REALLY Frustrating Brightwork Issue

Back in May I went around all the cap rail on Sonas, scraped out and sanded all the spots, filled with four coats of poly, then went over everything with three coats. It all looked great.

About four weeks ago the varnish on my bow cap rail literally exploded! The varnish on the other cap rails is fine - the top coat is flaking a bit but nothing more than the usual Florida wear and tear, a light sanding in the spring and a couple of new coats will be fine.

The bow rail however looks like someone walked around and poured acid on it. I am now going to have to take a sander to it and bring it to all back to bare teak and start again.

Any ideas why this happened to the bow rail and not the rest? I was wondering if doing this in May when there may have been humidity in the air trapped moisture under the poly - but wouldn't that have happened to the rest as well?

I did have mechanics on the bow dismantling and rebuilding my windlasss but I can't see how they could have caused this.

First photo is what I was doing in May, others are examples of the rail now.

I would venture that it's all the result of entrapped water in the cracks and/or the joint between the sections of wood.

I'm speculating a bit, but it seems there are black spots or streaks common to the problem areas. That is likely to be mould & mildew. Prep with sanding wont remove it all, there will be some that is in the grain, or just under the surface. The natural oil in the teak can feed it, enabling it to grow. Once it has cracked the varnish then it can really get going....

So I am thinking that part of the answer will be to wash the teak with both detergent and a bleach solution prior to varnish.

Lots or folks advocate heat gun to remove old varnish to minimise sanding. It is possible that a benefit of doing that is that the heat could kill the mould & mildew also.

What is the varnish that you use?

Menz, if you're gonna go after mold consider something like Moldex. It will kill the phylie growing into the wood. Bleach can't do that, it only works at the surface. Couple threads on the stuff in TF somewhere.

I'm not so sure about the mold theory.



Was the rail totally dry when you applied the coats of 'poly'?
What brand 'poly' did you use exactly?
Polyurethane is not varnish BTW..
Is it possible you applied poly over varnish?
Did you do a light sanding (320) between coats?



"the essence of good paint work is good preparation

Since 1902, Epifanes has been setting the highest standards of paint quality in beauty, preservation and performance."

bligh said:

I'm not so sure about the mold theory.




What brand 'poly' did you use exactly?
Polyurethane is not varnish BTW..

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I know, just a generic term for the action!

If I remember correctly it was Helmsman Spar Urethane.

Can't see any photos... Did you use polyurethane or varnish? If polyurethane, which one? I had some issues with Perfection Plus last summer. One event was with dew settling on the surface after applying a coat late in the day. Turned the coating opaque. The other was small eruptions that split and left a white line at the split.

I subsequently covered any late day coats with plastic after the 2-part material had "kicked", and they turned out fine. Will sand the sections with eruptions in the Spring and start over.

menzies said:

If I remember correctly it was Helmsman Spar Urethane.

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Helmsman is not the best you could use. 'Twere me, I would sand if all off to bright wood, then apply two coats of West System or your favorite epoxy diluted with MEK to the consistency of paint thinner, or use Adams penetrating epoxy, let it kick off and outgas for a week. Wet sand smooth with 200 grit, then apply Flagship, Epithanes or some suitable high quality varnish. Seven coats minimum. The Spruce mast on my Cape George stayed bright for around 5 years handled this way.



And now you know why I don't have any bright work on my boats anymore.

It certainly sounds like a moisture related issue. In 29 years of caring for the massive amounts of varnished teak on my GB42, I never had more than an occasional lifting of the varnish in smallish areas usually well over a year or more after application. My final iteration of teak care from bared wood (rarely done with some areas acreting 30 coats or more of Epifanes) was to wipe bared wood with acetone and apply two coats of CPES in quick succession. Before the sixteenth hour after the CPES, I applied the first coat of unthinned Epifanes so it would chemically bond to the CPES, or so the theory goes. After that, it was build up to a minimum of six coats of varnish with relatively agressive sanding after coat three and lighter sanding thereafter. Good for a year before a single light coat would be applied and thereafter for years and years.

Incompatible coatings it appears to me.

I had that problem w colored bottom paint years ago. Painted the bottom w a vinyl coating that I think was an aircraft coating as well.
The original bottom paint was yellow and the vinyl stuff (can’t remember the name) was light green.

Ran the boat from Marysville to Edmonds (Seattle) the next day and over half the green was ... gone.
It was determined that they were not compatible .. adhesion wise I’m quite sure.


I always use kerosene and small amounts of varnish to prime my varnish applications. No doubt about compatibility w 100% oil base product.

The photos are on a double thread I seemed to have created. I have asked a mod to combine.

I would agree with above. Mechanics using something on their hands that could cause condition?

Delfin said:

Helmsman is not the best you could use. 'Twere me, I would sand if all off to bright wood, then apply two coats of West System or your favorite epoxy diluted with MEK to the consistency of paint thinner, or use Adams penetrating epoxy, let it kick off and outgas for a week. Wet sand smooth with 200 grit, then apply Flagship, Epithanes or some suitable high quality varnish. Seven coats minimum. The Spruce mast on my Cape George stayed bright for around 5 years handled this way.



And now you know why I don't have any bright work on my boats anymore.

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I was just touching up in a few places and putting on some extra coats. Not a full revamp.

Thing is, the cap rails along the sides and cockpit are fine with what I did. So what happened on the bow. Maybe I'll never find out!

