factoid while reading about the care of a cedar shake roof... another reason for restoring an old canoe that was built using old cedar (they were talking about the longevity of cedar shakes):

"...An added factor is that more shakes and shingles are being manufactured today from younger,
less decay-resistant cedar since old, high-thujaplicin-content logs are no longer readily available."

 

[chris pearson]

Fitz,
I heard throwing it on a huge fire will take them off. Sorry, couldn't resist, just beat Andre to it! Let us know if anything works.

 

[Fitz]

Halos

Thanks folks for the advice. My tripping buddy was considering a lightweight canoe in preparation for his old age, but he went and looked at one that had obviously seen salt water. Replacing tacks is a lot of work, but doable. I had just never tried to remove the halos before, so I was hoping for a magic bullet. I would just hate to put a great deal of time into a canoe, only to be staring at those white halos under new varnish. It is a shame, but we will look for another canoe.

Fitz.

 

[kayamedic]

I think Tom MacKenzie has used phosphoric acid (carefully) with success. But you should contact him to confirm. He has worked with a number of Louisiana humidity flowers.