Author Topic: Common SUP Board Repairs  (Read 1467 times)


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Common SUP Board Repairs
« on: January 26, 2021, 04:18:30 PM »
Thought I'd just share some common problems I've found with both used boards and having damage to my daily riding boards.  These tips might be helpful if you go to check out a used board or even a new one.

1.  Cracks around the handle.  This by far is my most common issue with boards.  Almost every board I've owned or had an issue that started with the glass splitting or separating around the handle.  From here once water gets in things progress.  If you are unlucky enough to have a board with any type of wood in the deck construction which is common, the water will soak through the whole board.  Best case delamination around the handle.
2.  Delamination.  This is a very common issue.  I always check by boards by pushing down in areas like the deck where I stand, around the vent plugs, fin boxes etc.  Delamination will only get worse so early detection is key.
2.  Fin boxes.  Cheap boards just rout a hole and pop in the fin box with some epoxy.  With any force these will crack and start letting water in. 
3.  Vent plug / Leash plug.  Same as above just epoxy holding they develop cracks or splits and start to let water in.
4.  Rail damage.  This is usually more obvious but I've seen almost undetectable splits that can leak if you don't really look close
5.  Nose/Tail damage.  As above this is also obvious but these can develop pinhole leaks as well.

Fix repair.
I fix any plastic to fiberglass repair the same.  No matter if its the handle/fin box/vent plug or leash plug.  I start by first drilling holes all around where the plastic meets the fiberglass about 1" apart.  Letting all the water drain prior to any glassing.  I'll then give it a good sanding with between 80 - 120 grit sandpaper to ensure good adhesion.  Then I'll take cabosil or any type of thickened resin and inject them with a syringe into each hole waiting for the resin to squirt out of the hole next to it.  Keep working around the board.  Then I'll put masking tape over the holes and flip the board over.  If you don't do this the resin keeps draining down into the board and you'll have to repeat this step.  Then for the last step I'll put masking tape over the plug and trim it as close as I can without letting resin run down into it.  Then I put 3 layers of glass matte, one just covering the plastic part and each additional one going 1-2" wider than the previous.

For any rail or other board damage I determine how best to get the water out.  Drill holes or just lean it in a position so it will drain.  Then sand the area down to make sure there is good adhesion.  Then lay 1-3 layers of fiberglass matte over the repair.  The first layer I make about 1" wider than the damage.  And each additional layer 1-2" wider than the last.

Delamination repair starts with determining the cause.  Did water get in, was it heat related?  Perhaps the vent plug failed?  From there I will mark with a marker the area that has delaminated.  I will take a brand new sharp sheet rock blade and cut out the delaminated part and remove the fiberglass.  It's important to cut the area well because pulling up on the fiberglass could delaminate more area.  Give it a good sanding and feather the fiberglass edges back 3-4".  From there make sure everything is dry and put 1-3 layers of fiberglass matte.  The first should just match the patch you cut out.  Then next 2 should overlap 1-2" from the previous layer.

Just thought it would be helpful for someone taking a look at buying a new board so they get a better understanding of things to look for an the work involved in fixing it.

My newest board I bought for $200 so I was fine with some repairs.  Turns out the handle delaminated and water soaked a lot of the deck area because they used a wood in the construction.

« Last Edit: January 26, 2021, 04:50:04 PM by StarboardSUPMan »


