Reply
 
Thread Tools Search this Thread Display Modes
 
Old 07-08-2020, 01:06 AM   #1
Newbie
 
City: Puget
Country: near Puget
Join Date: Jul 2020
Posts: 4
varnish failure at seams

Hello. I have a 34' trawler with bright work. There is a cap rail that runs all the way around the boat. I stripped and sanded it down years ago and varnished it. Each year I patch problem spots and put 3-5 coats on. It is not covered.


There are a few places that fail every year. They are at the seams where it appears to be two pieces of teak spliced together with some black stuff in between. Every year water gets in and the varnish fails.





Really though, these are not seams but small grooves cut in the wood with the black stuff in the grooves.





Why they did this I have NO idea. But they did.

What would be a good way to seal this area so it doesn't fail every year? I did have the black stuff replaced once but it still failed.


I'm tempted to just remove the black stuff and sand the grooves and just varnish over it.

Do any of yall have an idea on either what to use to fill in the seams that won't get water under it, or some way I could possibly put something over these spots to seal them?

Thanks for viewing.
Attached Thumbnails
Click image for larger version

Name:	20200705_142624[1].jpg
Views:	715
Size:	138.1 KB
ID:	104715   Click image for larger version

Name:	20200705_143253[1].jpg
Views:	710
Size:	198.2 KB
ID:	104716  
__________________
Advertisement

rlrrlrll is offline   Reply With Quote
Old 07-08-2020, 02:06 AM   #2
Guru
 
BruceK's Avatar
 
Join Date: Oct 2011
Posts: 11,223
The caulking seals timber joins. It`s likely leaking, failing at the edges. You could dig it out and replace with fresh polyurethane caulk, like Sikaflex 291. Then redo the varnish, covering the caulk as well. Tape the edges of the area to be filled before caulking.
__________________

__________________
BruceK
2005 Integrity 386 "Sojourn"
Sydney Australia
BruceK is offline   Reply With Quote
Old 07-08-2020, 03:39 AM   #3
TF Site Team
 
Insequent's Avatar
 
City: Brisbane
Country: Australia
Vessel Name: Insequent
Vessel Model: Ocean Alexander 50 Mk I
Join Date: Mar 2012
Posts: 2,820
The joint in question is a scarf joint between two separate pieces of timber, it is not merely a decorative groove. With changing temperature and moisture content the two pieces of teak move slightly and over time it cracks the varnish and allows moisture to then get under the varnish at the joint.

In theory a flexible high-oil varnish is less prone to the cracking than a hard or polyurethane finish. In practice is not as clear cut. Even with the best finishes I think that every couple of years the joint areas will need to be re-done. Well, that seems to be the case for the joints on my rails.

I bought my boat near Seattle, and in due course shipped it back to Australia. On some rails the joints that had been as tight as a drum, with wood touching wood, opened up to a 1/8" gap after I had been back for a while. I've used some black caulk in the joints since then (probably Sika 291) and the the joint looks good with smooth black caulk, but it still fails regarding moisture ingress after a few years. I woul love someone to come up with a solution that lasts longer!
__________________
Brian
Insequent is online now   Reply With Quote
Old 07-08-2020, 05:01 AM   #4
Guru
 
Cigatoo's Avatar
 
City: Narragansett Bay
Country: New England
Vessel Model: Grand Banks 36
Join Date: Sep 2016
Posts: 982
Quote:
Originally Posted by BruceK View Post
The caulking seals timber joins. It`s likely leaking, failing at the edges. You could dig it out and replace with fresh polyurethane caulk, like Sikaflex 291. Then redo the varnish, covering the caulk as well. Tape the edges of the area to be filled before caulking.
Clean out the caulking
wash with thinner / acetone
sand Groves with 80 grit
couple coats of thinned varnish in the groves to seal the wood
Re caulk with Sikaflex...taping as stated above
Now varnish the rails.
__________________
Charlie0
Cigatoo is offline   Reply With Quote
Old 07-08-2020, 06:21 AM   #5
Guru
 
Pete Meisinger's Avatar
 
City: Oconto, WI
Country: USA
Vessel Name: Best Alternative
Vessel Model: 36 Albin Aft Cabin
Join Date: Oct 2012
Posts: 1,377
Of course I don't know the make of the caulk you are using. But a very common one is Life Seal. There is a big difference between their caulk and their seal. The seal can be painted the caulk can not. I suspect that your caulk is not paintable, it may look like the varnish is adhering to the caulk but it probably is not. Once it releases a little or cracks, you get moisture penetration and failure.

