Repair Delamination

Its a really good explanation (not in his native language either). Humorous as well, "I made this highly complex model...."
I used a fast setting epoxy foaming resin when I repaired a board and it didnt expand much as it should because it was only about 10c, UK winter.
On the last syringe most of the cavities had already been filled, so squirting in a full syringe meant a lot slowly came back through the syringe. I was cleaning up and didnt notice the syringe expanding, then "pop" as it forced the plunger out. Epoxy went everywhere That stuff really sticks.
I later did another much smaller repair on a different board and the foaming resin expanded a lot more. It was maybe around 18c. That is 5 years ago and its still solid.

Great video, thanks! The part about leaving all the syringes in place was new to me. I covered some small flexible spots (1/2" x 1-3"), where the mast was denting the deck on the ridge that ran around the concave deck, with dual density deck padding, so far no problems, figured the padding would spread the load out and also strengthen the deck. If I had seen this video before doing that would have repaired the small spots before covering with padding. And assume he turned the board up side down for curing, so those syringes must of fit really tight to stay in place.

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Mark _australia said..
As much as I hate it due to the failures I see when used for mast track installs etc (dodgy) I'd like to try a foaming agent / additive for epoxy.
Not a foaming resin, the additive that works in any resin.,
Can't find it anywhere in Oz.

Anyone got brand/product names? Or Oz sources..?

Sorry Mark,
this is only from a German online shop ( where the bloke in the video obviously also gets his resin) so might not be worth considering for you due to shipping costs. They are reliable and cover a wide range of products and special offers though which might make a bulk order interesting even for someone in Western Australia.

shop.hp-textiles.com/shop/de/Fluessiges-Treibmittel-Schaumtreibmittel-HP-BEL11.html

Keep your repair videos coming, they're well appreciated.

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Mark _australia said..
^^ Thanks man. Might be worth buying o/s if I cant get local.
Can you translate please - how much additive to how much resin, to get how much expansion?
No point ordering a big one, if the small 50mL one would make a cubic metre of foam ...

shop.hp-textiles.com/shop/en/Liquid-foaming-agent-HP-BEL11.html
data sheet: www.hp-textiles.com/TDS/EN/Fillers_Additive/HP-BEL_Series/GTDS.pdf

For this kind of dodgy fix , I do it a little different .
With a sharp Stanley knife , cut a inch square hole in middle of effected area .
Sand the square plug a mm smaller each side .
Tape around hole at least six inches wide . The more the better . Resin has a habit of going everywhere.
Using a large 100 ml syringe , ( EBay ) , and those fat straws with the little spoon on the end . ( slurpee straws ) EBay 100 x $15 inc del .
Squash spoon end a bit with fingers .
The spoon end should slide nicely between the delam .The rounded and curved end surprisingly slides in . The straw crushes flat when poking in hole sideways .Have spare straws ready in case .
Large syringes fit in the straw perfect. If not , tape around nozzle so it does . Do a dry run first making sure straw is tight on syringe and straw easily slides between the delam area.
Push the straw all the way in to the edge of the delam , connect syringe and squirt in some resin.
Repeat half a dozen times going round in a circle . You may have to change to a new straw if it gets to wrinkled..
This way the resin starts at the edge of the void and goes towards the hole in the middle . No air voids .
Use way too much resin and let it come out the hole . Lightly push down If area has bulged . Important on bottom of board , not on the top . Mop up mess .
Put the square plug back in the hole .
Cover in thin plastic sheet and place bag of soil on top.
With the weight on top , some resin will come out of the square hole around the plug .
When resin has gelled , remove bag of soil , remove plastic sheet , remove tape around hole . No mess. No fuss .
Sand plug area , lightly roll on layer resin over sanded plug area , sprinkle with caster sugar .
Done
Its a less ugly fix . You just see a 1 mm line around the plug.

Ps : for this I use Surfset Flex resin . It is very slow curing making little heat and it sets quite soft . Plastic like , not hard and brittle like normal resin .

Few good tips in the video... Using one syringe per hole is a good idea to prevent the excess flowing out.

Massive delam not a good selling point especially when its not even a slapper....

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Mark _australia said..
^^ Thanks man. Might be worth buying o/s if I cant get local.
Can you translate please - how much additive to how much resin, to get how much expansion?
No point ordering a big one, if the small 50mL one would make a cubic metre of foam ...

Select to expand quote

Mark _australia said..
^^ Thanks man. Might be worth buying o/s if I cant get local.
Can you translate please - how much additive to how much resin, to get how much expansion?
No point ordering a big one, if the small 50mL one would make a cubic metre of foam ...

They say it will expand by two to three times the volume you have to start with, so the 50 ml won't get you that far.
For 150 grams of resin you would obviously need 4,5 grams of the stuff, so 3%.
In the above example, one should obviously add 7,5g of this (PK22):
shop.hp-textiles.com/shop/de/advanced_search_result.php?categories_id=0&keywords=pk22&inc_subcat=1
(In order to make the resulting foam smoother and more homogenous)
I have never used any of the two myself, so can't say much.

Anyway, wouldn't two-part marine foam bond better with the eps core? I do have my doubts about the foamed (expanded?) epoxy still being too rigid.
Having watched the video where the above bloke repairs a duotone carbon boom leaving a wooden stick inside, I'm not fully convinced he knows what he's doing.

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The Windsurfing Shed said..

Mark _australia said..
Massive delam not a good selling point especially when its not even a slapper....

Pretty sure it has nothing to do with construction but good hard previous life

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

It is a foil board, why would it delam on the bottom from a "good hard previous life"?

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Sandman1221 said..

The Windsurfing Shed said..

Mark _australia said..
Massive delam not a good selling point especially when its not even a slapper....

Pretty sure it has nothing to do with construction but good hard previous life

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

It is a foil board, why would it delam on the bottom from a "good hard previous life"?

Don't forget the foil is a massive lever. Run it into the ground and it wants to rip the box out in the front. Powered up, it wants to move upwards through the board in the front, potentially ripping the box at the rear. With the bottom laminate connected to the box (hopefully), delam isn't an unlikely result, especially once you start jumping your foilboard. Mate of mine massively delamed his brandnew Ensis wingboard in the first session although I guess that the forces in winging are a lot smaller due to lack of a mastfoot.

Yeah that FMX has had a 'hard' life.

Before any damage I was vain and wanted to keep the nice look of the new board unblemished.
It took about 20 good catapults before the first signs of damage appeared on the nose.
Then I had the board 'professionally' repaired twice in 2 weeks after finally cracking it, only to find on the 3rd catapult that they must have used fast-set resin and melted foam inside the nose invicibly.
So for the 3rd nose job I did it myself (as Remi pointed out).
www.seabreeze.com.au/forums/Windsurfing/Foiling/Foil-board-Repair-Job-The-new-nose-you-all-need?page=1

Since then I suspect water got in a small crach either around the repair, or more likely a small dent on the rail.
I noticed this water coming out a pin-hole in the rear cut-out area a few weeks before the delamination.
Board sailed fine delaminated, even winning a state slalom race!

Fixed now, just waiting for spray paint and new EVA foam floor mat (20mm x 1m x 1m) to be cut to size.