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Re: Common SUP Board Repairs
« Reply #1 on: January 28, 2021, 07:33:47 AM »
When buying a used board, be suspect of paint jobs as they can hide repairs.  Most of the used boards that I bought with repairs (either home or professional) were all substandard (to my standard).  Also be suspect of any non-stock items like a deck pad, which could be covering up a repair.  I've had boards that had hidden repairs under paint and deck pads.  Also be suspect of rail tape, I've had leaks hidden under them.  Inspect the goretex vent as if I've had used boards where water was getting in there.  For me, it is easier to buy a used board that needs a repair, rather than having to strip and redo an existing substandard repair.
I would add to feel the board for spongy sections.  Any spongy sections will most likely need to be stripped and reglassed.  Discolorations are often a clue for spongy sections.
I also make a note of the fins the previous owner was using.  Perhaps they were not using the optimal set-up, hence the motivation for selling the board.  Experiment with fins.
I would add that gorilla glue is great for repairs ({Thank you beasho}i.e. rejoining snaps, gap filler, plugging holes drilled for water draining, etc).
Avoid solvents like tetrahydrofuran, diethyl ether, polyester/polystyrene resin for eps as they will dissolve the foam.  Isopropanol is safe.
When doing repairs of painted boards, remove all the paint before a repair.  If you can get a color swatches from a paint company, that makes matching colors easier (I've been using Rustoleum Painter's Touch (2X Paint + Primer).  Home Depot has a pamphlet with color swatches so you can take it home and try to match.  If your board falls between shades, go with the darker shade.  A darker shade has a dirty look to it, where a lighter shade just looks off.  Before painting, I do a rough sand, followed by rubbing alcohol.  A warm windless day are ideal painting conditions.  Use masking tape to prevent overspray.  Keep the can at least 12" away and keep the can constantly moving to prevent pooling. 
If your epoxy does not have uv protectant, you may want to finish off painting with a clear uv protective coat to prevent repairs from yellowing over time.
Inspect the surf leash string, replace if any wears show.
For detecting leaks, I take the board out in salt water, then put it on the roof rack of my car and ideally park it in the sun on a warm day.  Any water drips on my car are suspect.  Often you will get salt residue on the board where the crack/hole is located.  If there is water in the board, drill 1/4 holes for the water to drain {thank you beasho}.  I don't rush this process (a month draining in the summer sun, if it is winter time, I wait till summer).  A 1/2 pound of water weight in the nose can make the difference between a dog and a magic board.
My cheapest sup was $50 with both leash plugs missing and a chunk of foam missing from the middle of the board and the tail, and both the nose and tail needed tlc. 
Keeping an old truck going is greener than buying a new Prius.  I got to think that buying used SUPs is the same.
If you don't have any tools, a random orbital sander, a variable speed polisher (different diameter attachments), and a hand drill are worth having.  I find chisels useful.    Knock off brands work fine.  I also use a Dremel tool (not knock off).
If you get more serious, you are going to want a proper shaping stand to save your back (~belly button height).
« Last Edit: January 28, 2021, 08:34:37 AM by sflinux »
Quiver Shaped by: Joe Blair, Blane Chambers, Kirk McGinty, and Bob Pearson.
Me: 195#, 6'2"

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Re: Common SUP Board Repairs
« Reply #2 on: January 28, 2021, 12:08:50 PM »
And for repairs that are less complex, like gouges and such, I have sworn by Marine-Tex for years, repairing Laser sailboats and SUPS.

Its just a high grade epoxy. A potential 'con' is that it's not inherently flexible, so shouldn't be used on large repairs or areas where that may be an issue. But for small repairs its great. I clean out the repair area and edges, tape around it to keep the epoxy localized, apply as smoothly as possible (to minimize later sanding), post cure sanding, then match the paint. 

Its a great, permanent repair that you don't notice. What more to ask for.

From the mfgr:

“Marine-Tex is a heavy-duty structural epoxy, used to repair aluminum, fiberglass and wooden boats, reinstall loose or stripped fasteners, permanently bond dissimilar metals without galvanic corrosion, and fill gouges in wood, metal and fiberglass, making repaired areas stronger than before.
Marine-Tex is an excellent choice for repairing problem areas located below the waterline. Marine-Tex is resistant to water and many chemicals.”
Bullet V2; RS 14x26; JL Destroyer 9'8; BluePlanet 9'4


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Re: Common SUP Board Repairs
« Reply #3 on: January 28, 2021, 04:22:37 PM »
sflinux - thanks for that reply.  very detailed, hit a bunch of areas I missed!

I used Rustoleum Painters Touch and it came out looking like a new board.  Got my recommendation!


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Re: Common SUP Board Repairs
« Reply #4 on: January 28, 2021, 08:19:45 PM »
I saw a study once on the environmental impact of surfboards measuring resin use, waste, and other products. the conclusion was that repairing boards over their life used more materials--especially resin--than building them. I didn't actually believe the study, in fact, it seemed inflated and kind of stupid, but it's an interesting counterpoint to the green argument. That isn't the reason I more or less quit repairing my boards in the conventional way. Mostly I'm just lazy, and I don't mind the look of a piece of aluminum tape. But as long as the leaker isn't structural I'm just as happy with well-adhered tape that adds no discernable weight. Of course, you have to be comfortable with your board looking like it has cartoon bandaids on it.
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Re: Common SUP Board Repairs
« Reply #5 on: February 05, 2021, 08:21:16 PM »
Drilling holes is good but check out the "Board Lady". Filling them with epoxy just makes a hard spot, it is an old school repair that I used to do. Try Gorilla glue or marine expanding foam, sand then cover with cloth and epoxy.


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