Read the caulk tube carefully, it must be paintable.

pete
Pete Meisinger is offline   Reply With Quote
Old 07-08-2020, 06:23 AM   #6
Guru
 
Pete Meisinger's Avatar
 
City: Oconto, WI
Country: USA
Vessel Name: Best Alternative
Vessel Model: 36 Albin Aft Cabin
Join Date: Oct 2012
Posts: 1,377
Also look underneath the cap rail, the faulty caulk may be on the bottom, allowing moisture to come up from below.

Also that stanchion could be introducing moisture into the groove. You should remove and rebed it.

pete
Pete Meisinger is offline   Reply With Quote
Old 07-08-2020, 07:04 AM   #7
Veteran Member
 
BigTime's Avatar
 
City: Jacksonville
Country: United States
Vessel Name: Shady Grove
Vessel Model: TMC Custom 41 Trawler & S-2 10.3 Sail
Join Date: Nov 2018
Posts: 51
I spoke to a couple of Awlwood factory reps at last years Miami Boat Show about this very same issue , cap rail scarf joints. Their opinion is that there is no long term solution. The joint is going to move , you can't do anything about that , and all wood clear coats that we use are going to crack because of the movement if you try to overcoat the joint. Just another PIA of maintaining exterior wood on our boats.
BigTime is offline   Reply With Quote
Old 07-08-2020, 08:26 AM   #8
Guru
 
City: Great Lakes
Country: USA
Vessel Model: OA 440
Join Date: Aug 2017
Posts: 561
In an earlier thread regarding cap rails a forum member recommended scraping the grooves clean, then applying the clear finish, then reapply the seam sealer. If the seam sealer is not UV tolerant, do something to make it so...perhaps a 2-part product over the sealer, or maybe something like 301 protectant. I used Interlux Perfection Plus, which is highly UV tolerant compared to any varnish product, and liberally worked it into those cleaned joints. A polyurethane sealant is next...then I’ll try the 301 product applied with Q-tips.
Rufus is offline   Reply With Quote
Old 07-08-2020, 10:00 AM   #9
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 16,912
We use a high oil varnish that apparently is flexible enough as we have little trouble w the water ingression at the cap-rail joints. That is: McCloskey’s Mano’War Marine Spar Varnish.

The OP has wide seams but he was probably using hard varnish to keep feet from scuffing the finish. I had that issue 12 years ago using a water based West System varnish. It failed soon and badly. Then I decided the scuff marks on the cap-rail were just fine w me. Been using McClosky’s varnish ever since.
I don’t like appearing to be selling a brand product but in this case it’s justified IMO because it’s hard to identify a high oil varnish from a high resin varnish. Years ago the paint manufacturers were required to put the ingredients on the can and the prtcentages of each element included. One just picked a varnish w a high oil content. Now short of asking a manufacturer like Interlux or Petitt what can one do? And who knows what Interlux or Petitt will tell you over the phone.
But re the McClosiy’s Spar varnish I know from experience. I was taking a class in college (industrial Education) on finishes such as paint. I asked the proff what the best varnish would be for my planked wood boat. He said to find a varnish made w phenolic resin and a high percentage of oil .. Tung oil or Linseed oil w a slight preference to Tung oil. So it was simple then as they put all the ingredients on the can. This was in 1969. Somewhere down through the years they dropped that requirement and one was left to salesmen, hearsay and product hype to choose finishes.
So w my newfound knowledge I found that, after much shopping that McCloskey’s Mano’War Marine Spar Varnish fit the professor’s recommendations. I’ve been using it all these years. It was called “Boat Coat” then. Now it also says “maximum UV protection”.

