Rust Stains on Hull Planks

by Walt

Do rust stains mean the fasteners are failing?

The boat is ironed fastened and has stains bleeding out on some of the fasteners.

The boat is old and needs a lot of TLC but this could be a show stopper.

Comments for Rust Stains on Hull Planks

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rust stain on hull planks
by: j jarvis

If the boat's to your liking and the boat has only been half done look at the price, if its cheap do the math, ask a ship wright.

There's a few simple tests that cost little, like ask who did the work, or you like it take the plunge, make it the head turner that got your attention.

It's just wood and bolts and they move and you will hear lots of stories like why did I sell that boat?

Look and see that sails, ringing, mast, boom, bow spit, make sure all this is in top shape, have it hulled out, do the work, that cheep best money you will ever spend do I have the money, can I do it my self do I have the time.

Mike and his friends will be there to answer your questions but most boats have a history, ask around the dock.

White boats don't lie, you see every blemish, not saying paint it blue but it helps.

Love wood

Electrolysis/metal corrosion
by: Mike

Soaking the fastening hole with epoxy would probably help protect the wood and reduce further bleeding of the rust in the wood.

However to prevent electrolysis the whole fastener would have to be sealed.

Best to use the most noble metal fastener available.

Unfortunately ‘electrolysis’ is very difficult to pin down, so much depends on what other metals are in the vicinity, the type (acidity) of the wood, how much electric current is straying in the water (some of which could be from neighbouring boats), the salinity of the water, etc.

by: Anonymous

Yes I agree with the comment to pull a few fastenings to check out their in wood diameter.

Having a sprung bow plank in a gale off the cape is not the time to find out that the rust stain was a tell tale "colour sign" of a deeper fastening issue.

So I would be wondering what type of fastenings were used in the refastening below the water line and replace with a galvanically compatible metal as the old galvanized iron fastenings are no longer available in some areas.

My question would be, what is a galvanically compatible metal to iron and zinc assuming the wood surrounding the old fastening is probably full of iron and zinc ions ready to do the watusy with any new bronze or stainless steel fastening that replaces it and possibly cause early corrosion.

Would soaking the fastening hole with epoxy do ?

Rotting around
by: Ivan

Hi Walt,

I have a timber boat, 30' and was fastened with iron.

The iron fastenings are great, most of them at least.

Now, the problem is not the fastenings but the timber around, old timber starts to rot and badly if it is not checked.

Would be good if you start digging around those rust areas and see whether the timber is good or decaying.


Wooden Boat Fasteners
by: Mike

Hi Walt,

As she has been refastened below the waterline there shouldn't be a problem.

Might be worth finding out what she was refastened with, hopefully either copper or silicon bronze.

You can either start another blog with the photos or email them to me as attachments to, I'd love to see them and I can post them from here.

An automatic bilge pump is cheap and easy enough to fit, my boat stays afloat year round and doesn't leak but I feel better knowing that there is an automatic pump and full battery, just in case.

rusted fasteners
by: walt

Thanks for the response. The owner says that they do not need replacing- but the boat- 43 foot sailboat was built in the 30's.

they are on the hull planking, above the water line. The boat was refastend below the waterline- and sits on a morring year round with NO auto bildge pump- it does not leak!

The highest concentration is the bow area. I have a couple photos- but dont see how to up load- maybe start a new blog...

I am interested in buying the boat- but have never owned a wooden boat and am not sure what i am looking at when it comes to the hull planking and frames.

Rusty Iron Fasteners
by: Mike

The stains mean that the fasteners are rusting but not necessarily failing.

Unfortunately the only way to tell is to draw the fastener and have a look.

The advantage of using iron bolts especially on a working boat was that as the timbers ‘worked’ the bolt holes would eventually widen enough to allow water ingress.

This would then start the rusting process, but the surface iron as it oxidises, expands, so this would then tighten up in the bolt hole thus slowing down the water ingress, until the next time.

The drawback of course is that eventually there isn’t enough solid iron left in the bolt for it to do its job.

So where are these fasteners of yours?

Could they not be replaced if necessary?

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