Anyone got advice on how to repair delamination?

I am thinking of drilling a grid of small holes and using a large syringe to inject epoxy. Then quickly roll the board around, tapping it up and down. Then "popping" the delaminated section up/down. All to get the resin spread out as far as possible. Then weight the board with bags of potting mix or salt and hope it sets back in full contact with the foam.

I did this on a smaller soft spot under footstraps. But I am pretty sure it would not work on a large area like that

boardlady.com/injection.htm

Looks like a pretty new board, you must be bummed.

Hopefully Mark chimes in

be careful with what epoxy you use ,
i did a rushed repair the night before a race with West 206 and ended up with a big cavity instead , there is nowhere for the heat to go and you will be pumping in alot of resin.
normally it has worked fine for small repairs.

looks like a big delam ;
maybe consider cutting and peeling away the delam skin and sticking it back down with epiglue or similar, then you can be sure that you have proper coverage.
a mate did this with a sup and it went ok .

yep, be interested to hear from others who have done this.

I have done similar on a Hobie 14 hull that had delaminated. Work out the extent of the delamination and use a white board marker to show the limit of the delamination. Then mask tape that area. Next, using a Sharpie marker, plot a grid of say 10cm squares and drill a small hole at each grid line intersection just deep enough to penetrate the outer skin. The hole should be of a size where the syringe nozzle fits tightly (less mess). Inject enough resin so that a little flows from nearest holes. Repeat for other holes. Wipe off any extruded excess resin before it sets. I would be inclined to not place weights on the board unless you know that the core surface is uniformally flat, you could end up with an uneven surface. White pigment can be added to the resin to help in disguising the holes, unless you intended repainting/coating.

Depends if we are talking PVC layer delam, or only the outer glass......? If the latter, it is much easier as you only need to get a small amount of resin between the two and then hold it down.
Former far more common unfortunately.

Then, is the shape still the same (vee, concave?) or has it curved outwards. If the latter it will need weighting.

Remember styro sucks up like a sponge so lots of resin injection and the board upside down will not achieve a lot. If its a PVC layer delam we need to inject lots of holes, tape over them and then placed right way up so the resin spreads out over the whole bottom laminate instead of just disappearing into the middle of the board. (if you deconstructed this method later you will see lots of pillars of resin soaked styro with not much bottom adhesion at all. Holes to the bottom is a much better result.
Now that is fine if the bottom shape is unchanged, but if it needs to be pushed back against the core then we need to vac bag it (can't weight the bottom whilst its right way up..... so a dilemma.....

And yes super slow hardender..... do it in the evening .... let it sit couple days to be safe

Key....as said in the evening in cooling temps.

also a lot depend on the condition of the core. Some of the repairs I've done, the core has broken up, leaving bits floating around inside. you can't just cut it off and glue back down, or inject and weight either, the bottom shape would be haywire. The whole section needs the core routed out to remove damaged foam, new foam inserted and shaped, it's vaguely possible you could reuse the old laminate, but I've never managed it, always had to make a new one.

Which part is delaminated?

^^ I don't think that's a logo on the bottom

Been repaired 3x at the nose. So not a new board (2019) and worked. Hard. I want to revive it until new stock arrives in the country.

www.seabreeze.com.au/forums/Windsurfing/Foiling/Foil-board-Repair-Job-The-new-nose-you-all-need?page=1

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berowne said..
Anyone got advice on how to repair delamination?

I am thinking of drilling a grid of small holes and using a large syringe to inject epoxy. Then quickly roll the board around, tapping it up and down. Then "popping" the delaminated section up/down. All to get the resin spread out as far as possible. Then weight the board with bags of potting mix or salt and hope it sets back in full contact with the foam.

Instead of epoxy I would inject 2K PU foam which is expanding. Then once it is has expanded somewhat I would put something heavy on the delaminated part to keep the original shape and make sure there are holes where excess material can escape while the foam continues to expand.

^^^ Not for an area that size. You can't maintain the rocker it will be wavy due to the pressure

However as this is a foil board the bottom is not so relevant, and its knocked about too, so maybe in this case

Expanding foam will distort the bottom. Injecting resin will go into the EPS foam it won't spread around like you want it to unless you inject bucket loads, but that will cause heat build up. Cut out delam, paint resin on removed inner surface, suck back on, re glass cut edges, fill up any extra concaves that have formed from crushed foam and vac bagging.