Short of wide seams and high oil varnish there’s not much one can do about water under the varnish at the seams problem. It isn’t limited to the seams though as everywhere the varnish coating has been penetrated (Like w screws) water will get in and under the varnish, turn it a milky whitish color and loosen the finish around the seam or bolt/screw hole. And where it’s not whitish it will be black.

About this last comment I don’t have experience but I highly suspect that many coats of varnish around seams and screw penetrations may make the finish much stronger and able to withstand much more flexing and movement. The experts like Rebecca Whittman advise many coats (like 7-10) of varnish to be the minimum. I don’t think I’ve ever gotten to ten coats. More like 4-5. Others may be only putting on 2 coats. Looks great after 2-3 coats and many will not have the time for 10 coats. But refinish time will be much sooner. THIS MAY WELL BE THE REASON MANY TO MOST HAVE SUCH A NEGATIVE OPINION ABOUT VARNISH. Just not enough coats.

Another thought is to varnish up to the caulk but not over it. Again a wide seam to be caulked may allow for the movement.

Another thought is to grind out the seams in a wider “V” shape so the seam is wide on top.

But grinding out the seams can’t be reversed. Just can’t put the wood back.
But a combination of wide seams, flexible high oil varnish and many coats may be a very satisfactory solution. If one can stick to the job at hand for 8+ coats ducking wet weather and windy days w lots of dust. Sanding can fix that too .. not to mention more coats.
__________________
Eric

North Western Washington State USA
Nomad Willy is online now   Reply With Quote
Old 07-08-2020, 10:04 AM   #10
Senior Member
 
RonR's Avatar
 
City: Everett
Country: USA
Vessel Name: Andiamo
Vessel Model: Egg Harbor 33í
Join Date: May 2019
Posts: 291
We are getting ready to do a few rails with like seams. My neighbor's look perfect so I asked him how he did it.

Removed all the black stuff, sanded everything down including the joints with 80 grit. Used Perfection plus to build it smooth, including in the joint itself but not over filling the joint. Then he added 5 coats of varnish. Then he taped it up and put the black stuff back in, but did not over coat it with varnish as he said it will just crack as its a joint that moves. Time will tell if its the way to go or not.
RonR is offline   Reply With Quote
Old 07-08-2020, 10:23 AM   #11
DDW
Guru
 
City: San Francisco
Country: USA
Join Date: Apr 2018
Posts: 1,234
Quote:
Originally Posted by Insequent View Post
The joint in question is a scarf joint between two separate pieces of timber, it is not merely a decorative groove.
Normally, yes, but in this case it is decorative, as the OP says. Look at the grain. Stupid detail.

Anywhere the varnish ends, moisture gets under. The caulk in the joint it causing the varnish to bridge the joint between the wood and caulk, which have very different movements. The long term fix would be to remove the caulk, and have a shipwright patch the groove with a graving piece. Shorter term, remove the caulk, sand down in the groove, varnish the groove, then recaulk. You will have continuous varnish on the wood.
DDW is offline   Reply With Quote
Old 07-08-2020, 10:39 AM   #12
Guru
 
syjos's Avatar


 
City: Gig Harbor
Country: USA
Vessel Name: Sandpiper
Vessel Model: Bluewater 40 Pilothouse Trawler
Join Date: Nov 2012
Posts: 2,059
I have a couple joints like that.

I took out the caulk and sanded the seam to clean wood, Then masked around the seam and brushed epoxy into the seam. Kept brushing the epoxy on to soak into end grain. Let it get tacky and applied more epoxy. Let that dry over night. Mixed WEST 404 High Density Adhesive Filler and 403 Microfibers into epoxy and filled the seam with the mixture. Squeegee the epoxy flush and smooth. After a weeks cure, sand seam lightly and varnish.

The epoxy creates a strong bond between the two pieces of wood and since it is not flexible, will not crack the varnish over it. The epoxy filler expands and contracts about the same as the wood.

The joints that I did the above to has not cracked in 12 years. I did remove the varnish about 8 years ago and epoxied the teak before varnishing.
syjos is online now   Reply With Quote
Old 07-08-2020, 10:51 AM   #13
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 16,912
I knnd’a like RonR’s neighbor’s solution.

