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Thread: Repairing Checks in Spars

  1. #1
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    Default Repairing Checks in Spars

    I'd like to know my options.

    I'm refinishing the spruce spars on my old gaff topsail cutter. Last time the rig was down was in 1993 but the rig is in surprisingly good shape. I had a couple glue lines in the mast that I repaired with splines. Now I'm on to the gaff and boom and I have some small checks and glue line faults I've been washing with a weak oxalic bleach and soap to kill any mold and minimize the black marks.

    FA8150D4-20C4-4E49-B49B-0DC3FB57C915_1_201_a.jpeg

    B91546A5-05BF-43C1-90E3-F4B3C10AF45D_4_5005_c.jpeg

    These checks are small and splining seems pretty invasive so can I fill with an epoxy like Gflex? or is there a better approach? I'm also thinking of injecting some penetrating epoxy first to give the epoxy something to hold onto. My concern is that I'm creating some hard spots that may create additional checking later.

    Rich

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    Default Re: Repairing Checks in Spars

    Quote Originally Posted by Lemsteraak View Post
    My concern is that I'm creating some hard spots that may create additional checking later.

    Rich
    Just so. Use something that will squeeze out if the wood swells. Traditionally beeswax. Or may be a mixture of beeswax and linseed.
    It really is quite difficult to build an ugly wooden boat.

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  3. #3
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    Default Re: Repairing Checks in Spars

    A lot of Dutch traditional ships have sturdy wooden masts and solid gaffs and booms.
    The checking is quite common, the best "repair" is to keep them filled up with raw linseed oil.

  4. #4
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    Default Re: Repairing Checks in Spars

    My former boat had a mast with checks that had been filled with a beeswax mix of some kind. It was not completely water tight, so rain got in but did not come out. The mast rotted at the lower end of the checks. I suggest either being sure that they are water tight, or only apply a finish and live with them. Good luck, keep us posted.

  5. #5
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    Default Re: Repairing Checks in Spars

    How big are these spars?
    Are they center grown or off cuts or glued ?

  6. #6
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    Default Re: Repairing Checks in Spars

    Thank you guys for the input. I'm going to use a "boat soup" with beeswax on the checks in the AYC laid decks. Hadn't thought of it for spars.

    - Wizbang 13 - I have the mast done already, it is built up and hollow so I used splines where the glue joints failed. I figure there would be a bit of give and will return the mast to full strength. I've got that spar varnished and in storage. Here is what the spline looked like before it was faired and varnished. Pretty invasive for a small check or glue line.

    IMG_0195.jpg

    The checks and failed glue lines I'm concerned with are on the gaff and boom pictured in my last post. Both are built up, solid but have suffered from exposure. I would like to figure out a filler or glue that flexes so I can apply spar varnish over. I can go with an exotic coating like Coelans which breathes like a spar varnish and fills gaps and is flexible but.... It is a plastic so it doesn't have the nice feel of a natural spar varnish. Both of these spars will be stored on the "gallows" so I can get to them easily for maintenance. I don't believe the checks affect the strength of the spars much, anyway they are overbuilt like all good gaffers are.

  7. #7
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    Default Re: Repairing Checks in Spars

    If the spare are glued , then re glue them !no effing beeswax , no boat soup, no epoxy killing chemicals. Dive in with a skilsaw and FILL the Kerfs with west 105 and 403, not soft go bing g flex.
    All this futzing is what leads to “ glue failure” .
    fill the cracks and checks and 5 coats of cetol
    only a grown spar or side of a tree should get the old fashion treatment , not a glued spar .
    you have any idea of how HOT your decks will get with that junk on them ?
    bruce

  8. #8
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    Default Re: Repairing Checks in Spars

    Quote Originally Posted by wizbang 13 View Post
    If the spare are glued , then re glue them !no effing beeswax , no boat soup, no epoxy killing chemicals. Dive in with a skilsaw and FILL the Kerfs with west 105 and 403, not soft go bing g flex.
    All this futzing is what leads to “ glue failure” .
    fill the cracks and checks and 5 coats of cetol
    only a grown spar or side of a tree should get the old fashion treatment , not a glued spar .
    you have any idea of how HOT your decks will get with that junk on them ?
    bruce
    Bruce, I was discussing the checking, not the glue line failure. Give me some credit do.
    It really is quite difficult to build an ugly wooden boat.