I've done a delamed deck with the drilled holes, epoxy and sandbag thing (concave deck so I needed to press it back down). It was late autumn and used slow hardener so that helped. A few years later, things are still okay although I'm more careful to let it vent on warm days. Like yours, mine was a foil board that had had a few misadventures. My foam seemed to be in good shape and it didn't take that much epoxy. Drill the holes shallowly so you aren't injecting epoxy deep into the foam instead. It travels pretty quickly along the surface. I think I did holes 8-10cm apart. Board isn't nearby but I'll check the distance if you need that info. mark_australia's tip to turn it upside down is great - wish I had had that option as I needed to press the deck back down and lacked a vacuum at the time.

If you feel the foam is in good shape, no harm in trying, I'd think. It'll quickly become apparent if you need to peel the whole thing off and start fresh.

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Mark _australia said..
^^^ Not for an area that size. You can't maintain the rocker it will be wavy due to the pressure

However as this is a foil board the bottom is not so relevant, and its knocked about too, so maybe in this case

Oh yeah. The two part foam I used for soft spots on my deck, did result in a lumpy deck. Although I did put the foam in after I removed I sanded off some glass. Might have been better if I did the foam injection prior to the sanding....

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Paducah said..
I've done a delamed deck with the drilled holes, epoxy and sandbag thing (concave deck so I needed to press it back down). It was late autumn and used slow hardener so that helped. A few years later, things are still okay although I'm more careful to let it vent on warm days. Like yours, mine was a foil board that had had a few misadventures. My foam seemed to be in good shape and it didn't take that much epoxy. Drill the holes shallowly so you aren't injecting epoxy deep into the foam instead. It travels pretty quickly along the surface. I think I did holes 8-10cm apart. Board isn't nearby but I'll check the distance if you need that info. mark_australia's tip to turn it upside down is great - wish I had had that option as I needed to press the deck back down and lacked a vacuum at the time.

If you feel the foam is in good shape, no harm in trying, I'd think. It'll quickly become apparent if you need to peel the whole thing off and start fresh.

Exactly thanks.

I'm trying to find something I can put UNDER the board, right way up, to press against the hull to seal the skin against the foam while applying weight from the top.

An airblader would be good but don't have a 2x1m wide air bag... and If I did I'd be tempted to Vac.

Shame the kids don't have a sandpit I could mould into the bottom concave shape perfectly...

Oh well, creativity coming.

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berowne said..

Paducah said..
I've done a delamed deck with the drilled holes, epoxy and sandbag thing (concave deck so I needed to press it back down). It was late autumn and used slow hardener so that helped. A few years later, things are still okay although I'm more careful to let it vent on warm days. Like yours, mine was a foil board that had had a few misadventures. My foam seemed to be in good shape and it didn't take that much epoxy. Drill the holes shallowly so you aren't injecting epoxy deep into the foam instead. It travels pretty quickly along the surface. I think I did holes 8-10cm apart. Board isn't nearby but I'll check the distance if you need that info. mark_australia's tip to turn it upside down is great - wish I had had that option as I needed to press the deck back down and lacked a vacuum at the time.

If you feel the foam is in good shape, no harm in trying, I'd think. It'll quickly become apparent if you need to peel the whole thing off and start fresh.

Exactly thanks.

I'm trying to find something I can put UNDER the board, right way up, to press against the hull to seal the skin against the foam while applying weight from the top.

An airblader would be good but don't have a 2x1m wide air bag... and If I did I'd be tempted to Vac.

Shame the kids don't have a sandpit I could mould into the bottom concave shape perfectly...

Oh well, creativity coming.

No place to put some play sand? Maybe some garbage bags lining a wooden frame filled with sand?

Other thought - a memory foam mattress topper?

Or, time to put together a cheap vacuum bag rig. Finally broke down and bought the pieces myself to enable my hacking on older boards.

You've done nice work before. I'm sure this one will turn out, too.