What the difference is, is that he’s varnishing the caulking groove before caulking (if I read it right). This means that the caulk will mate w the varnish rather than the wood. Paint and probably caulking prefer a textured surface to bond to and the caulk to varnish join surface may not hold being a smooth surface. And there is a very narrow strip at the bottom of the groove of varnish that will be very prone to failure as well as it’s so narrow. And then the varnish over the top is just as prone to fail as if he just caulked first and varnished later w the caulking attached to the wood. And the caulk to varnish inside the seam groove joint may or probably will fail and let water in and down to the almost certain to fail “varnish joint” at the bottom of the groove. Then there’s water in the joint thereafter.

But if it works for him it may work for others.
I wonder if any shipwrights do it that way?
__________________
Eric

North Western Washington State USA
Nomad Willy is online now   Reply With Quote
Old 07-08-2020, 11:06 AM   #14
Guru
 
City: Boston
Country: US
Vessel Name: Adelante
Vessel Model: IG 30
Join Date: Nov 2016
Posts: 882
1) sand and repair every year or two
or
2) inlay a 1/4" brass butterfly joint on top of the zig zag to stop movement.
SoWhat is offline   Reply With Quote
Old 07-08-2020, 11:08 AM   #15
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 16,912
syjos wrote;
“ The epoxy creates a strong bond between the two pieces of wood and since it is not flexible, will not crack the varnish over it. The epoxy filler expands and contracts about the same as the wood. ”

Sounds really good but if the filler expands and contracts w the wood the top coat of varnish will need to flex the same amount as if he just caulked the seam and top coated as usual. You can’t stop the cap-rail plank form expanding and contracting. The varnish on top of the filler will need to expand and contract the same as w regular caulk.
The problem isn’t that the caulk fails it’s that the varnish film fails. So making the seam wide and using a flexible varnish seems the answer to me.
What are some of the other variables in your method? Like #of varnish coats?
__________________
Eric

North Western Washington State USA
Nomad Willy is online now   Reply With Quote
Old 07-08-2020, 11:34 AM   #16
Senior Member
 
jungpeter's Avatar
 
City: Everett
Country: US
Vessel Name: LIBERTY
Vessel Model: TOLLY 48
Join Date: Mar 2013
Posts: 265
Hi rlrrlrll,

You're going to get as many opinions on this issue as Carter has Little Liver Pills. And everybody's got their own version of snake oil and/or mouse milk to make your life better. So here's my $.02:

As BigTime said,
Quote:
I spoke to a couple of Awlwood factory reps at last years Miami Boat Show about this very same issue , cap rail scarf joints. Their opinion is that there is no long term solution. The joint is going to move , you can't do anything about that , and all wood clear coats that we use are going to crack because of the movement if you try to overcoat the joint. Just another PIA of maintaining exterior wood on our boats.
Mother Earth will have Her way, regardless of what mortal man chooses to combat Her desires. Yup, wood moves. Yup, wood clear coats don't move the same way. Result? A PIA for those of us that chose to maintain exterior wood. You've asked a good question, but doubt you'll get a good answer.

So, another $.02 opinion: covered moorage may help, a boathouse may help more.

Regards,

Pete
jungpeter is offline   Reply With Quote
Old 07-08-2020, 12:02 PM   #17
Guru
 
syjos's Avatar


 
City: Gig Harbor
Country: USA
Vessel Name: Sandpiper
Vessel Model: Bluewater 40 Pilothouse Trawler
Join Date: Nov 2012
Posts: 2,059
Quote:
Originally Posted by Nomad Willy View Post
syjos wrote;
ď The epoxy creates a strong bond between the two pieces of wood and since it is not flexible, will not crack the varnish over it. The epoxy filler expands and contracts about the same as the wood. Ē

Sounds really good but if the filler expands and contracts w the wood the top coat of varnish will need to flex the same amount as if he just caulked the seam and top coated as usual. You canít stop the cap-rail plank form expanding and contracting. The varnish on top of the filler will need to expand and contract the same as w regular caulk.
The problem isnít that the caulk fails itís that the varnish film fails. So making the seam wide and using a flexible varnish seems the answer to me.
What are some of the other variables in your method? Like #of varnish coats?
Because the epoxy filler is hard and similiar in density to the wood, it expands and contracts about the same as the wood. Instead of the flexible seam experiencing the majority of the movement, the expansion and contraction is taking place in the whole length of the wood. The varnish is flexible enough to move with the wood, as long as the wood is protected from excessive moisture intrusion.