I had these problems when I first got my boat.
With regards to the surface breakdown I sanded back to bare teak and then applied three coats of Everdure, before varnishing.
With regards to the joints I made up a template. routed out the joint and then used Sika to seal them and allow for movement, before varnishing.


Cheers
Parry

Parry said:

I had these problems when I first got my boat.
With regards to the surface breakdown I sanded back to bare teak and then applied three coats of Everdure, before varnishing.
With regards to the joints I made up a template. routed out the joint and then used Sika to seal them and allow for movement, before varnishing.


Cheers
Parry

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Very nice work

Double threads merged per Menzies request Some posts may seem odd or out of sequence as a result.

Insequent said:

Double threads merged per Menzies request Some posts may seem odd or out of sequence as a result.

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Thanks. Either big thumbs or slow Internet in the wilds of Florida - or both!

bligh said:

I'm not so sure about the mold theory.

snip..

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Fair enough, I did say that I was speculating!

Perhaps a close inspection of the rails will clarify whether the black streaks are the cause of the varnish failure, or an effect arising from the varnish failure. If Menzies is able to verify whether there are any black streaks under intact (not cracked) varnish that could shed some light on the theory.

Insequent said:

Fair enough, I did say that I was speculating!

Perhaps a close inspection of the rails will clarify whether the black streaks are the cause of the varnish failure, or an effect arising from the varnish failure. If Menzies is able to verify whether there are any black streaks under intact (not cracked) varnish that could shed some light on the theory.

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There isn't. The black spots are were the poly was totally off and water was able to saturate. During this trip I used sandpaper to take off all the loose stuff around it to stop the concentrated saturation.

So now when I get back I need to get after it all.

Thanks for clarifying.

More, better theories anyone?

A heat gun to remove most if not all, followed by sanding, would be my approach. Why did it happen, no concrete ideas.
The rails could be at a bad height for a man with recent spinal surgery, or anyone really. Is sitting and moving the seat along feasible, as opposed to standing and continued slight bending.
As an ortho once said: "I hear a lot of complaints of back pain from people bending over the basin to clean their teeth. I`m yet to be persuaded it`s the weight of the toothbrush".

Personally I would tend to think about 2 things looking at the pictures:

1. Crack in varnish that allowed water ingress resulting in varnish peeling off. On one picture one of the small clear spot has a small crack in the middle. I saw the same aspect on some varnish wood used in wet area.

2. Coat of varnish over another coat that was no fully dried. This keep the underneath coat tacky and subject to peel off.

L

menzies said:

There isn't. The black spots are were the poly was totally off and water was able to saturate. During this trip I used sandpaper to take off all the loose stuff around it to stop the concentrated saturation.

So now when I get back I need to get after it all.

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Well, when you get back to it, Do what that fellow Parry did. His work looks gorgeous.

Hmmmm, it says this thread was moved, but it looks like it was moved to where it was originally posted?

Spec’d my last boat to have no exterior teak having messed with teak for too many years and pulling varnish. In this case would.
Take dental tools and scrap out between each joint.
Apply fungicide into joints.
Murantic acid wash then acetone
Tape and re apply sealant ( allow sufficient dry days if end grain moist prior if necessary)
Wood the whole thing
Murantic acid wash if discolored then acetone wash.
Wait for at least a week of dry days.
Sand to good color. Acid should have gotten rid of most discoloration.
Epiphanies with the usual slow build up of progressively less thinner to at least 8 coats.
Then down to annual light sand and one coat if not in the tropics or biannual if in the tropics.
Wooding a boat is such a major PIA do it once right and save time in the long run. Having different products in different areas never looks right. Your or credit card labor is so much more expensive than the products involved no reason to not use epiphanes or other very high quality varnish.

menzies said:

If I remember correctly it was Helmsman Spar Urethane.

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I just redid 15 outside knotty alder wood doors and windows on our AZ residence using Helmsman Spar varnish by Minwax. Wonderful stuff to apply. They make both a water and oil based product. Which did you use?

On our boat teak caprail we use the Awl Wood system. Results have been spectacular but done by a group of pros who know the product well and its intricacies.

Now I think it’s water (moisture).

In the post #1 you can see the black spots in the center of the peel/damage spots.

Lou_tribal said:

Personally I would tend to think about 2 things looking at the pictures:

1. Crack in varnish that allowed water ingress resulting in varnish peeling off. On one picture one of the small clear spot has a small crack in the middle. I saw the same aspect on some varnish wood used in wet area.

2. Coat of varnish over another coat that was no fully dried. This keep the underneath coat tacky and subject to peel off.

L

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This is what I see as well. Another helpful step is to put a varnish sealer down before varnishing. Seals the wood nicely. Helmsman is simply not a great product. Stay away from them.

Delfin said:

Helmsman is not the best you could use. 'Twere me, I would sand if all off to bright wood, then apply two coats of West System or your favorite epoxy diluted with MEK to the consistency of paint thinner, or use Adams penetrating epoxy, let it kick off and outgas for a week. Wet sand smooth with 200 grit, then apply Flagship, Epithanes or some suitable high quality varnish. Seven coats minimum. The Spruce mast on my Cape George stayed bright for around 5 years handled this way.



And now you know why I don't have any bright work on my boats anymore.

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A recent article in Boat/US magazine about coatings test gave Helmsman high marks. I use it. It's very easy to use and forgiving. Certainly the best for the money IMO, but you know what they say about opinions!

Gary