Cut the delam out and reuse it if the core is solid, replace if you have to. Here is inexpensive vacuum pump
www.harborfreight.com/25-cfm-vacuum-pump-61245.html
compositeenvisions.com/product/vacuum-bagging-starter-kit-947/

Add a gauge and a relief valve. Put these inexpensive pumps outside the shop when running, they burn/vaporize oil. Pass the hose through a window or door. A collector pot is nice but not essential for repairs. Don't suck water out of a wet board unless you have a collector pot. When you first turn on the vacuum you can let the pressure drop to 25 psi for a period of about 15 minutes (depends on board volume) then you need to use the by bass valve to keep the pressure at 10-15 psi for the remainder of the cure. The preasure will not crush the foam at first but eventually the vacuum hauls all the air out of the blank then it crushes. Using full vacuum for 15 minutes helps compact the lami and get better resin ratios but don't multitask and forget!

That board cost thousands, spend a hundred or two and do it right. You will get a better result and so will the next person that gets that sweet board.

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berowne said..
Anyone got advice on how to repair delamination?

I am thinking of drilling a grid of small holes and using a large syringe to inject epoxy. Then quickly roll the board around, tapping it up and down. Then "popping" the delaminated section up/down. All to get the resin spread out as far as possible. Then weight the board with bags of potting mix or salt and hope it sets back in full contact with the foam.

I've done exactly what you're thinking but with 2 part expanding foam and drilling a grid over the effected area. Slowly injecting into the void and only one line at a time. Cover with a plastic lined board and clamp. The excess is forced into the next line. Keep repeating until finished. The board is still going strong. You could also use the wood glue that reacts with moisture too. Not sure of the name.

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kato said..

berowne said..
Anyone got advice on how to repair delamination?

I am thinking of drilling a grid of small holes and using a large syringe to inject epoxy. Then quickly roll the board around, tapping it up and down. Then "popping" the delaminated section up/down. All to get the resin spread out as far as possible. Then weight the board with bags of potting mix or salt and hope it sets back in full contact with the foam.

I've done exactly what you're thinking but with 2 part expanding foam and drilling a grid over the effected area. Slowly injecting into the void and only one line at a time. Cover with a plastic lined board and clamp. The excess is forced into the next line. Keep repeating until finished. The board is still going strong. You could also use the wood glue that reacts with moisture too. Not sure of the name.

One water activated glue is gorilla glue.

Trouble is - often does not harden in the centre. Unless there is a pretty humid core of course.
I use it only for very shallow stuff where one can be sure of atmospheric moisture curing it, or for a core crack that is still moist

If spending $16 on the big bottle of that, may as well spend $40 on the proper 2 pac stuff like Era polyurethane

Then, just drill and fill with pu glue or whatever.
I did it to try out a board, worked well. I set something super heavy on it (but ideally you want to respect hull shape!) And did it in 3 steps. The whole hull pretty much. Board had sit on a roof for years...

Sand foam flush then use some kind of waterproof filler then paint

OK, so this was SCARY!

1. Take a perfectly good (ok so somewhat damaged - if you know you know ! ) FMX Hyperion 91 race winning foil board... and drill 50 holes into it!


2. Spend about an hour folding and rolling blankets and towels to perfectly follow the hull contours


and make sure it is flat...



Then flip the setup so the timber sheet is on the ground and the board can sit right side up.

Add a layer of plastic drop sheet and 'peel ply' or other nylon / artificial material to absorb excess resin. I damn hope this peels off!


3. Draw a grid of holes about 10cm apart.


4. Close your eyes, Say sorry to #FMX and start drilling.

IMPORTANT: Don't stop at the carbon layer... I had to also drill through the DIVINICELL layer as my delamination was deeper !


5. No picture... but I used a 100mL syringe with a 4mm nozzle (the drill bit was matching 4mm).


I pumped exactly 400mL of resin in.
Between refills of the syringe I 'pumped' or 'popped' the delaminated sections up and down to such and spread the resin out and around.
After injecting some resin was bubbling out of some holes so I used a scraper to smooth it out and spread it around 4 neighbouring holes.
I then popped that section of delaminated hull trying to draw the excess resin into the hull by pushing the resin over the holes.
I then scrapped all the excess resin off, and smoothed it off even more with a rag.
I also rolled the board around and tapped it up and down on the edges to help spread the resin inside the board.