The epoxy in the seam turns the two pieces of wood into one continuous length, expanding and contracting equally through it's length.
syjos is online now   Reply With Quote
Old 07-08-2020, 12:10 PM   #18
Guru
 
Brooksie's Avatar
 
City: Cape Cod, MA
Country: USA
Vessel Name: Island Seeker
Vessel Model: Willard 36 Sedan
Join Date: Oct 2007
Posts: 1,109
Quote:
Originally Posted by syjos View Post
I have a couple joints like that.

I took out the caulk and sanded the seam to clean wood, Then masked around the seam and brushed epoxy into the seam. Kept brushing the epoxy on to soak into end grain. Let it get tacky and applied more epoxy. Let that dry over night. Mixed WEST 404 High Density Adhesive Filler and 403 Microfibers into epoxy and filled the seam with the mixture. Squeegee the epoxy flush and smooth. After a weeks cure, sand seam lightly and varnish.

The epoxy creates a strong bond between the two pieces of wood and since it is not flexible, will not crack the varnish over it. The epoxy filler expands and contracts about the same as the wood.

The joints that I did the above to has not cracked in 12 years. I did remove the varnish about 8 years ago and epoxied the teak before varnishing.

This seems (no pun) the best solution. Using West's G-Flex would make it even better as the final filler b/c it has great flexibility and often won't crack when regular epoxy will. Once the end grain is saturated with epoxy I don't think your varnish will lift even if the caulking fails if you want to continue to use caulking
Brooksie is offline   Reply With Quote
Old 07-08-2020, 12:15 PM   #19
Guru
 
rgano's Avatar
 
City: Southport, Florida
Country: USA
Vessel Name: FROLIC
Vessel Model: Mainship 30 Pilot II since 2015. GB-42 1986-2015. Former Unlimited Tonnage Master
Join Date: Oct 2007
Posts: 1,859
Send a message via Skype™ to rgano
You cannot sand out the grove without having to level the rest of the rail. Then you will be left with the much thinner wood-to-wood joint which the filled groove was covering. I had a Grand Banks with wooden hand and cap rails with several joints, but none were grooved and filled like yours. There would occasionally be a crinkle at a joint a year or so after the last coat of Epifanes varnish, but never anything as serious as the drying out and bleaching in the photos you show. That may have been thanks to the fact that when I wooded out the rails I applied a couple of coats of clear penetrating epoxy sealer. This stuff takes a full 24 hours to cure. I waited 16 hours after the CPES went down (with extra applied to the joint areas) and applied the first coat of varnish to get it to chemically bond to the CPES. Six coats minimum of varnish in order to have sufficient UV protection and a maintenance coat at least once a year thereafter. To resolve your issue, I would remove the caulk from the joints and sand the groove well before applying CPES liberally to the area. Then varnish and sand the groove before applying thee black caulk.
__________________
Rich Gano
FROLIC (2005 MainShip 30 Pilot II)
Panama City area
rgano is online now   Reply With Quote
Old 07-08-2020, 12:20 PM   #20
Guru
 
syjos's Avatar


 
City: Gig Harbor
Country: USA
Vessel Name: Sandpiper
Vessel Model: Bluewater 40 Pilothouse Trawler
Join Date: Nov 2012
Posts: 2,059
Quote:
Originally Posted by Brooksie View Post
This seems (no pun) the best solution. Using West's G-Flex would make it even better as the final filler b/c it has great flexibility and often won't crack when regular epoxy will. Once the end grain is saturated with epoxy I don't think your varnish will lift even if the caulking fails if you want to continue to use caulking
Using G-Flex is a great idea! Never considered it as a seam filler.
__________________

syjos is online now   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 08:45 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012
×