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    Default Re: Repairing Checks in Spars

    Nick, commenting on a spar repair before we know if it is a tree or a built thing is like telling someone to caulk a boat with cotton but we do not know it is plywood.
    Not hammering you or anyone else, you do not see my straight forward brash American nature by now?
    if the spar is glued up , there should be no beeswax even in the checks.... there should be no gd checks in a glued spar in the first place . Folks will freak out over a spray of silicone will contaminate a whole boat, but wax on a glued spar is okay?
    please don’t be insulted by things I say here, I just sometimes get frustrated and blurt things out. I’m the guy that folks been asking to “ take a look” at their boat problems for a long time.
    bruce

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    Default Re: Repairing Checks in Spars

    Quote Originally Posted by Lemsteraak View Post
    Before deciding on how to repair this split, I would be asking myself, why did it split. That straight line gap is between two glued together pieces of wood. So glue failure is a real possibility. Another is that the mating surfaces were not prepared properly. Glue type is a factor. So I'm basically with Bruce (wizbang) here. Stick to glue/epoxy for a repair. A spline doesn't seem out of order to me.

    Jeff

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    Default Re: Repairing Checks in Spars

    I’m still not sure how these are built ... “ built up and hollowed out” the heck is that? Split, center gouged out and stuck back together? Cuz that would be daft . The grain and checks look like how they would be on a tree , not built of vg boards .

  12. #12
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    Default Re: Repairing Checks in Spars

    Quote Originally Posted by Lemsteraak View Post
    Now I'm on to the gaff and boom and I have some small checks and glue line faults

    B91546A5-05BF-43C1-90E3-F4B3C10AF45D_4_5005_c.jpeg

    Rich
    Quote Originally Posted by wizbang 13 View Post
    I’m still not sure how these are built ... “ built up and hollowed out” the heck is that? Split, center gouged out and stuck back together? Cuz that would be daft . The grain and checks look like how they would be on a tree , not built of vg boards .
    Does how the wood was assembled matter that much. It has drying checks, that will run if they are held open by a hard filler, and failing glue, that is more worrying, as lpatric in #10 points out.
    It really is quite difficult to build an ugly wooden boat.

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  13. #13
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    Default Re: Repairing Checks in Spars

    Well that photo looks like two different boards that are de laminating.
    That is either crap boards or crap epoxying.... aka too
    Much clamping pressure in search of a pretty glue line.
    Yes, it DOES Matter . We are not holding them open, we are repairing a bad lamination.
    dive in with a Kerf , fill it . Easy peasy, coulda done it ten times by now

  14. #14
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    Default Re: Repairing Checks in Spars

    Our Dutch Safety board ( comparable with NTSB in the USA) investigated a deadly incident with a wooden spar.
    We have an extensive charter fleet of large Dutch traditional ships.
    There is a short English summary, but the pictures and animation clip speak for themself. I suggest you take a look.
    https://www.onderzoeksraad.nl/en/pag...mast-harlingen
    Last edited by dutchpp; 06-20-2021 at 12:52 PM.

  15. #15
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    Default Re: Repairing Checks in Spars

    Solid fir or larch spars(Pole masts containing the tree center in the center) rot from the inside out. I urge folks to bore a big hole from the truck straight down and keep the hole filled with wood preservative. Keep the core poisoned. But that is not what we have here.