6. Lay board right side up on moulded blanket 'bed' and weight with 80kg of salt...

7. Somewhat nervous that the moulded blanket pile didn't exactly match the hull shape... I waited for more than the 'pot time' of the resin to expire, so about 25-30 minutes given todays temp. I waited about 40 minutes, then flipped the board.

During the flip I noticed the peel-ply was pretty saturated with excess resin, so I hope enough stayed on the foam/divinycell/carbon fibre layer to fix the delamination.

We have to wait until tomorrow to see! Wish me luck!

Good luck!

Good luck Berowne ! fingers crossed !
reminded me of my cooking days in Alsace !

I think you will have a beautiful resin-soaked blanket sculpture

No seriously, hope it works out but very hard to get even pressure all over

I left an abplus board in the car once and the whole of the underside popped off the core
I cut right through the underside sandwich with a Stanley knife, all along both rails and across the front about 50mm in from the rail.( Left it attached at the rear)
Peeled bottom sandwich away from core l, where still attached
Sprayed thinned epoxy to EPS and the peeled back sandwich
Closed it and vacced it with a vacuum cleaner.
Once set I chamfered the cut
line down and laid into it 50mm woven carbon tape
Filled and faired
I can't remember the weight gain but it was negligible
It's been in use ever since, about 8-10 years ago, I recently gave it to my friend who loves it.
The core was " torn" away from the sandwich and hence rough, but it all fit back together so had good contact. As it popped in the car, it hadn't worked and got loads of loose bits broken away, so it didn't need filling.

Good news.
the Phoenix rises again!
Delamination repaired
But now I have a small amount of cleaning to do. Table cloth worked well as peel ply. (Wish I thought to order some a week ago!).

Just one blob of hard epoxy to remove. All the rest "bleed" into the material and peeled off easily. Except a few small sections where it has stuck.


A hand pressure test across the hull shows no more movement! I just hope it is watertight.
Oout of 400mL of resin probably added 300g weight. On top of prior repairs probably the heaviest FMX ever.
Happy for 2 hours work.

Any hole that does not have noticeable bleed out, or is not plugged with epoxy, I would double check to make sure it is solid underneath, and if not maybe inject again?

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berowne said..
OK, so this was SCARY!

1. Take a perfectly good (ok so somewhat damaged - if you know you know ! ) FMX Hyperion 91 race winning foil board... and drill 50 holes into it!


2. Spend about an hour folding and rolling blankets and towels to perfectly follow the hull contours


and make sure it is flat...



Then flip the setup so the timber sheet is on the ground and the board can sit right side up.

Add a layer of plastic drop sheet and 'peel ply' or other nylon / artificial material to absorb excess resin. I damn hope this peels off!


3. Draw a grid of holes about 10cm apart.


4. Close your eyes, Say sorry to #FMX and start drilling.

IMPORTANT: Don't stop at the carbon layer... I had to also drill through the DIVINICELL layer as my delamination was deeper !


5. No picture... but I used a 100mL syringe with a 4mm nozzle (the drill bit was matching 4mm).


I pumped exactly 400mL of resin in.
Between refills of the syringe I 'pumped' or 'popped' the delaminated sections up and down to such and spread the resin out and around.
After injecting some resin was bubbling out of some holes so I used a scraper to smooth it out and spread it around 4 neighbouring holes.
I then popped that section of delaminated hull trying to draw the excess resin into the hull by pushing the resin over the holes.
I then scrapped all the excess resin off, and smoothed it off even more with a rag.
I also rolled the board around and tapped it up and down on the edges to help spread the resin inside the board.

6. Lay board right side up on moulded blanket 'bed' and weight with 80kg of salt...

7. Somewhat nervous that the moulded blanket pile didn't exactly match the hull shape... I waited for more than the 'pot time' of the resin to expire, so about 25-30 minutes given todays temp. I waited about 40 minutes, then flipped the board.

During the flip I noticed the peel-ply was pretty saturated with excess resin, so I hope enough stayed on the foam/divinycell/carbon fibre layer to fix the delamination.

We have to wait until tomorrow to see! Wish me luck!

Great work it will be 100% stuck I think
Handy tip for others doing the drilling for this operation
Have a piece of dowel on the drill bit to control hole depth
All the best