  16. #16
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    Default Re: Repairing Checks in Spars

    Bruce many solid tree spars are split in half, and the centre skill sawed into half circles, and finished with HOOOGE round router bit. It can prevent the bigger cracks (checks) that solid tree spars suffer from., then glued back together.

  17. #17
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    Default Re: Repairing Checks in Spars

    Quote Originally Posted by lupussonic View Post
    Bruce many solid tree spars are split in half, and the centre skill sawed into half circles, and finished with HOOOGE round router bit. It can prevent the bigger cracks (checks) that solid tree spars suffer from., then glued back together.
    Seems daft to me . Caveman building . This done on these big euro charter boats? I can only imagine a Rube Goldberg invented doing that much work to make a tree lighter or save on checking .

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    Default Re: Repairing Checks in Spars

    No it has been done for 500 years on European working boats.. Before glue was good enough, and gave longevity to the spars.

    Euro charter boats are 100% plastic with aluminium masts.

    I have no idea who Rübe Goldberg is, nor the relevance to doing it traditionally.

    Point is, the OP may be correct re how his mast is constructed.

    Fancy that eh?

  19. #19
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    Default Re: Repairing Checks in Spars

    I've had a glue joint on a mast fail comletely half way through a race. I'd built the mast nearly 50 years before with a long forgotten glue. Not bad I thought. Problem is the whole boat was built with the same glue…………….

  20. #20
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    Default Re: Repairing Checks in Spars

    rube goldberg means jury rigged/cobbled together in american slang.I dunno the origin of the saying.
    500 years it's been done...caveman chit like I said .Why do it in the last 50 years since epoxy?
    The dutch boat above that killed 3 people from a rotten topmast... that was not alloy.

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    Default Re: Repairing Checks in Spars


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    Default Re: Repairing Checks in Spars

    Quote Originally Posted by wizbang 13 View Post
    rube goldberg means jury rigged/cobbled together in american slang.I dunno the origin of the saying.
    500 years it's been done...caveman chit like I said .Why do it in the last 50 years since epoxy?
    The dutch boat above that killed 3 people from a rotten topmast... that was not alloy.
    Rube Goldberg was a famous cartoonist (among other things), who drew cartoons of complicated and convoluted contraptions to accomplish everyday things, such as the "self-operating napkin" pictured below. In this example, lifting the soup spoon to your mouth sets in motion a variety of improbable things that ends with the napkin patting your lips:

    Rube_Goldberg's_'Self-Operating_Napkin'_(cropped).gif

    https://en.wikipedia.org/wiki/Rube_Goldberg



    Regarding the spar repair, I will defer to those with more knowledge than I - other than to say that splining the glue failure seems like a wise choice.

    ETA: Cross-posted with ulav8r.

  23. #23
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    Default Re: Repairing Checks in Spars

    Splining is 3 times the work

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    Default Re: Repairing Checks in Spars

    Well, it appears there are a lot of different ways to repair a crack. Wizbang, I tend to agree with you, just repair it. Which brings me to Dutchpp's comments. Turns out, I'm familiar with Aaks (Dutch Sailing Barges) and their masts. Oregon Pine in English is old growth clear vertical grain Douglas Fir from Oregon. I found the old Aak, with a huge Oregon Pine mast in Florida about 40 years ago. The mast was delaminated on me. Not much danger of breaking because it was so oversized. Since we were in a very small town near the Everglades without much in the way of resources, I just dug out the failed glue and put in epoxy and clamped it with huge hose clamps. It has held perfectly to this day, go figure.

  25. #25
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    Default Re: Repairing Checks in Spars

    While you are here Lemsteraak, please tell us exactly how your mast in the original post is constructed?

    Also, we all hope you understand the difference between a failed glue line 'crack' and a drying 'crack' in a dimensional timber spar.

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    Default Re: Repairing Checks in Spars

    Quote Originally Posted by pandelume View Post
    Rube Goldberg was a famous cartoonist (among other things), who drew cartoons of complicated and convoluted contraptions to accomplish everyday things, such as the "self-operating napkin" pictured below. In this example, lifting the soup spoon to your mouth sets in motion a variety of improbable things that ends with the napkin patting your lips:

    Rube_Goldberg's_'Self-Operating_Napkin'_(cropped).gif

    https://en.wikipedia.org/wiki/Rube_Goldberg



    Regarding the spar repair, I will defer to those with more knowledge than I - other than to say that splining the glue failure seems like a wise choice.

    ETA: Cross-posted with ulav8r.
    Who came first? Goldberg or Heath Robinson?

    https://en.wikipedia.org/wiki/W._Heath_Robinson
    It really is quite difficult to build an ugly wooden boat.

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    Default Re: Repairing Checks in Spars

    Quote Originally Posted by wizbang 13 View Post
    Splining is 3 times the work
    How wide and deep a kerf would you say can be filled with West 105 and 403 before a spline would be better?

  28. #28
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    Default Re: Repairing Checks in Spars

    Lupussonic, thanks for your input. I'm not concerned about the mast, it did have a failing glue joint I believe caused by the mast being overstressed. Icorresponded with the builder and agreed that splining was the best method to repair the mast. I made a spline the same thickness as my circular saw blade and cut a kerf removing the failing glue joint and used G-Flex to bond the spline in place.

    The following are some pictures of the mast as it was built back in 1976. It is a solid spar, cut in two with an internal slot for an electrical wire to the top. The mast is built from clear sitka spruce, a prized and difficult to source wood here in Oregon, where it is grown. Sitka Spruce is prized for it's strength to weight ratio but difficult to work as it has a lot of internal stress in the wood, difficulty to glue and its affinity to rot if left unprotected. The mast is in good shape because the builder used mast bands with very few fasteners so no entry points for water even though the protective paint was compromised. I've refinished the mast bright, there are some dark areas where rot was starting to form. I bleached as well as I could and I'll keep an eye on those areas.

    Mast copy.jpg

    - On to my concern, the checks in the gaff and failing glue line in the boom. The gaff is solid but suffered from exposure. The checks you see in the first post I believer are because the wood dried from sun and cracked due to freezing. The cracks or checks are really too small to spline and run cross grain so I thought maybe a flexible epoxy type glue to fill and strengthen so I can varnish. The boom suffers from a small area with a failing glue joint as shown in my first post. It is solid, split and bonded. The failing glue joint is small and appears to be because of age and exposure. I don't see any evidence of the boom being overstressed. My thought again was a flexible epoxy like glue to bond and fill. Really, my first thought was just to ignore and varnish over the crack but I just know that the varnish will crack and let water in so then I'd have to repair it properly eventually.

  29. #29
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    Default Re: Repairing Checks in Spars

    Quote Originally Posted by Lemsteraak View Post
    - On to my concern, the checks in the gaff and failing glue line in the boom. The gaff is solid but suffered from exposure. The checks you see in the first post I believer are because the wood dried from sun and cracked due to freezing. The cracks or checks are really too small to spline and run cross grain so I thought maybe a flexible epoxy type glue to fill and strengthen so I can varnish. The boom suffers from a small area with a failing glue joint as shown in my first post. It is solid, split and bonded. The failing glue joint is small and appears to be because of age and exposure. I don't see any evidence of the boom being overstressed. My thought again was a flexible epoxy like glue to bond and fill. Really, my first thought was just to ignore and varnish over the crack but I just know that the varnish will crack and let water in so then I'd have to repair it properly eventually.
    Do not fill those drying checks in the gaff with anything hard. Use something that can be squeezed out.
    Repair the failed glue line on the boom using the same technique that you used on the mast. Do you know what glue was used? Before poxy glues like casein or urea formaldehyde were popular. If they were used, that glue line failure may yet progress further.
    It really is quite difficult to build an ugly wooden boat.

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